The healthy gut microbiome is important in maintaining health and preventing various chronic and metabolic diseases through interactions with the host via different gut-organ axes, such as the gut-brain, gut-liver, gut-immune, and gut-lung axes. The human gut microbiome is relatively stable, yet can be influenced by numerous factors, such as diet, infections, chronic diseases, and medications which may disrupt its composition and function. Therefore, microbial resilience is suggested as one of the key characteristics of a healthy gut microbiome in humans. However, our understanding of its definition and indicators remains unclear due to insufficient experimental data. Here, we review the impact of key drivers including intrinsic and extrinsic factors such as diet and antibiotics on the human gut microbiome. Additionally, we discuss the concept of a resilient gut microbiome and highlight potential biomarkers including diversity indices and some bacterial taxa as recovery-associated bacteria, resistance genes, antimicrobial peptides, and functional flexibility. These biomarkers can facilitate the identification and prediction of healthy and resilient microbiomes, particularly in precision medicine, through diagnostic tools or machine learning approaches especially after antimicrobial medications that may cause stable dysbiosis. Furthermore, we review current nutrition intervention strategies to maximize microbial resilience, the challenges in investigating microbiome resilience, and future directions in this field of research.

Chronic metabolic inflammation is a common mechanism linked to the development of metabolic disorders such as obesity, diabetes, and cardiovascular disease (CVD). Chronic metabolic inflammation often related to alterations in gut homeostasis, and pathological processes involve the activation of endotoxin receptors, metabolic reprogramming, mitochondrial dysfunction, and disruption of intestinal nuclear receptor activity. Recent investigations into homeostasis and chronic metabolic inflammation have revealed a novel mechanism which is characterized by a timing interaction involving multiple components and targets. This article explores the positive impact of tea consumption on metabolic health of populations, with a special focus on the improvement of inflammatory indicators and the regulation of gut microbiota. Studies showed that tea consumption is related to the enrichment of gut microbiota. The relative proportion of Firmicutes/Bacteroidetes (F/B) is altered, while the abundance of Lactobacillus, Bifidobacterium, and A. muciniphila increased significantly in most of the studies. Thus, tea consumption could provide potential protection from the development of chronic diseases by improving gut homeostasis and reducing chronic metabolic inflammation. The direct impact of tea on intestinal homeostasis primarily targets lipopolysaccharide (LPS)-related pathways. This includes reducing the synthesis of intestinal LPS, inhibiting LPS translocation, and preventing the binding of LPS to TLR4 receptors to block downstream inflammatory pathways. The TLR4/MyD88/NF-κB p65 pathway is crucial for anti-metaflammatory responses. The antioxidant properties of tea are linked to enhancing mitochondrial function and mitigating mitochondria-related inflammation by eliminating free radicals, inhibiting NLRP3 inflammasomes, and modulating Nrf2/ARE activity. Tea also contributes to safeguarding the intestinal barrier through various mechanisms, such as promoting the synthesis of short-chain fatty acids in the intestine, activating intestinal aryl hydrocarbon receptor (AhR) and farnesoid X receptor (FXR), and improving enteritis. Functional components that improve chronic metabolic inflammation include tea polyphenols, tea pigments, TPS, etc. Tea metabolites such as 4-Hydroxyphenylacetic acid and 3,4-Dihydroxyflavan derivatives, etc., also contribute to anti-chronic metabolic inflammation effects of tea consumption. The raw materials and processing technologies affect the functional component compositions of tea; therefore, consuming different types of tea may result in varying action characteristics and mechanisms. However, there is currently limited elaboration on this aspect. Future research should conduct in-depth studies on the mechanism of tea and its functional components in improving chronic metabolic inflammation. Researchers should pay attention to whether there are interactions between tea and other foods or drugs, explore safe and effective usage and dosage, and investigate whether there are individual differences in the tea-drinking population leading to different effects of tea intervention. Ultimately, the application of tea drinking could be a universal therapy for regulating intestinal homeostasis, anti-chronic metabolic inflammatory responses, and promoting metabolic health.

The human intestinal tract plays a pivotal role in safeguarding the body against noxious substances and microbial pathogens by functioning as a barrier. This barrier function is achieved through the combined action of physical, chemical, microbial, and immune components. Tea (Camellia sinensis) is the most widely consumed beverage in the world, and it is consumed and appreciated in a multitude of regions across the globe. Tea can be classified into various categories, including green, white, yellow, oolong, black, and dark teas, based on the specific processing methods employed. In recent times, there has been a notable surge in scientific investigation into the various types of tea. The recent surge in research on tea can be attributed to the plethora of bioactive compounds it contains, including polyphenols, polysaccharides, pigments, and theanine. The processing of different teas affects the active ingredients to varying degrees, resulting in a range of chemical reactions and the formation of different types and quantities of ingredients. The bioactive compounds present in tea are of great importance for the maintenance of the integrity of the intestinal barrier, operating through a variety of mechanisms. This literature review synthesizes scientific studies on the impact of the primary bioactive compounds and different processing methods of tea on the intestinal barrier function. This review places particular emphasis on the exploration of the barrier repair and regulatory effects of these compounds, including the mitigation of damage to different barriers following intestinal diseases. Specifically, the active ingredients in tea can alleviate damage to physical barriers and chemical barriers by regulating barrier protein expression. At the same time, they can also maintain the stability of immune and biological barriers by regulating the expression of inflammatory factors and the metabolism of intestinal flora. This investigation can establish a strong theoretical foundation for the future development of innovative tea products.

Tea, derived from the young leaves and buds of the Camellia sinensis plant, is a popular beverage that may influence the host microbiota. Its consumption has been shown to promote the growth of beneficial bacterial species while suppressing harmful ones. Simultaneously, host bacteria metabolize tea compounds, resulting in the production of bioactive molecules. Consequently, the health benefits associated with tea may stem from both the favorable bacteria it nurtures and the metabolites produced by these microbes. The gut microbiota plays a vital role in mediating the systemic immune homeostasis linked to tea consumption, functioning through complex pathways that involve the gut-lung, gut-brain, and gut-liver axes. Recent studies have sought to establish connections between tea, its bioactive compounds, and immune regulation via the gut microbiota. In this paper, we aim to summarize the latest research findings in this field.

The human gut harbors a complex and diverse microbiota essential for maintaining health. Diet is the most significant modifiable factor influencing gut microbiota composition and function, particularly through bioactive compounds like polyphenols, dietary fibers, and carotenoids found in vegetables, fruits, seafood, coffee, and green tea. These compounds regulate the gut microbiota by promoting beneficial bacteria and suppressing harmful ones, leading to the production of key microbiota-derived metabolites such as short-chain fatty acids, bile acid derivatives, and tryptophan metabolites. These metabolites are crucial for gut homeostasis, influencing gut barrier function, immune responses, energy metabolism, anti-inflammatory processes, lipid digestion, and modulation of gut inflammation. This review outlines the regulatory impact of typical bioactive compounds on the gut microbiota and explores the connection between specific microbiota-derived metabolites and overall health. We discuss how dietary interventions can affect disease development and progression through mechanisms involving these metabolites. We examine the roles of bioactive compounds and their metabolites in the prevention and treatment of diseases including inflammatory bowel disease, colorectal cancer, cardiovascular diseases, obesity, and type 2 diabetes mellitus. This study provides new insights into disease prevention and underscores the potential of dietary modulation of the gut microbiota as a strategy for improving health.

The gut microbiota, a complex ecosystem of microorganisms in the human gastrointestinal tract (GI), plays a crucial role in maintaining metabolic health and influencing disease susceptibility. Dysbiosis, or an imbalance in gut microbiota, has been linked to the development of type 2 diabetes mellitus (T2DM) through mechanisms such as reduced glucose tolerance and increased insulin resistance. A balanced gut microbiota, or eubiosis, is associated with improved glucose metabolism and insulin sensitivity, potentially reducing the risk of diabetes-related complications. Various strategies, including the use of prebiotics like inulin, fructooligosaccharides, galactooligosaccharides, resistant starch, pectic oligosaccharides, polyphenols, β-glucan, and Dendrobium officinale have been shown to improve gut microbial composition and support glycemic control in T2DM patients. These prebiotics can directly impact blood sugar levels while promoting the growth of beneficial bacteria, thus enhancing glycemic control. Studies have shown that T2DM patients often exhibit a decrease in beneficial butyrate-producing bacteria, like Roseburia and Faecalibacterium, and an increase in harmful bacteria, such as Escherichia and Prevotella. This review aims to explore the effects of different prebiotics on T2DM, their impact on gut microbiota composition, and the potential for personalized dietary interventions to optimize diabetes management and improve overall health outcomes.

Polyphenols are organic chemical compounds naturally present in plants, renowned for their anti-inflammatory, antioxidant, immunomodulatory, anticancer, and cardiovascular protective properties. Their bioactivity and bioavailability can vary widely depending on the methods of food processing and interactions with the gut microbiome. These factors can induce changes in polyphenols, affecting their ability to achieve their intended health benefits. Thus, it is essential to develop and apply food processing methods that optimize polyphenol content while maintaining their bioactivity and bioavailability. This review aims to explore how various food processing techniques affect the quantity, bioactivity, and bioavailability of polyphenols, as well as their interactions with the gut microbiome, which may ultimately determine their health effects.

Previous observational studies have suggested that gut microbiota might be associated with vitiligo. However, owing to the limitations in observational studies of reverse causality and confounders, it remains unclear that whether and how the causal relationships exist. The results suggested that pylum.Bacteroidetes, family.BacteroidalesS24.7, genus.LachnospiraceaeND3007, genus.Marvinbryantia are protective factors for vitiligo. Conversely, family.Lachnospiraceae, order.Burkholderiales, genus.Adlercreutzia, genus.Catenibacterium and genus.Lachnospira are risk factors for vitiligo. In addition, the causative connection between dietary factors and the gut microbiota associated with vitiligo was also investigated. The results revealed that 'alcohol intake versus 10 years pervious' results in a reduction in the abundance of genus.Lachnospiraceae ND3007 and family.BacteroidalesS24.7, bread intake leads to a reduction of genus.Marvinbryantia, 'average weekly red wine intake' is linked to a decrease in the abundance of order.Burkholderiales, tea intake is associated with an augmentation in the abundance of genus.Catenibacterium, salad/raw vegetable intake elevates the abundance of order.Burkholderiales. In summary, this Mendelian randomization study substantiates potential causal effects of gut microbiota on vitiligo. Modulating the gut microbiota through regulating dietary composition may be a novel strategy for preventing vitiligo.

The pathogenesis of Attention-Deficit Hyperactivity Disorder (ADHD) is thought to be multifactorial, with a potential role for the bidirectional communication between the gut microbiome and brain development and function. Since the "golden-standard" medication therapy with methylphenidate (MPH) is linked to multiple adverse effects, there is a need for alternative treatment options such as dietary polyphenols. These secondary plant metabolites exert antioxidant and anti-inflammatory effects, but much less is known about their impact on the gut microbiota. Since polyphenols are believed to modulate gut microbial composition, interventions might be advantageous in ADHD therapy. Therefore, intervention studies with polyphenols in ADHD therapy investigating the gut microbial composition are highly relevant.

Besides the primary research questions addressed previously, this study explored a potential prebiotic effect of the polyphenol-rich French Maritime Pine Bark Extract (PBE) compared to MPH and a placebo in pediatric ADHD patients by studying their impact on the gut microbiota via amplicon sequencing of the full length 16S rRNA gene ribosomal subunit (V1-V9).

One interesting finding was the high relative abundance of Bifidobacteria among all patients in our study cohort. Moreover, our study has identified that treatment (placebo, MPH and PBE) explains 3.94% of the variation in distribution of microbial taxa (adjusted p-value of 0.011).

Our small sample size (placebo: n = 10; PBE: n = 13 and MPH: n = 14) did not allow to observe clear prebiotic effects in the patients treated with PBE. Notwithstanding this limitation, subtle changes were noticeable and some limited compositional changes could be observed.

doi: 10.1186/S13063-017-1879-6.

Tea is a highly popular beverage, primarily due to its unique flavor and aroma as well as its perceived health benefits. The impact of tea on the gut microbiome could be an important means by which tea exerts its health benefits since the link between the gut microbiome and health is strong. This review provided a discussion of the bioactive compounds in tea and the human gut microbiome and how the gut microbiome interacts with tea polyphenols. Importantly, studies were compiled on the impact of differently processed tea, which contains different polyphenol profiles, on the gut microbiota from in vivo animal feeding trials, in vitro human fecal fermentation experiments, and in vivo human feeding trials from 2004-2024. The results were discussed in terms of different tea types and how their impacts are related to or different from each other in these three study groups.

Breast cancer (BC) is one of the most common cancers worldwide and a leading cause of cancer-related deaths among women. The escalating incidence of BC underscores the necessity of multi-level treatment. BC is a complex and heterogeneous disease involving many genetic, lifestyle, and environmental factors. Growing evidence suggests that nutrition intervention is an evolving effective prevention and treatment strategy for BC. In addition, the human microbiota, particularly the gut microbiota, is now widely recognized as a significant player contributing to health or disease status. It is also associated with the risk and development of BC. This review will focus on nutrition intervention in BC, including dietary patterns, bioactive compounds, and nutrients that affect BC prevention and therapeutic responses in both animal and human studies. Additionally, this paper examines the impacts of these nutrition interventions on modulating the composition and functionality of the gut microbiome, highlighting the microbiome-mediated mechanisms in BC. The combination treatment of nutrition factors and microbes is also discussed. Insights from this review paper emphasize the necessity of comprehensive BC management that focuses on the nutrition-microbiome axis.

In the aging process, physiological decline occurs, posing a substantial threat to the physical and mental well-being of the elderly and contributing to the onset of age-related diseases. While traditional perspectives considered the maintenance of life as influenced by a myriad of factors, including environmental, genetic, epigenetic, and lifestyle elements such as exercise and diet, the pivotal role of symbiotic microorganisms had been understated. Presently, it is acknowledged that the intestinal microbiota plays a profound role in overall health by signaling to both the central and peripheral nervous systems, as well as other distant organs. Disruption in this bidirectional communication between bacteria and the host results in dysbiosis, fostering the development of various diseases, including neurological disorders, cardiovascular diseases, and cancer. This review aims to delve into the intricate biological mechanisms underpinning dysbiosis associated with aging and the clinical ramifications of such dysregulation. Furthermore, we aspire to explore bioactive compounds endowed with functional properties capable of modulating and restoring balance in this aging-related dysbiotic process through epigenetics alterations.

The aim of the study was to develop and evaluate a novel dietary index for gut microbiota (DI-GM) that captures dietary composition related to gut microbiota profiles. We conducted a literature review of longitudinal studies on the association of diet with gut microbiota in adult populations and extracted those dietary components with evidence of beneficial or unfavorable effects. Dietary recall data from the National Health and Nutrition Examination Survey (NHANES, 2005-2010, n = 3812) were used to compute the DI-GM, and associations with biomarkers of gut microbiota diversity (urinary enterodiol and enterolactone) were examined using linear regression. From a review of 106 articles, 14 foods or nutrients were identified as components of the DI-GM, including fermented dairy, chickpeas, soybean, whole grains, fiber, cranberries, avocados, broccoli, coffee, and green tea as beneficial components, and red meat, processed meat, refined grains, and high-fat diet (≥40% of energy from fat) as unfavorable components. Each component was scored 0 or 1 based on sex-specific median intakes, and scores were summed to develop the overall DI-GM score. In the NHANES, DI-GM scores ranged from 0-13 with a mean of 4.8 (SE = 0.04). Positive associations between DI-GM and urinary enterodiol and enterolactone were observed. The association of the novel DI-GM with markers of gut microbiota diversity demonstrates the potential utility of this index for gut health-related studies.

A growing body of evidence suggests that cancer remains a significant global health challenge, necessitating the development of novel therapeutic approaches. In recent years, the molecular crosstalk between polyphenols and gut microbiota has emerged as a promising pathway for cancer prevention. Polyphenols, abundant in many plant-based foods, possess diverse bioactive properties, including antioxidant, anti-inflammatory, and anticancer activities. The gut microbiota, a complex microbial community residing in the gastrointestinal tract, plays a crucial role in a host's health and disease risks. This review highlights cancer suppressive and oncogenic mechanisms of gut microbiota, the intricate interplay between gut microbiota modulation and polyphenol biotransformation, and the potential therapeutic implications of this interplay in cancer prevention. Furthermore, this review explores the molecular mechanisms underpinning the synergistic effects of polyphenols and the gut microbiota, such as modulation of signaling pathways and immune response and epigenetic modifications in animal and human studies. The current review also summarizes the challenges and future directions in this field, including the development of personalized approaches that consider interindividual variations in gut microbiota composition and function. Understanding the molecular crosstalk could offer new perspectives for the development of personalized cancer therapies targeting the polyphenol-gut axis. Future clinical trials are needed to validate the potential role of polyphenols and gut microbiota as innovative therapeutic strategies for cancer treatment.

Gestational diabetes mellitus (GDM) is an escalating public health concern due to its association with short- and long-term adverse maternal and child health outcomes. Dysbiosis of microbiota within the gastrointestinal tract has been linked to the development of GDM. Modification of microbiota dysbiosis through dietary adjustments has attracted considerable attention as adjunct strategies to improve metabolic disease. Diets high in fibre and polyphenol content are associated with increased gut microbiota alpha diversity, reduced inflammation and oxidative processes and improved intestinal barrier function. This review explores the potential of fibre and polyphenol supplementation to prevent GDM by investigating their impact on gut microbiota composition and function.

The intestinal-level host-microbiota interaction has been implicated in the pathogenesis of chronic diseases. The current review is intended to provide a comprehensive insight into deciphering whether intestinal-level bioactivities mediate the overall metabolic health benefits of green tea catechins.

We have comprehensively discussed pre-clinical and clinical evidences of intestinal-level changes in metabolism, microbiota, and metabolome due to catechin-rich green tea treatments, ultimately limiting metabolic diseases. Exclusive emphasis has been given to purified catechins and green tea, and discussions on extraintestinal mechanisms of metabolic health benefits were avoided.

A literature search for relevant pre-clinical and clinical studies was performed in various online databases (e.g., PubMed) using specific keywords (e.g., catechin, intestine, microbiota). Out of all the referred literature, ∼15% belonged to 2021-2023, ∼51% were from 2011-2020, and ∼32% from 2000-2010.

The metabolic health benefits of green tea catechins are indeed influenced by the intestinal-level bioactivities, including reduction of mucosal inflammation and oxidative stress, attenuation of gut barrier dysfunction, decrease in intestinal lipid absorption and metabolism, favorable modulation of mucosal nuclear receptor signaling, alterations of the luminal global metabolome, and mitigation of the gut dysbiosis. The results from the recent clinical studies support the pre-clinical evidences. The challenges and pitfalls of the currently available knowledge on catechin bioactivities have been discussed, and constructive directions to harness the translational benefits of green tea through future interventions have been provided.

The metabolism, metabolome, and microbiota at the intestinal epithelia play critical roles in catechin metabolism, pharmacokinetics, bioavailability, and bioactivities. Especially the reciprocal interaction between the catechins and the gut microbiota dictates the metabolic benefits of catechins.

Green tea is a popular beverage worldwide. The abundant green tea catechin (-)-epigallocatechin gallate (EGCG) is a potent in vitro inhibitor of intestinal UDP-glucuronosyltransferase (UGT) activity (Ki  ~2 μM). Co-consuming green tea with intestinal UGT drug substrates, including raloxifene, could increase systemic drug exposure. The effects of a well-characterized green tea on the pharmacokinetics of raloxifene, raloxifene 4'-glucuronide, and raloxifene 6-glucuronide were evaluated in 16 healthy adults via a three-arm crossover, fixed-sequence study. Raloxifene (60 mg) was administered orally with water (baseline), with green tea for 1 day (acute), and on the fifth day after daily green tea administration for 4 days (chronic). Unexpectedly, green tea decreased the geometric mean green tea/baseline raloxifene AUC0-96h ratio to ~0.60 after both acute and chronic administration, which is below the predefined no-effect range (0.75-1.33). Lack of change in terminal half-life and glucuronide-to-raloxifene ratios indicated the predominant mechanism was not inhibition of intestinal UGT. One potential mechanism includes inhibition of intestinal transport. Using established transfected cell systems, a green tea extract normalized to EGCG inhibited 10 of 16 transporters tested (IC50 , 0.37-12 μM). Another potential mechanism, interruption by green tea of gut microbe-mediated raloxifene reabsorption, prompted a follow-up exploratory clinical study to evaluate the potential for a green tea-gut microbiota-drug interaction. No clear mechanisms were identified. Overall, results highlight that improvements in current models and methods used to predict UGT-mediated drug interactions are needed. Informing patients about the risk of co-consuming green tea with raloxifene may be considered.

Cardiometabolic diseases like hypertension, type 2 diabetes mellitus, atherosclerosis, and obesity have been associated with changes in the gut microbiota structure, or dysbiosis. The beneficial effect of polyphenols on reducing the incidence of this chronic disease has been confirmed by numerous studies. Polyphenols are primarily known for their anti-inflammatory and antioxidant properties, but they can also modify the gut microbiota. According to recent research, polyphenols positively influence the gut microbiota, which regulates metabolic responses and reduces systemic inflammation. This review emphasizes the prebiotic role of polyphenols and their impact on specific gut microbiota components in patients at cardiometabolic risk. It also analyzes the most recent research on the positive effects of polyphenols on cardiometabolic health. While numerous in vitro and in vivo studies have shown the interaction involving polyphenols and gut microbiota, additional clinical investigations are required to assess this effect in people.

A meta-analysis study was performed to systematically assess the association between tea consumption and CRC risk.

Cochrane Library, Embase, PubMed, and Web of Science were retrieved to collect articles in English since 24 July 2023. Databases were searched and evaluated by two reviewers independently.We screened the literature based on inclusion and exclusion criteria. After determining the random effect model or fixed utility model based on a heterogeneity test, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.

We included fourteen articles in this meta-analysis. We analyzed the data using a random effect model to explore the association between tea consumption and CRC because of apparent heterogeneity (P < 0.001, I2 = 99.5%). The combined results of all tests showed that there is no statistically significant association between tea consumption and CRC risk (OR = 0.756, 95%CI = 0.470-1.215, P = 0.247). Subsequently, subgroup analysis and sensitivity analysis were performed. Excluding any single study, the overall results ranged from 0.73 (95%CI = 0.44-1.20) to 0.86 (95%CI = 0.53-1.40). It was determined that there was no significant publication bias between tea consumption and CRC risk (P = 0.064) by Egger's tests.

The results indicated that tea consumption may not be significantly associated with the development of CRC.

Tea reduces colon cancer risk by 24%, but the estimate is uncertain. The actual effect on risk can range from a reduction of 51% to an increase of 18%, but regional and population differences may cause differences.

Radiation-induced mucositis is the most common, debilitating and painful acute toxicity associated with active treatment in head and neck cancer area, severely affecting more than 65% of patients. Oral microbiota significantly changes during cancer therapy and appears to be involved on its pathophysiology. This review aims to present a comprehensive update of new etiopathogenic factors and treatments that may decrease the incidence of mucositis, mainly modifications of dietary interventions to modify microbiome. Despite advances in recent years, its management is mainly symptomatic opioid-based with variable results on different substances analyzed for its prevention. Immunonutrition seems to play a significant role, particularly the supplementation of compounds such as fatty acids, polyphenols or selected probiotics have shown to promote commensal bacteria diversity and reduced incidence of ulcerative mucositis. Modification of the microbiome is a promising preventive treatment for mucositis although its evidence is still scarce. Large studies are needed to demonstrate the efficacy of interventions on microbiome and its clinical impact on radiation-induced mucositis.

Convincing evidence has suggested the health potentials of oolong tea (OT) on gut microbiota homeostasis; however, limited population-based studies exist regarding the effect of OT consumption on human gut microbial and metabolic profile. This pilot study explored gut microbial and metabolic changes in healthy adults with a 3-week oolong tea intake. Our findings showed that OT treatment significantly altered gut microbial diversity (Shannon index, 5.4±0.1 vs. 5.7±0.1 pre- and post-OT treatment), reorganized gut microbiota composition, enriched Bacteroides and Prevotella, decreased Megamonas, and improved gastrointestinal function. Also, gut microbes from overweight subjects with BMI >23.9 exhibited greater responses to OT treatment compared with normal-weight counterparts. Metabolomic analysis identified OT intake-induced 23 differential metabolites and 10 enriched metabolic pathways. This study may provide new insights into the association among OT intervention, host gut microbiome and metabolic profile, and improve the knowledge of clinical strategies and personalized nutrition.

Although experimental evidence supports anticancer effects of flavonoids, the influence of flavonoid intake on colorectal cancer (CRC) survival remains unknown.

This study aimed to assess the association of postdiagnostic flavonoid intake with mortality.

We prospectively assessed the association of postdiagnostic flavonoid intake with CRC-specific and all-cause mortality in 2552 patients diagnosed with stage I-III CRC in 2 cohort studies-the Nurses' Health Study and the Health Professionals Follow-up Study. We assessed the intake of total flavonoids and their subclasses using validated food frequency questionnaires. We used the inverse probability-weighted multivariable Cox proportional hazards regression model to calculate the hazard ratio (HR) of mortality after adjusting for prediagnostic flavonoid intake and other potential confounders. We performed spline analysis to evaluate dose-response relationships.

The mean [standard deviation (SD)] age of patients at diagnosis was 68.7 (9.4) y. During 31,026 person-y of follow-up, we documented 1689 deaths, of which 327 were due to CRC. The total flavonoid intake was not associated with mortality, but a higher intake of flavan-3-ols was suggestively associated with lower CRC-specific and all-cause mortality, with multivariable HR (95% CI) per 1-SD increases of 0.83 (0.69-0.99; P = 0.04) and 0.91 (0.84-0.99; P = 0.02), respectively. The spline analysis showed a linear relationship between postdiagnostic flavan-3-ol intake and CRC-specific mortality (P = 0.01 for linearity). As the major contributor to flavan-3-ol intake, tea showed an inverse association with CRC-specific and all-cause mortality, with multivariable HRs per 1 cup/d of tea of 0.86 (0.75-0.99; P = 0.03) and 0.90 (0.85-0.95; P < 0.001), respectively. No beneficial associations were found for other flavonoid subclasses.

Higher intake of flavan-3-ol after CRC diagnosis was associated with lower CRC-specific mortality. Small, readily achievable increases in the intake of flavan-3-ol-rich foods, such as tea, may help improve survival in patients with CRC.

Red wine polyphenolic complexes have attracted increasing attention as potential modulators of human metabolic disease risk. Our previous study discovered that red wine high-molecular-weight polymeric polyphenolic complexes (HPPCs) could inhibit key metabolic syndrome-associated enzymes and favorably modulate human gut microbiota (GM) in simulated colonic fermentation assay in vitro. In this work, the efficacy of HPPC supplementation (150 and 300 mg/kg/day, respectively) against high-fat diet (HFD)-induced metabolic disturbance in mice was investigated. HPPCs effectively attenuated HFD-induced obesity, insulin resistance, and lipid and glucose metabolic dysregulation and ameliorated inflammatory response and hepatic and colonic damage. It also improved the relative abundance of Bacteroidetes and Firmicutes, consistent with an anti-obesity phenotype. The favorable modulation of GM was further supported by improvement in the profile of fecal short-chain fatty acids. The higher dosage generally had a better performance in these effects than the low dosage. Moreover, serum metabolite profiling and pathway enrichment analysis revealed that HPPCs significantly modulated vitamin B metabolism-associated pathways and identified N-acetylneuraminic acid and 2-methylbutyroylcarnitine as potential biomarkers of the favorable effect on HFD-induced metabolic dysregulation. These findings highlight that dietary supplementation with red wine HPPCs is a promising strategy for the management of weight gain and metabolic dysregulation associated with HFD.

Personalised and precision nutrition uses information on individual characteristics and responses to nutrients, foods and dietary patterns to develop targeted nutritional advice that is more effective in improving the diet and health of each individual. Moving away from the conventional 'one size fits all', such targeted intervention approaches may pave the way to better population health, including lower burden of non-communicable diseases. To date, most personalised and precision nutrition approaches have been focussed on tackling obesity and cardiometabolic diseases with limited efforts directed to cancer prevention and for cancer survivors. Advances in understanding the biological basis of cancer and of the role played by diet in cancer prevention and in survival after cancer diagnosis, mean that it is timely to test and to apply such personalised and precision nutrition approaches in the cancer area. This endeavour can take advantage of the enhanced understanding of interactions between dietary factors, individual genotype and the gut microbiome that impact on risk of, and survival after, cancer diagnosis. Translation of these basic research into public health action should include real-time acquisition of nutrigenomic and related data and use of AI-based data integration methods in systems approaches that can be scaled up using mobile devices.

This four-season observational study aimed to examine the mediating role of the gut microbiota in the associations between green tea and catechin intakes and glucose metabolism in individuals without type 2 diabetes mellitus (T2DM). In each of the 4 seasons, 85 individuals without T2DM (56 male [65.9%]; mean [standard deviation] age: 43.3 [9.4] years) provided blood samples, stool samples, 3-day weighed dietary records, and green tea samples. Catechin intake was estimated by analyzing the tea samples. Linear mixed-effects model analysis showed that green tea intake was negatively associated with fasting blood glucose and insulin levels, even after considering the seasonal variations. Of the gut microbial species associated with green tea intake, the mediation analysis revealed that Phocaeicola vulgatus mediated the association between green tea intake and fasting blood glucose levels. These findings indicate that green tea can improve glucose metabolism by decreasing the abundance of P. vulgatus that is associated with elevated blood glucose levels in individuals without T2DM.

It is generally accepted that diet-derived polyphenols are bioactive compounds with several potentially beneficial effects on human health. In general, polyphenols have several chemical structures, and the most representative are flavonoids, phenolic acids, and stilbenes. It should be noted that the beneficial effects of polyphenols are closely related to their bioavailability and bioaccessibility, as many of them are rapidly metabolized after administration. Polyphenols-with a protective effect on the gastrointestinal tract-promote the maintenance of the eubiosis of the intestinal microbiota with protective effects against gastric and colon cancers. Thus, the benefits obtained from dietary supplementation of polyphenols would seem to be mediated by the gut microbiota. Taken at certain concentrations, polyphenols have been shown to positively modulate the bacterial component, increasing Lactiplantibacillus spp. and Bifidobacterium spp. involved in the protection of the intestinal barrier and decreasing Clostridium and Fusobacterium, which are negatively associated with human well-being. Based on the diet-microbiota-health axis, this review aims to describe the latest knowledge on the action of dietary polyphenols on human health through the activity of the gut microbiota and discusses micro-encapsulation of polyphenols as a strategy to improve the microbiota.

Post-operative atrial fibrillation (POAF) is one of the most common complications of cardiac surgery. However, the underlying mechanism is not well understood. Alterations in the gut microbiota are associated with the development of atrial fibrillation (AF). The aim of this study was to explore the relationship between gut microbiota and POAF.

Fecal samples were collected before surgery from 45 patients who underwent coronary artery bypass grafting with POAF and 90 matched patients without POAF (1:2). 16S rRNA sequencing was used to detect the microbiome profiles of 45 POAF patients and 89 matched patients (one sample in the no-POAF group was deleted owing to low quality after sequencing). Plasma 25-hydroxy vitamin D level was measured by ELISA.

Compared to the patients without POAF, gut microbiota composition was remarkably changed in the patients with POAF, with an increase in Lachnospira, Acinetobacter, Veillonella and Aeromonas, and a decrease in Escherichia-Shigella, Klebsiella, Streptococcus, Brevundimonas and Citrobacter. Furthermore, plasma 25-hydroxy vitamin D levels were decreased in POAF patients and negatively correlated with an abundance of Lachnospira.

The gut microbiota composition between patients with and without POAF is significantly different, implying that gut microbiota may play a role in the pathogenesis of POAF. Further studies are needed to fully clarify the role of gut microbiota in the initiation of AF.

A comprehensive review of research over the last decade was conducted to carry out this work. The main objective of this work is to present relevant evidence of the effect of honey intake on the human intestinal microbiota and its relationship with the improvement of various chronic diseases, such as cirrhosis, metabolic syndrome, diabetes, and obesity, among others. Therefore, this work focuses on the health-improving honey dietary supplementation implications associated with specific changes in the human microbiota and their biochemical mechanisms to enhance the proliferation of beneficial microorganisms and the inhibition of pathogenic microorganisms. Consumption of honey polyphenols significantly improves people's health conditions, especially in patients with chronic disease. Hence, honey intake unequivocally constitutes an alternative way to enhance health and could be used to prevent some relevant chronic diseases.

Animal and small-cohort human studies have shown that tea consumption affects the gut microbiome, but evidence from large cohort studies is lacking.

We examined associations between tea consumption and gut microbiome composition among older Chinese adults.

The study included 1179 men and 1078 women from the Shanghai Men's and Women's Health Studies, who reported tea drinking status, type, amount, and duration at baseline and follow-up surveys (1996-2017) and were free of cancer, cardiovascular disease, and diabetes at stool collection (2015-2018). Fecal microbiome was profiled using 16S rRNA sequencing. Associations of tea variables with microbiome diversity and taxa abundance were evaluated using linear or negative binomial hurdle models after adjusting for sociodemographics, lifestyle, and hypertension status.

Mean age at stool collection was 67.2 ± 9.0 y in men and 69.6 ± 8.5 y in women. Tea drinking was not associated with microbiome ɑ-diversity in men or women; however, all tea variables were associated with β-diversity in men (P < 0.001). Significant associations with taxa abundance were also observed mostly in men. Current tea drinking, mainly green tea drinking, was associated with increase in orders Synergistales and RF39 in men (β = 0.30 to 0.42, all PFDR ≤ 0.10) but not in women (PInteraction-sex = 0.01). Also, increase in families Coriobacteriaceae, Odoribacteraceae, genera Collinsella, Odoribacter, and species Collinsella aerofaciens, Coprococcus catus, and Dorea formicigenerans were observed among men who drank >3.3 cups (781 mL)/d compared to that of nondrinkers (all PFDR <0.10). The increased Coprococcus catus related to tea drinking was more evident among men without hypertension and inversely associated with the prevalence of hypertension (OR: 0.90; 95% CI: 0.84, 0.97; PFDR = 0.03).

Tea consumption may affect gut microbiome β-diversity and abundance of some bacteria, which may contribute to reduced hypertension risk in Chinese men. Future studies should examine the sex-specific tea-gut microbiome associations and how certain bacteria may mediate the health benefits of tea.

Cancer stem cells (CSCs) are strongly associated with high tumourigenicity, chemotherapy or radiotherapy resistance, and metastasis and recurrence, particularly in colorectal cancer (CRC). Therefore, targeting CSCs may be a promising approach. Recently, discovery and research on phytochemicals that effectively target colorectal CSCs have been gaining popularity because of their broad safety profile and multi-target and multi-pathway modes of action.

This review aimed to elucidate and summarise the effects and mechanisms of phytochemicals with potential anti-CSC agents that could contribute to the better management of CRC.

We reviewed PubMed, EMBASE, Web of Science, Ovid, ScienceDirect and China National Knowledge Infrastructure databases from the original publication date to March 2022 to review the mechanisms by which phytochemicals inhibit CRC progression by targeting CSCs and their key signalling pathways. Phytochemicals were classified and summarised based on the mechanisms of action.

We observed that phytochemicals could affect the biological properties of colorectal CSCs. Phytochemicals significantly inhibit self-renewal, migration, invasion, colony formation, and chemoresistance and induce apoptosis and differentiation of CSCs by regulating the Wnt/β-catenin pathway (e.g., diallyl trisulfide and genistein), the phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin pathway (e.g., caffeic acid and piperlongumine), the neurogenic locus notch homolog protein pathway (e.g., honokiol, quercetin, and α-mangostin), the Janus kinase-signal transducer and activator of transcription pathway (e.g., curcumin, morin, and ursolic acid), and other key signalling pathways. It is worth noting that several phytochemicals, such as resveratrol, silibinin, evodiamine, and thymoquinone, highlight multi-target and multi-pathway effects in restraining the malignant biological behaviour of CSCs.

This review demonstrates the potential of targeted therapies for colorectal CSCs using phytochemicals. Phytochemicals could serve as novel therapeutic agents for CRC and aid in drug development.

Intensive livestock and poultry farming in China largely relied on the use of in-feed antibiotics until July 2020. The consequences of antibiotic overuse in animal feed include accumulation in animal products and the development of bacterial antibiotic resistance, both of which threaten food safety and human health. China has now completely banned the circulation of commercial feed containing growth-promoting drug additives (except Chinese herbal medicine). Therefore, alternatives to in-feed antibiotics in animal production are greatly needed. Natural phenolic compounds (NPCs) exist widely in plants and are non-toxic, non-polluting, highly reproducible, and leave little residue. Many natural flavonoids, phenolic acids, lignans, and stilbenes have polyphenol chemical structures and exhibit great potential as alternatives to antibiotics. In this review we delineate the characteristics of plant-derived NPCs and summarize their current applications as alternatives to in-feed antibiotics, aiming to provide new strategies for antibiotic-free feeding and promote the development of more sustainable animal husbandry practices.

The tea plant (C. sinensis) has traditionally been consumed worldwide as "tea" for its many health benefits, with the potential for the prevention and therapy of various conditions. Regardless of its long history, the use of tea plants in modern times seems not to have changed much, as the beverage remains the most popular form. This review aimed to compile scientific information about the role and action of tea plants, as well as their status concerning clinical applications, based on the currently available evidence, with a focus on metabolic syndrome, mainly covering obesity, diabetes, and cardiovascular disease. It has been recognized that these diseases pose a significant threat to public health, and the development of effective treatment and prevention strategies is necessary but still challenging. In this article, the potential benefits of tea plants and their derived bioactive components (such as epigallocatechin-3-gallate) as anti-obesity, anti-diabetic, and anti-cardiovascular agents are clearly shown and emphasized, along with their mechanisms of action. However, according to the status of the clinical translation of tea plants, particularly in drug development, more substantial efforts in well-designed, randomized, controlled trials are required to expand their applications in treating the three major metabolic disorders and avoiding the toxicity caused by overconsumption.

Obesity-related cardiometabolic disorders are driven by inflammation, oxidative stress, and gut dysbiosis. Green tea catechins protect against cardiometabolic disorders by anti-inflammatory, antioxidant, and prebiotic activities. However, whether obesity alters catechin bioavailability remains unknown. We hypothesized that obesity would decrease catechin bioavailability due to altered gut microbiota composition. Obese and healthy persons completed a pharmacokinetics trial in which a confection formulated with green tea extract (GTE; 58% epigallocatechin gallate, 17% epigallocatechin, 8% epicatechin, 6% epicatechin gallate) was ingested before collecting plasma and urine at timed intervals for up to 24 h. Stool samples were collected prior to confection ingestion. Catechins and γ-valerolactones were assessed by LC-MS. Obesity reduced plasma area under the curve (AUC_0-12h) by 24-27% and maximum plasma concentrations by 18-36% for all catechins. Plasma AUC_0-12h for 5'-(3',4'-dihydroxyphenyl)-γ-valerolactone and 5'-(3',4',5'-trihydroxyphenyl)-γ-valerolactone, as well as total urinary elimination of all catechins and valerolactones, were unaffected. ⍺-Diversity in obese persons was lower, while Slackia was the only catechin-metabolizing bacteria that was altered by obesity. Ascorbic acid and diversity metrics were correlated with catechin/valerolactone bioavailability. These findings indicate that obesity reduces catechin bioavailability without affecting valerolactone generation, urinary catechin elimination, or substantially altered gut microbiota populations, suggesting a gut-level mechanism that limits catechin absorption.

Diet actively influences gut microbiota and body homeostasis. The predominance of beneficial species results in symbiosis, while dysbiosis is characterized by an imbalance between microbial communities. Food plays a key role in this dynamic and in promoting the health of individuals. Ilex paraguariensis, also known as yerba mate, is a traditional plant from Latin America that has a complex matrix of bioactive substances, including methylxanthines, triterpenes, saponins, and phenolics. The consumption of yerba mate is associated with antioxidant, cardioprotective, anti-inflammatory, and anti-obesity effects. However, to the best of our knowledge, there have been no studies on yerba mate as a modulating agent of intestinal microbiota. Phenolics are the major compounds in yerba mate and have been reported to act in modulating the microbiome. In this review, we explore the activity of yerba mate as a possible stimulant of gut microbiota and present its main phenolics and their biological effects. We also propose different mechanisms of action of these phenolics and possible doses for their effectiveness.

Polyphenols are known to interact with gut microbes that play key roles in maintaining gut health, but the role of gut microbiota modulation by polyphenols in mitigating colonic diseases is not fully established. We hypothesize that the interaction of polyphenols with the gut microbiota contributes to the attenuation of colitis and colitis-associated colon cancer (CAC). To test this hypothesis, we examined the effects of dietary supplementation of polyphenol-rich grape powder (GP) on azoxymethane (AOM) and dextran sulfate sodium (DSS)-induced colitis, CAC and the gut microbiota in mice (study 1), and further compared anti-colitis effects of GP in regular and antibiotic-treated mice (study 2). Compared to the control diet that has matched non-polyphenol contents, 10% GP, but not 3% GP, attenuated AOM-DSS induced colitis and tumor multiplicity by 29% (p<0.05). Ten percent GP increased gut bacterial evenness and counteracted CAC-induced decrease of bacterial evenness and changes of microbial composition. Remarkably, gut bacterial functional profiles of healthy mice and diseased mice fed 10% GP were similar, and both were significantly different from those of diseased mice with the control diet. Furthermore, 10% GP increased the relative abundance of butyrate-producing bacteria in the Lachnospiraceae family and enhanced the concentrations of fecal butyrate. Additionally, 10% GP mitigated DSS-induced colitis in conventional mice, but not the antibiotic-treated, gut microbe-depleted mice. Collectively, our studies demonstrate that grape polyphenols alleviate colonic diseases and prevent disease-associated dysbiosis, and their interaction with the gut microbiota may play a causative role in the protection of gut health.

Processed foods make up about 70 percent of the North American diet. Sulfites and other food preservatives are added to these foods largely to limit bacterial contamination. The mouth microbiota and its associated enzymes are the first to encounter food and therefore likely to be the most affected.

Eight saliva samples from ten individuals were exposed to two sulfite preservatives, sodium sulfite and sodium bisulfite. One sample set was evaluated for bacteria composition utilizing 16s rRNA sequencing, and the number of viable cells in all sample sets was determined utilizing ATP assays at 10 and 40-minute exposure times. All untreated samples were analyzed for baseline lysozyme activity, and possible correlations between the number of viable cells and lysozyme activity.

Sequencing indicated significant increases in alpha diversity with sodium bisulfite exposure and changes in relative abundance of 3 amplicon sequence variants (ASV). Sodium sulfite treated samples showed a significant decrease in the Firmicutes/Bacteroidetes ratio, a marginally significant change in alpha diversity, and a significant change in the relative abundance for Proteobacteria, Firmicutes, Bacteroidetes, and for 6 ASVs. Beta diversity didn't show separation between groups, however, all but one sample set was observed to be moving in the same direction under sodium sulfite treatment. ATP assays indicated a significant and consistent average decrease in activity ranging from 24-46% at both exposure times with both sulfites. Average initial rates of lysozyme activity between all individuals ranged from +/- 76% compared to individual variations of +/- 10-34%. No consistent, significant correlation was found between ATP and lysozyme activity in any sample sets.

Sulfite preservatives, at concentrations regarded as safe by the FDA, alter the relative abundance and richness of the microbiota found in saliva, and decrease the number of viable cells, within 10 minutes of exposure.

Sleep disorders have received widespread attention nowadays, which have been promoted by the accelerated pace of life, unhealthy diets and lack of exercise in modern society. The chemical medications to improve sleep has shown serious side effects and risks with high costs. Therefore, it is urgent to develop efficient nutraceuticals from natural sources to ensure sleep quality as a sustainable strategy. As the second most consumed beverage worldwide, the health-promoting effects of tea have long been widely recognized. However, the modulatory effect of teas on sleep disorders has received much less attention. Tea contains various natural sleep-modulating active ingredients such as L-theanine (LTA), caffeine, tea polyphenols (TPP), tea pigments, tea polysaccharides (TPS) and γ-aminobutyric acid (GABA). This review focuses on the potential influence and main regulating mechanisms of different tea active ingredients on sleep, including being absorbed by the small intestine and then cross the blood-brain barrier to act on neurons in the brain as neurotransmitters, manipulating the immune system and further affect sleep-wake cycle by regulating the levels of cytokines, and controlling the gut microbes to maintain the homeostasis of circadian rhythm. Current research progress and limitations are summarized and several future development directions are also proposed. This review hopes to provide new insights into the future elucidation of the sleep-regulating mechanisms of different teas and their natural active ingredients and the development of tea-based functional foods for alleviating sleep disorders. HighlightsNatural sleep-modulating active ingredients in tea have been summarized.Influences of drinking tea or tea active ingredients on sleep are reviewed.Three main regulating mechanisms of tea active ingredients on sleep are explained.The associations among nervous system, immune system and intestinal microbiota are investigated.The potential of developing delivery carriers for tea active ingredients is proposed.

Rheumatoid arthritis (RA) is a systemic autoimmune disease, in addition, gut microbiota plays an important role in the etiology of RA. However, our understanding of alterations to the gut fungal microbiota in Chinese population with RA is still limited.

Serum samples were obtained from 62 patients with RA, and 39 age- and gender-matched healthy controls (HCs). Fecal samples were obtained from 42 RA patients and 39 HCs. Fecal fungal microbiota targeting internal transcribed spacer region 2 (ITS2) rRNA genes was investigated using MiSeq sequencing, as well as their associations with some diagnostic biomarkers for RA.

Our results showed that the fungal diversity did not alter in RA patients but taxonomic composition of the fecal fungal microbiota did. The gut mycobiota of RA patients was characterized by decreased abundance of Pholiota, Scedosporium, and Trichosporon. The linear discriminant analysis (LDA) effect size analysis (LEfSe) analysis identified several RA-enriched fungal genera, which were positively correlated with most RA biomarkers. Furthermore, since RA is an age- and gende-related disease, we classified RA patients into subgroups with age and gender and analyzed the sequencing results. Our data demonstrated that Wallemia and Irpex were the most discriminatory against RA patients over 60 years old, while Pseudeurotiaceae was the most discriminatory against female RA patients.

The case-control study presented here confirmed the alterations of gut fungal microbiota in Chinese patients with RA, and we speculated that the fungal dysbiosis may contribute to RA development.

The intestinal tract of a healthy human body hosts many microorganisms that are closely linked to all aspects of people's lives. The impact of intestinal flora on host health is no longer limited to the gut but can also affect every organ in the body through various pathways. Studies have found that intestinal flora can be altered by external factors, which provides new ideas for treating some diseases. Tea polyphenols (TP), a general term for polyphenols in tea, are widely used as a natural antioxidant in various bioactive foods. In recent years, with the progress of research, there have been many experiments that provide strong evidence for the ability of TP to regulate intestinal flora. However, there are very few studies on the use of TP to modify the composition of intestinal microorganisms to maintain health or treat related diseases, and this area has not received sufficient attention. In this review, we outline the mechanisms by which TP regulates intestinal flora and the essential role in maintaining suitable health. In addition, we highlighted the protective effects of TP on intestinal mucosa by regulating intestinal flora and the preventive and therapeutic effects on certain chronic diseases, which will help further explore measures to prevent related chronic diseases.

Kombucha is a fermented tea made from a Symbiotic Culture of Bacteria and Yeast (SCOBY) with a long history of use as a health tonic. It is likely that most health benefits come from the tea and fermentation metabolites from specific microbial communities. Despite its growing importance as a functional health drink, the microbial ecosystem present in kombucha has not been fully documented. To characterize the microbial composition and biochemical properties of 'The Good Brew' original base kombucha, we used metagenomics amplicon (16S rRNA and ITS) sequencing to identify the microbial communities at the taxonomic level. We identified 34 genera with 200 microbial species yet described in kombucha. The dominance of organic acid producing microorganisms Acetobacter, Komagataeibacter and Starmerella are healthy for the human gut and their glucose metabolising activities have a putative role in preventing conditions such as diabetes and obesity. Kombucha contains high protein (3.31 µg/mL), high phenolic content (290.4 mg/100 mL) and low sugars (glucose: 1.87 g/L; sucrose 1.11 g/L; fructose: 0.05 g/L) as compared to green tea. The broad microbial diversity with proven health benefits for the human gut suggests kombucha is a powerful probiotic. These findings are important to improve the commercial value of kombucha and uncover the immense prospects for health benefits.

Numerous nutraceuticals and botanical food supplements are used with the intention of modulating body weight. A recent review examined the main food supplements used in weight loss, dividing them according to the main effects for which they were investigated. The direct or indirect effects exerted on the intestinal microbiota can also contribute to the effectiveness of these substances. The aim of this review is to evaluate whether any prebiotic effects, which could help to explain their efficacy or ineffectiveness, are documented in the recent literature for the main nutraceuticals and herbal food supplements used for weight loss management. Several prebiotic effects have been reported for various nutraceutical substances, which have shown activity on Bifidobacterium spp., Lactobacillus spp., Akkermansia muciniphila, Faecalibacterium prausnitzi, Roseburia spp., and the Firmicutes/Bacteroidetes ratio. Different prebiotics have beneficial effects on weight and the related metabolic profile, in some cases even acting on the microbiota with mechanisms that are completely independent from those nutraceuticals for which certain products are normally used. Further studies are necessary to clarify the different levels at which a nutraceutical substance can exert its action.