Human milk oligosaccharides (HMOs) are bioactive components of breast milk with diverse health benefits, including shaping the gut microbiota, modulating the immune system, and protecting against infections. HMOs exhibit dynamic secretion patterns during lactation, influenced by maternal genetics and environmental factors. Their direct and indirect antimicrobial properties have garnered significant research interest. However, a comprehensive understanding of the secretion dynamics of HMOs and their correlation with antimicrobial efficacy remains underexplored.

To synthesize current evidence on the secretion dynamics of HMOs during lactation and evaluate their antimicrobial roles against bacterial, viral, and protozoal pathogens.

A systematic search of PubMed, Scopus, Web of Science, and Cochrane Library focused on studies investigating natural and synthetic HMOs, their secretion dynamics, and antimicrobial properties. Studies involving human, animal, and in vitro models were included. Data on HMO composition, temporal secretion patterns, and mechanisms of antimicrobial action were extracted. Quality assessment was performed using validated tools appropriate for study design.

A total of 44 studies were included, encompassing human, animal, and in vitro research. HMOs exhibited dynamic secretion patterns, with 2'-fucosyllactose (2'-FL) and lacto-N-tetraose peaking in early lactation and declining over time, while 3-fucosyllactose (3-FL) increased during later stages. HMOs demonstrated significant antimicrobial properties through pathogen adhesion inhibition, biofilm disruption, and enzymatic activity impairment. Synthetic HMOs, including bioengineered 2'-FL and 3-FL, were structurally and functionally comparable to natural HMOs, effectively inhibiting pathogens such as Pseudomonas aeruginosa, Escherichia coli, and Campylobacter jejuni. Additionally, HMOs exhibited synergistic effects with antibiotics, enhancing their efficacy against resistant pathogens.

HMOs are vital in antimicrobial defense, supporting infant health by targeting various pathogens. Both natural and synthetic HMOs hold significant potential for therapeutic applications, particularly in infant nutrition and as adjuncts to antibiotics. Further research, including clinical trials, is essential to address gaps in knowledge, validate findings, and explore the broader applicability of HMOs in improving maternal and neonatal health.

Isomalto-oligosaccharides (IMO) are prebiotic oligosaccharides that have shown promise in improving insulin sensitivity and glucose metabolism, making them potential therapeutic agents for Type 2 Diabetes (T2D). IMO selectively stimulates beneficial gut microbiota, particularly Bifidobacterium and Lactobacillus, leading to the production of short-chain fatty acids (SCFAs) like acetate, propionate, and butyrate. These SCFAs play a pivotal role in enhancing the release of gut hormones such as GLP-1 (Glucagon-like peptide-1) and PYY (Peptide YY), which improve insulin secretion and promote satiety, thus improving glucose homeostasis. Clinical studies have reported that IMO supplementation can lower HbA1c by 0.5% and reduce postprandial glucose spikes, demonstrating its efficacy in glycemic control. Additionally, IMO promotes insulin sensitivity by reducing inflammation and enhancing adiponectin levels. Although the current findings are promising, further research is needed to determine optimal dosing, long-term safety, and the role of individual gut microbiomes in tailoring IMO interventions. Future studies focusing on personalized nutrition strategies and the synergistic effects of IMO with other lifestyle interventions could enhance its applicability as a key component in T2D management.

This review explores the impact of Lactiplantibacillus plantarum on diabetes management and discusses the potential mechanism.

Recent studies have highlighted that gut dysbiosis has emerged as a key factor in the development of diabetes. In this context, probiotics, specifically Lactiplantibacillus plantarum, offer potential benefits in modulating gut microbiota and improving metabolic health. Several studies have demonstrated the positive impact of L. plantarum on glycemic control, insulin sensitivity, and inflammatory markers in diabetic animal models. The potential mechanisms of action of L. plantarum in diabetes management include inhibiting enzymes involved in glucose metabolism, modulating inflammatory responses, improving insulin sensitivity, restoring gut microbiota, and producing short-chain fatty acids.

The article concludes that L. plantarum is a promising candidate for managing glucose hemostasis, thus offering a potential alternative or adjunct to conventional approaches. However, further clinical studies are necessary to understand the exact mechanism and long-term effects of L. plantarum in humans.

Obesity is a condition of chronic low-grade inflammation affecting peripheral organs of the body, as well as the central nervous system. The adipose tissue dysfunction occurring under conditions of obesity is a key factor in the onset and progression of a variety of diseases, including neurodegenerative disorders. Mitochondria, key organelles in the production of cellular energy, play an important role in this tissue dysfunction. Numerous studies highlight the close link between obesity and adipocyte mitochondrial dysfunction, resulting in excessive ROS production and adipose tissue inflammation. This inflammation is transmitted systemically, leading to metabolic disorders that also impact the central nervous system, where pro-inflammatory cytokines impair mitochondrial and cellular functions in different areas of the brain, leading to neurodegenerative diseases. To date, several bioactive compounds are able to prevent and/or slow down neurogenerative processes by acting on mitochondrial functions. Among these, some molecules present in the Mediterranean diet, such as polyphenols, carotenoids, and omega-3 PUFAs, exert a protective action due to their antioxidant and anti-inflammatory ability. The aim of this review is to provide an overview of the involvement of adipose tissue dysfunction in the development of neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and multiple sclerosis, emphasizing the central role played by mitochondria, the main actors in the cross-talk between adipose tissue and the central nervous system.

The gut microbiota is a key modulator of human health and the status of major diseases including cancer, diabetes and inflammatory bowel disease. Central to microbiota survival is the ability to metabolise complex dietary and host-derived glycans, including intestinal mucins. The prominent human gut microbe Bacteroides thetaiotaomicron (B. theta) is a versatile and highly efficient complex glycan degrader thanks to the expansion of gene clusters termed polysaccharide utilisation loci (PULs). While the mechanism of action for several singular dietary glycan-induced PULs have been elucidated, studies on the unusually high number of mucin-inducible PULs in B. theta significantly lag behind. Here we show that a mucin inducible PUL BT4240-50 encodes activities consistent with the processing and metabolism of mucin O-glycoproteins and their core sugar N-acetylgalactosamine (GalNAc). PUL BT4240-50 was also shown to be important for competitive growth on mucins in vitro, encoding a kinase (BT4240) critical for GalNAc metabolism. Additionally, BT4240-kinase was shown to be essential for glycosaminoglycan metabolism, extending the PULs function beyond mucins. These data advance our understanding of glycoprotein metabolism at mucosal surfaces, highlighting GalNAc as a key metabolite for competitive microbial survival in the human gut.

Heart failure (HF) has become an immense health concern affecting almost 1-2% of the population globally. It is a complex syndrome characterized by activation of the sympathetic nervous system and the Renin-Angiotensin-Aldosterone (RAAS) axis as well as endothelial dysfunction, oxidative stress, and inflammation. The recent literature points towards the interaction between the intestinal flora and the heart, also called the gut-heart axis. The human gastrointestinal tract is naturally inhabited by various microbes, which are distinct for each patient, regulating the functions of many organs. Alterations of the gut microbiome, a process called dysbiosis, may result in systemic diseases and have been associated with heart failure through inflammatory and autoimmune mechanisms. The disorder of intestinal permeability favors the translocation of microbes and many metabolites capable of inducing inflammation, thus further contributing to the deterioration of normal cardiac function. Besides diet modifications and exercise training, many studies have revealed possible gut microbiota targeted treatments for managing heart failure. The aim of this review is to demonstrate the impact of the inflammatory environment induced by the gut microbiome and its metabolites on heart failure and the elucidation of these novel therapeutic approaches.

Non-alcoholic fatty liver disease (NAFLD) is increasing worldwide and has become the greatest potential risk for cirrhosis and hepatocellular carcinoma. The metabolites produced by the gut microbiota act as signal molecules that mediate the interaction between microorganisms and the host and have biphasic effects on human health. The gut microbiota and its metabolites, short-chain fatty acids (SCFAs), have been discovered to ameliorate many prevalent liver diseases, including NAFLD. Currently, SCFAs have attracted widespread attention as potential therapeutic targets for NAFLD, but the mechanism of action has not been fully elucidated. This article summarizes the mechanisms of short-chain fatty acids of gut microbiota metabolites to regulate the metabolism of glucose and lipid, maintain the intestinal barrier, alleviate the inflammatory response, and improve the oxidative stress to improve NAFLD, in order to provide a reference for clinical application.

Sarcopenia refers to the decline in skeletal muscle mass and function. Due to its increased mortality rate and severe disability, the clinical importance of sarcopenia is becoming increasingly prominent. Although the exact cause of sarcopenia is not fully understood, the gut microbiota (GM) plays a crucial role in the pathogenesis of sarcopenia, and increasing evidence suggests that gut dysbiosis may be associated with disease development. In the past few decades, the use of probiotics has surged, few studies have explored their impact on sarcopenia prevention and treatment. Lactobacillus probiotics are commonly used for gut health and immune support, but their mechanism in sarcopenia via the gut-muscle axis remains uncertain. This review highlights the treatment challenges, GM's role in sarcopenia, and the potential of Lactobacillus as an adjunct therapy. In addition, we also discuss the possible mechanisms by which Lactobacillus affect muscle function, such as alleviating inflammatory states, clearing excessive reactive oxygen species (ROS), improving skeletal muscle metabolism, enhancing intestinal barrier function and modulating the gut microbiota and its metabolites. These mechanisms may collectively contribute to the preservation of muscle mass and function, offering a promising avenue for advancing microbial therapies for sarcopenia.

Obesity prevalence has steadily increased over the past decades. Standard approaches, such as increased energy expenditure, lifestyle changes, a balanced diet, and the use of specific drugs, are the conventional strategies for preventing or treating the disease and its associated complications. Fermented foods and their subsequent bioactive constituents are now believed to be a novel strategy that can complement already existing approaches for managing and preventing this disease. Recent developments in systems biology and bioinformatics have made it possible to model and simulate compounds and disease interactions. The adoption of such in silico models has contributed to the discovery of novel fermented product targets and helped in testing hypotheses regarding the mechanistic impact and underlying functions of fermented food components. From the studies explored, key findings suggest that fermented foods affect adipogenesis, lipid metabolism, appetite regulation, gut microbiota composition, insulin resistance, and inflammation related to obesity, which could lead to new ways to treat these conditions. These outcomes were linked to probiotics, prebiotics, metabolites, and complex bioactive substances produced during fermentation. Overall, fermented foods and their bioactive compounds show promise as innovative tools for obesity management by influencing metabolic pathways and overall gut health.

Liubao tea, a traditional dark tea, has gained widespread recognition for various health benefits. In this study, the effects of Liubao tea extract (LTE) on obesity-related hyperlipidemia and the potential mechanism involved were explored. Anti-obesity compounds such as tricetin, isovitexin, tiliroside, etc. in LTE were identified. In high-fat diet mouse models, LTE effectively reduced tissues, organs, and body weight growth, and restored abnormal serum lipid levels. LTE could reverse adipocyte enlargement, lipid accumulation, and hepatic microstructure abnormalities. Notably, LTE reshaped gut microbiota by boosting beneficial bacteria (e.g., Bacteroides, Akkermansia, Psychrobacter) and suppressing harmful bacteria (e.g., Dubosiella, Faecalibaculum). Spearman correlation analysis unveiled significant associations between serum lipid levels, weight gain, LTE dosage, and gut microbiota, underlining the modulatory effects of LTE on metabolic disorders via the regulation of intestinal microbiota. Collectively, LTE could serve as a potential therapy for obesity-related hyperlipidemia prevention.

In recent years, the consumption of postbiotics has gained significant attention due to their potential health benefits. However, their application in the bakery industry remains underutilized. This review focuses on recent advances in the use of postbiotics, specifically the metabolites of lactic acid bacteria, in bakery products. We provide a concise overview of the multifaceted benefits of postbiotics, including their role as natural antioxidants, antimicrobials, and preservatives, and their potential to enhance product quality, extend shelf-life, and contribute to consumer welfare. This review combines information from various sources to provide a comprehensive update on recent advances in the role of postbiotics in bakery products, subsequently discussing the concept of sourdough as a leavening agent and its role in improving the nutritional profile of bakery products. We highlighted the positive effects of postbiotics on bakery items, such as improved texture, flavor, and shelf life, as well as their potential to contribute to overall health through their antioxidant properties and their impact on gut health. Overall, this review emphasizes the promising potential of postbiotics to revolutionize the bakery industry and promote healthier and more sustainable food options. The integration of postbiotics into bakery products represents a promising frontier and offers innovative possibilities to increase product quality, reduce food waste, and improve consumer health. Further research into refining techniques to incorporate postbiotics into bakery products is essential for advancing the health benefits and eco-friendly nature of these vital food items.

Objective: Biotics are increasingly being used in the treatment of irritable bowel syndrome (IBS). This study aimed to assess the efficacy and safety of a mixture of microencapsulated sodium butyrate, probiotics (Lactocaseibacillus rhamnosus DSM 26357, Lactobacillus acidophilus DSM 32418, Bifidobacterium longum DSM 32946, Bifidobacterium bifidum DSM 32403, and Bifidobacterium lactis DSM 32269), and short-chain fructooligosaccharides (scFOSs) in IBS patients. Methods: This was a randomized, double-blind, placebo-controlled trial involving 120 adult participants with IBS. The primary outcome of the 12-week intervention was the improvement in IBS symptoms and quality of life (QOL), assessed with the use of IBS-Adequate Relief (IBS-AR), IBS-Global Improvement Scale (IBS-GIS), IBS-Symptom Severity Score (IBS-SSS), and IBS-QOL. Secondary outcomes were the number and type of stools (assessed via the Bristol Stool Form scale), patient-recorded symptoms, anthropometric parameters, and levels of selected inflammatory cytokines. Results: As early as at 4 weeks, there was a higher percentage of patients in the biotic group reporting adequate relief of symptoms (based on IBS-AR) than in the placebo group (64.7% vs. 42.0%, respectively, p = 0.023). At 12 weeks, fewer patients in the biotic group reported a 'worsening of symptoms' (based on IBS-GIS) than in the placebo group (5.9% vs. 16.0% respectively, p = 0.015). There were no significant differences between groups in IBS-QOL or IBS-SSS or any of the secondary outcome measures except the patient-recorded 'urgency to defecate' (p = 0.015) at week 12, which was significantly lower in the biotic group. The intervention was safe and well tolerated. Conclusions: A biotic mixture consisting of microencapsulated butyrate, probiotics, and small amounts of scFOSs is safe and effective in improving gastrointestinal symptoms in patients with IBS.

Intervertebral disk degeneration (IDD) is a common clinical spinal disease and one of the main causes of low back pain (LBP). Generally speaking, IDD is considered a natural degenerative process with age. However, with the deepening of research, people have discovered that IDD is not only related to age, but also has many factors that can induce and accelerate its progression. In addition, the pathogenesis of IDD remains unclear, resulting in limited traditional treatment methods that cannot effectively prevent and treat IDD. Conservative treatment may lead to patients' dependence on drugs, and the pain relief effect is not obvious. Similarly, surgical treatment is highly invasive, with a longer recovery time and a higher recurrence rate. With the deepening of exploration, people have discovered that intestinal microorganisms are an important symbiotic microbial community in the human body and are closely related to the occurrence and development of various diseases. Changes in intestinal microorganisms and their metabolites may affect the body's inflammatory response, immune regulation, and metabolic processes, thereby affecting the health of the intervertebral disk. In this context, the gut microbiota has received considerable attention as a potential target for delaying or treating IDD. This article first introduces the impact of gut microbes on common distal organs, and then focuses on three potential mechanisms by which gut microbes and their metabolites influence IDD. Finally, we also summarized the methods of delaying or treating IDD by interfering with intestinal microorganisms and their metabolites. Further understanding of the potential mechanisms between intestinal microorganisms and IDD will help to formulate reasonable IDD treatment strategies to achieve ideal therapeutic effects.

Obesity, a prevalent and multifactorial disease, is linked to a range of metabolic abnormalities, including insulin resistance, dyslipidemia, and chronic inflammation. These imbalances not only contribute to cardiometabolic diseases but also play a significant role in cancer pathogenesis. The rising prevalence of obesity underscores the need to investigate dietary strategies for effective weight management for individuals with overweight or obesity and cancer. This European Society for the Study of Obesity (EASO) position statement aimed to summarize current evidence on the role of obesity in cancer and to provide insights on the major nutritional interventions, including the Mediterranean diet (MedDiet), the ketogenic diet (KD), and the intermittent fasting (IF), that should be adopted to manage individuals with overweight or obesity and cancer. The MedDiet, characterized by high consumption of plant-based foods and moderate intake of olive oil, fish, and nuts, has been associated with a reduced cancer risk. The KD and the IF are emerging dietary interventions with potential benefits for weight loss and metabolic health. KD, by inducing ketosis, and IF, through periodic fasting cycles, may offer anticancer effects by modifying tumor metabolism and improving insulin sensitivity. Despite the promising results, current evidence on these dietary approaches in cancer management in individuals with overweight or obesity is limited and inconsistent, with challenges including variability in adherence and the need for personalized dietary plans.

The early-life gut microbiota (GM) is increasingly recognized for its contributions to human health and disease over time. Microbiota composition, influenced by factors like race, geography, lifestyle, and individual differences, is subject to change. The GM serves dual roles, defending against pathogens and shaping the host immune system. Disruptions in microbial composition can lead to immune dysregulation, impacting defense mechanisms. Additionally, GM aids digestion, releasing nutrients and influencing physiological systems like the liver, brain, and endocrine system through microbial metabolites. Dysbiosis disrupts intestinal homeostasis, contributing to age-related diseases. Recent studies are elucidating the bacterial species that characterize a healthy microbiota, defining what constitutes a 'healthy' colonic microbiota. The present review article focuses on the importance of microbiome composition for the development of homeostasis and the roles of GM during aging and the age-related diseases caused by the alteration in gut microbial communities. This article might also help the readers to find treatments targeting GM for the prevention of various diseases linked to it effectively.

Argan oil, rich in unsaturated fatty acids and polyphenols, exerts beneficial effects on both the intestinal and skin microbiotas. In the gut, it promotes the growth of beneficial bacteria, such as lactobacilli, while reducing pathogenic bacteria, due to its anti-inflammatory properties that help maintain microbial balance. Additionally, it improves the integrity of the intestinal mucosa, reducing the risk of dysbiosis. On the skin, argan oil hydrates and balances the lipid environment, creating a favorable setting for beneficial microorganisms, while also possessing antimicrobial and anti-inflammatory properties that soothe conditions like eczema and acne. Thus, argan oil is valuable for overall health, supporting digestion and skin health. The objective of this review is to provide a summary of the benefits of argan oil for alternative and complementary medicine. An exhaustive search of the literature was carried out using targeted keywords. A set of 83 articles were selected and analyzed. As the mechanisms of action of argan oil are not completely understood, this work highlighted the benefits of this oil by analyzing its nutritional properties and its beneficial effects on the intestinal and skin microbiotas. Indeed, argan oil is valuable for overall health.

Pectin, a natural polysaccharide predominantly sourced from the cell walls of terrestrial plants, is widely regarded for its gelling, thickening, and stabilizing properties, which have extensive applications in the food, pharmaceutical, and biotechnological industries. This review discusses the mechanistic pathways by which pectin mediates its lipid-lowering properties, such as pectin's antioxidant activity, the modulation of gut microbiota, its anti-inflammatory properties, its capacity to bind bile acids and cholesterol, and its impact on the expression of genes associated with lipid metabolism. To enhance its hypolipidemic properties, chemical, physical, and enzymatic modification techniques are explored. Additionally, the synergistic effects of pectin in combination with other bioactive compounds such as phytosterols and polyphenols, as well as its potential in nanocarrier-mediated delivery systems for lipid-lowering agents, are highlighted. The review also conducts a critical analysis of the safety and regulatory considerations associated with pectin use, emphasizing the necessity for comprehensive toxicological evaluations and adherence to regulatory standards. This paper underscores the growing potential of pectin not only as a dietary fiber but also as a multifaceted agent for ameliorating hyperlipidemia, catalyzing a shift toward more targeted and efficacious lipid-lowering strategies.

Wheat germ is known for its antioxidant, anti-inflammatory, and disease resistance properties in animals. However, its effect on the gut of Sichuan white geese remains unclear.

In this study, thirty 250-day-old geese were divided into three equal groups, the control group, LWG group (21.8% wheat germ) and HWG group (43.6% wheat germ), the experiment lasted 12 weeks. We assessed various aspects of geese intestinal health, including barrier function, digestibility, antioxidant capacity, immunity, microbiota, and metabolism.

The study revealed a significant increase in villus height (VH), villus height-to-crypt depth (VH/CD) ratio, amylase, and lipase activities in the duodenum and ileum, increased putrescine levels in the duodenum and jejunum, as well as spermidine levels in the jejunum (P < 0.05). LWG increased the total antioxidant capacity (T-AOC) in the duodenum, while decreasing levels of intestinal malondialdehyde (MDA), serum lipopolysaccharide (LPS), interleukin-6 (IL-6), and diamine oxidase (DAO) activity (P < 0.05). Furthermore, LWG increased the relative abundance of Oscillospiraceae_unclassified, Ligilactobacillus, and Roseburia, as well as increased levels of acetic acid, butyric acid, and valeric acid, while decreasing the relative abundance of Subdoligranulum, Flavonifractor, and Klebsiella. Additionally, we observed 17 up-regulated genes and 25 down-regulated genes in the jejunum, which are associated with the cell cycle and immunity. These genes play roles in pathways such as the p53 signaling pathway, cell cycle regulation, and pathways associated with immune modulation. On the other hand, HWG increased intestinal VH and spermidine levels, as well as amylase and lipase activities in the duodenum (P < 0.05). It also elevated ileal T-AOC and sIgA levels (P < 0.05), while reducing intestinal MDA content, serum LPS levels, DAO activity, and propionic acid in cecum contents (P < 0.05). Moreover, HWG increased the relative abundance of Ligilactobacillus, Oscillospiraceae_unclassified, and Roseburia (P < 0.05).

Overall, wheat germ diets, particularly the LWG diet demonstrated the ability to enhance antioxidant capacity, digestibility, immunity, and barrier properties of the intestinal tract, while modulating the gut microbiota and metabolism. Therefore, wheat germ diets hold promise in improving intestinal health by preserving barrier function and regulating flora structure.

Obesity disrupts glucose metabolism, leading to insulin resistance (IR) and cardiometabolic diseases. Consumption of cow's milk and other dairy products may influence glucose metabolism. Within the complex matrix of cow's milk, various carbohydrates, lipids, and peptides act as bioactive molecules to alter human metabolism. Here, we summarize data from human studies and rodent experiments illustrating how these bioactive molecules regulate insulin and glucose homeostasis, supplemented with in vitro studies of the mechanisms behind their effects. Bioactive carbohydrates, including lactose, galactose, and oligosaccharides, generally reduce hyperglycemia, possibly by preventing gut microbiota dysbiosis. Milk-derived lipids of the milk fat globular membrane improve activation of insulin signaling pathways in animal trials but seem to have little impact on glycemia in human studies. However, other lipids produced by ruminants, including polar lipids, odd-chain, trans-, and branched-chain fatty acids, produce neutral or contradictory effects on glucose metabolism. Bioactive peptides derived from whey and casein may exert their effects both directly through their insulinotropic effects or renin-angiotensin-aldosterone system inhibition and indirectly by the regulation of incretin hormones. Overall, the results bolster many observational studies in humans and suggest that cow's milk intake reduces the risk of, and can perhaps be used in treating, metabolic disorders. However, the mechanisms of action for most bioactive compounds in milk are still largely undiscovered.

Gastrointestinal cancer is a worldwide health challenge due to its dramatically increasing prevalence and as a leading cause of cancer-related mortality. Increasing evidence has illustrated the vital role of gut microbes-derived metabolites in gastrointestinal cancer progression and treatment. Microbial metabolites are produced by the gut microbiota that utilizes both extrinsic dietary components and intrinsic host-generated compounds. Meanwhile, certain categories of metabolites such as short-chain fatty acids, bile acids, tryptophan, and indole derivatives, are linked to gastrointestinal malignancy. In this review, the major classes of microbial metabolites and their impacts on various gastrointestinal cancers including colorectal cancer, gastric cancer, and hepatocellular carcinoma, have been introduced. The application of microbial metabolites as predictive biomarkers for early diagnosis and prognosis of gastrointestinal cancer has also been explored. In addition, therapeutic potential of strategies that target microbial metabolites against gastrointestinal cancer is further evaluated.

Globally, type 2 diabetes mellitus (T2DM) is a major threat to the public's health, particularly in low- and middle-income countries (LMICs). The production of short-chain fatty acids (SCFAs) by the gut microbiota has been reported to have the potential to reduce the prevalence of T2DM, particularly in LMICs where the disease is becoming more common. Dietary fibers are the primary source of SCFAs; they can be categorized as soluble (such as pectin and inulin) or insoluble (such as resistant starches). Increased consumption of processed carbohydrates, in conjunction with insufficient consumption of dietary fiber, has been identified as a significant risk factor for type 2 diabetes (T2DM). However, there are still controversies over the therapeutic advantages of SCFAs on human glucose homeostasis, due to a lack of studies in this area. Hence, a few questions need to be addressed to gain a better understanding of the beneficial link between SCFAs and glucose metabolism. These include the following: What are the biochemistry and biosynthesis of SCFAs? What role do SCFAs play in the pathology of T2DM? What is the most cost-effective strategy that can be employed by LMICs with limited laboratory resources to enhance their understanding of the beneficial function of SCFAs in patients with T2DM? To address the aforementioned questions, this paper aims to review the existing literature on the protective roles that SCFAs have in patients with T2DM. This paper further discusses possible cost-effective and accurate strategies to quantify SCFAs, which may be recommended for implementation by LMICs as preventive measures to lower the risk of T2DM.

The gut microbiome, a complex assembly of microorganisms, significantly impacts human health by influencing nutrient absorption, the immune system, and disease response. These microorganisms form a dynamic ecosystem that is critical to maintaining overall well-being. Prebiotics and probiotics are pivotal in regulating gut microbiota composition. Prebiotics nourish beneficial bacteria and promote their growth, whereas probiotics help maintain balance within the microbiome. This intricate balance extends to several aspects of health, including maintaining the integrity of the gut barrier, regulating immune responses, and producing metabolites crucial for metabolic health. Dysbiosis, or an imbalance in the gut microbiota, has been linked to metabolic disorders such as type 2 diabetes, obesity, and cardiovascular disease. Impaired gut barrier function, endotoxemia, and low-grade inflammation are associated with toll-like receptors influencing proinflammatory pathways. Short-chain fatty acids derived from microbial fermentation modulate anti-inflammatory and immune system pathways. Prebiotics positively influence gut microbiota, whereas probiotics, especially Lactobacillus and Bifidobacterium strains, may improve metabolic outcomes, such as glycemic control in diabetes. It is important to consider strain-specific effects and study variability when interpreting these findings, highlighting the need for further research to optimize their therapeutic potential. The aim of this report is therefore to review the role of the gut microbiota in metabolic health and disease and the effects of prebiotics and probiotics on the gut microbiome and their therapeutic role, integrating a broad understanding of physiological mechanisms with a clinical perspective.

The influence of gut microbiota in the onset and development of several metabolic diseases has gained attention over the last few years. Diet plays an essential role in gut microbiota modulation. Western diet (WD), characterized by high-sugar and high-fat consumption, alters gut microbiome composition, diversity index, microbial relative levels, and functional pathways. Despite the promising health effects demonstrated by polyunsaturated fatty acids, their impact on gut microbiota is still overlooked. The effect of Fish oil (omega-3 source) and Pomegranate oil (punicic acid source), and a mixture of both oils in gut microbiota modulation were determined by subjecting the oil samples to in vitro fecal fermentations. Cecal samples from rats from two different dietary groups: a control diet (CD) and a high-fat high-sugar diet (WD), were used as fecal inoculum. 16S amplicon metagenomics sequencing showed that Fish oil + Pomegranate oil from the WD group increased α-diversity. This sample can also increase the relative abundance of the Firmicutes and Bacteroidetes phylum as well as Akkermansia and Blautia, which were affected by the WD consumption. All samples were able to increase butyrate and acetate concentration in the WD group. Moreover, tyrosine concentrations, a precursor for dopamine and norepinephrine, increase in the Fish oil + Pomegranate oil WD sample. GABA, an important neurotransmitter, was also increased in WD samples. These results suggest a potential positive impact of these oils' mixture on gut-brain axis modulation. It was demonstrated, for the first time, the great potential of using a mixture of both Fish and Pomegranate oil to restore the gut microbiota changes associated with WD consumption.

The global prevalence of obesity currently exceeds 1 billion people and is accompanied by an increase in the aging population. Obesity and aging share many hallmarks and are leading risk factors for cardiometabolic disease and premature death. Current anti-obesity and pro-longevity pharmacotherapies are limited by side effects, warranting the development of novel therapies. The gut microbiota plays a major role in human health and disease, with a dysbiotic composition evident in obese and aged individuals. The bidirectional communication system between the gut and the central nervous system, known as the gut-brain axis, may link obesity to unhealthy aging. Modulating the gut with microbiome-targeted therapies, such as biotics, is a novel strategy to treat and/or manage obesity and promote longevity. Biotics represent material derived from living or once-living organisms, many of which have therapeutic effects. Pre-, pro-, syn- and post-biotics may beneficially modulate gut microbial composition and function to improve obesity and the aging process. However, the investigation of biotics as next-generation therapeutics has only just begun. Further research is needed to identify therapeutic biotics and understand their mechanisms of action. Investigating the function of the gut-brain axis in obesity and aging may lead to novel therapeutic strategies for obese, aged and comorbid (e.g., sarcopenic obese) patient populations. This review discusses the interrelationship between obesity and aging, with a particular emphasis on the gut microbiome, and presents biotics as novel therapeutic agents for obesity, aging and related disease states.

Inter-individual human variability, driven by various genetic and environmental factors, complicates the ability to develop effective population-based early disease detection, treatment and prognostic assessment. The microbiome, consisting of diverse microorganism communities including viruses, bacteria, fungi and eukaryotes colonizing human body surfaces, has recently been identified as a contributor to inter-individual variation, through its person-specific signatures. As such, the microbiome may modulate disease manifestations, even among individuals with similar genetic disease susceptibility risks. Information stored within microbiomes may therefore enable early detection and prognostic assessment of disease in at-risk populations, whereas microbiome modulation may constitute an effective and safe treatment tailored to the individual. In this Review, we explore recent advances in the application of microbiome data in precision medicine across a growing number of human diseases. We also discuss the challenges, limitations and prospects of analysing microbiome data for personalized patient care.

Overweight and obesity are characterized by excessive fat mass accumulation produced when energy intake exceeds energy expenditure. One plausible way to control energy expenditure is to modulate thermogenic pathways in white adipose tissue (WAT) and/or brown adipose tissue (BAT). Among the different environmental factors capable of influencing host metabolism and energy balance, the gut microbiota is now considered a key player. Following pioneering studies showing that mice lacking gut microbes (that is, germ-free mice) or depleted of their gut microbiota (that is, using antibiotics) developed less adipose tissue, numerous studies have investigated the complex interactions existing between gut bacteria, some of their membrane components (that is, lipopolysaccharides), and their metabolites (that is, short-chain fatty acids, endocannabinoids, bile acids, aryl hydrocarbon receptor ligands and tryptophan derivatives) as well as their contribution to the browning and/or beiging of WAT and changes in BAT activity. In this Review, we discuss the general physiology of both WAT and BAT. Subsequently, we introduce how gut bacteria and different microbiota-derived metabolites, their receptors and signalling pathways can regulate the development of adipose tissue and its metabolic capacities. Finally, we describe the key challenges in moving from bench to bedside by presenting specific key examples.

Autoimmune thyroiditis (AIT), also known as Hashimoto's thyroiditis (HT) or chronic lymphocytic thyroiditis, is a prevalent autoimmune disorder. Despite its high prevalence, the pathogenesis of AIT remains unclear. Previous studies have suggested a potential association between gut microbiota and AIT. However, whether this relationship is causal or coincidental remains uncertain. To address this gap in knowledge, our study aimed to investigate the potential causal association between gut microbiota and AIT using the two-sample Mendelian randomization (MR) method.

Summary-level gut microbiota data comprising 211 taxa (131 genera, 35 families, 20 orders, 16 classes, and 9 phyla) were obtained from the comprehensive MiBioGen study. Genetic associations with 22 gastrointestinal diseases were extracted from the UK Biobank, FinnGen study, and various extensive GWAS studies. A meticulous MR analysis was conducted to evaluate the causal relationship between genetically predicted gut microbiota and these gastrointestinal diseases. Sensitivity analyses and tests for heterogeneity were systematically performed to validate the reliability of our findings.

Six gut microbiota species showed significant associations with AIT according to the IVW method. Among them, the following exhibited negative associations with AIT: family Alcaligenaceae, family Pasteurellaceae (ID: 3689), family Peptococcaceae, genus Lachnospira, genus Victivallis, and order Pasteurellales (ID: 3688). No evidence of pleiotropy or heterogeneity was detected.

The MR analysis uncovered a causal relationship at the genetic prediction level between specific gut microbiota and AIT. These findings offer novel insights into the mechanisms governing the development of AIT mediated by gut microbiota. This knowledge could inform the design of future interventions, potentially involving microbiome-related strategies, to address the mechanisms associated with AIT development.

The pathogenesis of age-related macular degeneration (AMD), a degenerative retinopathy, remains unclear. Administration of anti-vascular endothelial growth factor agents, antioxidants, fundus lasers, photodynamic therapy, and transpupillary warming has proven effective in alleviating symptoms; however, these interventions cannot prevent or reverse AMD. Increasing evidence suggests that AMD risk is linked to changes in the composition, abundance, and diversity of the gut microbiota (GM). Activation of multiple signaling pathways by GM metabolites, including lipopolysaccharides, oxysterols, short-chain fatty acids (SCFAs), and bile acids (BAs), influences retinal physiology. Traditional Chinese medicine (TCM), known for its multi-component and multi-target advantages, can help treat AMD by altering GM composition and regulating the levels of certain substances, such as lipopolysaccharides, reducing oxysterols, and increasing SCFA and BA contents. This review explores the correlation between GM and AMD and interventions for the two to provide new perspectives on treating AMD with TCM.

Cirrhosis is the end result of liver fibrosis in chronic liver diseases. Studying the mechanisms of its development and developing measures to slow down and regress it based on this knowledge seem to be important tasks for medicine. Currently, disorders of the gut-liver axis have great importance in the pathogenesis of cirrhosis. However, gut dysbiosis, which manifests as increased proportions in the gut microbiota of Bacilli and Proteobacteria that are capable of bacterial translocation and a decreased proportion of Clostridia that strengthen the intestinal barrier, occurs even at the pre-cirrhotic stage of chronic liver disease. This leads to the development of bacterial translocation, a process by which those microbes enter the blood of the portal vein and then the liver tissue, where they activate Kupffer cells through Toll-like receptor 4. In response, the Kupffer cells produce profibrogenic cytokines, which activate hepatic stellate cells, stimulating their transformation into myofibroblasts that produce collagen and other elements of the extracellular matrix. Blocking bacterial translocation with antibiotics, probiotics, synbiotics, and other methods could slow down the progression of liver fibrosis. This was shown in a number of animal models but requires further verification in long-term randomized controlled trials with humans.

Intake of whole grain foods is associated with improving metabolic profile compared to refined grain products, but the underlying mechanism remains unclear. The present study examined the effects of brown rice (BRR) or germinated brown rice (GBR) supplementation on fecal short-chain fatty acids (SCFAs), and relationship with gut microbiota, metabolism and inflammation in high fat (HF)-diet-fed mice. The results demonstrated that an HF diet supplemented with BRR or GBR comparably increased the abundance of fecal isobutyric acid compared to that in mice receiving HF+white rice (WHR) diet (p < 0.01). The abundance of valeric acid in HF+GBR-diet-fed mice was higher than those receiving HF+WHR diet (p < 0.05). The abundances of fecal isobutyric acid negatively correlated with fasting plasma glucose, insulin, cholesterol, triglycerides, tumor necrosis factor-α, plasminogen activator inhibit-1, monocyte chemotactic protein-1 and homeostatic model assessment of insulin resistance (p < 0.01). The abundance of valeric acids negatively correlated with insulin resistance (p < 0.05). The abundances of isobutyric acid positively correlated with Lactobacillus, but negatively correlated with Dubosiella genus bacteria (p < 0.05). The findings demonstrated that the increases in SCFAs in the feces of BRR and GBR-treated mice were associated with improvements in gut microbiome, metabolic and inflammatory profile, which may contribute to the antidiabetic and anti-inflammatory effects of the whole grains in HF-diet-fed mice.