Breath testing to diagnose intestinal microbial overgrowth (MO) is being increasingly utilized, in part due to direct-to-consumer testing modalities. However, the concept of breath testing in the diagnosis of MO is controversial due to numerous limitations regarding optimal substrate, diagnostic thresholds, and confounding variables. We provide seven real-world cases which comprehensively illustrate the principles and nuances of the interpretation of breath testing.

We highlight recent studies which examine the optimal substrate for breath testing (glucose versus lactulose), the subtypes and clinical significance of breath test patterns including hydrogen, methane, and hydrogen-sulfide, elevated baseline gas levels, and confounders to breath test interpretation including transit time and diet. Reviewing the latest evidence, we provide recommendations for a personalized interpretation of breath tests utilizing unique patient factors. We conclude with an algorithm to assist clinicians in providing more accurate diagnoses.

Acute abdominal complaints constitute up to 40% of all emergency department (ED) presentations in oncology patients due to a multitude of causes. Small bowel pathologies present a diagnostic challenge due to their diverse range and frequently overlapping clinical presentation. In oncology patients, structural changes resulting from tumor growth, surgery and treatment effects can further complicate the diagnostic process. Due to a weakened immune system, oncology patients are also highly susceptible to infections of the gastrointestinal tract (GIT). Traditional computed tomography (CT) scans are used as the gold standard diagnostic modality. However, three-dimensional (3D) postprocessing techniques including maximal intensity projection (MIP), volume rendering (VR) and cinematic rendering (CR) have been employed to aid image evaluation. For a balanced and organized approach to describe diagnostic challenges in this complex population, we have divided the pictorial essay into two parts. The first part focuses on tumor- and infection-associated causes, as summarized below in the visual abstract. The second part will address treatment-related complications, including chemotherapy, radiotherapy, immunotherapy, graft-versus-host disease and post-surgical complications.

Survival rates after a diagnosis of cancer are improving. Poorly managed gastrointestinal (GI) side effects can interfere with delivery of curative cancer treatment. Long-term physical side effects of cancer therapy impinge on quality of life in up to 25% of those treated for cancer, and GI side effects are the most common and troublesome.

To provide comprehensive, practical guidance on the management of acute and chronic luminal gastrointestinal symptoms arising during and after treatment for cancer METHODS: A multidisciplinary expert group including patients treated for cancer, divided into working parties to identify, and synthesise recommendations for the optimal assessment, diagnosis and appropriate interventions for luminal GI side effects of systemic and local cancer therapies. Recommendations were developed using the principles of the BMJ AGREE II reporting.

103 recommendations were agreed. The importance of the patient perspective and what can be done to support patients are emphasised. Key physiological principles underlying the development of GI toxicity arising from cancer therapy are outlined. Individual symptoms or symptom clusters are poor at distinguishing the underlying cause(s), and investigations are required if empirical therapy does not lead rapidly to significant benefits. Patients frequently have multiple GI causes for symptoms; all need to be diagnosed and optimally treated to achieve resolution. Investigations and management approaches now known to be ineffective or of questionable benefit are highlighted.

The physical, emotional and financial costs to individuals, their families and society from cancer therapy can be considerable. Identifying and signposting affected patients who require specialist services is the role of all clinicians. Progress in the treatment of cancer increasingly means that patients require expert, multidisciplinary supportive care providing effective and safe treatment at every stage of the cancer journey. Development of such expertise should be prioritised as should the education of health professionals and the public in what, when and how acute and chronic gastrointestinal symptoms and complications should be managed.

Digestive functional disorders are among the most frequent reasons for medical consultation and a significant source of medical wandering. Therapeutic management of these patients is difficult, particularly due to the absence of specific treatment linked to an incomplete understanding of the pathophysiological mechanisms. In a certain number of these patients, the symptoms are accompanied by a small intestinal bacterial overgrowth (SIBO). This entity, historically identified in specific post-surgical situations, seems finally very common and associated with very diverse pathologies. The diagnosis of SIBO is currently being made more accessible through the development of breathing tests. Therapeutic management, based mainly on antibiotic therapy and diet, remains to date largely empirical because it is based on few studies but the growing interest in SIBO should make it possible to identify effective treatments during robust clinical trials.

The gut microbiome is essential for children's normal growth and development, with its formation aligning closely with key stages of growth. Factors like birth method, feeding practices, and antibiotic exposure significantly shape the composition and functionality of the infant gut microbiome. Small intestinal bacterial overgrowth (SIBO) involves an abnormal increase in bacteria within the small intestine. This overgrowth can interfere with digestion, impair nutrient absorption, and lead to both local and systemic inflammation, potentially contributing to malnutrition. In this review, we provide a comprehensive overview of the current understanding of the relationship between SIBO and malnutrition, with a particular focus on the pediatric population. SIBO seems to play an important role in nutrient malabsorption through the gut microbiome imbalance, local inflammation, and disruption of the mucosal intestinal barrier. Additionally, SIBO is more prevalent in digestive disorders linked to malabsorption and malnutrition. Different therapeutic strategies for addressing malnutrition-related SIBO have been proposed. While antibiotics are the primary treatment for SIBO, their effectiveness in promoting weight gain among malnourished children remains uncertain. Hence, future research directed at the impact of microbiome imbalance on nutrient intake and absorption could bring to light new strategies for the effective prevention and treatment of malnutrition.

Patients with intestinal failure (IF) have abnormal intestinal anatomy, secretion, and dysmotility, which impairs intestinal homeostatic mechanisms and may lead to small intestinal bacterial overgrowth (SIBO). We conducted a systematic review and meta-analysis to determine the prevalence of SIBO in patients with IF and to identify risk factors for SIBO.

MEDLINE (PubMed) and Embase electronic databases were searched from inception to December 2023 for studies that reported the prevalence of SIBO in IF. The prevalence rates, odds ratio (OR), and 95% confidence intervals of SIBO in IF and the risk factors for SIBO in IF were calculated using random effects model.

Final dataset included nine studies reporting on 407 patients with IF. The prevalence of SIBO in IF was 57.5% (95% CI 44.6-69.4), with substantial heterogeneity in this analysis (I2 = 80.9, P = 0.0001). SIBO prevalence was sixfold higher in patients with IF who received parenteral nutrition (PN) compared with IF patients not on PN (OR = 6.0, 95% CI 3.0-11.9, P = 0.0001). Overall, the prevalence of SIBO in patients with IF using PPI/acid-suppressing agents (72.0%, 95% CI 57.5-83.8) was numerically higher compared with IF patients not using these agents (47.6%, 95% CI 25.7-70.2).

This systematic review and meta-analysis suggests that there is an increased risk of SIBO in patients with IF and that PN, and potentially, the use of PPI/acid-suppressing agents is risk factors for SIBO development in patients with IF. However, the quality of evidence is low and can be attributed to lack of case-control studies and clinical heterogeneity seen in the studies.

The widespread use of opioids for chronic pain management not only poses a significant public health issue but also contributes to the risk of tolerance, dependence, and addiction, leading to opioid use disorder (OUD), which affects millions globally each year. Recent research has highlighted a potential bidirectional relationship between the gut microbiome and OUD. This emerging perspective is critical, especially as the opioid epidemic intensifies, emphasizing the need to investigate how OUD may alter gut microbiome dynamics and vice versa. Understanding these interactions could reveal new insights into the mechanisms of addiction and tolerance, as well as provide novel approaches for managing and potentially mitigating OUD impacts. This comprehensive review explores the intricate bidirectional link through the gut-brain axis, focusing on how opiates influence microbial composition, functional changes, and gut mucosal integrity. By synthesizing current findings, the review aims to inspire new strategies to combat the opioid crisis and leverage microbiome-centred interventions for preventing and treating OUD.

Chronic pancreatitis is a progressive fibroinflammatory disorder with no currently satisfactory treatment. Emerging evidence suggests an association between gut microbial dysbiosis and chronic pancreatitis. Although direct causative evidence is lacking, it is hypothesized that the gut microbiota may play a pivotal role in modulating pancreatic function via the gut-pancreas axis. Thus, modulating the gut microbiota through the administration of probiotics or prebiotics may alleviate pancreatic disorders. In this review, we first propose the potential mechanisms by which specific probiotics or prebiotics may ameliorate chronic pancreatitis, including the alleviation of small intestinal bacterial overgrowth (SIBO), the facilitation of short-chain fatty acids' (SCFAs) production, and the activation of glucagon-like peptide-1 receptors (GLP-1Rs) in the pancreas. Since there are currently no probiotics or prebiotics used for the treatment of chronic pancreatitis, we discuss research in other disease models that have used probiotics or prebiotics to modulate pancreatic endocrine and exocrine functions and prevent pancreatic fibrosis. This provides indirect evidence for their potential application in the treatment of chronic pancreatitis. We anticipate that this research will stimulate further investigation into the gut-pancreas axis and the potential therapeutic value of probiotics and prebiotics in chronic pancreatitis.

The prevalence of small intestinal bacterial overgrowth (SIBO) is rising worldwide, particularly in nations with high rates of urbanization. Irritable bowel syndrome, inflammatory bowel illnesses, and nonspecific dysmotility are strongly linked to SIBO. Moreover, repeated antibiotic therapy promotes microorganisms' overgrowth through the development of antibiotic resistance. The primary cause of excessive fermentation in the small intestine is a malfunctioning gastrointestinal motor complex, which results in the gut's longer retention of food residues. There are anatomical and physiological factors affecting the functioning of the myoelectric motor complex. Except for them, diet conditions the activity of gastrointestinal transit. Indisputably, the Western type of nutrition is unfavorable. Some food components have greater importance in the functioning of the gastrointestinal motor complex than others. Tryptophan, an essential amino acid and precursor of the serotonin hormone, accelerates intestinal transit, and gastric emptying, similarly to fiber and polyphenols. Additionally, the effect of food on the microbiome is important, and diet should prevent bacterial overgrowth and exhibit antimicrobial effects against pathogens. Therefore, knowledge about proper nutrition is essential to prevent the development and recurrence of SIBO. Since the scientific world was unsure whether there was a long-term or potential solution for SIBO until quite recently, research on a number of the topics included in the article should be performed. The article aimed to summarize current knowledge about proper nutrition after SIBO eradication and the prevention of recurrent bacterial overgrowth. Moreover, a connection was found between diet, gut dysmotility, and SIBO.

It is well established that the preoperative nutritional status of gastric cancer (GC) patients significantly affects the prognosis of the operated patients, their overall survival, as well as the disease-specific survival. Existing data support that preoperative assessment of nutritional status and early correction of nutritional deficiencies exert a favorable effect on early postoperative outcomes. A variety of relevant indices are used to assess the nutritional status of GC patients who are candidates for surgery. The guidelines of almost all international organizations recommend the use of oral enteral nutrition (EN). Oncologically acceptable types of gastrectomy and methods of patient rehabilitation should take into account the expected postoperative nutritional status. The majority of data support that perioperative EN reduces complications and hospital stay, but not mortality. Oral EN in the postoperative period, albeit in small amounts, helps to reduce the weight loss that is a consequence of gastrectomy. Iron deficiency with or without anemia and low serum levels of vitamin B12 are common metabolic sequelae after gastrectomy and should be restored. EN also significantly helps patients undergoing neoadjuvant or adjuvant antineoplastic therapy. The occurrence of the so-called "postgastrectomy syndromes" requires dietary modifications and drug support. This review attempts to highlight the benefits of EN in GC patients undergoing gastrectomy and to emphasize the type of necessary nutritional management, based on current literature data.

Traditional right hemicolectomy (TRH) is the standard treatment for patients with nonmetastatic right colon cancer. However, the ileocecum, a vital organ with mechanical and immune functions, is removed in these patients regardless of the tumor location. This study aimed to evaluate the technical and oncological safety of laparoscopic ileocecal-sparing right hemicolectomy (LISH).

Patients who underwent LISH at two tertiary medical centers were matched 1:2 with patients who underwent TRH by propensity score matching based on sex, age, body mass index, tumor location, and disease stage. Data on surgical and perioperative outcomes were collected. Oncological safety was evaluated in a specimen-oriented manner. Lymph nodes (LNs) near the ileocolic artery (ICA) were examined independently in the LISH group. Disease outcomes were recorded for patients who completed one year of follow-up.

In all, 34 patients in the LISH group and 68 patients in the TRH group were matched. LISH added 8 minutes to the dissection of LNs around the ileocolic vessels (groups 201/201d, 202, and 203 LNs), without affecting the total operation time, blood loss, or perioperative adverse event rate. Compared with TRH, LISH had a comparable lymphadenectomy quality, specimen quality, and safety margin while preserving a more functional bowel. The LISH group had no cases of LN metastasis near the ICA. No difference was detected in the recurrence rate at the 1-year follow-up time point between the two groups.

In this dual-center study, LISH presented comparable surgical and oncological safety for patients with hepatic flexure or proximal transverse colon cancer.

Evaluating efficacy of probiotics combined with prebiotics in small intestinal bacterial overgrowth (SIBO) in subclinical hypothyroidism (SCH) in the second trimester. We collected data from 78 pregnant women with SCH (SCH group) and 74 normal pregnant women (control group) in second trimester, compare the differences in high sensitivity C-reactive protein (hsCRP), result of lactulose methane-hydrogen breath test and gastrointestinal symptoms assessed by GSRS scale between two groups. In SCH group, 32 patients with SIBO were selected as intervention group. Treatment with probiotics + prebiotics for 21 days; The differences of lipid metabolism, hsCRP, thyroid function level, methane-hydrogen breath test results and GSRS scores before and after treatment were compared to evaluate the therapeutic effect. (1) The positive rate of SIBO and methane, hsCRP levels in SCH group were higher than those in control group (P < 0.05), the total score of GSRS scale, mean score of indigestion syndrome, and constipation syndrome in SCH group were higher (P < 0.05). (2) The mean abundance of hydrogen and methane were higher in SCH group. (3) After treatment, serum levels of thyrotropin(TSH), total cholesterol(TC), triglyceride(TG), low-density lipoprotein (LDL), and hsCRP in intervention group were decreased, and high-density lipoprotein (HDL) was increased compared with before treatment (P < 0.05). (4) After treatment, methane positive rate, total score of GSRS scale, mean score of diarrhea syndrome, dyspepsia syndrome, and constipation syndrome were decreased (P < 0.05). (5) The average abundance of methane and hydrogen were lower. Probiotics combined with prebiotics are effective in the treatment of SIBO in pregnant SCH patients.Clinical Trial Registration Number: ChiCTR1900026326.

Small intestinal bacterial overgrowth (SIBO) is still difficult to diagnose. Quantitative culture of small intestine aspirate is recommended to be the gold standard. The methane and hydrogen breath tests are easily repeatable, sufficiently sensitive and highly specific for SIBO diagnosis. Our goal is to contrast the diagnostic value of the breath tests with jejunal aspiration cultures.

40 adult outpatients (age < 60) were enrolled in our study. Randomly, within 2 days, both the methane and the hydrogen breath test and jejunal aspiration culture were performed on each patient and the results of both tests were evaluated and contrasted.

The jejunal culture was positive (105CFU / mL) in 14/40(35%) subjects, the lactulose breath test (LBT) was positive in 18/40 (45%) subjects, and the glucose breath test (GBT) was positive in 12/40 (30%). The GBT showed good agreement (κ = 0.659) and LBT showed poor agreement (κ = 0.588) with the jejunal aspirate culture. The sensitivity, specificity, positive and negative predictive values of LBT/GBT were 85.7/71.4%,76.9/92.3%, 66.6/83.3% and 90.9/85.7%, respectively.

35% of patients with suspected SIBO are identified using jejunal aspirate cultures. For the identification of SIBO, GBT is more specific than LBT, but has a lower sensitivity. In individuals with suspected SIBO, the breath test should be initially due to its good agreement with the jejunal aspirate culture.

Several billion microorganisms reside in the gastrointestinal lumen, including viruses, bacteria, fungi, and yeast. Among them, probiotics were primarily used to cure digestive disorders such as intestinal infections and diarrhea; however, with a paradigm shift towards alleviating health through food, their importance is large. Moreover, recent studies have changed the perspective that probiotics prevent numerous ailments in the major organs. Probiotics primarily produce biologically active compounds targeting discommodious pathogens. This review demonstrates the implications of using probiotics from different genres to prevent and alleviate ailments in the primary human organs. The findings reveal that probiotics immediately activate anti-inflammatory mechanisms by producing anti-inflammatory cytokines such as interleukin (IL)-4, IL-10, IL-11, and IL-13, and hindering pro-inflammatory cytokines such as IL-1, IL-6, and TNF-α by involving regulatory T cells (Tregs) and T helper cells (Th cells). Several strains of Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus reuteri, Bifidobacterium longum, and Bifidobacterium breve have been listed among the probiotics that are excellent in alleviating various simple to complex ailments. Therefore, the importance of probiotics necessitates robust research to unveil the implications of probiotics, including the potency of strains, the optimal dosages, the combination of probiotics, their habitat in the host, the host response, and other pertinent factors.

Using hydrogen breath testing (HBT) to diagnose small intestinal bacterial overgrowth (SIBO) remains controversial in patients with functional gastrointestinal (GI) disorders, and unknown in those with hypermobility Ehlers-Danlos syndrome (hEDS). We assessed prevalence of positive HBTs in these groups, evaluated the predictive value of GI symptoms and the potential role of proton pump inhibitors (PPIs) on test results.

Sequential patients referred for HBT to a tertiary unit were classified into the following groups: GI maldigestion/malabsorption, GI sensorimotor disorders, hEDS, and functional GI disorders. All underwent standardized HBT, and the yield was assessed against symptoms and PPI use.

A total of 1062 HBTs were performed over 3 years (70% female, mean age 48 ± 16 years). Overall, 7.5% (80/1062) patients had a positive HBT. Prevalence of positive HBT was highest in patients with GI maldigestion/malabsorption (17.9%; DOR 16.16, p < 0.001), GI sensorimotor disorders (15.9%; DOR 8.84, p < 0.001), compared to functional GI disorders (1.6%; DOR 1.0) (p < 0.0001). None of the hEDS patients tested positive for HBT. A positive HBT was independently associated with increased age (DOR 1.03; p < 0.001) and symptoms of diarrhea (DOR 3.95; p < 0.0001). Patients on PPIs tended towards a positive HBT than patients off PPIs (16.1% vs 6.9%; DOR 2.47; p < 0.0001).

Less than 2% of patients with functional GI disorders, and none of the patients with hEDS had a positive HBT. Pre-test probability was higher in patients with: GI structural or neurological disorders; use of long-term PPIs and symptoms of diarrhea. These criteria may be helpful in making appropriate therapeutic decisions and avoiding unnecessary hydrogen breath testing.

Parkinson's disease (PD) is a common neurodegenerative disorder whose etiology remains largely unexplained. Several studies have aimed to describe a causative effect in the interactions between the gastrointestinal tract and the brain, for both PD pathogenesis and disease course. However, the results have been controversial. Helicobacter pylori and small intestinal bacterial overgrowth (SIBO) are theorized to be agents capable of triggering chronic proinflammatory changes with a possible neurotoxic effect, as well as a cause of erratic L-dopa response in PD patients. This review evaluates the individual and possibly synergistic influence of H. pylori and SIBO on PD, to provide an opportunity to consider prospective therapeutic approaches.

Inflammatory Bowel Disease (IBD) is a group of chronic idiopathic inflammatory diseases of the gastrointestinal (GI) tract associated with the dysbiosis of gut microbiota. Metabarcoding-based profiling of the gut microbiota of IBD patients is generally based on the stool samples collected from individual patients which rarely represent the mucosa-associated microbiota. The ideal sampling strategy for routine monitoring of the mucosal component of IBD has yet to be determined.

We hereby compare the microbiota composition of the colonic cleansing fluid (CCF) collected during colonoscopy with stool samples from IBD patients. The relationship between IBD and gut microbiota was revealed through the application of the 16S rRNA amplicon sequencing-based metabarcoding approach. CCF and stool samples were collected from IBD patients with Crohn's disease and ulcerative colitis.

The present study shows significant differences in the microbial composition of CCF samples, presumably indicating changes in the mucosal microbiota of IBD patients as compared to the control group. Short-chain fatty acid-producing bacteria under the family Lachnospiraceae, the actinobacterial genus Bifidobacterium, the proteobacterial Sutterella and Raoultella are found to contribute to the microbial dysbiosis of the mucosal flora in IBD patients.

CCF microbiota has the capacity to distinguish IBD patients from healthy controls and, thus, may constitute an alternative analysis strategy for the early diagnosis and disease progression in IBD biomarker research.

Small Intestinal Bacterial Overgrowth (SIBO) is a heterogenous syndrome from excessive bacteria in the small intestine lumen. It is unknown if differences in type of bacterial overgrowth lead to differences in symptoms.

Patients with suspected SIBO were recruited prospectively. Exclusion criteria were probiotics, antibiotics, or bowel prep in preceding 30 days. Clinical characteristics, risk factors, and labs were collected. Proximal jejunal aspiration via upper enteroscopy was performed. Aerodigestive tract (ADT) SIBO was defined as > 10⁵ CFU/mL of oropharyngeal and respiratory bacteria. Colonic-type SIBO was defined as > 10⁴ CFU/mL of distal small bowel and colon bacteria. Aims were to compare symptom profiles, clinical complications, labs, and underlying risk factors between ADT and colonic-type SIBO.

We consented 166 subjects. Aspiration was not obtained in 22 and SIBO was found in 69 (49%) of 144 subjects. Daily abdominal distention trended towards more prevalent in ADT SIBO versus colonic-type SIBO (65.2% vs 39.1%, p = 0.09). Patient symptom scores were similar. Iron deficiency was more prevalent in ADT SIBO (33.3% vs 10.3%, p = 0.04). Subjects with colonic-type SIBO were more likely to have a risk factor for colonic bacteria colonization (60.9% vs 17.4%, p = 0.0006). Subjects with ADT SIBO were more likely to have a risk factor for diminished gastric acid (91.3% vs 67.4%, p = 0.02).

We found differences in iron deficiency and underlying risk factors between ADT and colonic-type SIBO. However, distinct clinical profiles remained elusive. Future research is needed to develop validated symptom assessment tools and distinguish cause from correlation.

Lower gastrointestinal (GI) symptoms are a frequently encountered problem for clinicians managing patients with systemic sclerosis. The current management practices are focused on the treatment of symptoms with little information available on how to use GI investigations in daily practice. This review demonstrates how to integrate the objective assessment of common lower GI symptoms into clinical care with the aim of guiding clinical decision making. Understanding the type of abnormal GI function that is affecting a patient and determining which parts of the gut are impacted can help clinicians to target therapy more precisely.

The aim of this review is to summarize the current and emergent approaches to characterize the small intestinal microbiota and discuss the treatment options for management of small intestinal bacterial overgrowth (SIBO).

This review captures the growing body of evidence for the role of SIBO, a type of small intestinal dysbiosis in the pathophysiology various gastrointestinal and extraintestinal disorders. We have highlighted the drawbacks of the available methods for characterizing the small intestinal microbiota and focus on the new culture-independent techniques to diagnose SIBO. Although recurrence is common, targeted modulation of the gut microbiome as a therapeutic option for management of SIBO is associated with improvement in symptoms and quality of life.

As a first step to precisely characterize the potential link between SIBO and various disorders, we need to address the methodological limitations of the available traditional tests for diagnosing SIBO. There is an urgency to develop culture independent techniques that can be routinely used in clinical setting, that will enable characterization of the gastrointestinal microbiome and explore the response to antimicrobial therapy including the links between long-lasting symptom resolution and the microbiome.

The formation of liver cirrhosis (LC) is an unfavorable event in the natural history of chronic liver diseases and with the development of portal hypertension and/or impaired liver function can cause a fatal outcome. Decompensation of LC is considered the most important stratification variable for the risk of death. It is currently postulated that decompensation of LC occurs through an acute (including acute-on-chronic liver failure) and non-acute pathway. Acute decompensation of LC is accompanied by the development of life-threatening complications, characterized by an unfavorable prognosis and high mortality. Progress in understanding the underlying molecular mechanisms has led to the search for new interventions, drugs, and biological substances that can affect key links in the pathogenesis of acute decompensation in LC, for example the impaired gut-liver axis and associated systemic inflammation. Given that particular alterations in the composition and function of gut microbiota play a crucial role here, the study of the therapeutic possibilities of its modulation has emerged as one of the top concerns in modern hepatology. This review summarized the investigations that describe the theoretical foundations and therapeutic potential of gut microbiota modulation in acute decompensation of LC. Despite the encouraging preliminary data, the majority of the suggested strategies have only been tested in animal models or in preliminary clinical trials; additional multicenter randomized controlled trials must demonstrate their efficacy in larger patient populations.

Chronic intestinal pseudoobstruction (CIPO) is a rare, heterogenous, and severe form of gastrointestinal dysmotility.

Pertinent literature on pediatric and adult CIPO management has been assessed via PubMed, Scopus, and EMBASE from inception to June 2022. Prokinetics, aimed at restoring intestinal propulsion (e.g. orthopramides and substituted benzamides, acetyl cholinesterase inhibitors, serotonergic agents, and others), have been poorly tested and the available data showed only partial efficacy. Moreover, some prokinetic agents (e.g. orthopramides and substituted benzamides) can cause major side effects. CIPO-related small intestinal bacterial overgrowth requires treatment preferably via poorly absorbable antibiotics to avoid bacterial resistance. Apart from opioids, which worsen gut motility, analgesics should be considered to manage visceral pain, which might dominate the clinical manifestations. Nutritional support, via modified oral feeding, enteral, or parenteral nutrition, is key to halting CIPO-related malnutrition.

There have been significant roadblocks preventing the development of CIPO treatment. Nonetheless, the considerable advancement in neurogastroenterology and pharmacological agents cast hopes to test the actual efficacy of new prokinetics via well-designed clinical trials. Adequate dietary strategies and supplementation remain of crucial importance. Taken together, novel pharmacological and nutritional options are expected to provide adequate treatments forthese patients.

Breath testing has become a widely used tool to diagnose small intestinal bacterial overgrowths (SIBOs) and intestinal methanogen overgrowths (IMOs) in clinical settings. Owing to the heterogeneity in clinical manifestations and lack of standardization among centers performing breath testing, SIBO and IMO can be easily overlooked by the clinician. We studied the prevalence and symptoms of SIBO/IMO in French patients referred for breath testing after seeking medical advice.

Breath test data and symptoms of 331 patients were assessed for SIBO/IMO using the H 2 /CH 4 lactulose breath test (LBT). Wilcoxon test or χ 2 test were used to compare patients with SIBO/IMO with patients without SIBO/IMO. LBT positive patients (H 2 +, CH 4 +, and CH 4 +/H 2 +) were compared using Kruskal-Wallis test for continuous data or χ 2 test for categorical data.

Among the 186 (68.1%) patients tested positive for an overgrowth with 40.3%, 47.3%, and 12.4% for H 2 +, CH 4 + and CH 4 +/H 2 +, respectively, the presence of diarrhea was significantly increased in hydrogen type overgrowths ( P < 0.001). No significant difference according to age, gender, and symptoms was associated with a positive test except for joint pain that was less prevalent among LBT positive patients ( P = 0.038). In 86.5% of IMOs, positivity with CH 4 values ≥10 ppm could be identified at baseline.

There are little discriminating symptoms that can help the clinician to identify patients likely to have a SIBO/IMO. However, SIBO/IMOs remain a common disorder widely underdiagnosed that need further studies to better apprehend functional bowel disorders.

Abnormalities in gut microbiota have been suggested to be involved in the pathophysiology and progression of Parkinson's disease (PD). Gastrointestinal nonmotor symptoms often precede the onset of motor features in PD, suggesting a role for gut dysbiosis in neuroinflammation and α-synuclein (α-syn) aggregation. In the first part of this chapter, we analyze critical features of healthy gut microbiota and factors (environmental and genetic) that modify its composition. In the second part, we focus on the mechanisms underlying the gut dysbiosis and how it alters anatomically and functionally the mucosal barrier, triggering neuroinflammation and subsequently α-syn aggregation. In the third part, we describe the most common alterations in the gut microbiota of PD patients, dividing the gastrointestinal system in higher and lower tract to examine the association between microbiota abnormalities and clinical features. In the final section, we report on current and future therapeutic approaches to gut dysbiosis aiming to either reduce the risk for PD, modify the disease course, or improve the pharmacokinetic profile of dopaminergic therapies. We also suggest that further studies will be needed to clarify the role of the microbiome in PD subtyping and of pharmacological and nonpharmacological interventions in modifying specific microbiota profiles in individualizing disease-modifying treatments in PD.

Patients treated with right-sided hemicolectomy for colon cancer may suffer from long-term bowel dysfunction, including loose stools, urgency and faecal incontinence. The underlying causes are poorly understood. The aim of this case-control study was to investigate the aetiology of chronic loose stools among patients with right-sided hemicolectomy curatively operated for cancer.

Cases with chronic loose stools (Bristol stool type 6-7) after right-sided hemicolectomy were compared with a control group of patients with right-sided hemicolectomy without loose stools. All patients underwent a selenium-75 homocholic acid taurine (SeHCAT) scan to diagnose bile acid malabsorption (BAM) and a glucose breath test to diagnose small intestinal bacterial overgrowth (SIBO). Gastrointestinal transit time (GITT) was assessed with radiopaque markers. In a subgroup of patients, fibroblast growth factor 19 (FGF19) was measured in fasting blood. SIBO was treated with antibiotics and BAM was treated with bile acid sequestrants.

We included 45 cases and 19 controls. In the case group, 82% (n = 36) had BAM compared with 37% (n = 7) in the control group, p < 0.001. SIBO was diagnosed in 73% (n = 33) of cases with chronic loose stools and in 74% (n = 14) of controls, p = 0.977. No association between BAM and SIBO was observed. GITT was similar in cases and controls. No difference in median FGF19 was observed between cases and controls (p = 0.894), and no correlation was seen between FGF19 and SeHCAT retention (r_s 0.20, p = 0.294). Bowel symptoms among cases were reduced after treatment.

BAM and SIBO are common in patients having undergone right-sided hemicolectomy for cancer. Chronic loose stools were associated with BAM but not with SIBO.

Small Intestinal Bacterial Overgrowth (SIBO) is a form of dysbiosis that involves increased bacterial colonization of the small intestine with some of the bacteria more characteristic of the colon microbiota. The prevalence of SIBO over recent decades has been estimated to range from 2.5 to 22% (depending on the source) and to increase with age and among individuals with comorbidities. Recently, an increase in the number of diagnosed SIBO cases has been observed, which is primarily due to the availability of noninvasive breath tests that facilitate the diagnostic process. However, SIBO is still both a diagnostic and a therapeutic problem. This review presents the pathophysiology, manifestations, diagnostics, and recommended management of SIBO.

Despite the enthusiasm surrounding novel targeted agents and immunotherapies, chemotherapy remains the mainstay treatment for most human malignancies, either alone or in combination. Yet, the burden of chemotherapy-associated adverse events (CAAEs) remains high and, importantly, is associated with considerable morbidity, mortality and costs that affect patients across multiple dimensions, including physical, emotional and social functioning. CAAEs can directly affect patient outcomes and indirectly increase the risk of cancer recurrence by compromising treatment intensity and continuity. Systematic efforts to identify and critically summarize the evidence on management approaches for CAAEs remain limited. Herein, we review the most common acute CAAEs having a major effect on survival, quality of life, function and/or continuation of optimal therapy. We focus on selected acute toxicities that occur during treatment, summarizing their underlying pathophysiology, multifactorial aetiologies, evidenced-based treatments, prevention strategies and management recommendations. We also summarize the available evidence on risk factors, validated risk assessment tools and other efforts to optimize symptom control in patients most likely to benefit in order to personalize the prevention and treatment of acute CAAEs. Finally, we discuss innovative symptom monitoring and supportive care interventions that are under development to further improve the outcomes of patients with cancer.

Chronic intestinal pseudo-obstruction (CIP) is a rare motility disorder characterized by dilated small bowel in the absence of mechanical obstruction. CIP has a known association with small intestinal bacterial overgrowth (SIBO); however, data regarding association with specific subtypes such as methane-positive (M+) and hydrogen-positive (H+) SIBO are limited. Therefore, we conducted this study to characterize subtypes of SIBO in CIP and compare them with non-CIP patients.

The aim is to explore the association and prevalence of hydrogen and methane subtypes of SIBO in patients with CIP.

A retrospective chart review was conducted for 494 patients who underwent glucose breath tests (GBT) in 2019. CIP was diagnosed based on clinical suspicion and after ruling out mechanical obstruction. We also reviewed demographic data, including age, gender, body mass index, tobacco and alcohol history, medical comorbidities, use of proton pump inhibitors, and history of colectomy.

Among 494 patients, 7.7% (38) had CIP. The prevalence of M+ GBT in CIP patients was higher compared with non-CIP patients, and it was significant [52.6% (20/38) versus 11.8% (54/456), p < 0.001]. The prevalence of H+ GBT in our cohort of CIP patients was similar to that of non-CIP patients [23.7% (9/38) versus 25.7% (117/456), p = 0.941].

The prevalence of methane-positive GBT was higher in CIP patients than in patients without CIP. This finding further strengthens the hypothesis that the relationship between motility disorders and methanogen overgrowth is facilitative.

Symptoms of small intestinal bacterial overgrowth (SIBO) and celiac disease (CeD) often overlap, and studies suggest a link between SIBO and CeD. We thus conducted a systematic review and meta-analysis to compare SIBO prevalence in CeD patients and controls and assessed effects of antimicrobial therapy on gastrointestinal symptoms in SIBO positive CeD patients.

Electronic databases were searched until February 2022 for studies reporting SIBO prevalence in CeD. Prevalence rates, odds ratio (OR), and 95% confidence intervals (CI) of SIBO in CeD and controls were calculated.

We included 14 studies, with 742 CeD patients and 178 controls. The pooled prevalence of SIBO in CeD was 18.3% (95% CI: 11.4-28.1), with substantial heterogeneity. Including case-control studies with healthy controls, SIBO prevalence in CeD patients was significantly increased (OR 5.1, 95% CI: 2.1-12.4, P = 0.0001), with minimal heterogeneity. Utilizing breath tests, SIBO prevalence in CeD patients was 20.8% (95% CI: 11.9-33.7), almost two-fold higher compared with culture-based methods at 12.6% (95% CI: 5.1-28.0), with substantial heterogeneity in both analyses. SIBO prevalence in CeD patients nonresponsive to a gluten free diet (GFD) was not statistically higher as compared with those responsive to GFD (OR 1.5, 95% CI: 0.4-5.0, P = 0.511). Antibiotic therapy of SIBO positive CeD patients resulted in improvement in gastrointestinal symptoms in 95.6% (95% CI: 78.0-99.9) and normalization of breath tests.

This study suggests a link between SIBO and CeD. While SIBO could explain nonresponse to a GFD in CeD, SIBO prevalence is not statistically higher in CeD patients non-responsive to GFD. The overall quality of the evidence is low, mainly due to substantial "clinical heterogeneity" and the limited sensitivity/specificity of the available diagnostic tests.

Obesity is increasingly prevalent in the post-industrial era, with increased mortality rates. The gut microbiota has a central role in immunological, nutritional and metabolism mediated functions, and due to its multiplexity, it is considered an independent organ. Modern high-throughput sequencing techniques have allowed phylogenetic exploration and quantitative analyses of gut microbiome and improved our current understanding of the gut microbiota in health and disease. Its role in obesity and its changes following bariatric surgery have been highlighted in several studies. According to current literature, obesity is linked to a particular microbiota profile that grants the host an augmented potential for calorie release, while limited diversity of gut microbiome has also been observed. Moreover, bariatric surgery procedures represent effective interventions for sustained weight loss and restore a healthier microbiota, contributing to the observed fat mass reduction and lean mass increase. However, newer evidence has shown that gut microbiota is only partially recovered following bariatric surgery. Moreover, several targets including FGF15/19 (a gut-derived peptide), could be responsible for the favorable metabolic changes of bariatric surgery. More randomized controlled trials and larger prospective studies that include well-defined cohorts are required to better identify associations between gut microbiota, obesity, and bariatric surgery.

The development and application of next generation sequencing technologies for clinical gastroenterology research has provided evidence that microbial dysbiosis is of relevance for the pathogenesis of gastrointestinal and extra-intestinal diseases. Microbial dysbiosis is characterized as alterations of diversity, function, and density of the intestinal microbes. Emerging evidence suggests that alterations of the gastrointestinal microbiome are important for the pathophysiology of a variety of functional gastrointestinal conditions, e.g., irritable bowel syndrome (IBS) and functional dyspepsia (FD), also known as disorders of brain-gut axis interaction. Clinicians have for many years recognized that small intestinal bacterial overgrowth (SIBO) is typified by a microbial dysbiosis that is underpinned by abnormal bacterial loads in these sites. SIBO presents with symptoms which overlap with symptoms of FD and IBS, point toward the possibility that SIBO is either the cause or the consequence of functional gastrointestinal disorders (FGIDs). More recently, new terms including "intestinal methanogen overgrowth" and "small intestinal fungal overgrowth" have been introduced to emphasize the contribution of methane production by archea and fungi in small intestinal dysbiosis. There is emerging data that targeted antimicrobial treatment of SIBO in patients with FD who simultaneously may or may not have IBS, results in symptom improvement and normalization of positive breath tests. However, the association between SIBO and FGIDs remains controversial, since widely accepted diagnostic tests for SIBO are lacking. Culture of jejunal fluid aspirate has been proposed as the "traditional gold standard" for establishing the diagnosis of SIBO. Utilizing jejunal fluid culture, the results can potentially be affected by cross contamination from oropharyngeal and luminal microbes, and there is controversy regarding the best cut off values for SIBO diagnosis. Thus, it is rarely used in routine clinical settings. These limitations have led to the development of breath tests, which when compared with the "traditional gold standard," have sub-optimal sensitivity and specificity for SIBO diagnosis. With newer diagnostic approaches-based upon applications of the molecular techniques there is an opportunity to characterize the duodenal and colonic mucosa associated microbiome and associated gut microbiota dysbiosis in patients with various gastrointestinal and extraintestinal diseases. Furthermore, the role of confounders like psychological co-morbidities, medications, dietary practices, and environmental factors on the gastrointestinal microbiome in health and disease also needs to be explored.

There is a close link between multiple movement disorders and gastrointestinal dysfunction. Gastrointestinal symptoms may precede the development of the neurologic syndrome or may arise following the neurologic presentation. This review will provide an overview of gastrointestinal accompaniments to several well-known as well as lesser known movement disorders. It will also highlight several disorders which may not be considered primary movement disorders but have an overlapping presentation of both gastrointestinal and movement abnormalities.

In the clinical setting, small intestinal bacterial overgrowth (SIBO) is a frequent, but under-diagnosed entity. SIBO is linked to various gastrointestinal (GI) and non-GI disorders with potentially significant morbidity. The optimal management of SIBO is undefined while there is a lack of published consensus guidelines. Against this background, under the auspices of the Indian Neurogastroenterology and Motility Association (INMA), formerly known as the Indian Motility and Functional Diseases Association (IMFDA), experts from the Asian-Pacific region with extensive research and clinical experience in the field of gut dysbiosis including SIBO developed this evidence-based practice guideline for the management of SIBO utilizing a modified Delphi process based upon 37 consensus statements, involving an electronic voting process as well as face-to-face meetings and review of relevant supporting literature. These statements include 6 statements on definition and epidemiology; 11 on etiopathogenesis and pathophysiology; 5 on clinical manifestations, differential diagnosis, and predictors; and 15 on investigations and treatment. When the proportion of those who voted either to accept completely or with minor reservations was 80% or higher, the statement was regarded as accepted. The members of the consensus team consider that this guideline would be valuable to inform clinical practice, teaching, and research on SIBO in the Asian-Pacific region as well as in other countries.

Over the past decades, rifaximin has been used to treat with small intestinal bacterial overgrowth (SIBO), however, the true efficacy remains unknown. This systematic review and meta-analysis was performed to assess the safety and efficacy of rifaximin in treating with patients with SIBO.

Embase, Pubmed, Cochrane Central Register of Controlled Trials, and Web of Science were searched from inception to April, 2021 for published randomized controlled trials (RCTs) and observational studies with or without comparable arms.

A total of 21 observational studies and 5 RCTs involving 874 patients were included. The overall eradication rate according to intention-to-treat analysis (ITT) was 59% (95% CI: 50 to 69%; I2 = 90.69%) and to per protocol analysis (PP) 63% (95% CI: 53 to 72%; I2 = 90.32%). For 5 RCTs included comparing the efficacy between rifaximin and placebo or active controls, there was no significant difference (n = 203, risk ratio = 1.14, 95%CI: 0.59 to 2.19, P = 0.15, I2 = 38%). Subgroup analysis and meta-regression indicated a dose-dependent eradication rate of rifaximin for SIBO.

Rifaximin is effective and safe in eradicating SIBO, with a dose-dependent efficacy and commonly associated with the improvement of the gastrointestinal symptoms and underlying diseases.

Pediatric intestinal failure (PIF) is a relatively rare disease entity which requires focused interdisciplinary care and specialized nutrition management. There has long been a lack of consensus in the definition of key terms related to PIF due to its rarity and plethora of small studies rather than large trials. As such, the American Society for Parenteral and Enteral Nutrition (ASPEN) Pediatric Intestinal Failure Section, composed of clinicians from a variety of disciplines caring for children with intestinal failure, is uniquely poised to provide insight into this definition void. This document is the product of an effort by the Section to create evidence-based consensus definitions, with the goal of allowing for appropriate comparisons between clinical studies and measurement of longterm patient outcomes. This manuscript was approved by the ASPEN Board of Directors. This article is protected by copyright. All rights reserved.

Copper deficiency is a rare and potentially treatable cause of myeloneuropathy. The most common causes of acquired copper deficiency include malabsorption following gastric surgery and excessive zinc supplementation. Clinical manifestations can be localized to the dorsal spinal cord and present similarly to those that characterize classic vitamin B12 deficiency. In this report, we present the case of a 76-year-old female with copper deficiency myeloneuropathy as a presumed consequence of advanced systemic sclerosis (SSc).

Chronic intestinal failure (CIF) is a rare but feared complication of Crohn's disease. Depending on the remaining length of the small intestine, the affected intestinal segment, and the residual bowel function, CIF can result in a wide spectrum of symptoms, from single micronutrient malabsorption to complete intestinal failure. Management of CIF has improved significantly in recent years. Advances in home-based parenteral nutrition, in particular, have translated into increased survival and improved quality of life. Nevertheless, 60% of patients are permanently reliant on parenteral nutrition. Encouraging results with new drugs such as teduglutide have added a new dimension to CIF therapy. The outcomes of patients with CIF could be greatly improved by more effective prevention, understanding, and treatment. In complex cases, the care of patients with CIF requires a multidisciplinary approach involving not only physicians but also dietitians and nurses to provide optimal intestinal rehabilitation, nutritional support, and an improved quality of life. Here, we summarize current literature on CIF and short bowel syndrome, encompassing epidemiology, pathophysiology, and advances in surgical and medical management, and elucidate advances in the understanding and therapy of CIF-related complications such as catheter-related bloodstream infections and intestinal failure-associated liver disease.

Gastric cancer is the third leading cause of cancer mortality and is frequently associated with nutritional disorders, the detection and proper management of which can contribute to improving quality of life and survival. Being aware of the consequences and of the different treatments for this neoplasm allows us to offer an adequate nutritional approach. In surgical candidates, integration into ERAS-type programs is increasingly frequent, and includes a pre-surgical nutritional approach and the initiation of early oral tolerance. After gastrectomy, the new anatomical and functional state of the digestive tract may lead to the appearance of "post-gastrectomy syndromes", the management of which may require diet modification and medical treatment. Those who receive neoadjuvant or adjuvant antineoplastic therapy benefit from specific dietary recommendations based on intercurrent symptoms and/or artificial nutrition. In palliative patients, the nutritional approach should be carried out while respecting the principle of autonomy and weighing the risks and benefits of the intervention. The objective of this review is to highlight the importance and role of nutrition in patients with gastric cancer and to provide guidelines for nutritional management based on the current evidence.

A subset of chronic pancreatitis patients respond poorly to pancreatic enzyme replacement therapy. Small intestinal bacterial overgrowth (SIBO) is considered to be one of the major reasons for this poor response. Previous studies have reported a wide range of prevalence of SIBO in patients with chronic pancreatitis. We aimed to assess the prevalence of SIBO in chronic pancreatitis using quantitative jejunal aspirate culture and glucose hydrogen breath test (GHBT). The sensitivity and specificity of GHBT for the diagnosis of SIBO in chronic pancreatitis were also estimated.

Newly diagnosed chronic pancreatitis patients were recruited into the study. A detailed history and relevant laboratory tests were done. All patients underwent an endoscopy and jejunal fluid aspiration for bacterial cultures and GHBT to detect SIBO. The results of GHBT were compared with jejunal fluid aspirate culture.

The jejunal aspirate culture was positive in 18/48 (37.5%) patients while the GHBT showed that 14/48 (29%) patients had SIBO. The sensitivity, specificity, positive and negative predictive value of GHBT in our study was 44.4, 80, 57.14 and 70.59%, respectively.

SIBO is not uncommon in chronic pancreatitis patients. One-third of our study population had SIBO. GHBT has low sensitivity but had high specificity in the diagnosis of SIBO in chronic pancreatitis.