Irritable bowel syndrome and gut microbiota

Causal relationship between gut microbiota, lipids, and neuropsychiatric disorders: A Mendelian randomization mediation study

BACKGROUND

Numerous studies have shown an interconnection between the gut microbiota and the brain via the "gut-brain" axis. However, the causal relationships between gut microbiota, lipids, and neuropsychiatric disorders remain unclear. This study aimed to analyze potential associations among gut microbiota, lipids, and neuropsychiatric disorders-including AD, PD, ALS, MS, SCZ, MDD, and BD-using summary data from large-scale GWAS.

METHODS

Bidirectional Mendelian randomization (MR) with inverse variance weighting (IVW) was the primary method. Supplementary analyses included sensitivity analyses, Steiger tests, and Bayesian weighted MR (BWMR). Mediation analyses used two-step MR (TSMR) and multivariable MR (MVMR).

RESULTS

The analyses revealed 51 positive correlations (risk factors) (β > 0, P < 0.05) and 47 negative correlations (protective factors) (β < 0, P < 0.05) between gut microbiota and neuropsychiatric disorders. In addition, 35 positive correlations (β > 0, P < 0.05) and 22 negative correlations (β < 0, P < 0.05) between lipids and neuropsychiatric disorders were observed. Assessment of reverse causality with the seven neuropsychiatric disorders as exposures and the identified gut microbiota and lipids as outcomes revealed no evidence of reverse causality (P > 0.05). Mediation analysis indicated that the effect of the species Bacteroides plebeius on MDD is partially mediated through the regulation of phosphatidylcholine (16:0_20:4) levels (mediation proportion = 10.9 % [95 % CI = 0.0110-0.2073]).

CONCLUSION

This study provides evidence of a causal relationship between gut microbiota and neuropsychiatric disorders, suggesting lipids as mediators. These findings offer new insights into the mechanisms by which gut microbiota may influence neuropsychiatric disorders.

Advances in Fecal Microbiota Transplantation for Gut Dysbiosis-Related Diseases

This article provides an overview of the advancements in the application of fecal microbiota transplantation (FMT) in treating diseases related to intestinal dysbiosis. FMT involves the transfer of healthy donor fecal microbiota into the patient's body, aiming to restore the balance of intestinal microbiota and thereby treat a variety of intestinal diseases such as recurrent Clostridioides difficile infection (rCDI), inflammatory bowel disease (IBD), constipation, short bowel syndrome (SBS), and irritable bowel syndrome (IBS). While FMT has shown high efficacy in the treatment of rCDI, further research is needed for its application in other chronic conditions. This article elaborates on the application of FMT in intestinal diseases and the mechanisms of intestinal dysbiosis, as well as discusses key factors influencing the effectiveness of FMT, including donor selection, recipient characteristics, treatment protocols, and methods for assessing microbiota. Additionally, it emphasizes the key to successful FMT. Future research should focus on optimizing the FMT process to ensure long-term safety and explore the potential application of FMT in a broader range of medical conditions.

The Gut-Brain Axis in Irritable Bowel Syndrome: Implementing the Role of Microbiota and Neuroimmune Interaction in Personalized Prevention-A Narrative Review

Background and Purpose

Irritable bowel syndrome (IBS) is a disorder characterized by microbiota-neuroimmune interaction resulting in disturbance to the gut-brain axis (GBA). The purpose of this review is to garner an overview of the different pathophysiological mechanisms indicated in the development of IBS and the associated sequalae on gut microbiota alongside its role in the GBA. Moreover, we aim to provide an insight into the possibility of utilizing personalized medicine when managing said affected populations.

Methods

A comprehensive review was performed of the relevant literature pertaining to the current state of GBA alteration implicated in IBS, comprising microbiota-neuroimmune interaction alongside disturbance and activation, respectively. Different search databases were utilized, including PubMed/MEDLINE and ScienceDirect.

Results

The review demonstrated the most evident etiologies of IBS being the imbalance of microbiota and the alteration to the GBA. Furthermore, the interrelation between microbiota and neuroimmunity was discussed. Promising avenues for IBS prevention and management are offered through emerging research on the pathophysiological mechanisms indicated in IBS-associated GBA alteration. This entails a role for the involved interactions between microbiota modification and neuroimmunity activation.

Conclusion

Promising prospects for symptom prevention and management are signaled by the possibility of personalized therapy specifically designed to address the GBA dysfunction indicated in IBS. Policymakers and developers should encourage further study and allocate available resources to aid researchers in the implementation and identification of novel preventive therapeutics. Furthermore, physicians should advocate and integrate the use of personalized medical approaches of IBS to help ensure a better quality of life.

Periodic Changes in the Gut Microbiome in Women with the Mixed Type of Irritable Bowel Syndrome

Background: The mixed type of irritable bowel syndrome (IBS-M) is characterized by recurrent constipation and diarrhea. The cause of the variability of these symptoms is not sufficiently understood. The aim of this study was to perform metagenomic and metabolic assessment of the gut microbiome in constipation and diarrheal period of IBS-M. Methods: This study included 30 women, aged 28-47 years old, with the symptoms which aligned with those of IBS-M, according to the Rome IV Criteria. Results: In both periods of the disease, the dysbiosis index (DI), the Shannon diversity index (SDI), the hydrogen-methane and ammonia breath tests, as well as the selected bacterial metabolites (-p-hydroxyphenyl acetic acid (HPA), 3-indoxyl sulfate (Indican, 3-IS)), and hippuric acid (A) in urine, were determined. The dysbiosis index (DI) in the period of constipation was 3.73 ± 0.90 points, and in the diarrheal period it did not change significantly 3.93 ± 0.75 points (p > 0.05). During the diarrheal period, the diversity of bacteria increases from 2.16 ± 0.59 to 2.74 ± 0.50 points on the Shannon dietary index (p < 0.001). The gut microbiome profile also changed, especially during the diarrheal period where an abundance of Bifidobacterium spp. and Lactobacillus spp. decreased significantly. In addition, during this period, the levels of hydrogen and ammonia in breath air increased, while the methane level decreased. The differences also concern the results of urinary metabolites, especially related to hippuric acid and indican. During the diarrheal period, the levels of hydrogen and ammonia ions increased, while the methane level decreased. The differences also concern the results of urinary metabolites, especially related to hippuric acid and indican. Conclusions: In patients with IBS-M, periodic changes in the profile and metabolism of the gut microbiome occur, which coexist with recurrent symptoms such as constipation and diarrhea.

The potential of Sijunzi decoction in the fight against gastrointestinal disorders: a review

Sijunzi Decoction (SJZD) is a traditional Chinese medicine formula widely used in the treatment of gastrointestinal disorders. Clinical studies have substantiated the efficacy of SJZD in managing conditions such as functional dyspepsia, chronic gastritis, gastric cancer, irritable bowel syndrome, colorectal cancer, and ulcerative colitis. Despite its proven effectiveness, the precise mechanisms by which SJZD operates remain incompletely understood. In this study, we undertake a systematic review of both the clinical applications and the mechanistic underpinnings of SJZD in the context of gastrointestinal disease treatment. Research indicates that SJZD functions through a spectrum of mechanisms including the regulation of intestinal flora, alleviation of inflammation, modulation of immune responses, and facilitation of mucosal repair in the treatment of gastrointestinal ailments. This comprehensive analysis aims to provide a clearer understanding of how SJZD benefits patients with gastrointestinal disorders.

Physical Exercise as a Therapeutic Approach in Gastrointestinal Diseases

Background/Objectives: Physical exercise can have significant consequences for the gastrointestinal tract, which is why there have been studies into its influence on the treatment of conditions such as colorectal cancer, inflammatory bowel diseases (IBD), and irritable bowel syndrome (IBS), being that there is epidemiological evidence that exercise has a protective effect against colon cancer. This review aims to demonstrate the mechanisms of action of physical exercise in the gastrointestinal tract, as well as the benefits of exercise in diseases associated with the digestive system, in addition to gathering training recommendations in treating different gastrointestinal diseases. Results: Physical exercise modulates gastrointestinal motility, permeability, immune responses, and microbiota composition, with both beneficial and adverse effects depending on intensity and duration. Regular moderate exercise is associated with improved quality of life in IBD and IBS, reduced colorectal cancer risk, and potential symptom relief in constipation. However, high-intensity exercise may exacerbate gastroesophageal reflux symptoms and increase the risk of gastrointestinal bleeding. While aerobic exercise has been extensively studied, the effects of resistance training on gastrointestinal health remain underexplored. Conclusions: New methodologies and techniques, such as molecular biology and the study of gastric receptors, have led to advances in understanding the gastrointestinal changes associated with physical exercise. These advances cover different exercise intensities and are being investigated in both experimental models and clinical studies.

Probiotic Bifidobacterium reduces serum TMAO in unstable angina patients via the gut to liver to heart axis

Background and aims

Studies indicate that the gut microbiota and its metabolites are involved in the progression of cardiovascular diseases, and enterohepatic circulation plays an important role in this progression. This study aims to identify potential probiotics for the treatment of unstable angina (UA) and elucidate their mechanisms of action.

Methods

Initially, the gut microbiota from patients with UA and control was analyzed. To directly assess the effects of Bifidobacterium supplementation, 10 patients with UA were enrolled and administered Bifidobacterium (630 mg per intake twice a day for 1 month). The fecal metagenome, serum trimethylamine N-oxide (TMAO) levels, and other laboratory parameters were evaluated before and after Bifidobacterium supplementation.

Results

After supplementing with Bifidobacterium for 1 month, there were statistically significant differences (P < 0.05) in TMAO, aspartate aminotransferase, total cholesterol, and low-density lipoprotein compared to before. Additionally, the abundance of Bifidobacterium longum increased significantly, although the overall abundance of Bifidobacterium did not reach statistical significance. The gut microbiota, metabolites, and gut-liver axis are involved in the progression of UA, and potential mechanisms should be further studied.

Conclusions

Metagenomic analysis demonstrated a reduced abundance of Bifidobacterium in patients with UA. Supplementation with Bifidobacterium restored gut dysbiosis and decreased circulating TMAO levels in patients with UA. This study provides evidence that Bifidobacterium may exert cardiovascular-protective effects through the gut-liver-heart axis.

Clinical trial number

ChiCTR2400093946.

Predictors of response to a dietary intervention in patients with irritable bowel syndrome

BACKGROUND

Different diets have emerged as potential therapeutic options for patients with irritable bowel syndrome (IBS).

OBJECTIVE

To identify predictors of improvement after a low-FODMAP, low-starch and low-sucrose diet among patients with IBS.

METHODS

We performed a descriptive cross-sectional study including patients with IBS according to Rome IV criteria undertaking a social-media based program with a two-week dietary intervention. Patients completed an online survey before and after the intervention including the presence of intestinal and extra-intestinal symptoms, the IBS-SSS (irritable bowel syndrome symptoms severity scale) and the PHQ-9 (patient health questionnaire-9). Clinical improvement was defined as a decrease of at least 50% in IBS-SSS post dietary intervention. Variables associated with symptomatic response were identified with logistic regression analysis. A clinical score to predict response was created and tested with a with a receiver operating characteristic (ROC) curve analysis.

RESULTS

A total of 3583 patients with IBS were included. Mean IBS-SSS before and after dietary intervention was 295.5±52.32 and 240±48.66, respectively (p=0.01); 1178 (32.8%) patients showed clinical improvement. A mean basal IBS-SSS >400 (OR 3.04), chronic headache (OR 1.96), and chronic fatigue (OR 1.81) were significantly associated with symptomatic response. Patients with arthralgia (OR 0.41) and/or fibromyalgia (OR 0.33) were less likely to improve. Each variable received the following individuals scores: IBS-SSS >400: +2, chronic headache: +1.5, chronic fatigue: +1, arthralgia: -1, and fibromyalgia: -1. The ROC curve analysis of the proposed score showed an area under the curve of 0.72 (95% CI 0.69-0.76). A score ≥3 had a sensitivity of 72.64% and specificity of 60.56% for predicting symptomatic improvement.

CONCLUSIONS

There are clinical variables that could serve as reliable predictors of response to a low-FODMAP, low-sucrose, low-starch diet among patients with IBS. Further research is needed to understand the link between the presence of extra-intestinal symptoms and clinical improvement after dietary interventions for IBS.

Alterations in the Tongue Coating Microbiome in Patients With Diarrhea-Predominant Irritable Bowel Syndrome: A Cross-Sectional Study

The gut microbiota plays a critical role in the occurrence and development of IBS-D, however, IBS-D-associated tongue coating microbiome dysbiosis has not yet been clearly defined. To address this, we analyzed the structure and composition of the tongue coating microbiome in 23 IBS-D patients and 12 healthy controls using 16S rRNA high-throughput sequencing analysis. The 16S rRNA sequencing results revealed that the overall observed OTUs of tongue coating microbiome in IBS-D patients exhibited a significant decrease compared with the healthy controls. Alpha diversity analysis showed that the diversity and community richness were significantly reduced in IBS-D patients, and PCoA revealed a distinct clustering of tongue coating microbiome between the IBS-D patients and healthy controls. Microbial comparisons at the genus level showed that the abundance of Veillonella, Prevotella in IBS-D patients was higher than those in healthy controls, while Streptococcus, Haemophilus, Granulicatella, and Rothia were significantly reduced compared with the healthy volunteers. Functional analysis results showed significant differences in 88 functional metabolic pathways between the IBS-D patients and the healthy controls, including fatty acid biosynthesis. These findings identified the structure, composition, functionality of tongue coating microbiome in IBS-D patients, and hold promise the potential for therapeutic targets during IBS-D management.

Chronic Gastrointestinal Disorders and miRNA-Associated Disease: An Up-to-Date

Chronic gastrointestinal disorders such as inflammatory bowel diseases (IBDs) and irritable bowel syndrome (IBS) impose significant health burdens globally. IBDs, encompassing Crohn's disease and ulcerative colitis, are multifactorial disorders characterized by chronic inflammation of the gastrointestinal tract. On the other hand, IBS is one of the principal gastrointestinal tract functional disorders and is characterized by abdominal pain and altered bowel habits. Although the precise etiopathogenesis of these disorders remains unclear, mounting evidence suggests that non-coding RNA molecules play crucial roles in regulating gene expression associated with inflammation, apoptosis, oxidative stress, and tissue permeability, thus influencing disease progression. miRNAs have emerged as possible reliable biomarkers, as they can be analyzed in the biological fluids of patients at a low cost. This review explores the roles of miRNAs in IBDs and IBS, focusing on their involvement in the control of disease hallmarks. By an extensive literature review and employing bioinformatics tools, we identified the miRNAs frequently studied concerning these diseases. Ultimately, specific miRNAs could be proposed as diagnostic biomarkers for IBDs and IBS. Their ability to be secreted into biofluids makes them promising candidates for non-invasive diagnostic tools. Therefore, understanding molecular mechanisms through the ways in which they regulate gastrointestinal inflammation and immune responses could provide new insights into the pathogenesis of IBDs and IBS and open avenues for miRNA-based therapeutic interventions.

Human milk oligosaccharides: bridging the gap in intestinal microbiota between mothers and infants

Breast milk is an essential source of infant nutrition. It is also a vital determinant of the structure and function of the infant intestinal microbial community, and it connects the mother and infant intestinal microbiota. Human milk oligosaccharides (HMOs) are a critical component in breast milk. HMOs can reach the baby's colon entirely from milk and become a fermentable substrate for some intestinal microorganisms. HMOs can enhance intestinal mucosal barrier function and affect the intestinal function of the host through immune function, which has a therapeutic effect on specific infant intestinal diseases, such as necrotizing enterocolitis. In addition, changes in infant intestinal microbiota can reflect the maternal intestinal microbiota. HMOs are a link between the maternal intestinal microbiota and infant intestinal microbiota. HMOs affect the intestinal microbiota of infants and are related to the maternal milk microbiota. Through breastfeeding, maternal microbiota and HMOs jointly affect infant intestinal bacteria. Therefore, HMOs positively influence the establishment and balance of the infant microbial community, which is vital to ensure infant intestinal function. Therefore, HMOs can be used as a supplement and alternative therapy for infant intestinal diseases.

Exploring Gut Microbiota Imbalance in Irritable Bowel Syndrome: Potential Therapeutic Effects of Probiotics and Their Metabolites

Irritable bowel syndrome is a common functional gastrointestinal disorder characterized by recurrent abdominal discomfort, bloating, cramping, flatulence, and changes in bowel movements. The pathophysiology of IBS involves a complex interaction between motor, sensory, microbiological, immunological, and psychological factors. Diversity, stability, and metabolic activity of the gut microbiota are frequently altered in IBS, thus leading to a situation of gut dysbiosis. Therefore, the use of probiotics and probiotic-derived metabolites may be helpful in balancing the gut microbiota and alleviating irritable bowel syndrome symptoms. This review aimed to report and consolidate recent progress in understanding the role of gut dysbiosis in the pathophysiology of IBS, as well as the current studies that have focused on the use of probiotics and their metabolites, providing a foundation for their potential beneficial effects as a complementary and alternative therapeutic strategy for this condition due to the current absence of effective and safe treatments.

Deciphering the gut microbiota's role in diverticular disease: insights from a Mendelian randomization study

Background

Previous studies have indicated a potential association between gut microbiota and diverticular disease. However, the precise nature of this relationship remains unclear. In light of this, we decided to use a bidirectional two-sample Mendelian randomization (MR) study to investigate the causal relationship between gut microbiota and intestinal diverticular disease in greater depth.

Methods

To investigate the potential causal relationship between gut microbiota and intestinal diverticular disease, we conducted a two-sample MR study in a European ancestry. Genetic instrumental variables for gut microbiota were obtained from a genome-wide association study (GWAS) involving 5,959 participants. Summary statistics for intestinal diverticular disease were sourced from the IEU Open GWAS project, which included data from 5,193 cases and 457,740 controls. The analysis was primarily conducted using the inverse variance weighted method, with additional sensitivity analyses to assess the robustness of the findings.

Results

With regard to the findings, 11 microbial taxa were identified as having a potential causal relationship with intestinal diverticular disease. Specifically, the microbial taxa Caryophanales, Paenibacillaceae, Herbinix, Turicibacter, Turicibacteraceae, and Staphylococcus fleurettii were found to be positively associated with the risk of developing intestinal diverticular disease, while Chromatiales, Arcobacter, Herbidospora, Ligilactobacillus ruminis, and Megamonas funiformis were found to be negatively associated with the risk. Further reverse MR analysis did not reveal a reverse causal effect between these microbial taxa and intestinal diverticular disease.

Conclusion

Our MR analyses revealed a potential causal relationship between certain gut microbiota and intestinal diverticular disease, which may provide new directions for future intestinal diverticular disease prevention and treatment strategies.

Effects of Lactocaseibacillus paracasei subsp. paracasei NTU 101 on gut microbiota: a randomized, double-blind, placebo-controlled clinical study

BACKGROUND

Lactocaseibacillus paracasei subsp. paracasei NTU 101 (NTU101) is a well-known commercial probiotic with multiple health beneficial effects. In this study, the gut microbiota modulation effect of an NTU 101 product, Vigiis 101-LAB, on healthy human was investigated in a randomized, double-blind, placebo-controlled human trial.

RESULTS

Vigiis 101-LAB significantly modulated human gut microbiota at fourth and sixth weeks of trial (anosim analysis, P = 0.001). It also significantly improved peristalsis (P = 0.003) and shortened defecation interval of subjects. The shift of gut microbiota is significantly fit with defecation interval (P = 0.009) and stool shape (P = 0.001) of subjects.

CONCLUSION

Our results suggest that Vigiis 101-LAB promotes human intestinal health with improvement of peristalsis and fecal quality. The gut modulation effects of Vigiis 101-LAB subsequently raised the abundance of vitamin B7, vitamin K, pyrimidine and purine biosynthesis pathways. Vigiis 101-LAB may promote peristalsis via purinergic pathway and possibly conferring prophylactic benefits against irritable bowel syndrome with constipation. © 2024 Society of Chemical Industry.

Tea-derived exosome-like nanoparticles prevent irritable bowel syndrome induced by water avoidance stress in rat model

BACKGROUND AND AIM

Exosome-like nanoparticles (ELNs) have emerged as crucial mediators of intercellular communication, evaluated as potential bioactive nutraceutical biomolecules. We hypothesized that oral ELNs have some therapeutic effect on irritable bowel syndrome (IBS).

METHODS

In our study, ELNs from tea (Camellia sinensis) leaves were extracted by differential centrifugation. We investigated the role of ELNs by assessing visceral hypersensitivity, body weight, bowel habits, tight junctions, and corticotropin-releasing hormone (CRH) in rats subjected to water avoidance stress (WAS) to mimic IBS with and without ELNs (1 mg/kg per day) for 10 days.

RESULTS

The average diameter of ELNs from LCC, FD and MZ tea tree were 165 ± 107, 168 ± 94, and 168 ± 108 nm, the concentration of ELNs were 1.2 × 1013, 1 × 1013, and 1.5 × 1013 particles/mL, respectively. ELNs can be taken up by intestinal epithelial cells. In WAS rats, ELNs significantly restored weight, recovered tight junctions, decreased CRH, and CRH receptor 1 expression levels and inhibited abdominal hypersensitivity in comparison to positive control.

CONCLUSIONS

Oral tea-derived ELN improves symptoms of IBS by potentially modulating the CRH pathway.

Microbiome Shifts and Their Impact on Gut Physiology in Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is one of the most prevalent functional gastrointestinal disorders characterized by recurrent abdominal pain and altered bowel habits. The exact pathophysiological mechanisms for IBS development are not completely understood. Several factors, including genetic predisposition, environmental and psychological influences, low-grade inflammation, alterations in gastrointestinal motility, and dietary habits, have been implicated in the pathophysiology of the disorder. Additionally, emerging evidence highlights the role of gut microbiota in the pathophysiology of IBS. This review aims to thoroughly investigate how alterations in the gut microbiota impact physiological functions such as the brain-gut axis, immune system activation, mucosal inflammation, gut permeability, and intestinal motility. Our research focuses on the dynamic "microbiome shifts", emphasizing the enrichment or depletion of specific bacterial taxa in IBS and their profound impact on disease progression and pathology. The data indicated that specific bacterial populations are implicated in IBS, including reductions in beneficial species such as Lactobacillus and Bifidobacterium, along with increases in potentially harmful bacteria like Firmicutes and Proteobacteria. Emphasis is placed on the imperative need for further research to delineate the role of specific microbiome alterations and their potential as therapeutic targets, providing new insights into personalized treatments for IBS.

Gut Microbiota and Liver Regeneration: A Synthesis of Evidence on Structural Changes and Physiological Mechanisms

Liver regeneration (LR) is a unique biological process with the ability to restore up to 70% of the organ. This allows for the preservation of liver resections for various liver tumors and for living donor liver transplantation (LDLT). However, in some cases, LR is insufficient and interventions that can improve LR are urgently needed. Gut microbiota (GM) is one of the factors influencing LR, as the liver and intestine are intimately connected through the gut-liver axis. Thus, healthy GM facilitates normal LR, whereas dysbiosis leads to impaired LR due to imbalance of bile acids, inflammatory cytokines, microbial metabolites, signaling pathways, etc. Therefore, GM can be considered as a new possible therapeutic target to improve LR. In this review, we critically observe the current knowledge about the influence of gut microbiota (GM) on liver regeneration (LR) and the possibility to improve this process, which may reduce complication and mortality rates after liver surgery. Although much research has been done on this topic, more clinical trials and systemic reviews are urgently needed to move this type of intervention from the experimental phase to the clinical field.

Review of Codonopsis Radix biological activities: A plant of traditional Chinese tonic

ETHNOPHARMACOLOGICAL RELEVANCE

Codonopsis Radix, commonly known as Dangshen in Chinese, is frequently used to treat deficiencies of spleen and lung Qi, gastrointestinal discomfort, fatigue, asthmatic breathing, sallow complexion, lack of strength, shortness of breath, deficiencies of both Qi and blood, as well as impairments to both Qi and body fluids in suboptimal health status.

AIM OF THE REVIEW

This review systematically expounds on the modern pharmacological studies related to the use of Codonopsis Radix in invigorating Qi and nourishing the body in recent years. The aim is to provide theoretical research and reference for the in-depth and systematic exploration and development of the applications of Codonopsis Radix in the fields of food and medicine.

MATERIALS AND METHODS

This study employs "Codonopsis Radix," "Codonopsis," and "Dangshen" as keywords to gather pertinent information on Codonopsis Radix medicine through electronic searches of classical literature and databases such as PubMed, Elsevier, Google Scholar, Wiley, EMBASE, Cochrane Library, Web of Science, CNKI, Wanfang, VIP, and Baidu Scholar.

RESULTS

From previous studies, activities such as immune system modulation, gastrointestinal motility regulation, cardiac function revitalization, lung function improvement, blood circulation enhancement, aging process deceleration, learning and memory augmentation, fatigue resistance enhancement, and liver and kidney damage protection of Codonopsis Radix have been reported. Recognized as an important medicine and food homologous traditional Chinese herbal remedy for supplementing deficiencies, its mode of action is multi-elemental, multi-systemic, multi-organ, multi-mechanistic, and multi-targeted. Furthermore, the benefits of its tonic surpass its therapeutic value, establishing it as an extraordinary preventive and therapeutic medicine.

CONCLUSIONS

With its long history of traditional applications and the revelations of contemporary pharmacological research, Codonopsis Radix exhibits great potential as both a therapeutic agent and a dietary supplement for further research in medicine, nutrition, and healthcare.

Correlation between the neuroendocrine axis, microbial species, inflammatory response, and gastrointestinal symptoms in irritable bowel syndrome

BACKGROUND

This study examines the complex relationships among the neuroendocrine axis, gut microbiome, inflammatory responses, and gastrointestinal symptoms in patients with irritable bowel syndrome (IBS). The findings provide new insights into the pathophysiology of IBS and suggest potential therapeutic targets for improving patient outcomes.

AIM

To investigate the interactions between the neuroendocrine axis, gut microbiome, inflammation, and gastrointestinal symptoms in patients with IBS.

METHODS

Patients diagnosed with IBS between January 2022 and January 2023 were selected for the study. Healthy individuals undergoing routine check-ups during the same period served as the control group. Data were collected on neuroendocrine hormone levels, gut microbiome profiles, inflammatory biomarkers, and gastrointestinal symptomatology to analyze their interrelations and their potential roles in IBS pathogenesis.

RESULTS

IBS patients exhibited significant dysregulation of the neuroendocrine axis, with altered levels of cortisol, serotonin, and neuropeptides compared to healthy controls. The gut microbiome of IBS patients showed reduced diversity and specific alterations in bacterial genera, including Bifidobacterium, Lactobacillus, and Faecalibacterium, which were associated with neuroendocrine disturbances. Additionally, elevated levels of inflammatory markers, such as C-reactive protein, interleukin-6, and tumor necrosis factor-α, were observed and correlated with the severity of gastrointestinal symptoms like abdominal pain, bloating, and altered bowel habits.

CONCLUSION

The findings suggest that targeting the neuroendocrine axis, gut microbiome, and inflammatory pathways may offer novel therapeutic strategies to alleviate symptoms and improve the quality of life in IBS patients.

Oral administration of tea-derived exosome-like nanoparticles protects epithelial and immune barrier of intestine from psychological stress

Psychological stress disrupts the integrity of the intestinal barrier and is strongly linked to emotional disorders, behavioral changes, and gastrointestinal dysfunction. However, there are limited treatment options available for repairing the damage to the intestinal barrier. As a natural plant-based health beverage, tea (Camellia sinensis) has been shown to have various potentially advantageous effects on the intestinal barrier and immune function. In this study, we extracted bioactive molecules from tea leaves, named exosome-like nanoparticles (ELNs), and then examined their potential protective properties for the intestinal barrier. Through in vitro experimentation, we investigated whether tea-derived ELNs (TELNs) could offer a protective effect against lipopolysaccharides-induced damage to the intestinal barrier. In an in vivo experiment, rats were exposed to water avoidance stress and subsequently administered TELNs orally. The administration of TELNs resulted in the enhancement of the epithelial barrier in the intestine, effectively preventing bacterial translocation to the submucosae. Additionally, TELNs were found to improve the function of the intestinal immune barrier through the mediation of interleukin-22 and the increased secretion of antimicrobial peptide Reg3g. Notably, miR-44 and miR-54 in TELNs exhibited similar protective effects on the intestinal barrier. These findings suggest that TELNs possess the ability to restore the integrity of the intestinal barrier in the context of psychological stress.

The impact of depression-mediated gut microbiota composition on Irritable Bowel Syndrome: A Mendelian study

OBJECTIVE

This study uses a two-sample Mendelian randomization (MR) analysis to delineate the causal influence of gut microbiota on the occurrence of irritable bowel syndrome (IBS), concurrently assessing the potential mediating function of depression within this framework.

METHODS

Several two-sample MR methods were used to assess the causal repercussions of gut microbiota on the onset of both IBS and depression. Following this, gut microbiota and depression, which demonstrated notable causal associations, were integrated as exposure variables in a multivariable Mendelian randomization (MVMR) framework to construct a model encompassing gut microbiota, depression, and IBS. Mediation effects were assessed by examining the indirect pathway of gut microbiota → depression → IBS.

RESULTS

Two-sample MR analysis unveiled a statistically significant causal association (P < 0.05) between specific bacterial group within the gut microbiota, notably p_Actinobacteria(OR = 0.829225), c_Clostridia(OR = 0.798897), s_Desulfovibrio_piger(OR = 1.163912), g_Streptococcus(OR = 1.132735), c_Actinobacteria(OR = 0.829224), and the onset of IBS. In the MVMR analysis, the relationship between depression and IBS was significant across Model 3, Model 7, Model 8, and Model 13 (P < 0.05). Assessment of mediation effects revealed that c_Clostridia and o_Clostridiales indirectly impacted IBS through depression, with masking effect ratios of 168.46 % and 168.44 %, respectively.

CONCLUSION

These findings underscore a resilient causal association between the composition of gut microbiota and the initiation of IBS. Furthermore, depression serves as a mediator for particular groups of gut bacteria, thereby contributing to the development of IBS. These observations imply that interventions targeting mental health may potentially alleviate the risk of IBS onset attributable to adverse configurations of gut microbiota.

The role of miRNA in IBS pathogenesis, diagnosis and therapy: The latest thought

IBS is a prevalent clinical condition affecting bowel function. There is a restricted comprehension of its pathogenesis, an absence of particular diagnostic tools, and an insufficiency of efficient pharmacological remedies. MiRNAs are a highly conserved class of non-coding small molecule RNAs, with a length of 20-24 nucleotides. Research has shown the presence of a number of differentially expressed miRNAs in the colonic tissue and peripheral blood of IBS patients. Meanwhile, miRNAs have a critical role in gene expression and the pathology of IBS as they act as significant mediators of post-transcriptional gene silencing. The investigation of miRNA molecular regulatory networks proves useful in examining the convoluted pathogenesis of IBS. This paper presents a review of recent literature on miRNAs associated with IBS, explains how miRNAs contribute to the development of IBS, and assesses the potential usefulness of miRNA analysis for diagnosing and treating IBS.

Irritable Bowel Syndrome in the Elderly Population: A Comprehensive Review

Irritable bowel syndrome (IBS) is a fairly common functional digestive disorder; it occurs at any age but it is more common in adults and older adults. Patients experience a series of symptoms in which abdominal pain and changes in bowel movements stand out; some studies have revealed a possible association between IBS and psychological problems, such as anxiety and depression. Recent findings point to disorders of gut-brain interaction, disruption and alteration of gut microbiota and dysbiosis as key factors in the etiopathogenesis of IBS; aging is also one the factors involved. Most patients diagnosed with IBS required pharmacotherapy, greater caution needs to be considered when treating older patients because of the risk-benefit profile in the elderly. In this scenario, probiotics and non-pharmacological treatments appear as safe and accessible options. Clinicians must take into consideration the unique biopsychosocial factors in older adults when treating IBS. We aim to review critically recent literature on the topic of IBS as there is a need for consolidated guidelines.

Selenium deficiency induces irritable bowel syndrome: Analysis of UK Biobank data and experimental studies in mice

Irritable bowel syndrome (IBS) patients exhibit significantly lower levels of serum selenium (Se) compared to healthy controls. This study integrates a prospective cohort analysis and animal experiments to investigate Se deficiency as a potential risk factor for IBS. Using data from the UK Biobank, a longitudinal analysis was conducted to explore the associations between dietary Se intake and the risk of incident IBS. In animal study, C57BL/6 mice were fed diets with normal (0.2 ppm) or low (0.02 ppm) Se levels to assess the impacts of Se deficiency on IBS symptoms. Furthermore, we performed 16 S rRNA sequencing, untargeted colonic fecal metabolomics analysis, and colon transcriptome profiling to uncover the regulatory mechanisms underlying Se deficiency-induced IBS. The analysis of UK Biobank data revealed a significant correlation between low dietary Se levels and an increased incidence of IBS. In the experimental study, a low Se diet induced IBS symptoms, evidenced by elevated abdominal withdrawal reflex scores, colon inflammation, and severe pathological damage to the colon. Additionally, the low Se diet caused disturbances in gut microbiota, characterized by an increase in Faecalibaculum and Helicobacter, and a decrease in Bifidobacterium and Akkermansia. Combined colonic fecal metabolomics and colon transcriptome analysis indicated that Se deficiency might trigger IBS through disruptions in pathways related to "bile excretion", "steroid hormone biosynthesis", "arachidonic acid metabolism", and "drug metabolism-cytochrome P450". These findings underscore the significant adverse effects of Se deficiency on IBS and suggest that Se supplementation should be considered for IBS patients.

The Efficacy of Probiotics, Prebiotics, Synbiotics, and Fecal Microbiota Transplantation in Irritable Bowel Syndrome: A Systematic Review and Network Meta-Analysis

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder with gut microbiota imbalance playing a significant role. There are increasing numbers of research studies exploring treatment options involving probiotics, prebiotics, synbiotics, and fecal microbiota transplantation (FMT), but it is still uncertain which treatment option is superior. The research was conducted on various databases and unpublished trial data (up to February 2023). Randomized controlled trials (RCTs) were screened for adult patients with IBS comparing interventions with placebo. Probiotics, prebiotics, synbiotics, and FMT were assessed for their impact using mean difference and Bayesian network meta-analysis. Out of 6528 articles, 54 were included for probiotics, 7 for prebiotics/synbiotics, and 6 for FMT. Probiotics showed improvement in IBS symptoms, particularly with Bifidobacterium and Lactobacillus strains. Prebiotics and synbiotics did not show significant improvement. Network meta-analysis indicated the favorable effects of probiotics (OR = 0.53, 95% CI, 0.48 to 0.59) and FMT (OR = 0.46, 95% CI, 0.33 to 0.64) on IBS, with no serious adverse events reported. In short, probiotics and FMT are effective for managing IBS, with Bifidobacterium and Lactobacillus being dominant strains. However, the most effective probiotic combination or strain remains unclear, while prebiotics and synbiotics did not show significant improvement.

Modulation of Gut Microbiome and Autism Symptoms of ASD Children Supplemented with Biological Response Modifier: A Randomized, Double-Blinded, Placebo-Controlled Pilot Study

The etiology and mechanisms of autism and autism spectrum disorder (ASD) are not yet fully understood. There is currently no treatment for ASD for providing significant improvement in core symptoms. Recent studies suggest, however, that ASD is associated with gut dysbiosis, indicating that modulation of gut microbiota in children with ASD may thus reduce the manifestation of ASD symptoms. The aim of this pilot study (prospective randomized, double-blinded, placebo-controlled) was to evaluate efficacy of the biological response modifier Juvenil in modulating the microbiome of children with ASD and, in particular, whether Juvenil is able to alleviate the symptoms of ASD. In total, 20 children with ASD and 12 neurotypical children were included in our study. Supplementation of ASD children lasted for three months. To confirm Juvenil's impact on the gut microbiome, stool samples were collected from all children and the microbiome's composition was analyzed. This pilot study demonstrated that the gut microbiome of ASD children differed significantly from that of healthy controls and was converted by Juvenil supplementation toward a more neurotypical microbiome that positively modulated children's autism symptoms.

Gut microbial signatures of patients with diarrhea-predominant irritable bowel syndrome and their healthy relatives

AIMS

Irritable bowel syndrome (IBS) is a prevalent gastrointestinal disorder, encompassing diarrhea-predominant irritable bowel syndrome (IBS-D). Here, we utilized 16S rDNA gene sequencing to identify potential microbial drivers of IBS-D.

METHODS AND RESULTS

A total of 30 healthy relatives and 27 patients with IBS-D were recruited. Clinical data and fecal samples were collected from patients and controls. 16S rDNA gene sequencing was performed to obtain fecal bacterial data. Differences in community composition were evaluated utilizing analysis of similarity (ANOSIM) using Bray-Curtis dissimilarity. The Wilcoxon rank sum test was used to compare differences in taxa and functional pathways. Finally, the key gut microbiota was identified using the random forest algorithm. Gut microbiota diversity, estimated through the Observe, Chao1, and abundance-based coverage estimator (ACE) indices, was significantly lower in the IBS-D patients than in the healthy relatives. ANOSIM analysis further confirmed significant differences in the composition of the gut microbiota between IBS-D patients and healthy relatives, with an R value of 0.106 and a P-value of 0.005. Notably, the IBS-D patients exhibited a significant enrichment of specific bacterial genera, including Fusicatenibacter, Streptococcus, and Klebsiella, which may possess potential pathogenic properties. In particular, the bacterial genus Klebsiella demonstrated a positive correlation with irritable bowel syndrome severity scoring system scores. Conversely, healthy subjects showed enrichment of bacterial genera such as Alistipes, Akkermansia, and Dialister, which may be beneficial bacteria in IBS-D. Utilizing the random forest model, we developed a discriminative model for IBS-D based on differential bacterial genera. This model exhibited impressive performance, with an area under the curve value of 0.90. Additionally, our analysis did not reveal any gender-specific differences in the microbiota community composition among IBS-D patients.

CONCLUSIONS

Our findings offer preliminary insights into the potential relationship between intestinal microbiota and IBS-D. The identification model for IBS-D, grounded in gut microbiota, holds promising prospects for improving early diagnosis of IBS-D.

Gut Bacteria Provide Genetic and Molecular Reporter Systems to Identify Specific Diseases

With genetic information gained from next-generation sequencing (NGS) and genome-wide association studies (GWAS), it is now possible to select for genes that encode reporter molecules that may be used to detect abnormalities such as alcohol-related liver disease (ARLD), cancer, cognitive impairment, multiple sclerosis (MS), diabesity, and ischemic stroke (IS). This, however, requires a thorough understanding of the gut-brain axis (GBA), the effect diets have on the selection of gut microbiota, conditions that influence the expression of microbial genes, and human physiology. Bacterial metabolites such as short-chain fatty acids (SCFAs) play a major role in gut homeostasis, maintain intestinal epithelial cells (IECs), and regulate the immune system, neurological, and endocrine functions. Changes in butyrate levels may serve as an early warning of colon cancer. Other cancer-reporting molecules are colibactin, a genotoxin produced by polyketide synthetase-positive Escherichia coli strains, and spermine oxidase (SMO). Increased butyrate levels are also associated with inflammation and impaired cognition. Dysbiosis may lead to increased production of oxidized low-density lipoproteins (OX-LDLs), known to restrict blood vessels and cause hypertension. Sudden changes in SCFA levels may also serve as a warning of IS. Early signs of ARLD may be detected by an increase in regenerating islet-derived 3 gamma (REG3G), which is associated with changes in the secretion of mucin-2 (Muc2). Pro-inflammatory molecules such as cytokines, interferons, and TNF may serve as early reporters of MS. Other examples of microbial enzymes and metabolites that may be used as reporters in the early detection of life-threatening diseases are reviewed.

Influence of ethnic origin on the clinical characteristics and intestinal flora of irritable bowel syndrome: a prospective study between Han and Tibetan patients

Background

Few studies have focused on the clinical characteristics and intestinal flora of Tibetan patients with irritable bowel syndrome (IBS). The study aimed to compare the difference of between Tibetan and Han patients with IBS.

Methods

Patients who met inclusion and exclusion criteria were divided into the Tibet and Han groups. A simplified Gastrointestinal Symptom Rating Scale (GSRS)-based questionnaire was used to assess the IBS severity. Fecal samples from all subjects were collected for the analysis of gut microbiota using 16sRNA Illumina sequencing.

Results

No significant difference was found in the total symptom scores between two groups. However, Tibetans with IBS are more prone to bloating than Hans (17.41% vs 9.09%, p < 0.001). A profit shift in the gut microbiota was shown between the two groups. The ratio of Firmicutes/Bacteroidetes was significantly lower in the Tibet group than in the Han group (2.954 ± 0.78 vs 8.23 ± 2.04, p = 0.004). In the Tibet group, the level of the genus Blautia decreased significantly compared to the Han group, and there was a significant negative correlation between the level of Blautia and the bloating scores (Pearson r = -0.33, p = 0.025).

Conclusion

The characteristics of Tibetan patients differ from those of Han patients with IBS, not only in terms of the clinical symptoms, but also in the characteristics of intestinal flora. Tibetans with IBS are more prone to bloating, which might be due to the different gut microbiota. The genus Blautia may play a role in this mechanism.

Protective effect of Pediococcus pentosaceus Li05 on diarrhea-predominant irritable bowel syndrome in rats

Pediococcus pentosaceus Li05 (Li05) has demonstrated potential benefits in various intestinal and liver diseases, but its potential and mechanisms in relieving diarrhea have not been understood. The objective of this research was to examine the effects and mechanisms of Li05 in rats with diarrhea-predominant irritable bowel syndrome (IBS-D) induced by wrap restrain stress (WRS) and 4% acetic acid. The results demonstrated that Li05 effectively alleviated weight loss, visceral sensitivity and diarrhea in rats with IBS-D. It also improved intestinal and systemic inflammation by reducing the levels of chemokines and proinflammatory cytokines (GRO/KC, RANTES, IL-1β, IL-7, and IL-18). The 5-hydroxytryptamine (5-HT) signaling pathway is involved in regulating excessive intestinal motility and secretion in IBS-D. Li05 effectively reduced the expression levels of the 5-HT3B receptor (5-HT3BR) (p < 0.01) in the intestine. Additionally, Li05 intervention had a regulatory effect on the gut composition, with a decrease in the abundance of [Ruminococcus] gauvreauii group, Dubosiella, Erysipelatoclostridium and Blautia, and an increase in the abundance of Alloprevotella, Anaerotruncus and Mucispirillum. Furthermore, Li05 induced significant changes in fatty acid and amino acid metabolism in the gut of rats with IBS-D. These findings indicate that Li05 exhibits an effective improvement in IBS-D symptoms by reducing inflammation and modulating gut microbiota and metabolism. Based on the above results, Li05 holds promise as a potential probiotic for managing IBS-D.

Common gastrointestinal diseases and chronic obstructive pulmonary disease risk: a bidirectional Mendelian randomization analysis

Background: Observational studies suggest an association between gastrointestinal diseases and chronic obstructive pulmonary disease (COPD), but the causal relationship remains unclear. Methods: We conducted bidirectional Mendelian randomization (MR) analysis using summary data from genome-wide association study (GWAS) to explore the causal relationship between common gastrointestinal diseases and COPD. Gastrointestinal diseases included gastroesophageal reflux disease (GERD), peptic ulcer disease (PUD), irritable bowel syndrome (IBS), Crohn's disease (CD), ulcerative colitis (UC), functional dyspepsia (FD), non-infectious gastroenteritis (NGE), and constipation (CP). Significant MR analysis results were replicated in the COPD validation cohort. Results: Bidirectional MR analysis supported a bidirectional causal relationship between GERD and COPD, and COPD was also found to increase the risk of IBS and CP. Our study also provided evidence for a bidirectional causal relationship between PUD and COPD, although the strength of evidence may be insufficient. Furthermore, we provided evidence that there is no causal association between CD, UC, FD, NGE, and COPD. Conclusion: This study offers some evidence to clarify the causal relationship between common gastrointestinal diseases and COPD. Further research is needed to understand the underlying mechanisms of these associations.

Modulation of microbiota as a target in the management of patients with irritable bowel syndrome

Irritable  bowel syndrome  (IBS) is one of the  most common  diseases  of the  digestive  tract. IBS negatively  affects  the  quality of life and work ability of patients. It is generally  accepted that  IBS is an important medical  and social problem  associated with high financial  costs  both  on the  part of the  patient  and the  public health  system. The pathophysiology of the  disease involves the participation of many factors (genetic, dietary, psychosocial, infectious) and the mechanisms of their implementation, including  disruption  of interaction along  the  functional  “gut-brain axis”, visceral  hypersensitivity,  changes  in motility, low-grade  inflammation, increased permeability of the epithelial intestinal barrier, modulation of microbiota, changes  in neurohumoral  regulation and  processes of central  processing  of peripheral stimuli. Research  shows  an important role  for gut microbiota  in the development of IBS. Modulation of the intestinal microbiota  through  diet, the use of pre- and probiotics  or fecal microbiota transplantation is considered as a promising target  for disease  therapy. A reduction  in the number of bacteria of the genus  Bifidobacterium is described  as a universal  change  in the microbiota  in IBS, regardless of the clinical course and severity of the disease  and the possibility of using different  strains of Bifidobacterium in treatment regimens  for the disease  is of particular  interest. This article  provides  a review of the literature on modern  approaches to prescribing  probiotics  for IBS. Using our own clinical observations as an example, we demonstrated the effectiveness and safety of prolonged administration of the probiotic strain Bifidobacterium longum 35624®  for up to 12 weeks.

Human gut homeostasis and regeneration: the role of the gut microbiota and its metabolites

The healthy human gut is a balanced ecosystem where host cells and representatives of the gut microbiota interact and communicate in a bidirectional manner at the gut epithelium. As a result of these interactions, many local and systemic processes necessary for host functionality, and ultimately health, take place. Impairment of the integrity of the gut epithelium diminishes its ability to act as an effective gut barrier, can contribute to conditions associated to inflammation processes and can have other negative consequences. Pathogens and pathobionts have been linked with damage of the integrity of the gut epithelium, but other components of the gut microbiota and some of their metabolites can contribute to its repair and regeneration. Here, we review what is known about the effect of bacterial metabolites on the gut epithelium and, more specifically, on the regulation of repair by intestinal stem cells and the regulation of the immune system in the gut. Additionally, we explore the potential therapeutic use of targeted modulation of the gut microbiota to maintain and improve gut homeostasis as a mean to improve health outcomes.

Activation of the aryl hydrocarbon receptor in inflammatory bowel disease: insights from gut microbiota

Inflammatory bowel disease (IBD) is a chronic inflammatory intestinal disease that affects more than 3.5 million people, with rising prevalence. It deeply affects patients' daily life, increasing the burden on patients, families, and society. Presently, the etiology of IBD remains incompletely clarified, while emerging evidence has demonstrated that altered gut microbiota and decreased aryl hydrocarbon receptor (AHR) activity are closely associated with IBD. Furthermore, microbial metabolites are capable of AHR activation as AHR ligands, while the AHR, in turn, affects the microbiota through various pathways. In light of the complex connection among gut microbiota, the AHR, and IBD, it is urgent to review the latest research progress in this field. In this review, we describe the role of gut microbiota and AHR activation in IBD and discussed the crosstalk between gut microbiota and the AHR in the context of IBD. Taken as a whole, we propose new therapeutic strategies targeting the AHR-microbiota axis for IBD, even for other related diseases caused by AHR-microbiota dysbiosis.

Early life stress induces irritable bowel syndrome from childhood to adulthood in mice

Background

Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorder. Traditionally, early life stress (ELS) is predisposed to IBS in adult. However, whether ELS induces IBS in early life remains unclear.

Methods

Separated cohort studies were conducted in neonatal male pups of C57BL/6 mice by maternal separation (MS) model. MS and non-separation mice were scheduled to be evaluated for prime IBS-phenotypes, including visceral hypersensitivity, intestinal motility, intestinal permeability, and anxiety-like behavior. Ileal contents and fecal samples were collected and analyzed by 16S rRNA gene sequencing and bacterial community analyses. Subcellular structures of intestinal epithelial, such as epithelial tight junctions and mitochondria, were observed under transmission electron microscopy.

Results

MS induced visceral hypersensitivity and decreased total intestinal transit time from childhood to adulthood. In addition, MS induced intestinal hyperpermeability and anxiety-like behavior from adolescence to adulthood. Besides, MS affected intestinal microbial composition from childhood to adulthood. Moreover, MS disrupted intestinal mitochondrial structure from childhood to adulthood.

Conclusion

The study showed for the first time that MS induced IBS from early life to adulthood in mice. The disrupted intestinal mitochondrial structure and the significant dysbiosis of intestinal microbiota in early life may contribute to the initiation and progress of IBS from early life to adulthood.

Astaxanthin attenuated the stress-induced intestinal motility disorder via altering the gut microbiota

Gut microbiota and short-chain fatty acids (SCFAs) are recognized as key factors in the pathophysiology of irritable bowel syndrome. Astaxanthin is a carotenoid with strong antioxidant and anti-inflammatory activities. In this study, we examined the effects of astaxanthin on gut microbiota-, SCFAs-, and corticotropin-releasing factor (CRH)-induced intestinal hypermotility. Male Wistar rats (n=12 per group) were fed a diet with or without 0. 02% (w/w) astaxanthin for four weeks and CRH or saline was administered intravenously. The number of fecal pellets was counted 2 h after injection. Then the rats were sacrificed, and the cecal content were collected 3 h after injection. The number of feces was significantly increased by CRH injection in the control group (2.0 vs. 6.5; p=0.028), but not in the astaxanthin group (1.0 vs. 2.2; p=0.229) (n=6 per group). The cecal microbiota in the astaxanthin group was significantly altered compared with that in the control group. The concentrations of acetic acid (81.1 μmol/g vs. 103.9 μmol/g; p=0.015) and butyric acid (13.4 μmol/g vs. 39.2 μmol/g; p<0.001) in the astaxanthin group were significantly lower than that in the control group (n=12 per group). Astaxanthin attenuates CRH-induced intestinal hypermotility and alters the composition of gut microbiota and SCFAs.

Microbiota in Irritable Bowel Syndrome and Endometriosis: Birds of a Feather Flock Together-A Review

Endometriosis and irritable bowel syndrome (IBS) are chronic conditions affecting up to 10% of the global population, imposing significant burdens on healthcare systems and patient quality of life. Interestingly, around 20% of endometriosis patients also present with symptoms indicative of IBS. The pathogenesis of both these multifactorial conditions remains to be fully elucidated, but connections to gut microbiota are becoming more apparent. Emerging research underscores significant differences in the gut microbiota composition between healthy individuals and those suffering from either endometriosis or IBS. Intestinal dysbiosis appears pivotal in both conditions, exerting an influence via similar mechanisms. It impacts intestinal permeability, triggers inflammatory reactions, and initiates immune responses. Furthermore, it is entwined in a bidirectional relationship with the brain, as part of the gut-brain axis, whereby dysbiosis influences and is influenced by mental health and pain perception. Recent years have witnessed the development of microbiota-focused therapies, such as low FODMAP diets, prebiotics, probiotics, antibiotics, and fecal microbiota transplantation, designed to tackle dysbiosis and relieve symptoms. While promising, these treatments present inconsistent data, highlighting the need for further research. This review explores the evidence of gut dysbiosis in IBS and endometriosis, underscoring the similar role of microbiota in both conditions. A deeper understanding of this common mechanism may enable enhanced diagnostics and therapeutic advancements.

Network pharmacology and molecular docking reveal the immunomodulatory mechanism of rhubarb peony decoction for the treatment of ulcerative colitis and irritable bowel syndrome

Background: Ulcerative colitis (UC) and irritable bowel syndrome (IBS) share various similarities in clinical symptoms, pathogenesis, and treatment. UC concurrent IBS tends toward more severe symptoms and worse prognosis, and promising feasible therapies for the overlapping symptoms remains a challenge. Rhubarb peony decoction (RPD) is a well-known traditional Chinese medicine that has been widely applied in treating UC. RPD may exert extensive therapeutic effects on both IBS and UC. However, the common mechanism of its treatment remains unclear. We aimed to assess the potential pharmacological mechanism of RPD in the treatment of overlapping IBS and UC. Methods: The active components and targets of RPD were retrieved from ETCM, TCMSP, BATMAN-TCM, and TCM databases. The disease targets were screened by searching the DrugBank, OMIM, TTD, and PharmGKB databases. PPI network analysis was performed and visualized via the STRING platform and Cytoscape software. GO and KEGG enrichment analyses of the hub genes of RPD were predicted to elucidate the potential molecular mechanism. Subsequently, molecular docking was carried out to verify the combination of active compounds with core targets. Results: By integrating all targets of RPD and disease, a total of 31 bioactive ingredients were identified including quercetin, kaempferol, aloe-emodin, beta-sitosterol, and (+)-catechin, etc. JUN, TP53, MAPK1, RELA, MYC, and ESR1 were explored as potential therapeutic targets among 126 common drug-disease-related targets. They were enriched in the AGE-RAGE signaling pathway in diabetic complications, as well as the NF-kappa B signaling pathway and MAPK signaling pathway. Additionally, some active ingredients were identified as candidates for binding to the hub targets via molecular docking, further suggesting their anti-inflammatory and antioxidative properties. Conclusion: RPD may exert the overall treatment effect for UC and IBS overlap syndrome via the biological mechanism of "multi-ingredients, multi-targets, and multi-pathways" on inflammation, oxidative stress, immune, oncogenicity, and gut microbiota dysbiosis.

Maternal separation leads to dynamic changes of visceral hypersensitivity and fecal metabolomics from childhood to adulthood

We assessed dynamic changes in visceral hypersensitivity and fecal metabolomics through a mouse model of irritable bowel syndrome (IBS) from childhood to adulthood. A mouse model of IBS was constructed with maternal separation (MS) in early life. Male mice aged 25, 40, and 70 days were used. Visceral sensitivity was assessed by recording the reaction between the abdominal withdrawal reflex and colorectal distension. Metabolomics was identified and quantified by liquid chromatography-tandem mass spectrometry. The visceral sensitivity of the MS group was significantly higher than that of the non-separation (NS) group in the three age groups. The top four fecal differential metabolites in the different age groups were lipids, lipid molecules, organic heterocyclic compounds, organic acids and derivatives, and benzenoids. Five identical differential metabolites were detected in the feces and ileal contents of the MS and NS groups at different ages, namely, benzamide, taurine, acetyl-L-carnitine, indole, and ethylbenzene. Taurine and hypotaurine metabolism were the most relevant pathways at P25, whereas histidine metabolism was the most relevant pathway at P40 and P70. Visceral hypersensitivity in the MS group lasted from childhood to adulthood. The different metabolites and metabolic pathways detected in MS groups of different ages provide a theoretical basis for IBS pathogenesis.

Microbiota-sensitive drug delivery systems based on natural polysaccharides for colon targeting

Colon targeting is an ongoing challenge, particularly for the oral administration of biological drugs or local treatment of inflammatory bowel disease (IBD). In both cases, drugs are known to be sensitive to the harsh conditions of the upper gastrointestinal tract (GIT) and, thus, must be protected. Here, we provide an overview of recently developed colonic site-specific drug delivery systems based on microbiota sensitivity of natural polysaccharides. Polysaccharides act as a substrate for enzymes secreted by the microbiota located in the distal part of GIT. The dosage form is adapted to the pathophysiology of the patient and, thus, a combination of bacteria-sensitive and time-controlled release or pH-dependent systems can be used for delivery.

Abrupt Dietary Change and Gradual Dietary Transition Impact Diarrheal Symptoms, Fecal Fermentation Characteristics, Microbiota, and Metabolic Profile in Healthy Puppies

Dietary changes are inevitable for pets, yet little is known about the impact of different dietary change methods on the gastrointestinal response. The current comparative study evaluated the effects of different dietary changes on the diarrheal symptoms, fecal fermentation characteristics, microbiota, and metabolic profile of healthy puppies. A total of 13 beagle puppies were randomly divided into two groups; puppies in the abrupt change (AC) group were given 260 g of a chicken- and duck-based extruded diet (CD)daily for the one-week transition period, whereas puppies in the gradual transition (GT) group were fed according to a gradual transition ratio of a salmon-based extruded diet (SA) and a CD diets with a difference of 40 g per day for seven consecutive days. Serum samples were collected on D7, and fecal samples were collected on D0 and D7. The results indicated that GT reduced the incidence of diarrhea in puppies throughout the trial period. Dietary change methods had no influence on serum inflammatory factors or fecal SCFAs, but isovaleric acid was significantly reduced after GT. Meanwhile, 16S rRNA sequencing showed that the fecal microbiota was changed after different dietary changes. Compared with the bacterial changes after AC, the relative abundances of beneficial bacteria (i.e., Turicibacter and Faecalibacterium) in feces were increased after GT in puppies. Additionally, both GT and AC caused changes in amino acid metabolism, while AC also altered lipid metabolism. AC increased fecal histamine and spermine concentrations, but decreased concentrations of metabolites such as 5-hydroxyindoleacetic acid and serotonin. Our findings indicated that GT most likely reduced the diarrhea rate in puppies by modulating the composition and metabolism of the gut microbiota.

Irritable Bowel Syndrome and the Gut Microbiome: A Comprehensive Review

Irritable Bowel Syndrome (IBS) is a functional disorder of the gastrointestinal tract characterized by abdominal pain and altered bowel habits. It has a prevalence of 10 to 25% in the United States and has a high disease burden, as evidenced by reduced quality of life, decreased work productivity and increased healthcare utilization and costs. IBS has been associated with several intra-intestinal and extra-intestinal conditions, including psychiatric comorbidities. Although the pathophysiology of IBS has not been fully elucidated, it involves dysregulation of communication between the brain and gut (brain–gut axis) which is associated with alterations in intestinal motility, gut permeability, visceral hypersensitivity and gut microbiota composition. The purpose of this article is to review the role the gut microbiota plays in the pathophysiology of IBS, understand factors that affect the gut microbiome and explore the microbiome as a target of treatment.

Modulation of the gut microbiota: opportunities and regulatory aspects

The human gut is an intensively colonized organ containing microorganisms that can be health-promoting or pathogenic. This feature led to the development of functional foods aiming to fortify the former category at the expense of the latter. Since long, cultured products, including probiotics fortification, have been used for humans as live microbial feed additions. This review presents some of the microbes used as probiotics and discusses how supplementation with probiotics may help initiate and/or restore eubiotic composition of gut microbiota. Additionally, it considers safety and regulatory aspects of probiotics.

Alternation of the gut microbiota in irritable bowel syndrome: an integrated analysis based on multicenter amplicon sequencing data

BACKGROUND

Gut dysbacteriosis has been reported as one of the etiologies for irritable bowel syndrome (IBS). However, the association between gut microbiota and IBS is still inconclusive.

METHOD

A paired-sample study was designed by retrieving original multicenter 16 s-rRNA data of IBS patients and healthy controls from the GMrepo database. The propensity score matching (PSM) algorithm was applied to reduce confounding bias. The differential analysis of microbiota composition was performed at different taxonomic levels. The co-occurrence network was established. Subgroup analysis was performed to identify specific microbial compositions in different IBS subtypes.

RESULTS

A total of 1522 amplicon samples were initially enrolled. After PSM, 708 individuals (354 IBS and 354 healthy controls) were eligible for further analysis. A total of 1,160 genera were identified. We identified significantly changed taxa in IBS groups (IBS-enriched: the families Enterobacteriaceae, Moraxellaceae and Sphingobacteriaceae; the genera Streptococcus, Bacillus, Enterocloster, Sphingobacterium, Holdemania and Acinetobacter. IBS-depleted: the phyla Firmicutes, Euryarchaeota, Cyanobacteria, Acidobacteria and Lentisphaerae; the families Bifidobacteriaceae, Ruminococcaceae, Methanobacteriaceae and the other 25 families; the genera Faecalibacterium, Bifidobacterium and other 68 genera). The co-occurrence network identified three hub genera and six hub species (including Faecalibacterium prausnitzii) that may be involved in IBS pathophysiology. Strong positive interactions were identified among the Bifidobacterium longum, Bifidobacterium breve and Bifidobacterium adolescentis in the Bifidobacterium community.

CONCLUSION

This study provides quantitative analysis and visualization of the interaction between the gut microbiota and IBS. The identification of key species should be further validated to evaluate their causal relationships with the pathogenesis of IBS.

Modulation of the microbiota across different intestinal segments by Rifaximin in PI-IBS mice

BACKGROUND

Rifaximin has been increasingly applied in irritable bowel syndrome (IBS) treatment. Whether there were differences in the effects of rifaximin on microbiota from different intestinal segments, especially the small intestine where rifaximin predominantly acted, has not been confirmed.

METHODS

In this study, we used Trichinella spiralis infection to induce post infectious irritable bowel syndrome (PI-IBS) and measured visceral sensitivity of mice by means of abdominal withdrawal reflex (AWR) tests to colorectal distention (CRD). We compared the effects of rifaximin on the composition of ileal, colonic mucosal and fecal microbiota in PI-IBS mice.

RESULTS

Rifaximin significantly reduced AWR scores and increased pain threshold in PI-IBS mice, and this effect was associated with the change in the relative abundance of ileal mucosal microbiota. Rifaximin could obviously decrease ileum mucosal microbiota alpha diversity assessed by Shannon microbial diversity index. Meanwhile, the analysis of beta diversity and relative abundance of microbiota at phylum, family and genus levels showed that rifaximin could improve the microbiota structure of ileal mucosa. However, for colonic mucosal and fecal microbiota, this effect of rifaximin was not obvious. Rifaximin could reshape the correlation of genera between different intestinal segments.

CONCLUSION

Rifaximin improved visceral hypersensitivity in PI-IBS mice. Rifaximin mainly affected ileal mucosal microbiota, and its improvement effect on IBS might be closely related to the improvement of ileal microbiota structure.

Smart capsule for targeted proximal colon microbiome sampling

The gastrointestinal (GI) tract, particularly the colon region, holds a highly diverse microbial community that plays an important role in the metabolism, physiology, nutrition, and immune function of the host body. Accumulating evidence has revealed that alteration in these microbial communities is the pivotal step in developing various metabolic diseases, including obesity, inflammatory bowel disease (IBD), and colorectal cancer. However, there is still a lack of clear understanding of the interrelationship between microbiota and diet as well as the effectiveness of chemoprevention strategies, including pre and probiotic agents in modifying the colonic microbiota and preventing digestive diseases. Existing methods for assessing these microbiota-diet interactions are often based on samples collected from the feces or endoscopy techniques which are incapable of providing information on spatial variations of the gut microbiota or are considered invasive procedures. To address this need, here we have developed an electronic-free smart capsule that enables site-specific sampling of the gut microbiome within the proximal colon region of the GI tract. The 3D printed device houses a superabsorbent hydrogel bonded onto a flexible polydimethylsiloxane (PDMS) disk that serves as a milieu to collect the fluid in the gut lumen and its microbiome by rapid swelling and providing the necessary mechanical actuation to close the capsule after the sampling is completed. The targeted colonic sampling is achieved by coating the sampling aperture on the capsule with a double-layer pH-sensitive enteric coating, which delays fluid in the lumen from entering the capsule until it reaches the proximal colon of the GI tract. To identify the appropriate pH-responsive double-layer coating and processing condition, a series of systematic dissolution characterizations in different pH conditions that mimicked the GI tract was conducted. The effective targeted microbial sampling performance and preservation of the smart capsule with the optimized design were validated using both realistic in vitro GI tract models with mixed bacteria cultures and in vivo with pigs as an animal model. The results from 16s rRNA and WideSeq analysis in both in vitro and in vivo studies showed that the bacterial population sampled within the retrieved capsule closely matched the bacterial population within the targeted sampling region (proximal colon). Herein, it is envisioned that such smart sampling capsule technology will provide new avenues for gastroenterological research and clinical applications, including diet-host-microbiome relationships, focused on human GI function and health. STATEMENT OF SIGNIFICANCE: The colonic microbiota plays a major role in the etiology of numerous diseases. Extensive efforts have been conducted to monitor the gut microbiome using sequencing technologies based on samples collected from feces or mucosal biopsies that are typically obtained by colonoscopy. Despite the simplicity of fecal sampling procedures, they are incapable of preserving spatial and temporal information about the bacteria through the gastrointestinal (GI) tract. In contrast, colonoscopy is an invasive and impractical approach to frequently assess the effect of dietary and therapeutic intake on the microbiome and their impact on the health of the patient. Here, we developed a non-invasive capsule that enables targeted sampling from the ascending colon, thereby providing crucial information for disease prediction and monitoring.

Deleterious Effect of Air Pollution on Human Microbial Community and Bacterial Flora: A Short Review

A balanced microbiota composition is requisite for normal physiological functions of the human body. However, several environmental factors such as air pollutants may perturb the human microbiota composition. It is noticeable that currently around 99% of the world's population is breathing polluted air. Air pollution's debilitating health impacts have been studied scrupulously, including in the human gut microbiota. Nevertheless, air pollution's impact on other microbiotas of the human body is less understood so far. In the present review, the authors have summarized and discussed recent studies' outcomes related to air pollution-driven microbiotas' dysbiosis (including oral, nasal, respiratory, gut, skin, and thyroid microbiotas) and its potential multi-organ health risks.

Interactions between gut microbiota and Parkinson's disease: The role of microbiota-derived amino acid metabolism

Non-motor symptoms (NMS) of Parkinson's disease (PD), such as constipation, sleep disorders, and olfactory deficits, may emerge up to 20 years earlier than motor symptoms. A series of evidence indicates that the pathology of PD may occur from the gastrointestinal tract to the brain. Numerous studies support that the gut microbiota communicates with the brain through the immune system, special amino acid metabolism, and the nervous system in PD. Recently, there is growing recognition that the gut microbiota plays a vital role in the modulation of multiple neurochemical pathways via the “gut microbiota-brain axis” (GMBA). Many gut microbiota metabolites, such as fatty acids, amino acids, and bile acids, convey signaling functions as they mediate the crosstalk between gut microbiota and host physiology. Amino acids' abundance and species alteration, including glutamate and tryptophan, may disturb the signaling transmission between nerve cells and disrupt the normal basal ganglia function in PD. Specific amino acids and their receptors are considered new potential targets for ameliorating PD. The present study aimed to systematically summarize all available evidence on the gut microbiota-derived amino acid metabolism alterations associated with PD.

Gut Microbiota Manipulation in Irritable Bowel Syndrome

Increased knowledge suggests that disturbed gut microbiota, termed dysbiosis, might promote the development of irritable bowel syndrome (IBS) symptoms. Accordingly, gut microbiota manipulation has evolved in the last decade as a novel treatment strategy in order to improve IBS symptoms. In using different approaches, dietary management stands first in line, including dietary fiber supplements, prebiotics, and probiotics that are shown to change the composition of gut microbiota, fecal short-chain fatty acids and enteroendocrine cells densities and improve IBS symptoms. However, the exact mixture of beneficial bacteria for each individual remains to be identified. Prescribing nonabsorbable antibiotics still needs confirmation, although using rifaximin has been approved for diarrhea-predominant IBS. Fecal microbiota transplantation (FMT) has recently gained a lot of attention, and five out of seven placebo-controlled trials investigating FMT in IBS obtain promising results regarding symptom reduction and gut microbiota manipulation. However, more data, including larger cohorts and studying long-term effects, are needed before FMT can be regarded as a treatment for IBS in clinical practice.

An Open-Label Trial Study of Quality-of-Life Assessment in Irritable Bowel Syndrome and Their Treatment

Background and objectives: Irritable bowel syndrome (IBS) does not only have a complex pathophysiological evolution with central and peripheral mechanisms. This study aimed to monitor the neuropsychiatric part of IBS and its management, following the quality of life of patients with IBS. Materials and Methods: Participants numbering 145 were investigated in this study for 6 months and were divided into four groups, namely the control group with a symptomatic period of less than 6 months (n = 34), the group with irritable bowel syndrome (IBS; n = 58), IBS and neuropsychiatric treatment (n = 32), and IBS with probiotic treatment (n = 22). Clinical and paraclinical analyses as well as quality of life were monitored by domestic and international psychological questionnaires. Results: It was observed that, in patients with pro-longed symptoms, neuropsychiatric impairment occurred more frequently, and both clinical and paraclinical analyses improved significantly (p < 0.05) more so in those with complex allopathic treatment and in those with probiotic treatment. There were no significant differences between the two research groups. Conclusions: It has been shown that the neuropsychological component of IBS plays an important role in its treatment, and modern probation therapy can achieve similar results to those of neuropsychiatry. This also requires further studies to ensure the best combination in the approach to IBS.