Irritable bowel syndrome

Frailty status and risk of irritable bowel syndrome in middle-aged and older adults: A large-scale prospective cohort study

BACKGROUND

Frailty is a public health problem for ageing society, however, evidence is lacking regarding its impact on intestinal functions. We aimed to examine prospective relationships of frailty and pre-frailty in middle-aged and older adults with incident irritable bowel syndrome (IBS) in a large-scale population-based cohort.

METHODS

Participants (aged 37-73 years) free of IBS, coeliac disease, inflammatory bowel disease and any cancer at baseline were included, using data from the UK Biobank (collected 2006-2010, 22 assessment centres). Participants without available primary care data were excluded. Frailty status was assessed using Fried phenotype including five criteria (weight loss, exhaustion, low grip strength, low physical activity, slow walking pace). Participants who met at least three criteria were defined as frail, and those who fulfilled one or two criteria were defined as pre-frail. Primary outcome was incident IBS. Cox proportional hazard model was conducted to examine the associated risk of incident IBS.

FINDINGS

Among 176,423 participants (mean age 56.19 years), 7994 (4.5%) and 78,957 (44.8%) were frail and pre-frail at baseline. During a median of 13.2-year follow-up, 4155 cases of incident IBS were identified. Compared with non-frail individuals, those with frail (HR = 1.80, 95% CI: 1.59-2.04) and pre-frail (HR = 1.21, 1.14-1.30) showed significantly higher risk of developing IBS after multivariable adjustment (P_trend < 0.001). Specifically, the positive association was not only observed in older adults (HR = 1.69, 1.37-2.08 for frail; 1.24, 1.12-1.39 for pre-frail), but also in middle-aged adults (HR = 1.90, 1.62-2.22 for frail; 1.19, 1.10-1.30 for pre-frail), both with P_trend < 0.001. Further sensitivity analysis and subgroup analysis indicated similar results.

INTERPRETATION

Frailty and pre-frailty in middle-aged and older adults are associated with increased risk of incident clinical diagnosis of IBS.

FUNDING

National Natural Science Foundation of China (No. 82070550) & National Key Research and Development Program of China (2022YFC2504002, 2022YFC2504003).

The Causal Association of Irritable Bowel Syndrome with Multiple Disease Outcomes: A Phenome-Wide Mendelian Randomization Study

BACKGROUND

This study aimed to identify novel associations between irritable bowel syndrome (IBS) and a broad range of outcomes.

METHODS

In total, 346,352 white participants in the U.K. Biobank were randomly divided into two halves, in which a genome-wide association study (GWAS) of IBS and a polygenic risk score (PRS) analysis of IBS using GWAS summary statistics were conducted, respectively. A phenome-wide association study (PheWAS) based on the PRS of IBS was performed to identify disease outcomes associated with IBS. Then, the causalities of these associations were tested by both one-sample (individual-level data in U.K. Biobank) and two-sample (publicly available summary statistics) Mendelian randomization (MR). Sex-stratified PheWAS-MR analyses were performed in male and female, separately.

RESULTS

Our PheWAS identified five diseases associated with genetically predicted IBS. Conventional MR confirmed these causal associations between IBS and depression (OR: 1.07, 95%CI: 1.01-1.14, p = 0.02), diverticular diseases of the intestine (OR: 1.13, 95%CI: 1.08-1.19, p = 3.00 × 10^-6), gastro-esophageal reflux disease (OR: 1.09, 95%CI: 1.05-1.13, p = 3.72 × 10^-5), dyspepsia (OR: 1.21, 95%CI: 1.13-1.30, p = 9.28 × 10^-8), and diaphragmatic hernia (OR: 1.10, 95%CI: 1.05-1.15, p = 2.75 × 10^-5). The causality of these associations was observed in female only, but not men.

CONCLUSIONS

Increased risks of IBS is found to cause a series of disease outcomes. Our findings support further investigation on the clinical relevance of increased IBS risks with mental and digestive disorders.

A psychological symptom based machine learning model for clinical evaluation of irritable bowel syndrome

Background: Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder characterized by recurrent abdominal pain associated with alterations  in stool form and/or stool frequency. Co-morbidities such as anxiety, depression, fatigue, and insomnia are frequently reported by patients suffering from IBS. Identification of these symptoms should thus be an integral part of an IBS assessment.      However, an optimal tool to screen for core psychological symptoms in IBS is still  missing. Here, we aim to develop a psychological symptom based machine learning model to efficiently help clinicians to identify patients suffering from IBS. Methods: We developed a machine learning workflow to select the most significant psychological features associated with IBS in a dataset including 49 patients with IBS and 35 healthy controls. These features were used to train three different types of machine learning models: logistic regression, decision trees and support vector machine classifiers; which were validated on a holdout validation dataset and an unseen test set. The performance of these models was compared in terms of balanced accuracy scores. Results: A logistic regression model including a combination of symptom features associated with anxiety and fatigue resulted in a balanced accuracy score of 0.93 (0.81-1.0) on unseen test data and outperformed the other comparable models. The same model correctly identified all patients with IBS in a test set (recall score 1) and misclassified one non-IBS subject (precision score 0.91). A complementary post-hoc leave-one-out cross validation analysis including the same symptom features showed similar, but slightly inferior results (balanced accuracy 0.84, recall 0.88, precision 0.86). Conclusions: Inclusion of machine learning based psychological evaluation can complement and improve existing clinical procedure for diagnosis of IBS.

Mechanism of Wuyao-Ginseng Medicine Pair in the Prevention and Treatment of Diarrhea-Type Irritable Bowel Syndrome Based on Gene Expression Omnibus Chip Data

Based on a Gene Expression Omnibus (GEO) chip analysis combined with network pharmacology and molecular docking technology, in this study we explored the molecular targets and mechanism of the wuyao-ginseng medicine pair in the prevention and treatment of diarrhea-type irritable bowel syndrome (IBS-D). The Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) was used to search for the chemical constituents and targets of wuyao and ginseng. The UniProt database was used to search for the target gene name. In the GEO database, IBS was searched to obtain GSE36701 and GSE14841 microarray data. We imported the intersection targets into the STRING database to construct a protein-protein interaction (PPI) network. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (Go) pathway analyses were performed using the Metascape database. A total of 30 active ingredients of wuyao-ginseng, 171 drug targets, 1257 IBS differentially expressed genes, and 20 drug-disease intersection genes were obtained from the GEO data. We screened the results and obtained the core active ingredients beta-sitosterol, DMPEC, Boldine, etc.; the core targets NCOA2, EGFR, VEGFA, etc.; and the key pathways P13K-Akt, MAPK, etc. The wuyao-ginseng medicine pair may be involved in inflammation-related signaling pathways, acting on disease targets such as NCOA2, EGFR, and VEGFA as well as pathways such as P13K-Akt and MAPK, thereby playing a key role in the prevention and treatment of IBS-D.

Oral and fecal microbiota in patients with diarrheal irritable bowel syndrome

Background

This study aimed at investigating the characteristics and correlation between oral (tongue coating) and fecal microbiota in patients with diarrheal irritable bowel syndrome (IBS-D).

Methods

Fifty-two IBS-D patients were chosen, with ten healthy volunteers serving as the normal control group. Tongue coating samples and fecal samples of subjects were sequenced for the 16S rRNA gene (V4-V5). Bioinformatics analysis was done on the test data to investigate oral and fecal microbiota composition characteristics in IBS-D patients.

Results

The microbial richness of tongue coating in IBS-D group was lower than that in the normal control group (P < 0.05). The beta diversity of tongue coating microbiota and fecal microbiota was significantly different in the IBS-D group compared to the normal control group (P < 0.05). Pseudomonadales (Pseudomonadaceae and Pseudomonas), Moraxellaceae, Parvimonas, Peptostreptococcus, and Alloprevotella were considerably high in number the tongue coating samples of the IBS-D group in comparison to the normal control group. Similarly, the fecal samples from the IBS-D group were significantly enriched in Alphaproteobacteria, Pseudomonadales (Pseudomonadaceae and Pseudomonas), Acidaminococcaceae, Phascolarctobacterium, Alloprevotella, and Escherichia compared to the normal control group.

Conclusions

The oral and fecal microbiotas of IBS-D patients differ from those of the control group; hence studying IBS-D from the perspective of the oral-gut microbiome axis is an interesting research avenue.

Fungal feelings in the irritable bowel syndrome: the intestinal mycobiome and abdominal pain

Although the gut microbiota consists of bacteria, viruses, and fungi, most publications addressing the microbiota-gut-brain axis in irritable bowel syndrome (IBS) have a sole focus on bacteria. This may relate to the relatively low presence of fungi and viruses as compared to bacteria. Yet, in the field of inflammatory bowel disease research, the publication of several papers addressing the role of the intestinal mycobiome now suggested that these low numbers do not necessarily translate to irrelevance. In this review, we discuss the available clinical and preclinical IBS mycobiome data, and speculate how these recent findings may relate to earlier observations in IBS. By surveying literature from the broader mycobiome research field, we identified questions open to future IBS-oriented investigations.

Efficacy of Oral Psyllium in Pediatric Irritable Bowel Syndrome: A Double-Blind Randomized Control Trial

OBJECTIVE

Pediatric irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder with variable response to various therapeutic agents. Psyllium has been proven to be effective in adults; however, there is no study in children. The objective of this study is to evaluate the efficacy of psyllium husk as compared to placebo in pediatric IBS patients.

METHODS

In this double-blind randomized controlled trial, 43 children were assigned to psyllium arm (Group A) and 38 into placebo arm (Group B). Severity is assessed at baseline and after 4 weeks of treatment using IBS severity scoring scale (IBS-SSS) and classified into mild, moderate, and severe categories. Categorical data was compared with chi-square test and paired categorical variable was compared with McNemer test.

RESULTS

Mean ages (±SD; in years) of Groups A and B were 9.87 (2.7) and 9.82 (3.17), respectively, with median duration of illness of 12 months. At baseline, type, severity, and parameters (IBS-SSS) of IBS were equally distributed in 2 groups. There was a significant reduction in median interquartile range (IQR) of total IBS-SSS in psyllium versus placebo [75 (42.5-140) vs 225 (185-270); P < 0.001] at 4 weeks. Similarly 43.9% in Group A versus 9.7% in Group B attained remission [IBS-SSS < 75 ( P < 0.0001)]. The mean difference in IBS-SSS between Group A and Group B was -122.85 with risk ratio of 0.64 (95% CI; 0.42-0.83; P = 0.001) and absolute risk reduction of 32% (NNT = 3).

CONCLUSIONS

Psyllium husk is effective for the therapy of pediatric IBS when compared with placebo in short term.

Global research progress of visceral hypersensitivity and irritable bowel syndrome: bibliometrics and visualized analysis

Background: Irritable bowel syndrome (IBS) is a group of functional intestinal disorders characterized by abdominal pain, bloating, and changes in bowel habits, and/or stool characteristics. Recent studies have shown that there has been a significant advancement in the study of visceral hypersensitivity in IBS. Through the use of bibliometrics, this study aims to provide a comprehensive overview of the knowledge structure and research hotpots of visceral hypersensitivity in IBS. Methods: Publications related to visceral hypersensitivity in IBS from 2012 to 2022 were searched on the web of science core collection (WoSCC) database. CiteSpace.6.1. R2 and Vosviewer 1.6.17 were used to perform bibliometric analysis. Results: A total of 974 articles led by China and the United States from 52 countries were included. Over the past decade, the number of articles on visceral hypersensitivity and IBS has steadily increased year by year. China, the United States, and Belgium are the main countries in this field. Univ Oklahoma, Univ Gothenburg, and Zhejiang University are the main research institutions. Simren, Magnus, Greenwood-van meerveld, Beverley, and Tack, Jan are the most published authors in this research field. The research on the causes, genes, and pathways involved in visceral hypersensitivity in IBS and the mechanism of IBS are the main topics and hotspots in this field. This study also found that gut microbiota may be related to the occurrence of visceral hypersensitivity, and probiotics may be a new method for the treatment of visceral hypersensitivity and pain, which may become a new direction for research in this field. Conclusion: This is the first bibliometric study to comprehensively summarize the research trends and developments of visceral hypersensitivity in IBS. This information provides the research frontier and hot topics in this field in recent years, which will provide a reference for scholars studying this field.

Bifico relieves irritable bowel syndrome by regulating gut microbiota dysbiosis and inflammatory cytokines

PURPOSE

Gut microbiota dysbiosis, a core pathophysiology of irritable bowel syndrome (IBS), is closely related to immunological and metabolic functions. Gut microbiota-based therapeutics have been recently explored in several studies. Bifico is a probiotic cocktail widely used in gastrointestinal disorders which relate to the imbalance of gut microbiota. However, the efficacy and potential mechanisms of Bifico treatment in IBS remains incompletely understood.

METHODS

Adopting a wrap restraint stress (WRS) -induced IBS mice model. Protective effect of Bifico in IBS mice was examined through abdominal withdrawal reflex (AWR) scores. 16S rDNA, ¹H nuclear magnetic resonance (¹H-NMR) and western blot assays were performed to analyze alterations of gut microbiota, microbiome metabolites and inflammatory cytokines, respectively.

RESULTS

Bifico could decrease intestinal visceral hypersensitivity. Although gut microbiota diversity did not increase, composition of gut microbiota was changed after treatment of Bifico, which were characterized by an increase of Proteobacteria phylum and Actinobacteria phylum, Muribaculum genus, Bifidobacterium genus and a decrease of Parabacteroides genus, Sutterella genus and Lactobacillus genus. Moreover, Bifico elevated the concentration of short-chain fatty acids (SCFAs) and reduced protein levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). From further Spearman's correlation analysis, Bifidobacterium genus were positively correlated with SCFAs including propionate, butyrate, valerate and negatively correlated with IL-6 and TNF-α.

CONCLUSION

Bifico could alleviate symptoms of IBS mice through regulation of the gut microbiota, elevating production of SCFAs and reducing the colonic inflammatory response.

Randomised clinical trial: effects of MD-7246 on irritable bowel syndrome with diarrhoea

BACKGROUND

MD-7246, a delayed-release formulation of linaclotide, is designed to target the ileocaecal junction and caecum with the aim of relieving abdominal pain independently of bowel function.

AIMS

To evaluate the efficacy, safety and dose-response of MD-7246 in patients with irritable bowel syndrome with diarrhoea (IBS-D).

METHODS

A randomised, double-blind, phase 2 clinical trial enrolled adult patients with IBS-D (Rome IV criteria). Patients were randomised to placebo or once-daily oral MD-7246 300, 600 or 1200 μg for 12 weeks. Abdominal and bowel symptoms were assessed daily. Key efficacy endpoints were change from baseline in abdominal pain and responder rates for a 30% reduction in abdominal pain in 6/12 weeks. Additional abdominal pain responder and exploratory bowel function endpoints were also assessed.

RESULTS

Among the 388 randomised patients, there was no significant difference in mean change from baseline in abdominal pain between the MD-7246 300 μg, 600 μg and 1200 μg groups and placebo (-1.93, -1.58, -1.95 and - 2.01, respectively; p > 0.05 for each group vs placebo). The abdominal pain responder rates in the MD-7246 groups were similar to or lower than those in the placebo group. All doses of MD-7246 had a minimal effect on bowel function and were generally well tolerated.

CONCLUSIONS

MD-7246 at the doses studied did not improve abdominal pain relative to placebo in an IBS-D patient population. Similarly, most additional efficacy endpoints showed no improvement with MD-7246 relative to placebo.

Multi-omics for biomarker approaches in the diagnostic evaluation and management of abdominal pain and irritable bowel syndrome: what lies ahead

Reliable biomarkers for common disorders of gut-brain interaction characterized by abdominal pain, including irritable bowel syndrome (IBS), are critically needed to enhance care and develop individualized therapies. The dynamic and heterogeneous nature of the pathophysiological mechanisms that underlie visceral hypersensitivity have challenged successful biomarker development. Consequently, effective therapies for pain in IBS are lacking. However, recent advances in modern omics technologies offer new opportunities to acquire deep biological insights into mechanisms of pain and nociception. Newer methods for large-scale data integration of complementary omics approaches have further expanded our ability to build a holistic understanding of complex biological networks and their co-contributions to abdominal pain. Here, we review the mechanisms of visceral hypersensitivity, focusing on IBS. We discuss candidate biomarkers for pain in IBS identified through single omics studies and summarize emerging multi-omics approaches for developing novel biomarkers that may transform clinical care for patients with IBS and abdominal pain.

Functional Implications and Clinical Potential of MicroRNAs in Irritable Bowel Syndrome: A Concise Review

MicroRNAs (miRNAs) are tiny (20-24 nucleotides long), non-coding, highly conserved RNA molecules that play a crucial role within the post-transcriptional regulation of gene expression via sequence-specific mechanisms. Since the miRNA transcriptome is involved in multiple molecular processes needed for cellular homeostasis, its altered expression can trigger the development and progression of several human pathologies. In this context, over the last few years, several relevant studies have demonstrated that dysregulated miRNAs affect a wide range of molecular mechanisms associated with irritable bowel syndrome (IBS), a common gastrointestinal disorder. For instance, abnormal miRNA expression in IBS patients is related to the alteration of intestinal permeability, visceral hyperalgesia, inflammatory pathways, and pain sensitivity. Besides, specific miRNAs are differentially expressed in the different subtypes of IBS, and therefore, they might be used as biomarkers for precise diagnosis of these pathological conditions. Accordingly, miRNAs have noteworthy potential as theragnostic targets for IBS. Hence, in this current review, we present an overview of the recent discoveries regarding the clinical relevance of miRNAs in IBS, which might be useful in the future for the development of miRNA-based drugs against this disorder.

Advancement in Therapeutic Intervention of Prebiotic-Based Nanoparticles for Colonic Diseases

Intestinal flora has become a therapeutic target for the intervention of colonic diseases (CDs) with better understanding of the interplay between microbiota and CDs. Depending on unique properties and prominent ability of regulating the intestinal flora, prebiotics can not only achieve a colon-specific drug delivery but also maintain the intestinal homeostasis, thus playing a positive role in the intervention of CDs. Currently, different studies on prebiotic-based nanoparticles have been contrived for colonic drug delivery and have shown great potential in curing various CDs, such as colitis and colorectal cancer. Nevertheless, there is a lack of systematic survey on the use of prebiotic nanoparticles for the treatment of CDs. This review aims to generalize the state-of-the-art of prebiotic nanomedicines specific for CDs. The species and function of intestinal flora and various kinds of prebiotics available as well as their regulating effects on intestinal flora were expounded. A variety of prebiotic nanoparticles pertinent to colon-targeted drug delivery systems were illustrated with particular emphasis on their curative activities on CDs. The efficacy and safety of prebiotic-based colonic drug delivery systems (p-CDDs) were also analyzed. In conclusion, the synergy between prebiotic nanoparticles and their cargos may hold promise for the treatment and intervention of CDs.

Alterations of the gut microbiota in coronavirus disease 2019 and its therapeutic potential

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a serious threat to global health. SARS-CoV-2 infects host cells primarily by binding to angiotensin-converting enzyme 2, which is coexpressed in alveolar type 2 cells and gut epithelial cells. It is known that COVID-19 often presents with gastrointestinal symptoms and gut dysbiosis, mainly characterized by an increase in opportunistic pathogens and a decrease in beneficial commensal bacteria. In recent years, multiple studies have comprehensively explored gut microbiota alterations in COVID-19 and highlighted the clinical correlation between dysbiosis and COVID-19. SARS-CoV-2 causes gastrointestinal infections and dysbiosis mainly through fecal-oral transmission and the circulatory and immune pathways. Studies have shown that the gut microbiota and its metabolites can regulate the immune response and modulate antiviral effects. In addition, the gut microbiota is closely related to gastrointestinal symptoms, such as diarrhea, a common gastrointestinal symptom among COVID-19. Therefore, the contribution of the gut microbiota in COVID-19 should not be overlooked. Strategies targeting the gut microbiota via probiotics, prebiotics and fecal microbiota transplantation should be considered to treat this patient population in the future. However, the specific alterations and mechanisms as well as the contributions of gut microbiota in COVID-19 should be urgently further explored.

A Cross-Sectional Study about Knowledge, Attitude, and Practices among Primary Health Care Physicians in Jazan Province, Saudi Arabia, Regarding Rome IV Criteria for Diagnosis of Irritable Bowel Syndrome

Background and objectives: Most individuals with irritable bowel syndrome (IBS) are diagnosed by primary health care (PHC) physicians. However, a significant percentage of patients remain undiagnosed or misdiagnosed owing to the lack of knowledge or a systematic strategy regarding the use of ROME IV criteria for the diagnosis of IBS. Thus, in this study, we aimed to assess the knowledge, attitude, and practices among primary health care physicians in Jazan Province, Saudi Arabia, regarding ROME IV criteria for the diagnosis of IBS. Methods: A cross-sectional study was conducted using a pretested self-administered questionnaire that determines participants' sociodemographic data and measures knowledge about ROME IV criteria, targeting PHC physicians in Jazan Province, Saudi Arabia. Data were analyzed using the Statistical Package for Social Sciences (SPSS) v.23. Results: We included 200 participants, and the majority of participants in our study (approximately 78%) were aware of the ROME IV diagnostic criteria for IBS; this awareness was associated with age, nationality, specialty, and classification. The participants' mean level of knowledge was 4.30 (out of 6). However, knowledge was higher among Saudi and family medicine doctors in this study, as compared to non-Saudi and doctors of other specialties. More than two-thirds of participants who were aware of ROME IV criteria thought that they are sufficient to diagnose IBS; however, only 47.5% of physicians reported using ROME IV frequently in their daily practice. Conclusions: Most of the participants of this study are aware of ROME IV criteria, and better knowledge was noted among Saudi and family medicine physicians. About 70% thought that ROME IV criteria are effective enough to diagnose IBS, and only about half of the participants use ROME IV criteria in their practice. Therefore, due to its high prevalence in the region, further efforts are required to disseminate basic knowledge and improve attitudes and practices related to ROME IV criteria among PHC physicians of all specialties.

Obesity Contributes to Inflammation in Patients with IBS via Complement Component 3 and C-Reactive Protein

Irritable Bowel Syndrome (IBS) is usually a lifelong state that disturbs the digestive system. IBS has been linked to low-grade inflammation and the release of inflammatory mediators into the bloodstream. This could be associated with the degree of obesity presented by patients with IBS. Reports imply that IBS is more frequent in obese patients than in the overall population, with a prevalence of up to 31%. Here, we evaluated the serum levels of immunological and inflammation molecules and their correlation with Body Mass Index in IBS patients and the healthy control (HC). Seventy-nine serum samples of the IBS patients and thirty-five of the HC group were analyzed to determine the levels of each molecule and compare them with their BMI. Serum levels of C3 and C4 were significantly increased in IBS patients. C3 and C4 levels were higher in IBS-M and IBS-D subtypes compared with the HC group. When patients were grouped by BMI, a positive correlation between serum C3 (r = 0.49, p < 0.0001) and CRP (r = 0.40, p < 0.001) levels was found. Our results show, for the first time, a correlation between immunological molecules and BMI in IBS patients, suggesting that the inflammatory nature of obesity could contribute to the development of the symptoms in IBS through the stimulation and release of proteins as complement components and CRP.

Methanogens and Hydrogen Sulfide Producing Bacteria Guide Distinct Gut Microbe Profiles and Irritable Bowel Syndrome Subtypes

INTRODUCTION

Irritable bowel syndrome (IBS) includes diarrhea-predominant (IBS-D) and constipation-predominant (IBS-C) subtypes. We combined breath testing and stool microbiome sequencing to identify potential microbial drivers of IBS subtypes.

METHODS

IBS-C and IBS-D subjects from 2 randomized controlled trials (NCT03763175 and NCT04557215) were included. Baseline breath carbon dioxide, hydrogen (H 2 ), methane (CH 4 ), and hydrogen sulfide (H 2 S) levels were measured by gas chromatography, and baseline stool microbiome composition was analyzed by 16S rRNA sequencing. Microbial metabolic pathways were analyzed using Kyoto Encyclopedia of Genes and Genomes collection databases.

RESULTS

IBS-C subjects had higher breath CH 4 that correlated with higher gut microbial diversity and higher relative abundance (RA) of stool methanogens, predominantly Methanobrevibacter , as well as higher absolute abundance of Methanobrevibacter smithii in stool. IBS-D subjects had higher breath H 2 that correlated with lower microbial diversity and higher breath H 2 S that correlated with higher RA of H 2 S-producing bacteria, including Fusobacterium and Desulfovibrio spp. The predominant H 2 producers were different in these distinct microtypes, with higher RA of Ruminococcaceae and Christensenellaceae in IBS-C/CH 4 + (which correlated with Methanobacteriaceae RA) and higher Enterobacteriaceae RA in IBS-D. Finally, microbial metabolic pathway analysis revealed enrichment of Kyoto Encyclopedia of Genes and Genomes modules associated with methanogenesis and biosynthesis of methanogenesis cofactor F420 in IBS-C/CH 4 + subjects, whereas modules associated with H 2 S production, including sulfate reduction pathways, were enriched in IBS-D.

DISCUSSION

Our findings identify distinct gut microtypes linked to breath gas patterns in IBS-C and IBS-D subjects, driven by methanogens such as M. smithii and H 2 S producers such as Fusobacterium and Desulfovibrio spp, respectively.

The Role of Calcium, 25-Hydroxyvitamin D, and Parathyroid Hormone in Irritable Bowel Syndrome: A Bidirectional Two-Sample Mendelian Randomization Study

Several observational studies have indicated the potential associations among calcium, vitamin D (Vit-D), and irritable bowel syndrome (IBS). However, the causal relationship deduced from these studies is subject to residual confounding factors and reverse causation. Therefore, we aimed to explore the bidirectional causal effects among serum calcium, Vit-D, PTH, and IBS at the genetic level by a two-sample Mendelian randomization (MR) analysis of the datasets from IEU OpenGWAS database. Sensitivity analyses were performed to evaluate the robustness. The estimates were presented as odds ratios (ORs) with their 95% confidence intervals (CIs). The results of the inverse variance weighted method did not reveal any causal relationship between the genetically predisposed calcium (OR = 0.92, 95% CI: 0.80-1.06, p = 0.25) and Vit-D (OR = 0.99, 95% CI: 0.83-1.19, p = 0.94) level and the risk of IBS. The bidirectional analysis demonstrated that genetic predisposition to IBS was associated with a decreased level of PTH (beta: -0.19, 95%CI: -0.34 to -0.04, p = 0.01). In conclusion, the present study indicates no causal relationship between the serum calcium and Vit-D concentrations and the risk of IBS. The potential mechanisms via which IBS affects serum PTH need to be further investigated.

Non-pharmacological strategies to treat irritable bowel syndrome: 2022 update

Irritable bowel syndrome (IBS) is a chronic functional disorder characterized by abdominal pain associated with changes in stool frequency or form, in absence of organic disease. The treatment of IBS is often challenging and should be individually adjusted according to the prevalent symptomatology. Pharmacological treatment for IBS with diarrhea includes peripheral opioid agonists, bile acid sequestrants and antibiotics, while IBS with constipation can be treated with soluble fibers, osmotic agents or prokinetics. In case of abdominal pain, the available pharmacological options are antispasmodics, peripheral opioid agonists or antidepressants. Along with pharmacotherapy, non-pharmacological interventions should be considered as they can play an important role in symptom control. The first-line approach includes lifestyle modifications and dietary advice. Microbiota manipulation through probiotics, prebiotics and symbiotics is a widely used strategy, although the evidence upon the most effective among these in specific IBS subtypes is still unclear. Fecal microbiota transplantation is still in experimental phase for IBS, but it is giving promising results. Psychological therapies may be effective in patients with IBS, despite their application can be limited by long duration, high costs and poor patient's acceptance. Alternative medicine approaches, such as acupuncture, body relaxation techniques, dietary supplements or Chinese herbs, have been proposed; however, the evidence upon their efficacy and safety is still controversial.

Clinical evidence of acupuncture and moxibustion for irritable bowel syndrome: A systematic review and meta-analysis of randomized controlled trials

Background

Acupuncture and moxibustion have been widely used in the treatment of Irritable Bowel Syndrome (IBS). But the evidence that acupuncture and moxibustion for IBS reduction of symptom severity and abdominal pain, and improvement of quality of life is scarce.

Methods

PubMed, Embase, Cochrane Library, Web of Science, Chinese National Knowledge Infrastructure (CNKI), Chinese Scientific Journals Database (VIP), Wanfang Database, China Biomedical Literature Service System (SinoMed), and unpublished sources were searched from inception until June 30, 2022. The quality of RCTs was assessed with the Cochrane Collaboration risk of bias tool. The strength of the evidence was evaluated with the Grading of Recommendations Assessment, Development and Evaluation system (GRADE). Trial sequential analysis (TSA) was conducted to determine whether the participants in the included trials had reached optimal information size and whether the cumulative data was adequately powered to evaluate outcomes.

Results

A total of 31 RCTs were included. Acupuncture helped reduce the severity of symptoms more than pharmaceutical drugs (MD, -35.45; 95% CI, -48.21 to -22.68; I ² = 71%). TSA showed the cumulative Z score crossed O'Brien-Fleming alpha-spending significance boundaries. Acupuncture wasn't associated with symptom severity reduction (SMD, 0.03, 95% CI, -0.25 to 0.31, I ² = 46%), but exhibited therapeutic benefits on abdominal pain (SMD, -0.24; 95% CI, -0.48 to -0.01; I ² = 8%) compared to sham acupuncture. Moxibustion show therapeutic benefits compared to sham moxibustion on symptom severity (SMD, -3.46, 95% CI, -5.66 to -1.27, I ² = 95%) and abdominal pain (SMD, -2.74, 95% CI, -4.81 to -0.67, I ² = 96%). Acupuncture (SMD, -0.46; 95% CI, -0.68 to -0.24; I ² = 47%) and the combination of acupuncture and moxibustion (SMD, -2.00; 95% CI, -3.04 to -0.96; I ² = 90%) showed more benefit for abdominal pain compared to pharmacological medications as well as shams. Acupuncture (MD, 4.56; 95% CI, 1.46-7.67; I ² = 79%) and moxibustion (MD, 6.97; 95% CI, 5.78-8.16; I ² = 21%) were more likely to improve quality of life than pharmaceutical drugs.

Conclusion

Acupuncture and/or moxibustion are beneficial for symptom severity, abdominal pain and quality of life in IBS. However, in sham control trials, acupuncture hasn't exhibited robust and stable evidence, and moxibustion's results show great heterogeneity. Hence, more rigorous sham control trials of acupuncture or moxibustion are necessary.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=262118, identifier CRD42021262118.

Modulation of colonic function in irritable bowel syndrome rats by electroacupuncture at ST25 and the neurobiological links between ST25 and the colon

Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disease characterized by abdominal pain and defecation disorders. Acupuncture therapy positively affects IBS, with ST25 being the main point. However, ST25 has mostly been used in conjunction with other acupoints. This study aimed to observe the therapeutic effect of electroacupuncture at ST25 alone in IBS and the neurobiological mechanism of ST25 associated with the colon. First, we observed the effect of electroacupuncture at ST25 on the visceral pain threshold and slow-wave discharge of the colon in IBS model rats. Second, we explored the neurobiological mechanism of ST25 associated with the colon using a neural tracer technique. The results showed that (1) electroacupuncture at ST25 alone can alleviate visceral hypersensitivity and restore normal slow-wave frequency and rhythm of the colon in IBS rats; (2) there is a close neuroanatomical connection between ST25 and the colon, i.e., in the dorsal root ganglion (DRG), ST25 is similar in innervation to the colon, mainly in the T8-L1 segment, while the presence of double-labeled positive neurons is present in a part of the DRG; retrogradely labeled motor neurons associated with ST25 were observed in the anterior horn of the spinal cord, and retrogradely labeled sympathetic postganglionic neurons associated with ST25 were observed in the sympathetic nerve chain. These findings suggested that the DRGs and the dorsal horn of the spinal cord are important targets for electroacupuncture at ST25 to reduce visceral hypersensitivity in IBS rats. The sympathetic ganglia may be an important site for ST25 to regulate intestinal motility. The neurobiological mechanism of ST25 action in IBS rats should be further investigated in the future by combining related techniques, such as pseudorabies virus, optogenetics, calcium imaging, and electrophysiology.

Linaclotide Reduced Response Time for Irritable Bowel Syndrome With Constipation Symptoms: Analysis of 4 Randomized Controlled Trials

INTRODUCTION

These post hoc analyses provide clinically relevant data concerning time to response for individual irritable bowel syndrome with constipation (IBS-C) symptoms after linaclotide use.

METHODS

Time-to-response data were pooled from 4 randomized controlled trials. Response time for abdominal symptoms (pain, discomfort, and bloating) and complete spontaneous bowel movements (CSBMs) were analyzed using the Kaplan-Meier method; patients were categorized as early responders (≤4 weeks), late responders (>4-12 weeks), or nonresponders.

RESULTS

Among 2,350 patients (1,172 placebo and 1,178 linaclotide 290 μg), >50% of patients with IBS-C who initiated linaclotide treatment experienced a decrease of ≥30% in abdominal pain, discomfort, or bloating within 3-4 weeks (median). The median time to achieving ≥3 CSBMs was 4 weeks. Although not all linaclotide-treated patients responded within 12 weeks, a late response occurred between 4 and 12 weeks in 1 in 6 patients for abdominal pain and in approximately 1 in 10 patients for CSBM frequency. Comparisons of early responders, late responders, and nonresponders for both response definitions indicated that women, Whites, and patients with less severe baseline abdominal symptoms were more likely to respond early.

DISCUSSION

Although treatment responses with linaclotide occurred in >50% of patients with IBS-C within 4 weeks of treatment initiation, benefits for individual abdominal symptoms and/or CSBM frequency can still occur between 4 and 12 weeks. A lack of improvement in one symptom does not negate the possibility of response for others, highlighting the importance of discussing all symptoms with patients and not assuming treatment futility at 4 weeks.

Current and Future Therapeutic Options for Irritable Bowel Syndrome with Diarrhea and Functional Diarrhea

Irritable bowel syndrome with diarrhea and functional diarrhea are disorders of gut-brain interaction presenting with chronic diarrhea; they have significant impact on quality of life. The two conditions may exist as a continuum and their treatment may overlap. Response to first-line therapy with antispasmodics and anti-diarrheal agents is variable, leaving several patients with suboptimal symptom control and need for alternative therapeutic options. Our aim was to discuss current pharmacologic options and explore alternative therapeutic approaches and future perspectives for symptom management in irritable bowel syndrome with diarrhea and functional diarrhea. We conducted a search of PubMed, Cochrane, clinicaltrial.gov, major meeting abstracts for publications on current, alternative, and emerging drugs for irritable bowel syndrome with diarrhea and functional diarrhea. Currently approved therapeutic options for patients with first-line refractory irritable bowel syndrome with diarrhea and functional diarrhea include serotonin-3 receptor antagonists, eluxadoline and rifaximin. Despite their proven efficacy, cost and availability worldwide impact their utilization. One-third of patients with disorders of gut-brain interaction with diarrhea have bile acid diarrhea and may benefit from drugs targeting bile acid synthesis and excretion. Further understanding of underlying pathophysiology of irritable bowel syndrome with diarrhea and functional diarrhea related to bile acid metabolism, gastrointestinal transit, and microbiome has led to evaluation of novel therapeutic approaches, including fecal microbiota transplantation and enterobacterial "crapsules". These opportunities to treat disorders of gut-brain interaction with diarrhea should be followed with formal studies utilizing large samples of well-characterized patients at baseline and validated response outcomes as endpoints for regulatory approval.

Patchouli alcohol improved diarrhea-predominant irritable bowel syndrome by regulating excitatory neurotransmission in the myenteric plexus of rats

Background and Purpose: Irritable bowel syndrome (IBS) is usually associated with chronic gastrointestinal disorders. Its most common subtype is accompanied with diarrhea (IBS-D). The enteric nervous system (ENS) modulates major gastrointestinal motility and functions whose aberration may induce IBS-D. The enteric neurons are susceptible to long-term neurotransmitter level alterations. The patchouli alcohol (PA), extracted from Pogostemonis Herba, has been reported to regulate neurotransmitter release in the ENS, while its effectiveness against IBS-D and the underlying mechanism remain unknown. Experimental Approach: In this study, we established an IBS-D model in rats through chronic restraint stress. We administered the rats with 5, 10, and 20 mg/kg of PA for intestinal and visceral examinations. The longitudinal muscle myenteric plexus (LMMP) neurons were further immunohistochemically stained for quantitative, morphological, and neurotransmitters analyses. Key Results: We found that PA decreased visceral sensitivity, diarrhea symptoms and intestinal transit in the IBS-D rats. Meanwhile, 10 and 20 mg/kg of PA significantly reduced the proportion of excitatory LMMP neurons in the distal colon, decreased the number of acetylcholine (Ach)- and substance P (SP)-positive neurons in the distal colon and restored the levels of Ach and SP in the IBS-D rats. Conclusion and Implications: These findings indicated that PA modulated LMMP excitatory neuron activities, improved intestinal motility and alleviated IBS-induced diarrheal symptoms, suggesting the potential therapeutic efficacy of PA against IBS-D.

Slow, deep breathing intervention improved symptoms and altered rectal sensitivity in patients with constipation-predominant irritable bowel syndrome

BACKGROUND AND AIM

Limited treatment options have been shown to alter the natural course of irritable bowel syndrome (IBS). Slow, deep breathing (SDB) is a common pain self-management intervention. This pilot study aimed to explore the impact of SDB on measures of autonomic and anorectal functions as well as patient-reported symptoms in constipation-predominant IBS (IBS-C).

METHODS

Eighty-five IBS-C patients were enrolled in this study and randomly assigned to the experimental group (Group A, n = 42) and the control group (Group B, n = 43). SDB was conducted at six breathing cycles per minute with an inhalation for 4 s and exhalation for 6 s at a ratio of 2:3 and repeated for 30 min during the intervention. All subjects underwent high-resolution anorectal manometry (HRAM) and completed the standardized IBS symptom severity system (IBS-SSS) questionnaire. Meanwhile, changes in stool consistency, weekly frequency of complete spontaneous bowel movements (CSBMs), and weekly frequency of spontaneous bowel movements (SBMs) were recorded. All IBS-C patients received electrocardiogram (ECG) recordings for heart rate variability (HRV) analysis at baseline, weeks 3, 6.

RESULTS

At baseline, no differences were found between Groups A and B. The IBS-SSS score and its five sub-scores of Group B patients were significantly higher at week 6 than those of Group A patients (all p < 0.001). Furthermore, compared with Group B patients, Group A patients had a significantly higher threshold volume for the first sensation (p < 0.001), desire to defecate (p = 0.017), and maximum tolerable volume (p = 0.018) at week 6 of the SDB treatment. We also noted significant improvements in stool consistency (p = 0.002), weekly SBM frequencies (p < 0.001), and weekly CSBM frequencies (p = 0.018) of Group A patients at week 6 when compared with Group B patients. Finally, the corrected high frequency (HF) of Group A patients was significantly higher than the HF of Group B patients at week 3 (p < 0.001) and at week 6 (p < 0.001). Likewise, patients in Group A had a significantly higher root mean square of the successive differences (RMSSD) than that of patients in Group B at week 3 (p < 0.001) and at week 6 (p < 0.001).

CONCLUSION

We found that a 6-week SDB intervention improved symptoms and altered rectal sensation in IBS-C patients. Moreover, SDB enhanced vagal activity. These findings suggest that the effect of SDB on IBS-C may be due to mechanisms involving autonomic responses.

Genetics of irritable bowel syndrome: shifting gear via biobank-scale studies

The pathophysiology of irritable bowel syndrome (IBS) is multifactorial and probably involves genetic predisposition and the effect of environmental factors. Unlike other gastrointestinal diseases with a heritable component, genetic research in IBS has been scarce and mostly characterized by small underpowered studies, leading to inconclusive results. The availability of genomic and health-related data from large international cohorts and population-based biobanks offers unprecedented opportunities for long-awaited, well-powered genetic studies in IBS. This Review focuses on the latest advances that provide compelling evidence for the importance of genes involved in the digestion of carbohydrates, ion channel function, neurotransmitters and their receptors, neuronal pathways and the control of gut motility. These discoveries have generated novel information that might be further refined for the identification of predisposed individuals and selection of management strategies for patients. This Review presents a conceptual framework, the advantages and potential limitations of modern genetic research in IBS, and a summary of available evidence.

Updates in interaction of gastroesophageal reflux disease and extragastroesophageal digestive diseases

INTRODUCTION

Gastroesophageal reflux disease (GERD) is one of the common chronic diseases with prevalence increasing in the last decades. Because of its prevalence and chronicity, GERD affects the quality of life and increases health-care costs. Gastroesophageal diseases leading to GERD have been thoroughly studied, while extragastroesophageal digestive diseases (EGEDDs) may coexist with GERD and affect the occurrence and persistence of GERD symptoms and therapeutic effect.

AREAS COVERED

In this review, we aim to summarize the EGEDDs correlated with GERD and explore the potential mechanisms of this interaction.

EXPERT OPINION

Individuals with troublesome GERD symptoms may have some common gastroesophageal etiologies, but EGEDDs may also overlap and impact on the progression of GERD, which are often ignored in clinic. The lesions in the small intestine, colon, and hepatobiliary tract as well as functional bowel disorders had positive or negative associations with GERD through potential mechanisms. These diseases aggravate GERD symptoms, increase the esophageal acid burden, cause esophageal hypersensitivity, and finally affect the response to therapy in GERD patients. Therefore, it is necessary to clear the interaction between GERD and EGEDDs and their mechanisms.

Novel insights into the pathogenic impact of diabetes on the gastrointestinal tract

Type 2 and type 1 diabetes are common endocrine disorders with a progressively increasing incidence worldwide. These chronic, systemic diseases have multiorgan implications, and the whole gastrointestinal (GI) tract represents a frequent target in terms of symptom appearance and interdependent pathophysiological mechanisms. Metabolic alterations linked with diabetic complications, neuropathy and disrupted hormone homeostasis can lead to upper and/or lower GI symptoms in up to 75% of diabetic patients, with multifactorial involvement of the oesophagus, stomach, upper and lower intestine, and of the gallbladder. On the other hand, altered gastrointestinal motility and/or secretions are able to affect glucose and lipid homeostasis in the short and long term. Finally, diabetes has been linked with increased cancer risk at different levels of the GI tract. The presence of GI symptoms and a comprehensive assessment of GI function should be carefully considered in the management of diabetic patients to avoid further complications and to ameliorate the quality of life. Additionally, the presence of gastrointestinal dysfunction should be adequately managed to improve metabolic homeostasis, the efficacy of antidiabetic treatments and secondary prevention strategies.

Functional Abdominal Cramping Pain: Expert Practical Guidance

Functional abdominal cramping pain (FACP) is a common complaint, which may present either on its own or in association with a functional gastrointestinal disorder. It is likely caused by a variety of, probably partly unknown, etiologies. Effective management of FACP can be challenging owing to the lack of usable diagnostic tools and the availability of a diverse range of treatment approaches. Practical guidance for their selection and use is limited. The objective of this article is to present a working definition of FACP based on expert consensus, and to propose practical strategies for the diagnosis and management of this condition for physicians, pharmacists, and patients. A panel of experts on functional gastrointestinal disorders was convened to participate in workshop activities aimed at defining FACP and agreeing upon a recommended sequence of diagnostic criteria and management recommendations. The key principles forming the foundation of the definition of FACP and suggested management algorithms include the primacy of cramping pain as the distinguishing symptom; the importance of recognizing and acting upon alarm signals of potential structural disease; the recognition of known causes that might be addressed through lifestyle adjustment; and the central role of antispasmodics in the treatment of FACP. The proposed algorithm is intended to assist physicians in reaching a meaningful diagnostic endpoint based on patient-reported symptoms of FACP. We also discuss how this algorithm may be adapted for use by pharmacists and patients.

Effects of a Low-Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyol Diet on Symptoms of Functional Abdominal Pain in Pediatric Patients

PURPOSE

Recently, great interest has been focused on dietary fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) for the treatment of functional abdominal pain (FAP). Several meta-analyses, including those on the adult population, have been published, potentiating its role. However, pediatric studies are scarce. We aimed to evaluate the effect of a low-FODMAP diet on the severity of FAP in children.

METHODS

This clinical trial included 50 patients aged 3-18 years with irritable bowel syndrome and FAP that were not otherwise specified. The patients were instructed to receive a low FODMAP diet guided by a dietitian. The primary outcome was the percentage of responders after 2 months of dietary intervention compared with baseline. Other outcomes included changes in stool consistency and quality of life (QoL) scores using the KIDSCREEN-10 questionnaire, and weight-for-age z-scores.

RESULTS

After the dietary intervention, 74% of patients showed more than 30% lower pain intensity, as examined using the Wong-Baker Faces pain rating scale. Their QoL significantly improved, and patients have gained weight.

CONCLUSION

A low FODMAP diet can improve pain intensity and QoL among children with functional abdominal pain, with no detrimental effects on body weight.

Potential of natural products in the treatment of irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a kind of functional bowel disease that is characterized by bellyache, abdominal distension, and diarrhea. Although not life-threatening, IBS has a long course and recurrent attacks and seriously affects the life quality of patients. Current drugs for treating IBS possess remarkable limitations, such as limited efficacy and severe adverse reactions. Therefore, developing novel medications to treat IBS is quite essential, and natural products may be a substantial source.

PURPOSE

This is the first systematic review elaborating the recent advancement of natural products as potential drugs for the therapy of IBS.

METHODS

A comprehensive retrieval of studies was carried out in scientific databases including PubMed, Web of Science, Elsevier, and CNKI. By using ("irritable bowel syndrome" OR "IBS") AND ("natural product" OR "natural compound" OR "phytochemical") as keywords, the eligible studies were screened, and the relevant information about therapeutic action and mechanism of natural products treating IBS was extracted.

RESULTS

Natural products against IBS consisted of four categories, namely, terpenoids, flavonoids, alkaloids, and phenols. Furthermore, the underlying mechanisms for natural products treating IBS were tightly associated with increased TJs and mucus protein expression, regulation of the brain-gut axis and gut microbiota structure, and inhibition of inflammatory response and intestinal mucosal damage.

CONCLUSION

Natural products could be extremely prospective candidate drugs used to treat IBS, and further preclinical and clinical researches are needed to guarantee their efficacy and safety.

Diagnosis and management of irritable bowel syndrome-like symptoms in ulcerative colitis

Both ulcerative colitis (UC) and irritable bowel syndrome (IBS) are chronic gastrointestinal (GI) conditions that show some typical features. Persistent GI symptoms typical for IBS are observed in patients with diagnosed UC. Both IBS and UC are characterised by dysregulation of the enteric nervous system, alterations in the gut flora, low-grade mucosal inflammation, and activation of the brain-gut axis. Therefore, it appears that there may be some overlap between the two conditions. It is rather difficult to tell if the lower gastrointestinal symptoms are secondary to coexisting IBS or a hidden UC condition.

The Role of Short Chain Fatty Acids in Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder that is characterized by abdominal pain and disordered bowel habits. The etiology of IBS is multifactorial, including abnormal gut-brain interactions, visceral hypersensitivity, altered colon motility, and psychological factors. Recent studies have shown that the intestinal microbiota and its metabolites short chain fatty acids (SCFAs) may be involved in the pathogenesis of IBS. SCFAs play an important role in the pathophysiology of IBS. We discuss the underlying mechanisms of action of SCFAs in intestinal inflammation and immunity, intestinal barrier integrity, motility, and the microbiota-gut-brain axis. Limited to previous studies, further studies are required to investigate the mechanisms of action of SCFAs in IBS and provide more precise therapeutic strategies for IBS.

Infantile Colic and the Subsequent Development of the Irritable Bowel Syndrome

Background/Aims

Little is known about the association between infantile colic and the later onset of irritable bowel syndrome (IBS).

Methods

This study examined all 917 707 children who were born in Korea between 2007 and 2008. Infantile colic was defined with 1 or more diagnoses of ICD-10 code R10.4 or R68.1 at the age of 5 weeks to 4 months, and infants with a diagnosis of infantile colic and without were allocated into the infantile colic group and the control group. IBS was defined as 2 or more diagnoses of ICD-10 code K58.X after 4 years of age. Each child was traced until 2017. The risk of IBS with infantile colic was evaluated using a Cox proportional hazards model with propensity score inverse probability of treatment weighting (IPTW).

Results

After IPTW, 363 528 and 359 842 children were allocated to the control group and the infantile colic group, respectively. The infantile colic group had a higher risk of developing IBS in childhood (hazard ratio [95% CI], 1.12 [1.10 to 1.13]) than the control group. Moreover, the subgroup analyses according to the feeding status, birth weight, sex, or economic status, showed that the risk of IBS with former infantile colic remained statistically significant.

Conclusions

Children with a diagnosis of infantile colic during the infant period had a significant risk of developing IBS after 4 years of age. Understanding the pathogenesis of infantile colic in the neonatal period may reduce the prevalence and severity of functional gastrointestinal disorders from childhood to adolescence to adulthood.

Fecal microbiota transplantation in patients with post-infectious irritable bowel syndrome: A randomized, clinical trial

Introduction

Research in recent years has shown the potential benefits of fecal microbiota transplantation (FMT) for irritable bowel syndrome (IBS). Acute infectious gastroenteritis is a well-established risk factor for developing such forms of IBS as post-infectious IBS (PI-IBS). However, the effective use of FMT in patients with IP-IBS has not yet been clarified.

Aim

The study aimed to conduct a single-center, randomized clinical trial (RCT) to assess FMT’s safety, clinical and microbiological efficacy in patients with PI-IBS.

Materials and methods

Patients with PI-IBS were randomized into two groups: I (standard-care, n = 29) were prescribed basic therapy, namely a low FODMAP diet, as well as Otilonium Bromide (1 tablet TID) and a multi-strain probiotic (1 capsule BID) for 1 month; II (FMT group, n = 30), each patient with PI-IBS underwent a single FMT procedure with fresh material by colonoscopy. All patients underwent bacteriological examination of feces for quantitative and qualitative microbiota composition changes. The clinical efficacy of treatment was evaluated according to the dynamics of abdominal symptoms, measured using the IBS-SSS scale, fatigue reduction (FAS scale), and a change in the quality of life (IBS-QoL scale).

Results

FMT was associated with rapid onset of the effect, manifested in a significant difference between IBS-SSS points after 2 weeks of intervention (p < 0.001). In other time points (after 4 and 12 weeks) IBS-SSS did not differ significantly across both groups. Only after 3 months of treatment did their QoL exceed its initial level, as well value for 2 and 4 weeks, to a significant extent. The change in the ratio of the main microbial phenotypes in the form of an increase in the relative abundance of Firmicutes and Bacteroidetes was recorded in all patients after 4 weeks. It should be noted that these changes were significant but eventually normalized only in the group of PI-IBS patients who underwent FMT. No serious adverse reactions were noted.

Conclusion

This comparative study of the results of FMT use in patients with PI-IBS demonstrated its effectiveness compared to traditional pharmacotherapy, as well as a high degree of safety and good tolerability.

Two Gold Kiwifruit Daily for Effective Treatment of Constipation in Adults-A Randomized Clinical Trial

Chronic constipation is highly prevalent worldwide and may be managed with two green or three gold kiwifruit daily. It is unknown whether a smaller standard serve of gold kiwifruit (two daily) is as effective in constipation management. The study aimed to improve chronic constipation with two gold kiwifruit and psyllium in lieu of a placebo daily over four weeks. Adult participants (18-65 years) with functional constipation (FC, n = 11), constipation-predominant irritable bowel syndrome (IBS-C, n = 13), and healthy controls (n = 32) were block-randomized to the treatment order: gold kiwifruit (2/day) or psyllium (fiber-matched, 7.5 g/day) for four weeks, followed by four weeks washout before crossover. Outcomes included alterations of Gastrointestinal Symptom Rating Scale (GSRS) domains and weekly complete spontaneous bowel movements (CSBM) as part of a larger study. Both interventions reduced GSRS constipation domain scores in all subjects compared to baseline values (p = 0.004). All participants reported significantly more weekly CSBM (p = 0.014). Two gold kiwifruit decreased straining (p = 0.021). Two gold kiwifruit daily are as effective as fiber-matched psyllium in treating constipation in adults and should be considered as a treatment option.

Acupuncture vs. antispasmodics in the treatment of irritable bowel syndrome: An adjusted indirect treatment comparison meta-analysis

Background: Acupuncture has been extensively applied to manage irritable bowel syndrome (IBS) in clinical practice in China. Some randomized controlled trials (RCTs) have demonstrated their efficacy, but it has rarely been compared with first-line antispasmodics to verify their effectiveness. Therefore, we compare acupuncture with antispasmodics in the treatment of IBS by using an adjusted indirect treatment comparison meta-analysis.

Methods: Embase, OVID Medline, and the Cochrane Central Register of Controlled Trials databases were searched from inception to 14 March 2022, with no language restrictions. RCTs comparing antispasmodics or acupuncture with placebo or one of the antispasmodics were enrolled. The primary outcome of interest was the improvement of abdominal pain. And the secondary outcomes of interest were the relief of global IBS symptoms and adverse events. The random-effects model was utilized to pool data. The effect size was measured by standardized mean difference (SMD) or relative ratio, and the effectiveness of acupuncture and different antispasmodics were ranked by P-scores.

Results: Thirty-five RCTs (n = 5,190) were included. The analysis showed that cimetropium, drotaverine, acupuncture, and pinarverium were superior over placebo in relieving abdominal pain; cimetropium (SMD, −3.00 [95%CI, −4.47 to −1.53], P-score = 0.99) ranked the most effective. In pairwise comparisons, acupuncture had a greater improvement than most antispasmodics except cimetropium and drotaverine in relieving abdominal pain, although the between-group difference was statistically insignificant. In the analysis of continuous outcome in the relief of global IBS symptoms, the result showed that pinaverium was more effective (SMD, 1.72 [95%CI, 0.53 to 2.92], P-score = 0.90) than placebo. Trimebutine and acupuncture had greater improvements than placebo, but no significant difference was shown between groups. In pairwise comparisons, acupuncture was more effective than pinaverium (SMD, −1.11 [95%CI, −1.94 to −0.28]) in relieving global IBS symptoms. In the analysis of adverse events, acupuncture had a lower adverse event rate than most of the other antispasmodics.

Conclusion: Cimetropium, drotaverine, and acupuncture were all better than placebo in improving abdominal pain. Acupuncture was preferred over pinaverium in relieving global IBS symptoms, and acupuncture had lower adverse events than most antispasmodics.

Psychosocial and Sensory Factors Contribute to Self-Reported Pain and Quality of Life in Young Adults with Irritable Bowel Syndrome

AIMS

Psychosocial and sensory factors, including anxiety, depression, and pressure pain threshold have been used to cluster chronic symptoms in irritable bowel syndrome (IBS). This study examined the contribution of psychosocial sensory factors on pain interference and quality of life (QOL) in this population.

DESIGN

We performed a cross-sectional analysis of baseline data from a randomized controlled trial.

SETTINGS

Two gastrointestinal clinics, general communities, and two large campuses of a public university in the Northeastern United States.

PARTICIPANTS/SUBJECTS

Eighty young adults with IBS aged 21 ± 2.57 years (76.25% female).

METHODS

Demographic and psychosocial factors including anxiety, depression, fatigue, cognition or general concerns, sleep disturbance, self-efficacy, coping, and food intake were measured as independent variables. Quantitative sensory testing was conducted to measure mechanical, thermal, and pressure pain thresholds. Self-reported pain measured by the brief pain inventory (BPI) and IBS-QOL were assessed as the outcome variables. Regression analysis and mediation analysis were conducted to determine the associated factors of IBS pain and QOL.

RESULTS

Age, sex, and psychosocial factors including coping, self-efficacy, alcohol intake, mechanical pain sensitivity, and cold pain threshold were significantly associated with pain interference (all p < 0.05). Coping, and self-efficacy were significantly associated with IBS-QOL (all p < 0.05). In the mediation analysis, coping catastrophizing and self-efficacy were indirectly associated with IBS-QOL mediated by fatigue.

CONCLUSIONS

Psychosocial factors including coping and self-efficacy, and quantitative sensory testing factors significantly correlate with self-reported pain and QOL among young adults with IBS. This preliminary research calls for further interventional studies that target personalized psychosocial and quantitative sensory factors to improve pain management and quality of life in IBS patients.

Immune-mediated food reactions in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder characterized by recurrent abdominal pain and an altered defecation pattern. Depending on the criteria used, it affects between 5 and 10% of the general population and has a serious impact on quality of life. Most patients with IBS show an induction or exacerbation of their symptoms, particularly abdominal pain, after eating certain foods. This raises the question of the role played by food in IBS pathophysiology. In this review, we describe the multiple risk factors of IBS, and we give an overview of the role of food as a trigger of IBS, distinguishing between immune and non-immune reactions to food. We finally highlight recent findings identifying an immune-mediated mechanism underlying food-induced abdominal pain in IBS.

A Low FODMAP Diet Reduces Symptoms in Treated Celiac Patients With Ongoing Symptoms-A Randomized Controlled Trial

BACKGROUND & AIMS

A gluten-free diet usually leads to mucosal remission in celiac disease, but persistent symptoms are common. A low fermentable oligo-, di-, monosaccharides and polyols (FODMAP) diet is an established treatment for irritable bowel syndrome (IBS). We have assessed the efficacy of a moderately low FODMAP diet on persistent symptoms in treated celiac patients.

METHODS

A randomized controlled trial was performed from 2018 to 2019 in 70 adults with biopsy-proven celiac disease. Inclusion criteria were as follows: persistent gastrointestinal symptoms defined by a Gastrointestinal Symptom Rating Scale (GSRS)-IBS version score of 30 or higher, gluten-free diet adherence for 12 months or longer, and serologic and mucosal remission. Participants were randomized to a low FODMAP-gluten-free diet (intervention) or usual gluten-free diet (control). The GSRS-IBS score was recorded at baseline and at weeks 1 to 4, and the Celiac Symptom Index at baseline and at week 4. Statistics included marginal models for repeated data and analyses of covariance.

RESULTS

We included 34 participants in the intervention group and 36 in the control group. Time development of GSRS-IBS total scores differed significantly between the groups (P_interaction < .001), evident after 1 week (mean difference in intervention vs control, -8.2; 95% CI, -11.5 to -5.0) and persisting through week 4 (mean difference in intervention vs control, -10.8; 95% CI, -14.8 to -6.8). Moreover, significantly lower scores were found for the dimensions of pain, bloating, diarrhea, and satiety (P_interaction ≤ .04), but not constipation (P_interaction = .43). FODMAP intake during the intervention was moderately low (mean, 8.1 g/d; 95% CI, 6.7-9.3 g/d). The Celiac Symptom Index was significantly lower in the intervention group at week 4 (mean difference, -5.8; 95% CI, -9.6 to -2.0).

CONCLUSIONS

A short-term moderately low FODMAP diet significantly reduced gastrointestinal symptoms and increased celiac disease-specific health, and should be considered for the management of persistent symptoms in celiac disease.

CLINICALTRIALS

gov: NCT03678935.

Wenshen-Jianpi prescription, a Chinese herbal medicine, improves visceral hypersensitivity in a rat model of IBS-D by regulating the MEK/ERK signal pathway

The goal of the study was to analyze whether WJP can alleviate visceral hypersensitivity in IBS-D model rats. In this study, 36 Sprague–Dawley (SD) rats aged 4 weeks old were randomly divided into two groups: the model group (n = 27) and the control group (n = 9). The rat model of IBS-D was established by modified compound methods for 4 weeks. After the modification, IBS-D rats were randomly divided into three groups, namely, the IBS-D model group (n = 9), the positive drug group (n = 9), and the WJP group (n = 9), with different interventions, respectively. The control group was fed and allowed to drink water routinely. The Bristol stool scale scores were used to assess the severity of diarrhea. Abdominal withdrawal reflex (AWR) scores were used to assess visceral sensitivity. Expression of TNF-α was measured, and histopathological examinations were performed to assess colon inflammation in IBS-D model rats. Key factors of the MEK/ERK signal pathway in the tissue of the colon and hippocampus were measured to analyze the mechanism of WJP. Compared with the control group, the Bristol stool scale scores in the model group were significantly increased (p < 0.0001). The scores of the WJP group were significantly decreased compared with the model group (p = 0.0001). Compared with the control group, AWR scores in the model group at each pressure level were significantly increased (p = 0.0003, p < 0.0001, p = 0.0007, and p = 0.0009). AWR scores of the WJP group were significantly decreased compared with the model group (p = 0.0003, p = 0.0007, p = 0.0007, and p = 0.0009). Compared with the control group, the model group had significantly higher expression of TNF-α in the colon tissue (p < 0.0001). However, the WJP group had significantly lower level of TNF-α compared with the model group (p < 0.0001). Meanwhile, compared with the control group, the relative expression of the proteins of p-MEK1/2, p-ERK1, and p-ERK2 in the colon tissue was significantly increased in the model group (p < 0.0001). Compared with the model group, the relative expression of the proteins in the colon tissue were significantly decreased in the WJP group (p < 0.0001, p = 0.0019, and p = 0.0013). Compared with the control group, the relative expression of the proteins of p-MEK1/2, p-ERK1, and p-ERK2 in the hippocampus tissue were significantly increased in the model group (p < 0.0001). Compared with the model group, the relative expression of the proteins in the hippocampus tissue were significantly decreased in the WJP group (p = 0.0126, p = 0.0291, and p = 0.0145). The results indicated that WJP can alleviate visceral hypersensitivity in IBS-D model rats, possibly mediated by downregulating the expression of TNF-α, p-MEK1/2, p-ERK1, and p-ERK2 in the colon tissue. At the same time, WJP also affects downregulating the expression of p-MEK1/2, p-ERK1, and p-ERK2 in the hippocampus tissue.

Global trends in research on irritable bowel syndrome and the brain–gut axis: Bibliometrics and visualization analysis

Irritable bowel syndrome (IBS) is a gastrointestinal disorder with no structural damage, and its pathogenesis remains unclear. Studies have shown that the brain–gut axis is closely related to the occurrence of IBS. However, studies of IBS related to the brain–gut axis have not been systematically analyzed by bibliometrics and visual analysis. This study is based on 631 publications in the Web of Science Core Collection (WoSCC) to analyze hot spots and trends in this field. The collaborations between different authors, institutions, countries, and keywords were bibliometrically analyzed by CiteSpace software. Meanwhile, VOSviewer analyzed the references. The results show that since 2012, the number of publications has been growing rapidly. According to the collaborative network analysis, the United States, the National University of Ireland, Cork, and J.F. Cryan are the countries, institutions, and authors contributing the most, respectively. Through keywords and literature analysis, mechanisms and therapy associated with IBS and the brain–gut axis have still been a research focus in recent years. Furthermore, the physiological and pathological mechanisms of the brain–gut axis influencing IBS (related to gastrointestinal dysfunction, vagus nerve, visceral pain, intestinal flora, serotonin, tryptophan metabolism, stress, brain-derived neurotrophic factor (BDNF), and malonyldialdehyde) are the future research trends, especially the mechanisms related to intestinal flora. This is the first bibliometric and visualization analysis of IBS and brain–gut axis-related literature to explore research hotspots and trends.

Impact of Bile Acid Diarrhea in Patients With Diarrhea-Predominant Irritable Bowel Syndrome on Symptoms and Quality of Life

BACKGROUND & AIMS

Bile acid diarrhea (BAD) affects approximately a quarter of patients with irritable bowel syndrome with diarrhea (IBS-D). We aimed to compare the demographics, bowel and somatic symptoms, and quality of life of patients with IBS-D, with or without BAD.

METHODS

On one occasion, patients with IBS-D (positive for Rome III criteria) completed the following questionnaires: bowel disease questionnaire, Hospital Anxiety and Depression inventory, general quality of life (Symptom Checklist-90), and IBS-specific quality of life. A fasting serum C4 level higher than 52.5 ng/mL was used as a biomarker for BAD. Statistical analysis included a multiple variable logistic model to identify strong predictors of BAD in IBS-D.

RESULTS

Among 219 patients (79% female) with IBS-D, 44 had BAD; the BAD group was significantly older and had a higher body mass index than the patients without BAD. Patients with BAD had more severe bowel dysfunction and impact on IBS-specific quality of life (need of toilet proximity) compared with patients with IBS-D without BAD. Patients with BAD were more likely than other IBS-D groups to receive antidiarrheals, bile acid binders, and antacid secretory agents. The severity of diarrhea and need of toilet proximity were predictors of BAD in IBS-D (P < .01). Patients with BAD were more likely to have a depression score higher than 8 on the Hospital Anxiety and Depression inventory.

CONCLUSIONS

There is a greater impact on bowel and somatic symptoms and quality of life in IBS-D with BAD compared with IBS-D without BAD. Screening for BAD in IBS-D is especially relevant, with more severe and frequent diarrhea along with urgency.

Systematic review and meta-analysis: efficacy of peppermint oil in irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is one of the most common disorders of gut-brain interaction, with a complex pathophysiology. Antispasmodics are prescribed as first-line therapy because of their action on gut dysmotility. In this regard, peppermint oil also has antispasmodic properties.

AIM

To update our previous meta-analysis to assess efficacy and safety of peppermint oil, particularly as recent studies have cast doubt on its role in the treatment of IBS METHODS: We searched the medical literature up to 2nd April 2022 to identify randomised controlled trials (RCTs) of peppermint oil in IBS. Efficacy and safety were judged using dichotomous assessments of effect on global IBS symptoms or abdominal pain, and occurrence of any adverse event or of gastro-oesophageal reflux. Data were pooled using a random effects model, with efficacy and safety reported as pooled relative risks (RRs) with 95% confidence intervals (CIs).

RESULTS

We identified 10 eligible RCTs (1030 patients). Peppermint oil was more efficacious than placebo for global IBS symptoms (RR of not improving = 0.65; 95% CI 0.43-0.98, number needed to treat [NNT] = 4; 95% CI 2.5-71), and abdominal pain (RR of abdominal pain not improving = 0.76; 95% CI 0.62-0.93, NNT = 7; 95% CI 4-24). Adverse event rates were significantly higher with peppermint oil (RR of any adverse event = 1.57; 95% CI 1.04-2.37).

CONCLUSIONS

Peppermint oil was superior to placebo for the treatment of IBS, but adverse events were more frequent, and quality of evidence was very low. Adequately powered RCTs of peppermint oil as first-line treatment for IBS are needed.

Research Trends of Moxibustion Therapy for Pain Treatment Over the Past Decade: A Bibliometric Analysis

Background

Accumulate evidence indicated that moxibustion has a positive effect on pain treatment. However, the bibliometric analysis of moxibustion on pain remains uncertain. Herein, this study aimed to explore the current hotspots and the research trends over the past decade to bring a great panorama in this field.

Methods

Publications were retrieved from the database Web of Science Core Collection (WoSCC) related to moxibustion therapy for pain treatment from January 1, 2012, to December 31, 2021. CiteSpace and Excel were applied to analyze the volume of publications, journals, cited journals, dual-map analysis, countries, institutes, authors, references, and keywords with citation bursts.

Results

A total of 360 publications were retrieved from 2012 to 2021. The annual number of publications increased steadily with some fluctuations over the past 10 years. "The Evid Based Complement Alternat Med" and "the Gut" were the top-cited journals in frequency and centrality. China and Shanghai University of Traditional Chinese Medicine were the most prolific country and institutions, respectively. Among authors, Huangan Wu was the most active author with the highest cited frequency. Jun Xiong, Fanrong Liang and Guixing Xu held the articles with higher centrality. In the ranking of frequency and centrality in cited references, the top one was the article published by Shamseer L and Deng HY, respectively. "Acupuncture" was the keyword with the highest frequency. Pain disease (including rheumatoid arthritis, knee osteoarthritis, herpes zoster), research method (including randomized controlled trial), and risk (including quality of life, economic burden, physical and psychological problems) were the hotspots and frontier trends in this field.

Conclusion

This bibliometric study reveals the current status and research trend in the treatment of pain with moxibustion. The formulation with bibliometric analysis further elicits hot spots and frontier issues in this field.

Effect of acupuncture for diarrhea-predominant irritable bowel syndrome: study protocol for a randomized clinical trial

Background

Diarrhea-predominant irritable bowel syndrome (IBS-D) is the most common subtype of IBS. Acupuncture is commonly used to treat IBS-D, but its effect is uncertain because of the poor quality of prior studies. This trial aims to evaluate the efficacy and safety of acupuncture treatment for IBS-D through comparisons with sham acupuncture.

Methods/design

This is a large-scale, multi-center, randomized, two-arm interventional clinical trial. Participants will take part in a total of 20 weeks of study, which contained 3 phases: 2-week screening, 6-week treatment, and 12-week follow-up. Based on the composite response rate of the primary endpoint in our pilot study (a sham acupuncture response rate of 27% and a true acupuncture of approximately 45%), 280 randomly allocated participants were planned. Eligible participants will be randomly assigned to the true acupuncture group and sham acupuncture group according to a ratio of 1:1, and a total of 15 sessions of treatment overall 6-week treatment period will be brought. The primary endpoint is a composite response rate at week 6, and the responder is defined as who responses in both abdominal pain intensity and stool consistency. Furthermore, composite response rates at other weeks, IBS Symptom Severity Scale, IBS Quality of Life, Adequate Relief scale, and individual IBS symptoms (abdominal pain, bloating, stool frequency) are chosen as secondary endpoints.

Discussion

This trial may provide high-quality evidence for the efficacy and safety of acupuncture in the treatment of IBS-D. The results of this study will be published in peer-reviewed journals.

Trial registration

Chinese Clinical Trial Registry: ChiCTR2100044762. Registered on 26 March 2021.

Maintenance of Intestinal Homeostasis in Diarrhea-Predominant Irritable Bowel Syndrome by Electroacupuncture Through Submucosal Enteric Glial Cell-Derived S-Nitrosoglutathione

Objective: To determine whether electroacupuncture (EA) maintains intestinal homeostasis in diarrhea-predominant irritable bowel syndrome (IBS-D) rats by repairing intestinal barrier function through enteric glial cell (EGC)-derived S-nitrosoglutathione (GSNO).

Methods: Sprague–Dawley rats were randomly divided into a control group (n = 10) and an IBS-D group (n = 20). These rats received senna solution by gavage and chronic unpredictable mild stress for 14 days and were further divided into a model group (n = 10) and an EA group (n = 10). Rats in the EA group were electroacupunctured at ST25 (Tianshu), ST36 (Zusanli), and LR3 (Taichong) for 20 min every day for 14 days. The abdominal withdrawal reflex (AWR), the percentage of time spent in open arms (OT%) in the elevated plus maze test, and the diarrhea index (DI) were measured. Histopathological examination was performed to evaluate the pathological features of the colon after sacrificing the rats. Transmission electron microscopy was used to observe the EGC in the muscle and submucosal layers. Enzyme-linked immunosorbent assay was performed to detect GSNO expression in the colon. Double immunofluorescence labeling was used to detect the colocalized GFAP and GSNO expressions in the muscle and submucosal layers. Plasma FITC-dextran was used to measure intestinal permeability, whereas western blot was used to detect ZO-1 and occludin expressions in the colon.

Results: OT% and ZO-1 and occludin expressions were significantly lower than those of the control group, whereas AWR scores, DI, GSNO expression in the colon, colocalized GFAP and GSNO expressions in the submucosal layer, and intestinal permeability were significantly higher than those of the control group. Structural EGC abnormalities were observed in the model group. After EA treatment, OT% and ZO-1 and occludin expressions increased significantly, whereas AWR scores, DI, GSNO expression, colocalized GFAP and GSNO expressions in the submucosal layer, and intestinal permeability decreased significantly. The EGC structure was then restored to its normal state.

Conclusion: EA treatment downregulates the submucosal EGC–derived GSNO expressions, repairs the intestinal barrier by upregulating the ZO-1 and occludin expression, and improves IBS-D symptoms, including visceral hypersensitivity, anxiety, and diarrhea, suggesting a potential role for EGC-derived GSNO in the regulation of intestinal homeostasis in IBS-D rats.

Non-alcoholic fatty liver is associated with increased risk of irritable bowel syndrome: a prospective cohort study

BACKGROUND

The relationship between non-alcoholic fatty liver degree as well as non-alcoholic fatty liver disease (NAFLD) and irritable bowel syndrome (IBS) remains poorly understood. We aimed to investigate the prospective association of non-alcoholic fatty liver degree as well as NAFLD with incident IBS in a large-scale population-based cohort.

METHODS

Participants free of IBS, coeliac disease, inflammatory bowel disease, alcoholic liver disease, and any cancer at baseline from the UK Biobank were included. Non-alcoholic fatty liver degree was measured by a well-validated fatty liver index (FLI), with FLI ≥ 60 as an indicator of NAFLD. Primary outcome was incident IBS. Cox proportional hazard model was used to investigate the associated risk of incident IBS.

RESULTS

Among 396,838 participants (mean FLI was 48.29 ± 30.07), 153,203(38.6%) were with NAFLD diagnosis at baseline. During a median of 12.4-year follow-up, 7129 cases of incident IBS were identified. Compared with non-NAFLD, NAFLD patients showed a 13% higher risk of developing IBS (HR = 1.13, 95%CI: 1.05-1.17) after multivariable adjustment. Compared with the lowest, the highest FLI quartile was associated with a significantly increased risk of IBS (HR_{Q4 VS Q1} = 1.21, 1.13-1.30, P_trend < 0.001). Specifically, the positive association between non-alcoholic fatty liver degree and IBS was also observed by per SD change of FLI (adjusted HR = 1.08, 1.05-1.10). Further sensitivity analysis and subgroup analysis indicated similar results, with the positive association particularly observed in females, but not in males.

CONCLUSIONS

High degree of non-alcoholic fatty liver as well as non-alcoholic fatty liver disease is associated with increased risk of incident IBS. Further studies are warranted to confirm the findings and elucidate the underlying biological mechanisms.

Alleviating insomnia should decrease the risk of irritable bowel syndrome: Evidence from Mendelian randomization

Background: Associations have been reported between sleep and irritable bowel syndrome (IBS). However, whether there exists a causation between them is still unknown.

Methods: We employed the Mendelian randomization (MR) design to explore the causal relationship between sleep and IBS. All genetic associations with sleep-related traits reached genome-wide significance (p-value < 5 × 10-8). The genetic associations with IBS were obtained from two independent large genome-wide association studies (GWAS), where non-FinnGen GWAS was in the discovery stage and FinnGen GWAS was in the validation stage. Primarily, the inverse-variance weighted method was employed to estimate the causal effects, and a meta-analysis was performed to combine the MR estimates.

Results: In the discovery, we observed that genetic liability to the “morning” chronotype could lower the risk of IBS [OR = 0.81 (0.76, 0.86)]. Also, the genetic liability to insomnia can increase the risk of IBS [OR = 2.86 (1.94, 4.23)] and such causation was supported by short sleep duration. In the validation stage, only insomnia displayed statistical significance [OR = 2.22 (1.09, 4.51)]. The meta-analysis suggested two genetically-determined sleep exposures can increase the risk of IBS, including insomnia [OR = 2.70 (1.92, 3.80)] and short sleep duration [OR = 2.46 (1.25, 4.86)]. Furthermore, the multivariable MR analysis suggested insomnia is an independent risk factor for IBS after adjusting for chronotype [OR = 2.32 (1.57, 3.43)] and short sleep duration [OR = 1.45 (1.13, 1.85)]. IBS cannot increase the risk of insomnia in the reverse MR analysis.

Conclusion: Genetic susceptibility to insomnia can increase the risk of IBS, and improving sleep quality, especially targeting insomnia, can help to prevent IBS.