Functional Gut Disorders Research Articles

Exploring the Interconnections of Functional Gut Disorders and Inflammatory Bowel Disease: A Narrative Review Article.

This review reveals details of the interaction between disorders of gut-brain interaction (DGBI) and inflammatory bowel disease (IBD) by providing an in-depth review of that relationship. The review provides a nuanced understanding of this multifaceted dynamic by spanning shared symptomatology, the impact of inflammation on functional aspects, and addressing diagnostic challenges, psychological influences, treatment strategies, and emerging research directions. By synthesizing current knowledge and identifying gaps in understanding, this article aims to contribute to the evolving discourse surrounding the interplay between IBD and DGBI, offering valuable insights for clinicians, researchers, and healthcare professionals navigating the complexities of gastrointestinal health.

Concentrations of Plasma Amino Acids and Neurotransmitters in Participants with Functional Gut Disorders and Healthy Controls.

Amino acids are important in several biochemical pathways as precursors to neurotransmitters which impact biological processes previously linked to functional gastrointestinal disorders (FGIDs). Dietary protein consumption, metabolic host processes, and the gut microbiome can influence the plasma concentration of amino acids and neurotransmitters, and their uptake by tissues. The aim of this analysis was to quantify 19 proteogenic and 4 non-proteogenic amino acids and 19 neurotransmitters (including precursors and catabolites, herein referred to as neurotransmitters) to ascertain if their circulating concentrations differed between healthy participants and those with FGIDs. Plasma proteogenic and non-proteogenic amino acids and neurotransmitters were measured using ultra-performance liquid chromatography and liquid chromatography-mass spectrometry, respectively, from 165 participants (Rome IV: irritable bowel syndrome (IBS-constipation, IBS-diarrhea), functional constipation, functional diarrhea, and healthy controls). There were significant differences (p < 0.05) in pairwise comparisons between healthy controls and specific FGID groups for branched-chain amino acids (BCAAs), ornithine, and alpha-aminobutyric acid. No other significant differences were observed for the neurotransmitters or any other amino acids analyzed. Multivariate and bivariate correlation analyses between proteogenic and non-proteogenic amino acids and neurotransmitters for constipation (constipation (IBS-C and functional constipation) and phenotypes diarrhea (IBS-D and functional diarrhea)) and healthy controls suggested that associations between BCAAs, 5-hydroxytryptophan, and kynurenine in combination with tyrosine, 3,4-dihydroxyphenylalanine, and 3,4-dihydroxyphenylacetic acid and associations with gamma-aminobutyric acid, glutamate, asparagine, and serine are likely disrupted in FGID phenotypes. In conclusion, although correlations were evident between some proteogenic and non-proteogenic amino acids and neurotransmitters, the results showed minor concentration differences in plasma proteogenic and non-proteogenic amino acids, amino acid-derived metabolites, and neurotransmitters between FGID phenotypes and healthy controls.

Front Cover

Neurogastroenterology & MotilityVolume 35, Issue 2 e14541 COVER IMAGEFree Access Front Cover First published: 31 January 2023 https://doi.org/10.1111/nmo.14541AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract Front cover C2: The cover image is based on the Original Article Visible abdominal distension in functional gut disorders: Objective evaluation by Elizabeth Barba et al., https://doi.org/10.1111/nmo.14466. Volume35, Issue2February 2023e14541 RelatedInformation

Evaluation of abdominal gas by plain abdominal radiographs.

Our aim was to determine the reliability of plain abdominal radiographs for the evaluation of abdominal gas content in patients with functional digestive symptoms. Abdominal CT scan scout views, mimicking a conventional plain abdominal radiograph, were obtained from 30 patients both during episodes of abdominal distension and basal conditions. Physicians (n=50) were instructed to rate the estimated volume of gas in the 60 images presented in random sequence using a scale graded from 0 to ≥600 ml. The gas volumes estimated in the scout views differed from those measured by CT by a median of 90 (95% CI 70-102)ml, and the misestimation was not related to the absolute volume in the image. The accuracy of the observers, measured by their mean misestimation, was not related to their specialty or the training status (misestimation by 96 (95% CI 85-104)ml in staff vs 78 (70-106)ml in residents; p=0.297). The accuracy was independent of the order of presentation of the images. Gas volume measured by CT in the images obtained during episodes of abdominal distension differed by a median of 39 (95% CI 29-66)ml from those during basal conditions, and this difference was misestimated by a median of 107 (95% CI 94-119)ml. The accuracy of these estimations was not related to the absolute gas volumes (R=-0.352; p < 0.001) or the magnitude of the differences. Plain abdominal radiographs have limited value for the evaluation of abdominal gas volume in patients with functional gut disorders.

Visible abdominal distension in functional gut disorders: Objective evaluation.

Visible abdominal distension has been attributed to: (A) distorted perception, (B) intestinal gas accumulation, or (C) abdominophrenic dyssynergia (diaphragmatic push and anterior wall relaxation). A pool of consecutive patients with functional gut disorders and visible abdominal distension included in previous studies (n= 139) was analyzed. Patients (61 functional bloating, 74 constipation-predominant irritable bowel syndrome and 4 with alternating bowel habit) were evaluated twice, under basal conditions and during a self-reported episode of visible abdominal distension; static abdominal CT images were taken in 104 patients, and dynamic EMG recordings of the abdominal walls in 76, with diaphragmatic activity valid for analysis in 35. (A) Objective evidence of abdominal distension was obtained by tape measure (increase in girth in 138 of 139 patients), by CT imaging (increased abdominal perimeter in 96 of 104 patients) and by abdominal EMG (reduced activity, i.e., relaxation, in 73 of 76 patients). (B) Intestinal gas volume was within ±300 ml from the basal value in 99 patients, and above in 5 patients, who nevertheless exhibited a diaphragmatic descent. (C) Diaphragmatic contraction was detected in 34 of 35 patients by EMG (increased activity) and in 82 of 103 patients by CT (diaphragmatic descent). In most patients complaining of episodes of visible abdominal distention: (A) the subjective claim is substantiated by objective evidence; (B) an increase in intestinal gas does not justify visible abdominal distention; (C) abdominophrenic dyssynergia is consistently evidenced by dynamic EMG recording, but static CT imaging has less sensitivity.

Hidden role of gut microbiome in mental health

IntroductionThe recent literature indicates that the gut microbiota may affect brain functions through endocrine and metabolic pathways, antibody production and the enteric network while supporting its possible role in the onset and maintenance of several neuropsychiatric disorders, neurodevelopment and neurodegenerative disorders.ObjectivesThe aim of this work is to discuss the role of probiotics, prebiotics, or synbiotics as a potential treatment for symptoms of depression, anxiety, and stress.MethodsPub Med database was searched using following key words: “probiotics”, “prebiotics”, “mental disorders”, “psychological disorders”.ResultsAlthough the exact mechanism is unknown, there is a link between the gut and mood disorders. Psychosocial factors, such as quality of life or well-being, are greatly influenced by gut function and there is a strong correlation between psychosocial features and gastrointestinal disorders. Elevated stress, anxiety, and depression are linked to intestinal dysbiosis and mood disorders are disproportionately high in patients with functional gut disorders. So, psychobiotics may provide benefit when used in conjunction with current antidepressant medications. Probiotics may exert their therapeutic benefits by restoring microbial balance in the gut, and also by minimizing gastrointestinal complaints, allowing for the effects of antidepressant medication to not be reduced. Stress and immune responses were improved following psychobiotic intervention in stressed adults. Psychobiotics offer potential alternative treatment options in mood disorders and their accompanying symptoms.ConclusionsPro and prebiotics can improve mental health and psychological function and can be offered as new medicines for common mental disorders. However, more clinical studies are required to support the clinical use of probiotics.DisclosureNo significant relationships.

Magnetic resonance imaging assessed enteric motility and luminal content analysis in patients with severe bloating and visible distension.

Gastrointestinal symptoms in functional gut disorders occur without any discernible structural gut abnormality. Preliminary observations on enteric MRI suggest possible abnormal content and motility of the terminal ileum (TI) in constipation-predominant IBS (IBS-C) with severe bloating, and in functional bloating and distension (FABD) patients. We investigated whether MRI can quantify differences in small bowel (SB) content and motility between patients and healthy controls (HCs). 11 IBS-C (mean age 40 [21-52] years; 10 women) and 7 FABD (36 [21-56]; all women) patients with bloating and 20 HCs (28 [22-48]; 6 women) underwent enteric MRI, including dynamic motility and anatomical sequences. Three texture analysis (TA) parameters assessed the homogeneity of the luminal content, with ratios calculated between the TI and (1) the SB and (2) the ascending colon. Four TI motility metrics were derived. Ascending colon diameter (ACD) was measured. A comparison between HCs and patients was performed independently for: (1) three TA parameters, (2) four TI motility metrics, and (3) ACD. Compared with HCs, patients had TI:colon ratios higher for TA contrast (p<0.001), decreased TI motility (lower mean motility [p=0.04], spatial motility variation [p=0.03], and area of motile TI [p=0.03]), and increased ACD (p=0.001). IBS-C and FABD patients show reduced TI motility and differences in luminal content compared with HCs. This potentially indicates reflux of colonic contents or delayed clearance of the TI, which alongside increased ACD may contribute to symptoms of constipation and bloating.

Probiotics for treatment of chronic constipation in children.

Probiotics for treatment of chronic constipation in children.

Montelukast suppresses the development of irritable bowel syndrome phenotype possibly through modulating NF-κB signaling in an experimental model.

Irritable bowel syndrome (IBS) is a functionalgut disorder with multi-factorial pathophysiology that causes recurring pain or discomfort in the abdomen, as well as altered bowel habits. Montelukast, a well-known cysteinyl leukotriene receptor 1 (CysLT1R) antagonist, is widely used for the anti-inflammatory management of asthma. The present study aimed to evaluate the effects of pharmacological inhibition of CysLT1R on acetic acid-induced diarrhea-predominant IBS (D-IBS) in rats. Behavioral pain responses to noxious mechanical stimulation were decreased in the montelukast-treated rats as compared to the model animals following colorectal distension (CRD)-induced visceral hypersensitivity. Stool frequency decreased dose-dependently by montelukast in IBS rats exposed to restraint stress. A significantly shorter immobility time was also observed in IBS rats who received montelukast vs IBS group in the forced swimming test (depression-like behavior). Furthermore, there were significant decreases in the NF-κB protein expression, inflammatory cytokine (TNF-α, and IL-1ß) levels, and histopathological inflammatory injuries concomitant with increased anti-inflammatory cytokine, IL-10, in montelukast-treated rats compared with the IBS group. Cysteinyl leukotriene production and CysLT1R mRNA expression showed no remarkable differences among the experimental groups. The present results suggest the possible beneficial effects of montelukast in the management of D-IBS symptoms. The molecular mechanismunderlying such effects, at least to some extent, might be through modulating CysLT1R-mediated NF-κB signaling. Yet, more studies are required to demonstrate the clinical potential of this drug for IBS therapy.

Intestinal ultrasound as first-line investigation in low-risk gastrointestinal symptoms: a new model of care.

Functional gut disorders (FGD) are common. Diagnosis is symptom based, although symptoms may be indistinguishable from inflammatory bowel disease. As a result of this, investigations are common, diagnostic yield is low. A streamlined novel model of care may reduce costly investigations. To compare a new model of care for patients with low-risk gastrointestinal symptoms to a matched historical cohort. Data were prospectively collected over 12 months. General practitioner referrals for low-risk abdominal symptoms were triaged to a new multidisciplinary clinic structure utilising intestinal ultrasound. Outcomes were compared to the historical model in the preceding 12 months. Duration of care (time from referral to discharge), number of contact episodes and investigations ordered were reviewed. Thirty-seven patients meeting strict inclusion criteria completed their care. Compared with the historical cohort, colonoscopies reduced from 0.7 to 0.05 per patient (P < 0.0001). Gastroenterology consults reduced from 1.5 to 1.2 (P = 0.303) and dietitian review increased from 0.8 to 1.5 (P < 0.0001). Total contact episodes reduced from 3.2 to 1.8 (P < 0.0001). Duration of care reduced from a median of 252 days to 130 days (interquartile ranges (IQR) 287 and 69, respectively; P < 0.0001). Time from first consultation to discharge reduced from 125 to 42 days (IQR 188 and 63; P < 0.0001). This multidisciplinary approach to care of low-risk abdominal symptoms significantly reduced contact episodes, time in care and invasive investigations. It decreased costly gastroenterology consultation and increased allied health exposure. It demonstrates improved health service outcomes.

An update on fecal microbiota transplantation for the treatment of gastrointestinal diseases.

Our understanding of the microbiome and its implications for human health and disease continues to develop. Fecal microbiota transplantation (FMT) is now an established treatment for recurrent Clostridioides difficile infection. There is also increasing evidence for the efficacy of FMT in inducing remission for mild-moderate ulcerative colitis. However, for other indications, data for FMT are limited, with randomized controlled trials rare, typically small and often conflicting. Studies are continuing to explore the role of FMT for many other conditions, including Crohn's disease, functional gut disorders, metabolic syndrome, modulating responses to chemotherapy, eradication of multidrug resistant organisms, and the gut-brain axis. In light of safety, logistical, and regulatory challenges, there is a move to standardized products including narrow spectrum consortia. However, the mechanisms underpinning FMT remain incompletely understood, including the role of non-bacterial components, which may limit success of novel microbial approaches.

Concentrations of Fecal Bile Acids in Participants with Functional Gut Disorders and Healthy Controls.

Bile acids are metabolites involved in nutrient absorption and signaling with levels influenced by dietary intake, metabolic processes, and the gut microbiome. We aimed to quantify 23 bile acids in fecal samples to ascertain if concentrations differed between healthy participants and those with functional gut disorders. Fecal bile acids were measured using liquid chromatography-mass spectrometry (LC-MS) in the COMFORT (The Christchurch IBS cohort to investigate mechanisms for gut relief and improved transit) cohort of 250 participants with Rome IV IBS (IBS-constipation (C), IBS-diarrhea (D), IBS-mixed (M)), functional gut disorders (functional constipation (FC), functional diarrhea (FD)) and healthy controls (FC n = 35, FD n = 13, IBS-C n = 24, IBS-D n = 52, IBS-M n = 29, and control n = 97). Dietary information was recorded to ascertain three-day dietary intake before fecal samples were collected. Fecal bile acid concentrations, predominantly primary bile acids, were significantly different between all functional gut disorder participants and healthy controls (CDCA p = 0.011, CA p = 0.003) and between constipation (FC + IBS-C) and diarrhea (FD + IBS-D) groups (CDCA p = 0.001, CA p = 0.0002). Comparison of bile acids between all functional groups showed four metabolites were significantly different, although analysis of combined groups (FC + IBS-C vs. FD + IBS-D) showed that 10 metabolites were significantly different. The bile acid profiles of FD individuals were similar to those with IBS-D, and likewise, those with FC were similar to IBS-C. Individuals with a diarrhea phenotype (FD + IBS-D) had higher concentrations of bile acids compared to those with constipation (FC + IBS-C). Bile acid metabolites distinguish between individuals with functional gut disorders and healthy controls but are similar in constipation (or diarrhea) whether classified as IBS or not.

Does pain sensitivity correlate with gastrointestinal symptoms in runners? An observational survey study.

Heightened pain sensitivity is common in functional gut disorders, but no research has examined whether it corresponds to exercise-associated gastrointestinal (GI) symptoms. We sought to explore whether scores on a questionnaire of pain sensitivity would correlate with GI symptoms during running. This is a cross-sectional study. The study involves 290 (137 male, 153 female) distance runners. Runners completed a survey inquiring about demographic, anthropometric and training information and rated GI symptoms at rest and during runs. In addition, the Pain Sensitivity Questionnaire (PSQ) was used to quantify pain sensitivity across all items (PSQ-Total) and on items typically rated as minor (PSQ-Minor). Spearman rho correlations were utilized to assess the associations between pain sensitivity and GI symptoms. Partial correlations were used to evaluate the associations after controlling for age, gender, running experience, body mass index and sleep problems. PSQ scores weakly correlated with several GI symptoms at rest (rho = 0.13-0.20; p < 0.05), which remained largely intact in partial correlation analyses (partial rho = 0.12-0.18). PSQ scores weakly correlated with fullness, bloating and gas during runs (rho = 0.12-0.18; p < 0.05); fullness and bloating remained significant in the partial correlation analyses (partial rho = 0.12-0.15). These results were relatively consistent for both the PSQ-Total and PSQ-Minor. Although PSQ scores only weakly correlate with certain GI symptoms among runners, the effect sizes are similar to that of other predictors of GI distress. These results suggest a minor possible role of pain sensitivity in the development of certain GI symptoms in runners.

Irritable Bowel Syndrome: Prevalence and Risk Factors in Jazan Region, Saudi Arabia.

BackgroundThe prevalence of irritable bowel syndrome (IBS) worldwide remains heterogeneous. In Saudi Arabia, there are insufficient studies on the prevalence of IBS among the general population, yet the prevalence of IBS in certain professional groups has been reported. This study was conducted to determine the prevalence of IBS and its associated risk factors in the Jazan Region of Saudi Arabia.MethodsAn online cross-sectional study was conducted from January to March 2020 in the Jazan Region of Saudi Arabia, using a multi-stage stratified sampling technique. The data were collected using a web-based validated Rome IV questionnaire. The Rome IV criteria are used to diagnose functional gut disorders, including IBS. Logistic regression analysis was used to determine the odds ratio (OR) with 95% confidence intervals (95% CI) for the selected risk factors.ResultsThe survey included 1554 participants with an overall IBS prevalence of 16%. Women had a higher incidence of IBS than men (55.3% and 44.7%, respectively). IBS-mixed (32.66%) and constipation-predominant (32.25%) were the most common subtypes. In multiple regression analysis, female gender (OR = 1.503, p-value = 0.037), stress (OR = 2.386, p-value = 0.000), anxiety (OR = 1.943, p-value = 0.000), and tobacco smoking (OR = 2.093, p-value = 0.001) showed a statistically significant association with IBS.ConclusionsThe prevalence of IBS in the southwest region of Saudi Arabia is high. Female sex, tobacco smoking, stress, and anxiety are the major risk factors associated with IBS.

Cannabis in Gastroenterology: Watch Your Head! A Review of Use in Inflammatory Bowel Disease, Functional Gut Disorders, and Gut-Related Adverse Effects.

Purpose of reviewTo review recent clinical evidence surrounding the use of cannabinoids and cannabis in gastrointestinal diseases, particularly inflammatory bowel disease (IBD) and functional gut disorders. A second aim is to evaluate the current status of gastrointestinal related adverse effects which have been linked to cannabis use, specifically cannabis hyperemesis syndrome (CHS) and acute pancreatitis.Recent findingsObservational and prospective studies suggest that cannabinoids improve IBD symptoms. Small prospective clinical trials have not shown any effects on objective inflammatory findings, other than one recent paper in ulcerative colitis, in abstract form only, which suggests endoscopic improvement. Short duration mechanistic studies in functional gut disorders suggest cannabinoids may attenuate gastric emptying and slow colonic motility but appear to have less effect on sensory thresholds in the gut.SummaryIn general, while mostly uncontrolled data suggests cannabis may improve symptoms in IBD (and to a lesser degree functional gut disorders), this is not likely due to any substantial anti-inflammatory effect. Much remains unknown about CHS etiology and complete abstinence from cannabinoids remains the generally accepted treatment strategy. Population-based studies do not suggest that cannabis use is related to acute pancreatitis. Further research is certainly warranted.

Primary care faecal calprotectin testing in children with suspected inflammatory bowel disease: a diagnostic accuracy study

ObjectiveTo determine the diagnostic accuracy of calprotectin to diagnose inflammatory bowel disease (IBD) in children in whom general practitioners (GPs) suspected IBD.DesignProspective observational cohort study of a new calprotectin-based primary...

Prebiotics and Community Composition Influence Gas Production of the Human Gut Microbiota.

Prebiotics confer benefits to human health, often by promoting the growth of gut bacteria that produce metabolites valuable to the human body, such as short-chain fatty acids (SCFAs). While prebiotic selection has strongly focused on maximizing the production of SCFAs, less attention has been paid to gases, a by-product of SCFA production that also has physiological effects on the human body. Here, we investigate how the content and volume of gas production by human gut microbiota are affected by the chemical composition of the prebiotic and the community composition of the microbiota. We first constructed a linear system model based on mass and electron balance and compared the theoretical product ranges of two prebiotics, inulin and pectin. Modeling shows that pectin is more restricted in product space, with less potential for H2 but more potential for CO2 production. An ex vivo experimental system showed pectin degradation produced significantly less H2 than inulin, but CO2 production fell outside the theoretical product range, suggesting fermentation of fecal debris. Microbial community composition also impacted results: methane production was dependent on the presence of Methanobacteria, while interindividual differences in H2 production during inulin degradation were driven by a Lachnospiraceae taxon. Overall, these results suggest that both the chemistry of the prebiotic and the composition of the microbiota are relevant to gas production. Metabolic processes that are relatively prevalent in the microbiome, such as H2 production, will depend more on substrate, while rare metabolisms such as methanogenesis depend more strongly on microbiome composition.IMPORTANCE Prebiotic fermentation in the gut often leads to the coproduction of short-chain fatty acids (SCFAs) and gases. While excess gas production can be a potential problem for those with functional gut disorders, gas production is rarely considered during prebiotic design. In this study, we combined the use of theoretical models and an ex vivo experimental platform to illustrate that both the chemical composition of the prebiotic and the community composition of the human gut microbiota can affect the volume and content of gas production during prebiotic fermentation. Specifically, more prevalent metabolic processes such as hydrogen production were strongly affected by the oxidation state of the probiotic, while rare metabolisms such as methane production were less affected by the chemical nature of the substrate and entirely dependent on the presence of Methanobacteria in the microbiota.

Responses to gastric gas in patients with functional gastrointestinal disorders.

Gas-related abdominal symptoms are common in patients with functional gut disorders, but the responses to cope with the large volumes of gas that enter daily into the stomach have not been studied in detail. Our aim was to evaluate transit and tolerance of gastric gas in patients with functional gastrointestinal disorders. In eight healthy volunteers and 24 patients with functional gut disorders (eight functional dyspepsia, eight belching disorder, and eight functional bloating) 1500ml of a gas mixture were infused into the stomach at 25ml/min. Belching, rectal gas evacuation, and abdominal perception were continuously recorded for 90minutes. Healthy subjects expelled the infused gas per rectum (1614±73ml), with a small rise in epigastric perception (score increment 1.0±0.4) and virtually no belching (1±1 belches). Patients with functional dyspepsia had a hypersensitive response to gastric gas, with a significant rise in epigastric perception (score increment 2.5±0.6; P=.045), a transient delay in rectal gas evacuation and similar belching as healthy controls. Patients with belching disorders responded to gastric gas with continuous belches (33±13 belches; P=.002), low epigastric perception, and a small reduction in rectal gas evacuation. Patients with functional bloating exhibited a slow transit response, with reduced rectal gas evacuation (1017±145ml; P=.002) and abdominal symptoms (score increment 2.5±0.7), but without compensatory belching. Different pathophysiological mechanisms underlay specific adaptive responses to gastric gas in patients with different functional gut disorders. Therapeutic interventions for gas-related abdominal symptoms should be addressed towards these specific pathophysiological disturbances.

Gut Microbial Metabolites and Biochemical Pathways Involved in Irritable Bowel Syndrome: Effects of Diet and Nutrition on the Microbiome

ABSTRACTThe food we consume and its interactions with the host and their gut microbiota affect normal gut function and health. Functional gut disorders (FGDs), including irritable bowel syndrome (IBS), can result from negative effects of these interactions, leading to a reduced quality of life. Certain foods exacerbate or reduce the severity and prevalence of FGD symptoms. IBS can be used as a model of perturbation from normal gut function with which to study the impact of foods and diets on the severity and symptoms of FGDs and understand how critical processes and biochemical mechanisms contribute to this impact. Analyzing the complex interactions between food, host, and microbial metabolites gives insights into the pathways and processes occurring in the gut which contribute to FGDs. The following review is a critical discussion of the literature regarding metabolic pathways and dietary interventions relevant to FGDs. Many metabolites, for example bile acids, SCFAs, vitamins, amino acids, and neurotransmitters, can be altered by dietary intake, and could be valuable for identifying perturbations in metabolic pathways that distinguish a “normal, healthy” gut from a “dysfunctional, unhealthy” gut. Dietary interventions for reducing symptoms of FGDs are becoming more prevalent, but studies investigating the underlying mechanisms linked to host, microbiome, and metabolite interactions are less common. Therefore, we aim to evaluate the recent literature to assist with further progression of research in this field.

A systematic review of the association between fibromyalgia and functional gastrointestinal disorders.

Background:Fibromyalgia and functional gastrointestinal disorders (FGID) including irritable bowel syndrome (IBS) are common conditions presenting in clinical settings and are more prevalent in women. While the relationship between IBS and fibromyalgia has been demonstrated, a review of the prevalence of the broader group of FGID in adults with fibromyalgia has not been undertaken. The aim of this review was to systematically review the published literature, identifying the comorbidity of FGID in people with fibromyalgia, and to discuss the clinical implications, limitations of current research and areas of interest for future researchMethods:Medline, Embase, CINAHL and Web of Science were searched during June 2019. Results were screened for original research articles meeting established criteria for identification of FGID in adults diagnosed with fibromyalgia.Results:A total of 14 studies involving 1340 adults with fibromyalgia, 363 healthy controls and 441 adults with other pathologies were included in this review. Only 1 of the 14 studies included surveyed the full range of FGID . Functional gut disorders were matched to Rome II criteria for reporting and comparison. In addition to increased abdominal pain and functional bloating or gas, IBS of mixed-pattern and constipation-types appear to be more prevalent than diarrhoea-predominant IBS in adults with fibromyalgia.Conclusion:This review confirms previous reports that IBS is common in people living with fibromyalgia and suggests that IBS-mixed and constipation types predominate. An association with a range of FGID other than IBS is suggested, but data are limited. Research exploring the association between fibromyalgia and functional gastrointestinal dysfunction beyond IBS are warranted.