Efficacy of Probiotics in Irritable Bowel Syndrome: Systematic Review and Meta-analysis.

BACKGROUND & AIMS: Some probiotics may be beneficial in irritable bowel syndrome (IBS), but differences in species and strains used, as well as endpoints reported, have hampered attempts to make specific recommendations as to which should be preferred. We updated our previous meta-analysis examining this issue. METHODS: MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched (up to March 2023). Randomized controlled trials (RCTs) recruiting adults with IBS, comparing probiotics with placebo were eligible. Dichotomous symptom data were pooled to obtain a relative risk of global symptoms, abdominal pain, or abdominal bloating or distension persisting after therapy, with a 95% confidence interval (CI). Continuous data were pooled using a standardized mean difference with a 95% CI. Adverse events data were also pooled. RESULTS: We identified 82 eligible trials, containing 10,332 patients. Only 24 RCTs were at low risk of bias across all domains. For global symptoms, there was moderate certainty in the evidence for a benefit of Escherichia strains, low certainty for Lactobacillus strains and Lactobacillus plantarum 299V, and very low certainty for combination probiotics, LacClean Gold S, Duolac 7s, and Bacillus strains. For abdominal pain, there was low certainty in the evidence for a benefit of Saccharomyces cerevisae I-3856 and Bifidobacterium strains, and very low certainty for combination probiotics, Lactobacillus, Saccharomyces, and Bacillus strains. For abdominal bloating or distension there was very low certainty in the evidence for a benefit of combination probiotics and Bacillus strains. The relative risk of experiencing any adverse event, in 55 trials, including more than 7000 patients, was not significantly higher with probiotics. CONCLUSIONS: Some combinations of probiotics or strains may be beneficial in IBS. However, certainty in the evidence for efficacy by GRADE criteria was low to very low across almost all of our analyses.

Randomized Placebo-Controlled Phase 3 Trial of Vibrating Capsule for Chronic Constipation.

BACKGROUND & AIMS: Despite therapeutic advances, effective treatments for chronic constipation remain an unmet need. The vibrating capsule is a nonpharmacologic, orally ingested, programmable capsule that vibrates intraluminally to induce bowel movements. We aimed to determine the efficacy and safety of the vibrating capsule in patients with chronic constipation. METHODS: We conducted a phase 3, double-blind, placebo-controlled trial of patients with chronic constipation, who were randomized to receive either a vibrating or placebo capsule, once daily, 5 days a week for 8 weeks. The primary efficacy end points were an increase of 1 or more complete spontaneous bowel movements per week (CSBM1 responder) or 2 or more CSBMs per week (CSBM2) from baseline during at least 6 of the 8 weeks. Safety analyses were performed. RESULTS: Among 904 patients screened, 312 were enrolled. A greater percentage of patients receiving the vibrating capsule achieved both primary efficacy end points compared with placebo (39.3% vs 22.1%, P = .001 for CSBM1; 22.7% vs 11.4% P = .008 for CSBM2). Significantly greater improvements were seen with the vibrating capsule for the secondary end points of straining, stool consistency, and quality-of-life measures compared with placebo. Adverse events were mild, gastrointestinal in nature, and similar between groups, except that a mild vibrating sensation was reported by 11% of patients in the vibrating capsule group, but none withdrew from the trial. CONCLUSIONS: In patients with chronic constipation, the vibrating capsule was superior to placebo in improving bowel symptoms and quality of life. The vibrating capsule was safe and well tolerated. (Clinical trials.gov, Number: NCT03879239).

Small Intestinal Bacterial Overgrowth-Pathophysiology and Its Implications for Definition and Management.

The concept of small intestinal bacterial overgrowth (SIBO) arose in the context of maldigestion and malabsorption among patients with obvious risk factors that permitted the small bowel to be colonized by potentially injurious colonic microbiota. Such colonization resulted in clinical signs, symptoms, and laboratory abnormalities that were explicable within a coherent pathophysiological framework. Coincident with advances in medical science, diagnostic testing evolved from small bowel culture to breath tests and on to next-generation, culture-independent microbial analytics. The advent and ready availability of breath tests generated a dramatic expansion in both the rate of diagnosis of SIBO and the range of associated gastrointestinal and nongastrointestinal clinical scenarios. However, issues with the specificity of these same breath tests have clouded their interpretation and aroused some skepticism regarding the role of SIBO in this expanded clinical repertoire. Furthermore, the pathophysiological plausibility that underpins SIBO as a cause of maldigestion/malabsorption is lacking in regard to its purported role in irritable bowel syndrome, for example. One hopes that the application of an ever-expanding armamentarium of modern molecular microbiology to the human small intestinal microbiome in both health and disease will ultimately resolve this impasse and provide an objective basis for the diagnosis of SIBO.

Probiotics in irritable bowel syndrome and inflammatory bowel disease: review of mechanisms and effectiveness.

PURPOSE OF REVIEW: The gastrointestinal (GI) microbiome has been implicated in the pathogenesis of inflammatory bowel disease (IBD) and has been linked with irritable bowel syndrome (IBS). The aim of this article is to critically review the emerging evidence for the mechanisms and effectiveness of probiotics in the management of these conditions. RECENT FINDINGS: The GI microbiome is strongly influenced by ageing, diet and disease. Probiotics may confer health effects to the host by modulating the metabolic activities of the microbiome to propagate anti-inflammatory effects and reinforce the intestinal barrier, and are considered to be safe to use. Many short-term studies have demonstrated the effectiveness of probiotics overall in IBS, with meta-analyses demonstrating efficacy across specific strains albeit with relatively small effect sizes. Within IBD, some probiotics appear to offer clinical benefit in ulcerative colitis but strain-specific effects are unclear. Evidence for the use of probiotics in Crohn's disease remains limited. SUMMARY: Probiotics offer considerable potential for the management of IBS and possibly in IBD, however, any benefits conferred appear to be strain-specific. High quality trials of specific probiotics in IBS and IBD, as well as laboratory investigations of their mechanism of action, are required in order to fully understand their potential therapeutic value.

Constipation in Parkinson's Disease.

Constipation is one of the most common gastrointestinal features of Parkinson's disease (PD), occurring in over 50% of all PD patients during the course of their disease. Furthermore, constipation is now recognized as an important, prodromal symptom and may predate the onset of the classical motor symptoms by decades. Thereafter, the prevalence and severity of constipation in PD tend to parallel the course of both motor and nonmotor phenomena such as cognitive decline and depression. Difficult defecation (obstructed defecation, dyssynergia) is the primary pathophysiology underlying constipation and likely reflects involvement by the PD process of one or more of the many skeletal muscle groups that are involved in effecting defecation. Management of constipation in PD may be complicated by several patient factors including dysphagia, cognitive impairment, depression, and weak sphincter tone. While the armamentarium available to those who treat constipation, in general, has expanded considerably in recent years, the evidence supporting any therapy in the management of this symptom in PD has remained slim.

Irritable Bowel Syndrome Symptoms in Nonalcoholic Fatty Liver Disease Patients Are an Indicator of Depression and Anxiety.

GOALS: Determine factors associated with Irritable bowel syndrome (IBS) in nonalcoholic fatty liver disease (NAFLD) patients. BACKGROUND: IBS affects 10% to 15% of the adult population worldwide and is linked to anxiety and depression. The impact of IBS-type symptoms in NAFLD patients is not well described. STUDY: A cross-sectional study of patients in the hepatology clinic at Houston Methodist Hospital was performed based on a respondent postal survey. IBS was defined by the Rome IV questionnaire, anxiety and depression were assessed with the Hospital Anxiety Depression scale. Patients with inflammatory bowel disease, colorectal carcinoma, or small bowel tumors were excluded. Patients were divided based on Rome IV diagnostic criteria for IBS and Hospital Anxiety Depression scale. RESULTS: 130 patients were included in the analysis, 38 satisfied Rome IV criteria for IBS (IBS group) versus 92 who did not (non-IBS group). Depression was more prevalent in the IBS group (18.4% vs 5.4%, P =0.01). Anxiety was also greater in the IBS group (31.6% vs 9.8%, P =0.002). Female sex, depression, and body mass index (BMI)>30 were independent predictors of IBS in NAFLD in 4 multiple logistic regression models. In newly diagnosed IBS patients, gamma-glutamyl transferase levels were lower (67.5 vs 28, P =0.04). Current abdominal pain was higher than 100% versus 81.3% ( P =0.045), as was pain associated with the change in stool frequency (96.3% vs 50%; P <0.001). CONCLUSION: Our study highlights the increased rate of IBS symptoms, depression, and anxiety in patients with NAFLD. Clinicians should be alert when IBS symptoms are reported by a NAFLD patient and be aware of the impact of these comorbidities on quality of life and response to therapy.

The Role of Fecal Microbiota Transplantation in the Induction of Remission in Ulcerative Colitis.

BACKGROUND: Considerable research supports an important role for the microbiome and/or microbiome-host immune system interactions in the pathogenesis of inflammatory bowel disease (IBD). Consequently, microbiota-modulating interventions, such as fecal microbiota transplantation (FMT), have attracted interest in the management of IBD, including ulcerative colitis (UC). SUMMARY: While the clinical response to FMT in UC has varied between different studies, results to date may offer guidance toward optimal use of FMT. Thus, increased microbiome biodiversity, the presence of short-chain fatty acid-producing bacteria, Clostridium clusters IV and XIVa, Odoribacter splanchnicus, and reduced levels of Caudovirales bacteriophages have been identified as characteristics of the donor microbiome that predict a positive response. However, inconsistency in FMT protocol between studies confounds their interpretation, so it is currently difficult to predict response and premature to recommend FMT, in general, as a treatment for UC. Additional randomized controlled trials designed based on previous findings and employing a standardized protocol are needed to define the role of FMT in the management of UC. KEY MESSAGES: There is a well-developed rationale for the use of microbiome-modulating interventions in UC. Despite variations in study protocol and limitations in study design that confound their interpretation, FMT seems to benefit patients with UC, overall. Available data identify factors predicting FMT response and should lead to the development of optimal FMT study protocols.

DNA sensor-associated type I interferon signaling is increased in ulcerative colitis and induces JAK-dependent inflammatory cell death in colonic organoids.

DNA sensor pathways can initiate inflammasome, cell death, and type I interferon (IFN) signaling in immune-mediated inflammatory diseases (IMIDs), including type I interferonopathies. We investigated the involvement of these pathways in the pathogenesis of ulcerative colitis (UC) by analyzing the expression of DNA sensor, inflammasome, and type I IFN biomarker genes in colonic mucosal biopsy tissue from control (n = 31), inactive UC (n = 31), active UC (n = 33), and a UC single-cell RNA-Seq dataset. The effects of type I IFN (IFN-ß), IFN-γ, and TNF-α on gene expression, cytokine production, and cell death were investigated in human colonic organoids. In organoids treated with cytokines alone, or in combination with NLR family pyrin domain-containing 3 (NLRP3), caspase, or JAK inhibitors, cell death was measured, and supernatants were assayed for IL-1ß/IL-18/CXCL10. The expression of DNA sensor pathway genes-PYHIN family members [absent in melanoma 2 (AIM2), IFI16, myeloid cell nuclear differentiation antigen (MNDA), and pyrin and HIN domain family member 1 (PYHIN1)- as well as Z-DNA-binding protein 1 (ZBP1), cyclic GMP-AMP synthase (cGAS), and DDX41 was increased in active UC and expressed in a cell type-restricted pattern. Inflammasome genes (CASP1, IL1B, and IL18), type I IFN inducers [stimulator of interferon response cGAMP interactor 1 (STING), TBK1, and IRF3), IFNB1, and type I IFN biomarker genes (OAS2, IFIT2, and MX2) were also increased in active UC. Cotreatment of organoids with IFN-ß or IFN-γ in combination with TNFα increased expression of IFI16, ZBP1, CASP1, cGAS, and STING induced cell death and IL-1ß/IL-18 secretion. This inflammatory cell death was blocked by the JAK inhibitor tofacitinib but not by inflammasome or caspase inhibitors. Increased type I IFN activity may drive elevated expression of DNA sensor genes and JAK-dependent but inflammasome-independent inflammatory cell death of colonic epithelial cells in UC.NEW & NOTEWORTHY This study found that patients with active UC have significantly increased colonic gene expression of cytosolic DNA sensor, inflammasome, STING, and type I IFN signaling pathways. The type I IFN, IFN-ß, in combination with TNF-α induced JAK-dependent but NLRP3 and inflammasome-independent inflammatory cell death of colonic organoids. This novel inflammatory cell death phenotype is relevant to UC immunopathology and may partially explain the efficacy of the JAKinibs tofacitinib and upadacitinib in patients with UC.

Greater Overlap of Rome IV Disorders of Gut-Brain Interactions Leads to Increased Disease Severity and Poorer Quality of Life.

BACKGROUND AND AIMS: Conditions such as irritable bowel syndrome (IBS), functional dyspepsia, and functional constipation are among the prevalent gastrointestinal (GI) disorders classified as disorders of gut-brain interaction (DGBI), which can adversely affect the lives of sufferers. This study aimed to assess the degree and consequences of overlapping DGBI in a large population-based global scale. METHODS: Internet survey data from 54,127 adults (49.1% women) in 26 countries were analyzed by 4 GI anatomic regions (esophageal, gastroduodenal, bowel, and anorectal). The number of DGBI-affected GI regions was assessed, including associations with sex, age, disease severity, quality of life, psychosocial variables, and health care utilization. RESULTS: A total of 40.3% of surveyed individuals met Rome IV criteria for a DGBI. The percentages with 1-4 DGBI-affected GI regions were 68.3%, 22.3%, 7.1%, and 2.3%, respectively. The IBS symptom severity score increased significantly from 1 (207.6) to 4 (291.6) regions, as did non-GI symptom reporting (somatization), anxiety and depression, concerns and embarrassment about bowel function, doctor visits, medications, and abdominal surgeries (all P < .0001). Quality of life decreased with increasing number of DGBI regions (P < .0001). In a logistic mixed model, non-GI symptoms (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.08-1.10), being very vs not concerned (OR, 2.55; 95% CI, 2.27-2.90), being very vs not embarrassed about bowel function (OR, 1.20; 95% CI, 1.08-1.33), and mean number of doctor visits (OR, 1.23; 95% CI, 1.115-1.32) were most strongly associated with number of DGBI regions. CONCLUSIONS: DGBI in multiple anatomic GI regions is associated with increased psychological comorbidity, health care utilization, and IBS severity. Physician awareness of overlap could improve quality of care, prevent unnecessary interventions, and yield more positive health outcomes.

Worldwide Prevalence and Burden of Functional Gastrointestinal Disorders, Results of Rome Foundation Global Study.

BACKGROUND & AIMS: Although functional gastrointestinal disorders (FGIDs), now called disorders of gut-brain interaction, have major economic effects on health care systems and adversely affect quality of life, little is known about their global prevalence and distribution. We investigated the prevalence of and factors associated with 22 FGIDs, in 33 countries on 6 continents. METHODS: Data were collected via the Internet in 24 countries, personal interviews in 7 countries, and both in 2 countries, using the Rome IV diagnostic questionnaire, Rome III irritable bowel syndrome questions, and 80 items to identify variables associated with FGIDs. Data collection methods differed for Internet and household groups, so data analyses were conducted and reported separately. RESULTS: Among the 73,076 adult respondents (49.5% women), diagnostic criteria were met for at least 1 FGID by 40.3% persons who completed the Internet surveys (95% confidence interval [CI], 39.9-40.7) and 20.7% of persons who completed the household surveys (95% CI, 20.2-21.3). FGIDs were more prevalent among women than men, based on responses to the Internet survey (odds ratio, 1.7; 95% CI, 1.6-1.7) and household survey (odds ratio, 1.3; 95% CI, 1.3-1.4). FGIDs were associated with lower quality of life and more frequent doctor visits. Proportions of subjects with irritable bowel syndrome were lower when the Rome IV criteria were used, compared with the Rome III criteria, in the Internet survey (4.1% vs 10.1%) and household survey (1.5% vs 3.5%). CONCLUSIONS: In a large-scale multinational study, we found that more than 40% of persons worldwide have FGIDs, which affect quality of life and health care use. Although the absolute prevalence was higher among Internet respondents, similar trends and relative distributions were found in people who completed Internet vs personal interviews.

Recognizing and Defining Occasional Constipation: Expert Consensus Recommendations.

Constipation is a common problem, affects 15% of the population, and is often self-diagnosed and self-managed. Over the past 3 decades, there have been significant advances in our understanding and management of chronic constipation, with the emerging recognition that occasional constipation (OC) is another subtype that falls outside current classifications. The purpose of this review was to describe the process of developing and proposing a new definition for OC based on expert consensus and taking into consideration the multifactorial nature of the problem such as alterations in bowel habit that include stool frequency and difficulty with stool passage, perception of the sufferer, duration of symptoms, and potential responsiveness to treatment. Leading gastroenterologists from 5 countries met virtually on multiple occasions through an online digital platform to discuss the problem of OC and recommended a practical, user-friendly definition: "OC can be defined as intermittent or occasional symptomatic alteration(s) in bowel habit. This includes a bothersome reduction in the frequency of bowel movements and/or difficulty with passage of stools but without alarming features. Bowel symptoms may last for a few days or a few weeks, and episodes may require modification of lifestyle, dietary habits and/or use of over-the-counter laxatives or bulking agents to restore a satisfactory bowel habit." Prospective studies are required to validate this definition and determine OC prevalence in the community. This review highlights current knowledge gaps and could provide impetus for future research to facilitate an improved understanding of OC and development of evidence-based management guidelines.

Gastrointestinal effects of diets low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols.

PURPOSE OF REVIEW: Food ingestion is an exacerbator of gastrointestinal symptoms, regardless of origin. Sufferers mistakenly assume that they have suffered an allergic reaction to a given food. Although classical IgE-mediated allergic reactions are rarely culpable, evidence for a role for intolerance to certain carbohydrates in irritable bowel syndrome (IBS) and related conditions increases. This review assesses the status of a commonly implicated group of poorly absorbed carbohydrates (fermentable oligosaccharides, disaccharides, monosaccharides and polyols - FODMAPs) in gastrointestinal pathophysiology. RECENT FINDINGS: Although evidence of efficacy for low FODMAP diets in IBS accumulates, the magnitude of this effect has declined in recent studies. Comparisons to other dietary approaches have revealed conflicting results; some suggest superiority, others find parity. Concerns had been raised regarding long-term nutritional, psychological and microbiological impacts of FODMAP restriction; providing that the diet is administered in the recommended manner, these do not appear to be clinically important. The mechanisms whereby FODMAPs cause gastrointestinal symptoms continue to be explored. SUMMARY: FODMAPS induce gastrointestinal symptoms in susceptible individuals and their restriction provides clinical benefits. The magnitude of these benefits, the superiority of FODMAP restriction over other dietary approaches and the mechanisms of its effects continue to be defined.

The alternative serotonin transporter promoter P2 impacts gene function in females with irritable bowel syndrome.

Irritable bowel syndrome (IBS) is a gut-brain disorder in which symptoms are shaped by serotonin acting centrally and peripherally. The serotonin transporter gene SLC6A4 has been implicated in IBS pathophysiology, but the underlying genetic mechanisms remain unclear. We sequenced the alternative P2 promoter driving intestinal SLC6A4 expression and identified single nucleotide polymorphisms (SNPs) that were associated with IBS in a discovery sample. Identified SNPs built different haplotypes, and the tagging SNP rs2020938 seems to associate with constipation-predominant IBS (IBS-C) in females. rs2020938 validation was performed in 1978 additional IBS patients and 6,038 controls from eight countries. Meta-analysis on data from 2,175 IBS patients and 6,128 controls confirmed the association with female IBS-C. Expression analyses revealed that the P2 promoter drives SLC6A4 expression primarily in the small intestine. Gene reporter assays showed a functional impact of SNPs in the P2 region. In silico analysis of the polymorphic promoter indicated differential expression regulation. Further follow-up revealed that the major allele of the tagging SNP rs2020938 correlates with differential SLC6A4 expression in the jejunum and with stool consistency, indicating functional relevance. Our data consolidate rs2020938 as a functional SNP associated with IBS-C risk in females, underlining the relevance of SLC6A4 in IBS pathogenesis.

AGA Clinical Practice Update on Small Intestinal Bacterial Overgrowth: Expert Review.

DESCRIPTION: Thanks to ready access to hydrogen breath testing, small intestinal bacterial overgrowth (SIBO) is now commonly diagnosed among individuals presenting with a variety of gastrointestinal and even nongastrointestinal symptoms and is increasingly implicated in lay press and media in the causation of a diverse array of disorders. Its definition, however, remains controversial and true prevalence, accordingly, undefined. The purpose of this review, therefore, was to provide a historical background to the concept of SIBO, critically review current concepts of SIBO (including symptomatology, pathophysiology, clinical consequences, diagnosis and treatment), define unanswered questions and provide a road map toward their resolution. METHODS: Best Practice Advice statements were developed following discussion by the 3 authors. Two authors each developed text around certain Best Practice Advice based on a review of available literature. All 3 authors reviewed the complete draft and after discussion, redrafting, and further review and revision, all of the authors agreed on a final draft. BEST PRACTICE ADVICE 1: The definition of SIBO as a clinical entity lacks precision and consistency; it is a term generally applied to a clinical disorder where symptoms, clinical signs, and/or laboratory abnormalities are attributed to changes in the numbers of bacteria or in the composition of the bacterial population in the small intestine. BEST PRACTICE ADVICE 2: Symptoms traditionally linked to SIBO include bloating, diarrhea, and abdominal pain/discomfort. Steatorrhea may be seen in more severe cases. BEST PRACTICE ADVICE 3: There is insufficient evidence to support the use of inflammatory markers, such as fecal calprotectin to detect SIBO. BEST PRACTICE ADVICE 4: Laboratory findings can include elevated folate and, less commonly, vitamin B-12 deficiency, or other nutritional deficiencies. BEST PRACTICE ADVICE 5: A major impediment to our ability to accurately define SIBO is our limited understanding of normal small intestinal microbial populations-progress in sampling technology and techniques to enumerate bacterial populations and their metabolic products should provide much needed clarity. BEST PRACTICE ADVICE 6: Controversy remains concerning the role of SIBO in the pathogenesis of common functional symptoms, such as those regarded as components of irritable bowel syndrome. BEST PRACTICE ADVICE 7: Management should focus on the identification and correction (where possible) of underlying causes, correction of nutritional deficiencies, and the administration of antibiotics. This is especially important for patients with significant maldigestion and malabsorption. BEST PRACTICE ADVICE 8: Although irritable bowel syndrome has been shown to respond to therapy with a poorly absorbed antibiotic, the role of SIBO or its eradication in the genesis of this response warrants further confirmation in randomized controlled trials. BEST PRACTICE ADVICE 9: There is a limited database to guide the clinician in developing antibiotic strategies for SIBO, in any context. Therapy remains, for the most part, empiric but must be ever mindful of the potential risks of long-term broad-spectrum antibiotic therapy.

The patient with irritable bowel syndrome-type symptoms: when to investigate and how?

PURPOSE OF REVIEW: Irritable bowel syndrome (IBS) is a very common disorder whose clinical presentation varies considerably between patients as well as within the same individual over time. Many of its symptoms, such as pain, diarrhea, constipation and bloating, may be manifestations of a host of other gastrointestinal diseases; some accompanied by increased mortality. This presents the clinician with a real dilemma: how to sensibly investigate the patient in which one suspects IBS but there is a nagging doubt that 'it could be something else'? Could one miss 'something serious'? This short review attempts to provide both an evidence-based response to these vexing questions and a practical guide to detecting alternative diagnoses in the subject with IBS-type symptoms. RECENT FINDINGS: Clinical features, patient demographics and the clinical context can help to significantly narrow the differential diagnosis of the individual with IBS-type symptoms and may permit a positive diagnosis of IBS. The advent of noninvasive serological and stool tests has greatly facilitated differentiation from celiac disease and inflammatory bowel disease, respectively. In the older, female diarrhea sufferer microscopic colitis should be considered. The role of bile acid diarrhea in the individual with diarrhea-predominant IBS is emphasized; the status of small intestinal bacterial overgrowth in IBS remain uncertain. SUMMARY: Attention to detail in the clinical evaluation of the individual with IBS-like symptoms will facilitate a selective and targeted approach to investigation. Wherever indicated, widely available serological and fecal tests will serve to bolster the diagnosis by excluding other options. Proceeding to more invasive testing should be dictated by clinical presentation and scenario with the threshold for intervention being generally lower among those with prominent diarrhea.

Rectal Distension Increased the Rectoanal Gradient in Patients with Normal Rectal Sensory Function.

BACKGROUND: Frequent observation of abnormal manometric patterns consistent with dyssynergia in healthy volunteers has warranted the need for reassessment of the current methods to enhance the diagnostic value of anorectal manometry in functional defecatory disorders. Whether rectal distention at simulated evacuation will affect anorectal pressure profile and increase rectoanal gradient is not known. METHODS: One hundred and eight consecutive patients with chronic constipation, 93 females, median age 53 years (interquartile range: 40-65), were studied. Simulated evacuation was performed firstly with empty balloon and subsequently after balloon distention to 50 and 100 ml. Anorectal pressures were compared. We also performed subgroup analysis in relation to outcome of balloon expulsion test (BET). In addition, we studied the effect of rectal distension on the rectoanal pressure gradient with respect to rectal sensory function. RESULTS: Rectal balloon distension at simulated evacuation improved rectoanal gradient and decreased the rate of dyssynergia during high-resolution anorectal manometry. In subgroup analysis, the increase in rectoanal gradient and correction of dyssynergia with rectal distension was limited to the patients who had normal BET and normal rectal sensory function. Rate of anal relaxation, residual anal pressures, and rectoanal gradient were significantly different between patients with and without normal BET at 50 ml of rectal distension. Rectoanal gradient recorded only after rectal distension, along with BMI and maximum tolerable volumes, could predict BET results independently in patients with chronic constipation. CONCLUSIONS: Rectal distension during simulated evacuation will affect the anorectal pressure profile. Increase in rectoanal gradient and correction of dyssynergia was only significant in patients with normal rectal sensory function and normal BET.

The microbiome and inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a chronic immune-mediated disease affecting the gastrointestinal tract. IBD consists of 2 subtypes: ulcerative colitis and Crohn disease. IBD is thought to develop as a result of interactions between environmental, microbial, and immune-mediated factors in a genetically susceptible host. Of late, the potential role of the microbiome in the development, progression, and treatment of IBD has been a subject of considerable interest and enquiry. Indeed, studies in human subjects have shown that the gut microbiome is different in patients with IBD compared with that in healthy control subjects. Other evidence in support of a fundamental role for the microbiome in patients with IBD includes identification of mutations in genes involved in microbiome-immune interactions among patients with IBD and epidemiologic observations implicating such microbiota-modulating risk factors as antibiotic use, cigarette smoking, levels of sanitation, and diet in the pathogenesis of IBD. Consequently, there has been much interest in the possible benefits of microbiome-modulating interventions, such as probiotics, prebiotics, antibiotics, fecal microbiota transplantation, and gene manipulation in the treatment of IBD. In this review we will discuss the role of the gut microbiome in patients with IBD; our focus will be on human studies.

Efficacy of pharmacological therapies in patients with IBS with diarrhoea or mixed stool pattern: systematic review and network meta-analysis.

OBJECTIVE: Over half of patients with IBS have either diarrhoea (IBS-D) or a mixed stool pattern (IBS-M). The relative efficacy of licenced pharmacological therapies is unclear in the absence of head-to-head trials. We conducted a network meta-analysis to resolve this uncertainty. DESIGN: We searched MEDLINE, Embase, Embase Classic, the Cochrane central register of controlled trials, and Clinicaltrials.gov through January 2019 to identify randomised controlled trials (RCTs) assessing the efficacy of licenced pharmacological therapies (alosetron, eluxadoline, ramosetron and rifaximin) in adults with IBS-D or IBS-M. Trials included in the analysis reported a dichotomous assessment of overall response to therapy, and data were pooled using a random effects model. Efficacy and safety of all pharmacological therapies were reported as a pooled relative risk with 95% CIs to summarise the effect of each comparison tested. Treatments were ranked according to their p score. RESULTS: We identified 18 eligible RCTs (seven alosetron, five ramosetron, two rifaximin and four eluxadoline), containing 9844 patients. All were superior to placebo for the treatment of IBS-D or IBS-M at 12 weeks, according to the Food and Drug Administration (FDA)-recommended endpoint for trials in IBS. Alosetron 1 mg twice daily was ranked first for efficacy, based on the FDA-recommended composite endpoint of improvement in both abdominal pain and stool consistency, effect on global symptoms of IBS and effect on stool consistency. Ramosetron 2.5µg once daily was ranked first for effect on abdominal pain. Total numbers of adverse events were significantly greater with alosetron 1 mg twice daily and ramosetron 2.5µg once daily, compared with placebo. Rifaximin 550 mg three times daily ranked first for safety. Constipation was significantly more common with all drugs, except rifaximin 550 mg three times daily. CONCLUSION: In a network meta-analysis of RCTs of pharmacological therapies for IBS-D and IBS-M, we found all drugs to be superior to placebo, but alosetron and ramosetron appeared to be the most effective.

Efficacy of psychological therapies for irritable bowel syndrome: systematic review and network meta-analysis.

OBJECTIVES: National guidelines for the management of irritable bowel syndrome (IBS) recommend that psychological therapies should be considered, but their relative efficacy is unknown, because there have been few head-to-head trials. We performed a systematic review and network meta-analysis to try to resolve this uncertainty. DESIGN: We searched the medical literature through January 2020 for randomised controlled trials (RCTs) assessing efficacy of psychological therapies for adults with IBS, compared with each other, or a control intervention. Trials reported a dichotomous assessment of symptom status after completion of therapy. We pooled data using a random effects model. Efficacy was reported as a pooled relative risk (RR) of remaining symptomatic, with a 95% CI to summarise efficacy of each comparison tested, and ranked by therapy according to P score. RESULTS: We identified 41 eligible RCTs, containing 4072 participants. After completion of therapy, the psychological interventions with the largest numbers of trials, and patients recruited, demonstrating efficacy included self-administered or minimal contact cognitive behavioural therapy (CBT) (RR 0.61; 95% CI 0.45 to 0.83, P score 0.66), face-to-face CBT (RR 0.62; 95% CI 0.48 to 0.80, P score 0.65) and gut-directed hypnotherapy (RR 0.67; 95% CI 0.49 to 0.91, P score 0.57). After completion of therapy, among trials recruiting only patients with refractory symptoms, group CBT and gut-directed hypnotherapy were more efficacious than either education and/or support or routine care, and CBT via the telephone, contingency management, CBT via the internet and dynamic psychotherapy were all superior to routine care. Risk of bias of trials was high, with evidence of funnel plot asymmetry; the efficacy of psychological therapies is therefore likely to have been overestimated. CONCLUSIONS: Several psychological therapies are efficacious for IBS, although none were superior to another. CBT-based interventions and gut-directed hypnotherapy had the largest evidence base and were the most efficacious long term. TRIAL REGISTRATION NUMBER: The study protocol was published on the PROSPERO international prospective register of systematic reviews (registration number CRD 42020163246).

Cancer cachexia: a multifactoral disease that needs a multimodal approach.

PURPOSE OF REVIEW: Cancer cachexia is a complex condition that occurs in approximately 50% of cancer patients and in 80% of those with advanced cancer. It is characterized by lean body mass loss, adipose tissue loss, altered metabolism, increased inflammation, and a decrease in quality of life. Cancer cachexia is a frustrating condition to manage and treatment requires an innovative approach. The purpose of this article is to review the current treatments for cancer cachexia and how they could be used in a multimodal approach. RECENT FINDINGS: Cancer cachexia has many causes, but is primarily a result of reduced energy-protein intake and altered metabolism augmented by a proinflammatory state. There is not a formal consensus on diagnosing cancer cachexia, but proactive screening and assessments for malnutrition are an effective first step toward identifying high-risk patients. Treatment of cancer cachexia includes optimizing nutrition care, using appropriate pharmacological agents, preserving lean body mass, and the cooperation of the healthcare team. SUMMARY: Cancer cachexia is a complex multifactorial condition that can only be successfully managed and treated with a multimodal approach that involves a multidisciplinary team that includes an oncology registered dietitian nutritionist and exercise physiologist that target early detection and management of cancer cachexia.