Irritable bowel syndrome: Diagnosis and pathogenesis

The low FODMAP diet in adolescents functional abdominal in a non-guided setting: a prospective multicenter cohort study

The purpose of this study is to evaluate the efficacy of a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) in adolescents with irritable bowel syndrome (IBS) and functional abdominal pain-not otherwise specified (FAP-NOS) in a non-guided setting, resembling clinical practice. This prospective multicenter cohort study conducted in 13 centers included patients aged 12-18 years diagnosed with IBS or FAP-NOS. Patients received educational material on FODMAPs, including extensive lists of high and low FODMAP foods and additional online information. They were instructed to replace high FODMAP foods with low FODMAP alternatives for the duration of 4 weeks. No dietician was consulted. The primary end point was the proportion of patients with treatment success (≥ 30% reduction of abdominal pain intensity) at 4 weeks. The key secondary outcome was adequate relief of IBS/FAP-NOS symptoms. Of the 325 included patients, 81 patients (24.9%) achieved treatment success (≥ 30% reduction of abdominal pain intensity) after 4 weeks, with higher rates in patients with IBS (29.3%) than FAP-NOS (16.8%, OR 2.16 (1.04-4.48)). Adequate relief was reported in 51 patients (15.7%). There was a significant decrease in abdominal pain intensity (2.2 (1.1) vs. 2.5 (1.0), P < 0.001), daily bloating (2.4 (2.1) vs. 2.8 (2.3), P < 0.001), and flatulence (2.4 (2.1) vs. 2.8 (2.3), P = 0.001). Adverse events were mild and infrequent.

CONCLUSION

The low FODMAP diet in a non-guided setting, mimicking clinical practice, yielded treatment success in almost 30% adolescents with IBS and 17% in FAP-NOS, suggesting it may not be the first treatment option for these patients.

TRIAL REGISTRATION

EUCTR2015-003293-32-NL.

WHAT IS KNOWN

• Irritable bowel syndrome (IBS) and functional abdominal pain-not otherwise specified (FAP-NOS) are common disorders in children which negatively impact quality of life. • While a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) has demonstrated effectiveness in adult IBS, its efficacy in pediatric IBS and FAP-NOS remains uncertain. • Clinical application of the low FODMAP diet often occurs without dietician consultation, contrary to controlled trial settings.

WHAT IS NEW

• The low FODMAP diet, without dietician guidance, resulted in treatment success in almost 30% of adolescents with IBS and only 17% with FAP-NOS. • With only 15.7% of participants achieving adequate relief of IBS/FAP-NOS symptoms, the non-guided low FODMAP diet may not be the first treatment option for pediatric IBS and FAP-NOS.

Inflammatory Prostatitis Plus IBS-D Subtype and Correlation with Immunomodulating Agent Imbalance in Seminal Plasma: Novel Combined Treatment

We recently demonstrated the effectiveness of long-term treatment with rifaximin and the probiotic DSF (De Simone formulation) in improving urogenital and gastrointestinal symptoms in patients with both chronic inflammatory prostatitis (IIIa prostatitis) and diarrhea-predominant irritable bowel syndrome (IBS-D), relative to patients with IBS-D alone. Because the low-grade inflammation of the intestine and prostate may be one of the reasons for co-developing both IIIa prostatitis and IBS-D, we designed the present study to once again evaluate the efficacy of combined rifaximin and DSF treatment in patients affected by IIIa prostatitis plus IBS-D, but we also measured seminal plasma pro-inflammatory (IL-6) and anti-inflammatory (IL-10) cytokines before and after treatment. Methods: We consecutively enrolled 124 patients with IIIa prostatitis and IBS-D (diagnosed using the Rome III criteria). Patients were randomized into two groups: group A (n = 64) was treated with rifaximin (seven days per month for three months) followed by DSF, and group B (n = 60) was treated with a placebo. By the end of the intervention, 68.7% and 62.5% of patients from group A reported improved NIH-CPSI (National Institute of Health's Chronic Prostatitis Symptom Index) and IBS-SSS (Irritable Bowel Syndrome Severity Scoring System) scores, respectively, compared to only 3.3% and 5% of the placebo group. Group A patients also had significantly lower mean seminal plasma levels of IL-6 (11.3 vs. 32.4 pg/mL) and significantly higher mean levels of IL-10 (7.9 vs. 4.4 pg/mL) relative to baseline, whereas the levels of IL-6 and IL-10 did not change in the placebo group. Conclusions: The combined treatment with rifaximin and DSF appears to represent the optimal approach for addressing a syndrome such as irritable bowel syndrome (IBS-D plus), which frequently co-occurs with prostatitis (IIIa prostatitis). This approach is particularly beneficial in cases where the symptoms are not always clearly delineated, the etiology is multifactorial, and the diagnosis is multilevel.

A Future Avenue of Treatment Ulcerative Colitis Targeting Macrophage Polarization: A Phytochemical Application

Background

Ulcerative colitis (UC) is a prevalent inflammatory bowel disease primarily impacting the mucosa of the colon. It is characterized by recurring and incurable symptoms and causes immense suffering and significant economic burden due to limited treatment options. Typical symptoms of UC include diarrhea, alterations in bowel patterns, bleeding from the rectum, rectal pain or urgency, anemia, and tiredness. Therefore, developing novel and effective treatment strategies for UC is imperative.

Purpose

This review aimed to explain how macrophage polarization contributes to UC development and compiled information on natural compounds with promising therapeutic potential that can target the macrophage phenotype and shed light on its potential mode of action.

Results

The phenotypic alteration of macrophages profoundly affects the development of UC, and these cells are essential for preserving intestinal immunological homeostasis. Evidence from research suggests that one effective method for UC prevention and therapy is to guide macrophage polarization toward the M2 phenotype. Phytochemicals, which are compounds extracted from plants, possess a wide array of biological activities. For example: Ginsenoside Rg1 emerges as a crucial regulator of macrophage polarization, promoting the M2 phenotype while inhibiting the M1 phenotype. Notably, their low toxicity and high effectiveness render them promising candidates for therapeutic interventions. These compounds have demonstrated encouraging protective effects against inflammation in the colon.

Conclusions

Exploring phytochemicals as a therapeutic avenue targeting macrophage polarization presents an innovative approach to treating UC.

Bridging the Gap: A Comprehensive Study on Traditional Chinese Medicine Strategies for Managing Adult Irritable Bowel Syndrome

Recent studies have witnessed the incorporation of herbal medicine into the management of Disorders of Gut-Brain Interactions (DGBIs), reflecting a paradigm shift toward holistic healing modalities. However, there still exists a substantial gap in comprehending the utilization of Traditional Chinese Medicine (TCM) for Irritable Bowel Syndrome (IBS), particularly beyond the confines of China. This study endeavors to bridge this knowledge gap by meticulously identifying existing guidelines, critically reviewing TCM practices, and crafting contemporary treatment recommendations. We systematically searched several databases to retrieve related evidence in June 2023. Firstly, we employed the AGREE II tool to evaluate the recommended for use of TCM in the treatment of IBS, establishing a structured treatment selection hierarchy for different TCM patterns of IBS patients. Subsequently, we conducted an expert questionnaire to gain insights into the common treatment methods and medication choices practiced by clinical TCM doctors. Based on CM theory and experts' opinions, IBS with predominant Diarrheal (IBS-D) is divided into five Chinese medicine syndrome patterns, and IBS with predominant Constipation (IBS-C) is classified to four. A total of 22[Formula: see text]CM prescriptions were recommended for the management of IBS, 13 for IBS-D and 9 for IBS-C. The findings provide IBS patients with enhanced treatment choices while offering clinical physicians more specific treatment regimens. This research is the first to conduct a comprehensive study that combines guidelines with real clinical practices in the realm of TCM IBS treatment. This serves as a foundation for providing more personalized treatment options and improving the quality of life for patients.

Probiotics, Prebiotics, Fecal Microbiota Transplantation, and Dietary Patterns in Inflammatory Bowel Disease

SCOPE

Inflammatory bowel disease (IBD) is one of the most common chronic and debilitating functional bowel disorders affecting around 11% of the population across the world. IBD is associated with 3.6 million physician visits per year, being the most common reason visiting a gastroenterologist and the second most common reason to be absent from work, sharply increasing the health care costs.

METHODS AND RESULTS

Several treatments seem to be effective in IBD symptoms relief, such as probiotics, prebiotics, fecal microbiota transplantation (FMT), and dietary patterns. Probiotics (living microorganisms that can be supplemented) can protect against pathogenic bacteria due to their antimicrobial qualities. Prebiotics (nondigestible food ingredients) promote the growth of beneficial microbial strains in the gut, giving a health benefit to the host. FMT is supposed to directly change the recipient's microbial composition when a transfer of gastrointestinal microbiota from a healthy donor is carried out. And finally, dietary patterns are in the spotlight, due to the presence of certain nutrients in the gastrointestinal tract affecting gastrointestinal motility, sensitivity, barrier function, and gut microbiota.

CONCLUSION

It is particularly important to know what treatment options are available and which are the most efficient in relieving IBD symptoms and improving IBD patient's quality of life.

Metabolic biomarkers in irritable bowel syndrome diagnosis

Irritable bowel syndrome (IBS) is a chronic gastrointestinal (GI) disorder characterized by altered bowel habits and abdominal discomfort during defecation. It significantly impacts life quality and work productivity for those affected. Global data suggests a slightly higher prevalence in females than in males. Today, unambiguous diagnosis of IBS remains challenging due to the absence of a specific biochemical, histopathological, or radiological test. Current diagnosis relies heavily on thorough symptom evaluation. Efforts by the Rome committees have established standardized diagnostic criteria (Rome I-IV), improving consistency and clinical applicability. Recent studies in this framework, seem to have successfully employed metabolomics techniques to identify distinct metabolite profiles in breath and stool samples of IBS patients, differentiating them from healthy controls and those with other functional GI disorders, such as inflammatory bowel disease (IBD). Building on this success, researchers are investigating the presence of similar metabolites in easily accessible biofluids such as urine, potentially offering a less invasive diagnostic approach. Accordingly, this review focuses on key metabolites specifically detected in IBS patients' biological specimens, with a focus on urinary metabolites, using various methods, particularly mass spectrometry (MS)-based techniques, including gas chromatography-MS (GC-MS), liquid chromatography-tandem MS (LC-MS/MS), and capillary electrophoresis-MS (CE-MS) metabolomics assays. These findings may make provision for a new set of non-invasive biomarkers for IBS diagnosis and management.

Fecal microbiota transplantation for irritable bowel syndrome: Current evidence and perspectives

In this editorial we comment on the article published in the recent issue of the World journal of Gastroenterology. We focus specifically on the mechanisms un-derlying the effects of fecal microbiota transplantation (FMT) for irritable bowel syndrome (IBS), the factors which affect the outcomes of FMT in IBS patients, and challenges. FMT has emerged as a efficacious intervention for clostridium difficile infection and holds promise as a therapeutic modality for IBS. The utilization of FMT in the treatment of IBS has undergone scrutiny in numerous randomized controlled trials, yielding divergent outcomes. The current frontier in this field seeks to elucidate these variations, underscore the existing knowledge gaps that necessitate exploration, and provide a guideline for successful FMT imple-mentation in IBS patients. At the same time, the application of FMT as a treatment for IBS confronts several challenges.

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

Background

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

Methods

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

Results

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

Conclusion

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

The Role of Nutraceutical Supplements in the Treatment of Irritable Bowel Syndrome: A Mini Review

BACKGROUND

Irritable bowel syndrome (IBS) is a prolonged bowel illness that is generally stress-related and is characterized by a variety of gastrointestinal problems, the most prominent of which is chronic visceral abdominal discomfort. As a result, IBS typically impacts sufferers' standard of living, and it is typically associated with depression and anxiety symptoms. IBS medication is based mostly on symptom alleviation. However, no effective medicines have been discovered too far. As a result, it is essential to discover novel anti-IBS medications.

OBJECTIVE

The purpose of this brief review is to describe the existing research on nutraceutical supplements in irritable bowel syndrome management, including probiotics, prebiotics, symbiotics, herbal products, and dietary fibers.

METHODS

This review covered the relevant papers from the previous twenty years that were available in different journals such as Science Direct, Elsevier, NCBI, and Web of Science that were related to the role and function of nutraceuticals in Irritable Bowel Syndrome.

RESULTS

Nutraceutical substances have a variety of modes of action, including restoring the healthy microbiome, improving the function of the gastrointestinal barrier, immunomodulatory, antiinflammatory, and antinociceptive properties. According to the literature, these substances not only can improve irritable bowel syndrome symptomatology but also have an excellent long-term safety profile.

CONCLUSION

Irritable bowel syndrome is a prolonged bowel illness with a lot of gastrointestinal problems. The nutraceuticals treatment works as an anti-IBS intervention and enhances patient compliance with minimum side effects since patients take it better than pharmaceutical treatments.

Long-Term Implicit Epigenetic Stress Information in the Enteric Nervous System and its Contribution to Developing and Perpetuating IBS

Psychiatric and mood disorders may play an important role in the development and persistence of irritable bowel syndrome (IBS). Previously, we hypothesized that stress-induced implicit memories may persist throughout life via epigenetic processes in the enteric nervous system (ENS), independent of the central nervous system (CNS). These epigenetic memories in the ENS may contribute to developing and perpetuating IBS. Here, we further elaborate on our earlier hypothesis. That is, during pregnancy, maternal prenatal stresses perturb the HPA axis and increase circulating cortisol levels, which can affect the maternal gut microbiota. Maternal cortisol can cross the placental barrier and increase cortisol-circulating levels in the fetus. This leads to dysregulation of the HPA axis, affecting the gut microbiota, microbial metabolites, and intestinal permeability in the fetus. Microbial metabolites, such as short-chain fatty acids (which also regulate the development of fetal ENS), can modulate a range of diseases by inducing epigenetic changes. These mentioned processes suggest that stress-related, implicit, long-term epigenetic memories may be programmed into the fetal ENS during pregnancy. Subsequently, this implicit epigenetic stress information from the fetal ENS could be conveyed to the CNS through the bidirectional microbiota-gut-brain axis (MGBA), leading to perturbed functional connectivity among various brain networks and the dysregulation of affective and pain processes.

Association of fructose consumption with prevalence of functional gastrointestinal disorders manifestations: results from Hellenic National Nutrition and Health Survey (HNNHS)

The study aimed to assess the total prevalence of functional gastrointestinal disorders (FGID), and separately, irritable bowel syndrome (IBS) among adults and to determine their potential association with fructose consumption. Data from the Hellenic National Nutrition and Health Survey were included (3798 adults; 58·9 % females). Information regarding FGID symptomatology was assessed using self-reported physician diagnosis questionnaires the reliability of which were screened using the ROME III, in a sample of the population. Fructose intake was estimated from 24 h recalls, and the MedDiet score was used to assess adherence to the Mediterranean diet. The prevalence of FGID symptomatology was 20·2 %, while 8·2 % had IBS (representing 40·2 % of total FGID). The likelihood of FGID was 28 % higher (95 %CI: 1·03-1·6) and of IBS 49 % (95 %CI: 1·08-2·05) in individuals with higher fructose intake than with lower intake (3rd tertile compared with 1st). When area of residence was accounted for, individuals residing in the Greek islands had a significantly lower probability of FGID and IBS compared with those residing in Mainland and the main Metropolitan areas, with Islanders also achieving a higher MedDiet score and lower added sugar intake, comparatively to inhabitants of the main metropolitan areas. FGID and IBS symptomatology was most prominent among individuals with higher fructose consumption, and this was most conspicuous in areas with a lower Mediterranean diet adherence, suggesting that the dietary source of fructose rather than total fructose should be examined in relation to FGID.

Different therapies of Chinese herbal medicine for diarrhea-predominant irritable bowel syndrome: A network meta-analysis of double-blinded, placebo-controlled trials

ETHNOPHARMACOLOGICAL RELEVANCE

Shuganjianpi Therapy (SGJP), Jianpi Therapy (JP), Shugan Therapy (SG), Jianpiwenshen Therapy (JPWS), and Shuganjianpiwenshen Therapy (SGJPWS), consisting of formulas from Chinese herbal medicine (CHM), have been tremendously applied to irritable bowel syndrome (IBS). However, it remains uncertain when exploring the preferable option among different CHM therapies for diarrhea-predominant irritable bowel syndrome (IBS-D).

AIM OF THE STUDY

To compare and rank the efficacy and safety of different CHM therapies for IBS-D.

MATERIALS AND METHODS

We searched randomized, double-blinded, placebo-controlled trials through mainstream databases from their inception to October 31, 2022. Eligible randomized controlled trials (RCTs) applied one of the CHM therapies as the experimental group and placebo as the control group. Two authors independently extracted data into a form and evaluated the quality of the retrieved articles by the Cochrane Risk of Bias Tool. At least one of the following outcomes was assessed: Serotonin, Neuropeptide Y (NPY), Incidence of Adverse Events (AE), and Irritable Bowel Syndrome-Severity Scoring System (IBS-SSS) with its subscales of Severity of Abdominal Pain (SAP), Frequency of Abdominal Pain (FAP), Severity of Abdominal Distension (SAD), Dissatisfaction with Bowel Habits (DBH), and Interference with Quality of Life (IQOL). A Bayesian network meta-analysis on a random-effect model was conducted using R 4.2.2 software.

RESULTS

1367 records were retrieved from databases in an initial search. Fourteen studies involving six interventions with 2248 participants were identified. Provided pairwise comparisons, the surface under the cumulative ranking curve (SUCRA) ranking, and cluster analysis, JPWS was the best option for ameliorating clinical symptoms simultaneously, which included IBS-SSS, SAP, FAP, SAD, DBH, and IQOL. As for AE, JPWS contributed to fewer adverse events than others as well. In respect of serum indicators, we noticed the dominance of SGJP in regulating both serotonin and NPY.

CONCLUSIONS

JPWS and SGJP were the most prominent CHM therapies for IBS-D in terms of clinical symptoms, including abdominal pain, distension, bowel habits, and improvement of quality of life. The effect of JP and SG for IBS-D required further investigation. As a potential candidate, SGJP may well treat IBS-D by mediating dysmotility, visceral hypersensitivity, and the gut-brain axis with an increase of NPY and a reduction of serotonin. For safety, JPWS was ideal for the fewest adverse events in the treatment of IBS-D. On account of a small sample size and possible geographical publication bias, more double-blinded and placebo-controlled trials with larger samples worldwide would be necessary for strengthening current evidence.

Does sourdough bread provide clinically relevant health benefits?

During the last decade, scientific interest in and consumer attention to sourdough fermentation in bread making has increased. On the one hand, this technology may favorably impact product quality, including flavor and shelf-life of bakery products; on the other hand, some cereal components, especially in wheat and rye, which are known to cause adverse reactions in a small subset of the population, can be partially modified or degraded. The latter potentially reduces their harmful effects, but depends strongly on the composition of sourdough microbiota, processing conditions and the resulting acidification. Tolerability, nutritional composition, potential health effects and consumer acceptance of sourdough bread are often suggested to be superior compared to yeast-leavened bread. However, the advantages of sourdough fermentation claimed in many publications rely mostly on data from chemical and in vitro analyzes, which raises questions about the actual impact on human nutrition. This review focuses on grain components, which may cause adverse effects in humans and the effect of sourdough microbiota on their structure, quantity and biological properties. Furthermore, presumed benefits of secondary metabolites and reduction of contaminants are discussed. The benefits claimed deriving from in vitro and in vivo experiments will be evaluated across a broader spectrum in terms of clinically relevant effects on human health. Accordingly, this critical review aims to contribute to a better understanding of the extent to which sourdough bread may result in measurable health benefits in humans.

Serotonin and Melatonin in Human Lower Gastrointestinal Tract

BACKGROUND AND AIMS

Melatonin is a ubiquitous hormone produced not only by the pineal gland but also by other organs and tissues. It is involved in the regulation of several gastrointestinal functions. The main cells responsible for the production and release of extrapineal melatonin are the enterochromaffin (EC) cells that produce serotonin. They are involved in the pathogenesis of neuromotor disorders that characterize functional gastrointestinal disorders and in the pathophysiology of inflammatory intestinal diseases. Our aim was the immunohistochemical highlighting on biopsy samples of normal gastrointestinal mucosa and in ulcerative colitis (UC) of immunoreactive cells for melatonin and serotonin in order to identify any differences in their distribution.

MATERIALS AND METHODS

Our prospective case-control study involves the highlighting on human mucosal biopsies of immunoreactive cells for melatonin and serotonin. All patients undergoing colonoscopy + ileoscopy were considered eligible for the study, divided into two groups: 1. patients with active ulcerative colitis (UC); 2. control group consisting of patients undergoing endoscopic examination for colorectal cancer screening.

RESULTS

Twenty-one patients were enrolled. The controls had a higher concentration of EC cells containing 5HT particularly in the rectum (p value ≤ 0.05). In patients with active colitis the expression of 5-HT-iR was greater in all tracts of the colon. The correlation analysis in UC patients shows that a higher expression of 5-HT-iR+ cells corresponds to a lower extension of the disease and a greater severity of the same.

CONCLUSIONS

5HT+ cells decreased in the case of UC compared to healthy controls. In the severe disease, there was an increase in the expression of melatonin-secreting cells, probably as a compensatory response to the inflammation and oxidative stress. This increase is negatively correlated with the extent of the disease and positively with the severity of the same.

Proteomic analysis of rat colonic mucosa following acupuncture treatment for irritable bowel syndrome with diarrhea

To investigate the molecular pathological mechanisms of irritable bowel syndrome with diarrhea (IBS-D) and elucidate the effects of acupuncture on IBS-D colonic mucosa protein abundance in rats, a label-free high-throughput liquid chromatography-tandem mass spectrometry (LC-MS)-based proteomics analysis was used to survey the global changes of colonic mucosa proteins between different groups. Sixteen Sprague-Dawley (SD) male rats were randomly divided into four groups: the control group (C); the IBS-D model group (M); the syndrome differentiation acupuncture group (SD) and the traditional acupuncture group (T). IBS-D model rats were obtained using the CAS (chronic acute combining stress model) method. Comparative bioinformatics analysis of the proteomic data was analyzed using MaxQuant software, Perseus software, online tools DAVID, VENNY and STRING. Functional enrichment and network analyses revealed a close relationship between IBS-D and several biological processes including energy metabolism, muscular excitation/contraction, and both traditional acupuncture and syndrome differentiation acupuncture can reverse the impairments of normal energy metabolism. Moreover, the syndrome differentiation acupuncture can regulate the protein cluster relating inflammation, wound repair and cell protection against oxidative stress which is associated with acupuncture analgesic effect. Differentially expressed proteins Atp5a1 and Bpnt1 were selected as representative proteins and subjected to western blotting. In conclusion, our study provides further insight into the pathological and molecular mechanisms of IBS-D and acupuncture treatments, and serves as an experimental basis for clinical applications.

Association of Diet, Body Mass Index, and Lifestyle on the Gastrointestinal Health Risk in a Sample of Adults

Gastrointestinal functional disorders are characterized by abnormalities in motility with visceral hypersensitivity, representing a global public health problem. We aimed to determine whether eating habits, lifestyle characteristics, and body mass index (BMI) are associated with gastrointestinal health risk. The Gastrointestinal Health (GIH) test of the World Gastroenterology Organization (WGO) and the Roma IV criteria were applied. We obtained information on food consumption habits and aerobic exercise, among other variables. Not exercising regularly, drinking water and eating vegetables less than recommended, having high body weight, and taking symptomatic medication were variables that explained 73% of the probabilities of not having good GIH (R² = 0.734). According to Rome IV criteria, women had a 50% higher risk than men of having functional bowel disorder (RR 1.6, 95% CI: 1.04, 2.45). Among the men studied, eating few or no vegetables and drinking less than 1 L of water daily was more frequent; however, the women had significantly more intestinal symptoms. In addition, constipation was higher among women than men (p = 0.020). All of the above explains the prognostic value of eating habits and the importance of paying attention to body weight to reduce the risk of gastrointestinal disease.

Long-term effects of fecal microbiota transplantation (FMT) in patients with irritable bowel syndrome

BACKGROUND

We recently found fecal microbiota transplantation (FMT) in irritable bowel syndrome (IBS) patients to be an effective and safe treatment after 3 months. The present follow-up study investigated the efficacy and safety of FMT at 1 year after treatment.

METHODS

This study included 77 of the 91 IBS patients who had responded to FMT in our previous study. Patients provided a fecal sample and completed five questionnaires to assess their symptoms and quality of life at 1 year after FMT. The dysbiosis index (DI) and fecal bacterial profile were analyzed using a 16S rRNA gene-based DNA probe hybridization. The levels of fecal short-chain fatty acids (SCFAs) were determined by gas chromatography.

RESULTS

There was a persistent response to FMT at 1 year after treatment in 32 (86.5%) and 35 (87.5%) patients who received 30-g and 60-g FMT, respectively. In the 30-g FMT group, 12 (32.4%) and 8 (21.6%) patients showed complete remission at 1 year and 3 months, respectively; the corresponding numbers in the 60-g FMT group were 18 (45%) and 11 (27.5%), respectively. Abdominal symptoms and the quality of life were improved at 1 year compared with after 3 months. These findings were accompanied by comprehensive changes in the fecal bacterial profile and SCFAs.

CONCLUSIONS

Most of the IBS patients maintained a response at 1 year after FMT. Moreover, the improvements in symptoms and quality of life increased over time. Changes in DI, fecal bacterial profile and SCFAs were more comprehensive at 1 year than after 3 months. www.clinicaltrials.gov (NCT03822299).

Effects of Internet-delivered Cognitive Behavioral Therapy in Patients with Irritable Bowel Syndrome: Systematic Review and Meta-Analysis (Preprint)

Background

Irritable bowel syndrome is a common functional gastrointestinal disorder that negatively affects all aspects of life. With the widespread use of the internet, internet-delivered cognitive behavioral therapy has been developed and applied to control symptoms and improve the quality of life of those with irritable bowel syndrome. However, few studies have systematically reviewed the effectiveness of internet-delivered cognitive behavioral therapy on irritable bowel syndrome.

Objective

This study aimed to systematically review studies that examined the use of internet-delivered cognitive behavioral therapy in patients with irritable bowel syndrome and to evaluate the effects of internet-delivered cognitive behavioral therapy on the improvement of symptom severity, quality of life, psychological status, and cost-effectiveness.

Methods

This meta-analysis involved the search of 6 databases for relevant publications. From the 1224 publications identified through database searches, 9 randomized controlled trials were finally included in the analysis.

Results

The internet-delivered cognitive behavioral therapies including exposure-based cognitive behavioral therapy, cognitive behavioral therapy for self-management, and cognitive behavioral therapy for stress management were provided in 5 to 13 sessions for 5 to 10 weeks. Internet-delivered cognitive behavioral therapy had medium-to-large effects on symptom severity (standardized mean difference [SMD] –0.633; 95% CI –0.861 to –0.4304), quality of life (SMD 0.582; 95% CI 0.396-0.769), and cost-effectiveness (–0.372; 95% CI –0.704 to –0.039) at postintervention. The effects on symptom severity remained over time even after the intervention, short-term follow-up (SMD –0.391; 95% CI –0.560 to –0.221), and long-term follow-up (SMD –0.357; 95% CI –0.541 to –0.172). There was no significant difference in psychological status, including anxiety and depression, in those with irritable bowel syndrome compared to the controls during the postintervention period.

Conclusions

This review demonstrates that internet-delivered cognitive behavioral therapy could be a cost-effective intervention for improving symptoms and the quality of life in patients with irritable bowel syndrome. However, studies are still insufficient regarding the use of internet-delivered cognitive behavioral therapy in these patients; therefore, more high-quality studies are required in the future.

Current status of fecal microbiota transplantation for irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a common gastrointestinal functional disorder. Although IBS is a benign condition, it reduces the quality of life considerably. While there is currently no effective treatment for this disorder, fecal microbiota transplantation (FMT) seems to be promising.

PURPOSE

The aim of this review was to analysis possible factors affecting the success or failure of the randomized controlled trials (RCTs) of FMT for IBS and highlighting the gaps in our knowledge that need to be filled and of sketching a possible model for successful FMT in IBS patients.

METHODS

A systematic search was conducted of literature published in English from January 2015 to December 2020 using the keywords: fecal microbiota transplantation, randomized trials, and IBS.

KEY RESULTS

Seven randomized controlled trials (RCTs) on the efficacy of FMT for IBS were found in the literature. Four of the seven RCTs found various positive effects, while the other three did not find any effect.

CONCLUSIONS AND INFERENCES

The efficacy of FMT for IBS appears to be donor-dependent. The effective (super) donor would need to have a favorable microbiota signature, and 11 clinical criteria that are known to be associated with a favorable microbiota have been suggested for selecting FMT donors for IBS. Comparing the microbiota of the effective donors with those of healthy subjects would reveal the favorable microbiota signature required for a super-donor. However, the studies reviewed were not designed to compare efficacy of different donor types. The dose of the fecal transplant is also an important factor influencing the outcome of FMT for IBS. However, further studies designed to test the effect of fecal transplant dose are needed to answer this question. Administering the fecal transplant to either the small or large intestine seems to be effective, but the optimal route of administration remains to be determined. Moreover, whether single or repeated FMT is more effective is also still unclear. A 1-year follow-up of IBS patients who received FMT showed that adverse events of abdominal pain, diarrhea, and constipation were both mild and self-limiting.

Investigation the Effectiveness of Duloxetine in Quality of Life and Symptoms of Patients with Irritable Bowel Syndrome

Background:

Selective norepinephrine-serotonin receptor inhibitors (SNRIs) such as duloxetine have already shown beneficial effects on symptoms in irritable bowel syndrome (IBS) patients. The purpose of the present investigation was to assess the efficacy of duloxetine in the symptom and quality of life improvement in diarrhea predominant-IBS (IBS-D) patients.

Materials and Methods:

IN a randomized, double-blind and placebo-controlled study, sixty patients diagnosed with IBS-D (ROM-IV criteria), referred to the gastrointestinal clinic of Rasoul-e-Akram Hospital of Iran university of medical sciences, randomly assigned in the treatment groups, group A: patients who received 135 mg mebeverine tablet twice a day combined with 30 mg duloxetine capsule per day and group B, who received the same regimen, except for placebo capsule once per day instead of duloxetine for twelve weeks. The assessment was performed using the IBS severity index, and IBS quality of life questionnaire (IBS-QOF) at baseline, and weeks 4, 8, and 12 after beginning the treatment. Drug adverse effects and compliance to treatment were evaluated every 2 weeks after starting the treatment.

Results:

Sixty patients completed the trial. The duloxetine group showed significantly greater improvement on the IBS symptoms (P < 0.001), and the IBS-QOF (P < 0.001) in comparison to the placebo group at the endpoint.

Conclusions:

This study showed that adding duloxetine to mebeverine is safe with good efficacy on symptoms and QOL improvement in IBS-D patients. Besides, this study showed that 12 weeks' treatment duration is significantly more effective than 4 weeks' treatment, and drug adverse effects are more prominently seen in the first 2 weeks of treatment.

Neurotransmitter Dysfunction in Irritable Bowel Syndrome: Emerging Approaches for Management

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder whose aetiology is still unknown. Most hypotheses point out the gut-brain axis as a key factor for IBS. The axis is composed of different anatomic and functional structures intercommunicated through neurotransmitters. However, the implications of key neurotransmitters such as norepinephrine, serotonin, glutamate, GABA or acetylcholine in IBS are poorly studied. The aim of this review is to evaluate the current evidence about neurotransmitter dysfunction in IBS and explore the potential therapeutic approaches. IBS patients with altered colorectal motility show augmented norepinephrine and acetylcholine levels in plasma and an increased sensitivity of central serotonin receptors. A decrease of colonic mucosal serotonin transporter and a downregulation of α2 adrenoceptors are also correlated with visceral hypersensitivity and an increase of 5-hydroxyindole acetic acid levels, enhanced expression of high affinity choline transporter and lower levels of GABA. Given these neurotransmitter dysfunctions, novel pharmacological approaches such as 5-HT₃ receptor antagonists and 5-HT₄ receptor agonists are being explored for IBS management, for their antiemetic and prokinetic effects. GABA-analogous medications are being considered to reduce visceral pain. Moreover, agonists and antagonists of muscarinic receptors are under clinical trials. Targeting neurotransmitter dysfunction could provide promising new approaches for IBS management.

Inter-hemispheric Functional Connections Are More Vulnerable to Attack Than Structural Connection in Patients With Irritable Bowel Syndrome

Background/Aims

Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disease characterized by recurrent abdominal pain and bowel dysfunction. However, the majority of previous neuroimaging studies focus on brain structure and connections but seldom on the inter-hemispheric connectivity or structural asymmetry. This study uses multi-modal imaging to investigate the abnormal changes across the 2 cerebral hemispheres in patients with IBS.

Methods

Structural MRI, resting-state functional MRI, and diffusion tensor imaging were acquired from 34 patients with IBS and 33 healthy controls. The voxel-mirrored homotopic connectivity, fractional anisotropy, fiber length, fiber number, and asymmetry index were calculated and assessed for group differences. In addition, we assessed their relevance for the severity of IBS.

Results

Compared with healthy controls, the inter-hemispheric functional connectivity of patients with IBS showed higher levels in bilateral superior occipital gyrus, middle occipital gyrus, precuneus, posterior cingulate gyrus, and angular gyrus, but lower in supplementary motor area. The statistical results showed no significant difference in inter-hemispheric anatomical connections and structural asymmetry, however negative correlations between inter-hemispheric connectivity and the severity of IBS were found in some regions with significant difference.

Conclusions

The functional connections between cerebral hemispheres were more susceptible to IBS than anatomical connections, and brain structure is relatively stable. Besides, the brain areas affected by IBS were concentrated in default mode network and sensorimotor network.

The effect of faecal microbiota transplantation on abdominal pain, stool frequency, and stool form in patients with moderate-to-severe irritable bowel syndrome: results from a randomised, double-blind, placebo-controlled study

BACKGROUND

Irritable bowel syndrome (IBS) is associated with intestinal dysbiosis. Therefore, faecal microbiota transplantation (FMT) has been hypothesised to have a positive effect in patients with IBS. In this study, we analysed previously unexamined data from our randomised, double-blind, placebo-controlled study (trial registration number NCT02788071). The objective was to evaluate the effect of FMT on abdominal pain, stool frequency, and stool form.

METHOD

The study included 52 adult patients with moderate-to-severe IBS assigned randomly to treatment with FMT capsules or placebo capsules (1:1) for 12 days. The patients were followed for a total of six months, during which they kept a daily symptom diary tracking their abdominal pain on a scale from 0-10 and their bowel movements using the Bristol Stool Form Scale (BSFS). Diary data were not collected before treatment start.

RESULTS

A statistically significant improvement in stool frequency was found in the FMT group from during treatment to post-treatment and 1 month. No statistically significant differences were found between groups at any time during the study for any of abdominal pain, stool frequency, and stool form (as measured by weighted stool score).

CONCLUSION

In this analysis of results from a randomised, double-blind, placebo-controlled study, we found no clinically beneficial effect of FMT on abdominal pain, stool frequency, or stool form. However, since the current literature on the potential role of FMT in treating IBS shows conflicting results, further studies are required. To assess treatment efficacy, we recommend future studies to include daily symptom diaries both before and after treatment intervention.

"Association between dietary inflammatory index (DII) and risk of irritable bowel syndrome: a case-control study"

BACKGROUND

Pathophysiology of IBS is not well recognized; however, several studies have shown the possible relationship between diet and risk of IBS. We assessed the ability of the dietary inflammatory index (DII) to predict the risk of IBS.

METHODS

The subjects were 155 IBS cases and 310 age- and sex-matched healthy controls (aged ≥18 years). The participants were recruited from June, 2019 to March, 2020. IBS was recognized using the Rome IV criteria. DII score was computed based on dietary intake using a 168-item FFQ. The DII score was calculated based on energy-adjusted amounts of nutrients using residual method. Logistic regression models were used to estimate multivariable odds ratios (ORs).

RESULTS

The mean DII score was significantly higher among IBS patients in comparison to healthy controls (0.78 ± 2.22 vs. - 0.39 ± 2.27). In crude model, increase in DII as continuous variable was associated with a significant increase in the risk of IBS (OR (95% CI): 1.26 (1.1-15.38)). Furthermore, the association remained significant even after adjusting for age and sex (OR (95% CI): 1.28 (1.1-17.41)) and after multivariate adjustment (OR (95% CI): 1.38 (1.2-1.56)). In crude, age and sex adjusted and multivariate-adjusted models subjects in fourth quartile of DII had higher OR in comparison to subjects in first quartile.

CONCLUSIONS

This study showed a possible positive association between a pro-inflammatory diet and the risk of IBS. Thus, encouraging intake of more anti-inflammatory dietary factors and reducing intake of pro-inflammatory factors may be a strategy for reducing risk of IBS.

Fecal microbiota transplantation for irritable bowel syndrome: An intervention for the 21st century

Irritable bowel syndrome (IBS) affects about 12% of the global population. Although IBS does not develop into a serious disease or increase mortality, it results in a considerable reduction in the quality of life. The etiology of IBS is not known, but the intestinal microbiota appears to play a pivotal role in its pathophysiology. There is no effective treatment for IBS, and so the applied treatments clinically focus on symptom relief. Fecal microbiota transplantation (FMT), an old Chinese treatment, has been applied to IBS patients in seven randomized controlled trials (RCTs). Positive effects on IBS symptoms in various degrees were obtained in four of these RCTs, while there was no effect in the remaining three. Across the seven RCTs there were marked differences in the selection processes for the donor and treated patients, the transplant dose, the route of administration, and the methods used to measure how the patients responded to FMT. The present frontier discusses these differences and proposes: (1) criteria for selecting an effective donor (superdonor); (2) selection criteria for patients that are suitable for FMT; (3) the optimal FMT dose; and (4) the route of transplant administration. FMT appears to be safe, with only mild, self-limiting side effects of abdominal pain, cramping, tenderness, diarrhea, and constipation. Although it is early to speculate about the mechanisms underlying the effects of FMT, the available data suggest that changes in the intestinal bacteria accompanied by changes in fermentation patterns and fermentation products (specifically short-chain fatty acids) play an important role in improving the IBS symptoms seen after FMT. FMT appears to be a promising treatment for IBS, but further studies are needed before it can be applied in everyday clinical practice.

Effects of Akkermansia muciniphila and Faecalibacterium prausnitzii on serotonin transporter expression in intestinal epithelial cells

PURPOSE

The highest level of peripheral serotonin in the body can be found in the gastrointestinal (GI) tract as its reservoir. There is complete interaction between human gastrointestinal microbiota and serotonin system. Serotonin in the GI is transferred by serotonin transporters (SERTs), which play a crucial role in the bioavailability of serotonin in the GI. SERT impairment is associated with the pathology of GI disorders. It is known that intestinal microbiota can regulate the SERT function. Therefore, it may be useful to regulate of SERT expression by modulation of microbiota and improvement of intestinal motility and GI sensation. In this study, we aimed to evaluate the effects of two next-generation probiotics, including Akkermansia muciniphila and Faecalibacterium prausnitzii, and their supernatants on SERT gene expression in human epithelial colorectal adenocarcinoma cells (Caco-2).

METHODS

The Caco-2 cells were treated with multiplicity of infection (MOI) ratio of 100 of A. muciniphila and F. prausnitzii, as well as their supernatants. After 24 h, SERT gene expression was examined by quantitative real-time polymerase chain reaction (qRT-PCR) assay.

RESULTS

A. muciniphila up-regulated the SERT mRNA level by 3.01 folds, compared to the control group. F. prausnitzii, similar to A. muciniphila, increased the expression of SERT gene in Caco-2 cells by 3.43 folds (P < 0.001). Moreover, the supernatants of A. muciniphila and F. prausnitzii significantly up-regulated the expression of SERT gene in the cell line by 2.4 and 5.7 folds, respectively, compared to the control group (P < 0.001).

CONCLUSIONS

The present results showed that A. muciniphila and F. prausnitzii, as well as their supernatants, increased the expression of SERT gene in Caco-2 cells. Therefore, they might be helpful in the microbiota-modulating treatment of inflammatory bowel diseases.

The relationship between dietary intakes and prevalence of irritable bowel syndrome in adolescent girls: A cross-sectional study

BACKGROUND

Irritable bowel syndrome (IBS) is the most prevalent functional gastrointestinal disorder (FGID) leading to substantial reduction in quality of life. This study was undertaken to assess the relationship between diet and prevalence of IBS in female adolescents.

METHODS

In this cross-sectional study, data were examined on 988 adolescent girls from different areas of Mashhad and Sabzevar cities, Iran. A 168-item validated and reliable food frequency questionnaire (FFQ) for dietary intake was used in all the study participants. A diagnosis of IBS was made using the Rome III criteria.

RESULTS

Dietary macronutrients, energy, and selected micronutrients of IBS patients were similar to healthy subjects. Comparing the intake of caffeine between groups with and without IBS showed a higher level of consumption in the individuals with IBS (p-value = 0.02; p trend = 0.03). There was a significant positive association between caffeine intake and risk of IBS (odds ratio [OR] = 1.88, after adjustment for potential confounding variables). Although there was no significant difference in intakes of total dietary fiber (p-value = 0.23) and insoluble dietary fiber (p-value = 0.09) between IBS-positive and IBS-negative subjects, their soluble dietary fiber intake was significantly different (p-value = 0.02, a significant negative association was seen between soluble dietary fiber intake and IBS prevalence, after adjustment for potential confounding variables [p trend = 0.02; OR = 0.59]).

CONCLUSIONS

The higher intake of caffeine was positively associated with IBS prevalence. Additionally, a negative association was seen between soluble dietary fiber intake and the chance of having IBS.

Inflammatory Biomarkers in Postural Orthostatic Tachycardia Syndrome with Elevated G-Protein-Coupled Receptor Autoantibodies

A growing body of evidence suggests that postural orthostatic tachycardia syndrome (POTS) may be an autoimmune disorder. We have reported in a previous manuscript that 89% of POTS patients (n = 55) had elevations in G-protein-coupled adrenergic A1 receptor autoantibodies and 53% had elevations in muscarinic acetylcholine M4 receptor autoantibodies, as assessed by ELISA. Patients with autoimmune disorders have been reported with a variety of elevated cytokines and cytokines (such as rheumatoid arthritis); thus, we evaluated a limited number of cytokines/chemokines in POTS patients with elevated adrenergic and muscarinic receptor autoantibodies. We utilized the plasma of 34 patients from a previous study; all of the patients (100%) had autoantibodies against the A1 adrenergic receptor and 55.9% (19/34) had autoantibodies against the M4 muscarinic acetylcholine receptor. In particular, the plasma cytokine/chemokine levels were measured as biomarkers of inflammation by Quantibody® technology (Raybiotech, Peachtree Corners, GA, USA). We also evaluated the platelet dense granule numbers, as these patients frequently complain of symptoms related to platelet dysfunction. Patients were predominantly young females who displayed a multitude of co-morbidities but generally reported viral-like symptoms preceding episodes of syncope. Eighty five percent (29/34) had platelet storage pool deficiency. Patients had elevations in five of ten cytokine/chemokines biomarkers (IL1β, IL21, TNFα, INFγ, and CD30), whereas two biomarkers had decreased levels (CD40L and RANTES). Our observations demonstrate that POTS patients known to have autoantibodies against the G-protein-coupled adrenergic A1 receptor have abnormal plasma concentrations of inflammatory cytokines.

Irritable Bowel Syndrome and Risk of Parkinson's Disease in Finland: A Nationwide Registry-Based Cohort Study

BACKGROUND

The gastrointestinal tract is considered as a potential origin of Parkinson's disease (PD) pathology. Besides constipation, appendectomy and inflammatory bowel disease have also been associated with a higher PD-risk, but findings have been inconsistent. To date, there is only one previous study suggesting that irritable bowel syndrome (IBS) is associated with an increased risk of PD.

OBJECTIVE

To evaluate whether IBS is associated with a higher risk of PD.

METHODS

In this retrospective registry-based cohort study, we identified 28,150 patients that were diagnosed with IBS (IBS+) during the years 1998-2014, using data from the Finnish Care Register for Health Care. In addition, 98,789 IBS-free reference subjects (IBS-) of same age and gender and living in the same municipality were included. The study subjects were followed until the end of the year 2014 to analyze the incidence of PD. The association between IBS and PD was assessed by a Cox proportional hazards model.

RESULTS

Diagnosis of IBS was associated with a higher hazard of PD with an adjusted hazard ratio (aHR) of 1.70 (95% CI 1.27-2.26). However, the ratio of hazard rates for PD between IBS+ and IBS- subjects was not constant over time. The Cox model with time-varying coefficient for IBS status showed that the hazard of PD was significantly higher in IBS patients only during the first two years of follow-up (aHR 2.96, 95% CI 1.78-4.92).

CONCLUSION

Our findings indicate that the association between IBS and PD is likely explained by reverse causation and detection bias. It remains open whether IBS is an actual risk factor or a prodromal symptom of PD.

The role of diet in the pathophysiology and management of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a chronic gastrointestinal (GI) disorder that reportedly affects 5% to 20% of the world population. The etiology of IBS is not completely understood, but diet appears to play an important role in its pathophysiology. Asian diets differ considerably from those in Western countries, which might explain differences in the prevalence, sex, and clinical presentation seen between patients with IBS in Asian and Western countries. Dietary regimes such as a low-fermentable oligo-, di-, monosaccharides, and polyols (FODMAP) diet and the modified National Institute for Health and Care Excellence (NICE) diet improve both symptoms and the quality of life in a considerable proportion of IBS patients. It has been speculated that diet is a prebiotic for the intestinal microbiota and favors the growth of certain bacteria. These bacteria ferment the dietary components, and the products of fermentation act upon intestinal stem cells to influence their differentiation into enteroendocrine cells. The resulting low density of enteroendocrine cells accompanied by low levels of certain hormones gives rise to intestinal dysmotility, visceral hypersensitivity, and abnormal secretion. This hypothesis is supported by the finding that changing to a low-FODMAP diet restores the density of GI cells to the levels in healthy subjects. These changes in gut endocrine cells caused by low-FODMAP diet are also accompanied by improvements in symptoms and the quality of life.

A Review of the Complex Relationship between Irritable Bowel Syndrome and Infertility

Irritable bowel syndrome (IBS) is a gastrointestinal disease that negatively affects up to 20% of the population. Infertility is defined as a disorder of the reproductive system described by lack of success in achieving pregnancy after more than a year of regular unprotected sexual intercourse. The main purpose of our review was to analyze the available literature regarding the IBS-infertility connection. Another secondary purpose of the present paper was to find out if oxidative stress may be the missing puzzle that may explain this possible correlation. After analyzing the available literature we concluded that oxidative stress is a plausible mediator of the connection between both female and male fertility and IBS. However, the data lacks in direct evidence to confirm this hypothesis. Nevertheless, it is recommended that certain levels of oxidative stress should not be exceeded in order to decrease IBS symptoms and increase the odds of conception given that generation of reactive oxygen species (ROS) is an aftermath of metabolically active cells. Therefore, reducing the oxidative stress by living a healthier lifestyle with a balanced diet, rich in micronutrients, limited in caffeine and alcohol, avoiding smoking and maintaining a normal body mass index with regular physical exercise may promote fertility and help diminishing IBS symptomatology. Studies with measurements of biological samples are needed in order to assess the complex relationship between oxidative stress, IBS and infertility.

NUTRITIONAL STATUS, QUALITY OF LIFE AND LIFE HABITS OF WOMEN WITH IRRITABLE BOWEL SYNDROME: A CASE-CONTROL STUDY

BACKGROUND

Irritable bowel syndrome is a functional and chronic gastrointestinal disorder that may cause abdominal pain and altered bowel habits, affecting the nutritional status and quality of life of its carriers. Its prevalence is high, affecting about 10% to 15% of the general population in developed countries, being more prevalent in women than in men in the proportion 2:1.

OBJECTIVE

The aim of our study was to compare the profile of body adiposity, life habits, and the quality of life of women with irritable bowel syndrome with a healthy control group.

METHODS

Case-control study on 70 women, 34 with irritable bowel syndrome and 36 healthy. We applied the "Irritable Bowel Syndrome Quality of Life Questionnaire"to assess quality of life. Body adiposity was assessed from body mass index, waist circumference, and waist-to-hip ratio. We investigated the self-reporting of gastrointestinal symptoms with food deemed as problematic for carriers of irritable bowel syndrome and the presence of typical comorbidities. Assessment of life habits included: practice of physical activities, alcoholism, smoking, daytime sleepiness, and exclusion of foods from the feeding routine. For statistical analysis we used the IBM SPSS program, with a significance level at 5%.

RESULTS

There was higher volume of central and general adiposity in the case group compared with the control group (P<0.05). Cases presented a higher chance of developing IBS-related comorbidities (P<0.05). About of 80% of patients with irritable bowel syndrome have excluded some food from the diet (P<0.01) and the total amount of troublesome foods varied from 7 to 21 (P<0.01). The case group featured worse quality of life compared with the control (P<0.05).

CONCLUSION

Compared to the control group, women with irritable bowel syndrome showed greater body adiposity, higher frequency of comorbidities, greater restriction on the consumption of problematic foods and worse quality of life.

Density of Musashi‑1‑positive stem cells in the stomach of patients with irritable bowel syndrome

Irritable bowel syndrome (IBS) affects ~12% of the global population. Although the etiology of IBS is not completely understood, several factors are known to serve a pivotal role in its pathophysiology, including genetic factors, diet, the intestinal microbiota, gastrointestinal endocrine cells and low‑grade inflammation. Musashi‑1 is expressed by stem cells and their early progeny, and is used as a stem cell marker. The low density of intestinal endocrine cells in patients with IBS is thought to be caused by decreased numbers of intestinal stem cells and their differentiation into enteroendocrine cells. The present study employed Musashi‑1 as a marker to detect stem cells in the stomach of 54 patients with IBS and 51 healthy subjects. The patients and controls underwent standard gastroscopy, and biopsy samples were taken from the corpus and antrum. Immunohistochemical staining of gastrin, somatostatin and Mushasi‑1 was carried out and semi‑quantified by computerized image analysis. The density (number of positive cells/mm2 epithelium) of gastrin‑positive cells in the controls and patients with IBS were 337.9±560 and 531.0±908 (median ± range; P<0.0001), respectively. For somatostatin‑positive cells, the density reached 364.4±526.0 in the healthy controls and 150.7±514.0 in patients with IBS (P<0.0001). The density of Musashi‑1‑positive cells was defined as the number of cells per gastric or pyloric gland neck. In the corpus, Musashi‑1‑positive cells density reached 3.0±7.0 in the corpus of the healthy controls and 3.8±7.7 in the patients with IBS. Moreover, the corresponding values in the antrum were 6.0±6.0 and 6.0±6.0, respectively. The Musashi‑1‑positive cell density did not differ significantly between the controls and patients with IBS in the corpus or antrum (P=0.4 and 0.3, respectively). These findings indicated that changes in the stomach endocrine cells observed in patients with IBS may not be explained by an abnormality in stem cells like those found in the small and large intestines of these patients.

Awareness and Utilization of ROME Criteria for Diagnosis of Inflammatory Bowel Syndrome among Primary Care Physicians in Riyadh, Saudi Arabia

INTRODUCTION

Irritable bowel syndrome (IBS) accounts for a reasonable number of medical encounters in primary care, yet a large proportion of cases remain undiagnosed or misdiagnosed due to non-application of systematic approach in such cases.

AIM

We aimed to assess the awareness, attitude and self-reported utilization of ROME criteria among primary care physicians.

METHODS

A cross sectional study was conducted among primary care physicians under ministry of health, Riyadh, Saudi Arabia (N=216). A pre-designed, structured, closed ended, self-administered questionnaire was used to collect the data. SPSS 20 was used for data analysis.

RESULTS

A great majority of physicians (about 86%) were aware about ROME criteria; about 57% were having detailed knowledge, while about 53% considered themselves skilled enough to use it confidently. Only 29% physicians reported to use it frequently in their day to day practice. Knowledge, attitude and practice were found to be significantly higher among family medicine specialty as compared to others (p<0.05), whereas knowledge and attitude were noted to be significantly higher among residents as compared to specialist (p<0.05). No association was noted with age, gender, nationality and duration of clinical experience (p>0.05).

CONCLUSION

We found a low utilization of ROME criteria among physicians with remarkable gap between awareness and practice.

Efficacy of faecal microbiota transplantation for patients with irritable bowel syndrome in a randomised, double-blind, placebo-controlled study

OBJECTIVE

Faecal microbiota transplantation (FMT) from healthy donors to patients with irritable bowel syndrome (IBS) has been attempted in two previous double-blind, placebo-controlled studies. While one of those studies found improvement of the IBS symptoms, the other found no effect. The present study was conducted to clarify these contradictory findings.

DESIGN

This randomised, double-blind, placebo-controlled study randomised 165 patients with IBS to placebo (own faeces), 30 g FMT or 60 g FMT at a ratio of 1:1:1. The material for FMT was obtained from one healthy, well-characterised donor, frozen and administered via gastroscope. The primary outcome was a reduction in the IBS symptoms at 3 months after FMT (response). A response was defined as a decrease of 50 or more points in the total IBS symptom score. The secondary outcome was a reduction in the dysbiosis index (DI) and a change in the intestinal bacterial profile, analysed by 16S rRNA gene sequencing, at 1 month following FMT.

RESULTS

Responses occurred in 23.6%, 76.9% (p<0.0001) and 89.1% (p<00.0001) of the patients who received placebo, 30 g FMT and 60 g FMT, respectively. These were accompanied by significant improvements in fatigue and the quality of life in patients who received FMT. The intestinal bacterial profiles changed also significantly in the groups received FMT. The FMT adverse events were mild self-limiting gastrointestinal symptoms.

CONCLUSIONS

FMT is an effective treatment for patients with IBS. Utilising a well-defined donor with a normal DI and favourable specific microbial signature is essential for successful FMT. The response to FMT increases with the dose. Trial registration www.clinicaltrials.gov (NCT03822299) and www.cristin.no (ID657402).

Possible role of intestinal stem cells in the pathophysiology of irritable bowel syndrome

The pathophysiology of irritable bowel syndrome (IBS) is not completely understood. However, several factors are known to play a role in pathophysiology of IBS such as genetics, diet, gut microbiota, gut endocrine cells, stress and low-grade inflammation. Understanding the pathophysiology of IBS may open the way for new treatment approaches. Low density of intestinal stem cells and low differentiation toward enteroendocrine cells has been reported recently in patients with IBS. These abnormalities are believed to be the cause of the low density of enteroendocrine cells seen in patients with IBS. Enteroendocrine cells regulate gastrointestinal motility, secretion, absorption and visceral sensitivity. Gastrointestinal dysmotility, abnormal absorption/secretion and visceral hypersensitivity are all seen in patients with IBS and haven been attributed to the low density the intestinal enteroendocrine cells in these patients. The present review conducted a literature search in Medline (PubMed) covering the last ten years until November 2019, where articles in English were included. Articles about the intestinal stem cells and their possible role in the pathophysiology of IBS are discussed in the present review. The present review discusses the assumption that intestinal stem cells play a central role in the pathophysiology of IBS and that the other factors known to contribute to the pathophysiology of IBS such as genetics, diet gut microbiota, stress, and low-grade inflammation exert their effects through affecting the intestinal stem cells. It reports further the data that support this assumption on genetics, diet, gut microbiota, stress with depletion of glutamine, and inflammation.

Possible role of peptide YY (PYY) in the pathophysiology of irritable bowel syndrome (IBS)

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder of unknown aetiology for which there is no effective treatment. Although IBS does not increase mortality, it reduces the quality of life and is an economic burden to both the patients themselves and society as a whole. Peptide YY (PYY) is localized in endocrine cells located in the ileum, colon and rectum. The concentration of PYY and the density of PYY cells are decreased in both the colon and rectum but unchanged in the ileum of patients with IBS. The low density of PYY cells in the large intestine may be caused by a decreased number of stem cells and their progeny toward endocrine cells. PYY regulates the intestinal motility, secretion and absorption as well as visceral sensitivity via modulating serotonin release. An abnormality in PYY may therefore contribute to the intestinal dysmotility and visceral hypersensitivity seen in IBS patients. Diet management involving consuming a low-FODMAP diet restores the density of PYY cells in the large intestine and improves abdominal symptoms in patients with IBS. This review shows that diet management appears to be a valuable tool for correcting the PYY abnormalities in the large intestine of IBS patients in the clinic.

Preliminary Biochemical Description of Brain Oxidative Stress Status in Irritable Bowel Syndrome Contention-Stress Rat Model

Background and objectives: Oxidative stress and inflammation have been implicated in the etiology of irritable bowel syndrome (IBS), a common gastrointestinal functional disease. This study aimed to further characterize the contention-stress rat model by exploring a possible correlation between oxidative stress markers measured in brain tissues with behavioral components of the aforementioned model. Thus, it is hereby proposed a possible IBS animal model relevant to pharmacological and complementary medicine studies. Materials and Methods: Wild-type male Wistar rats (n = 5/group) were chronically exposed to 6-hour/day contention, consisting of isolating the animals in small, vital space-granting plastic devices, for seven consecutive days. Following contention exposure, temporal lobes were extracted and subjected to biochemical analyses to assess oxidative stress-status parameters. Results: Our results show increased brain oxidative stress in contention-stress rat model: decreased superoxide dismutase and glutathione peroxidase activities and increased malondialdehyde production in the IBS group, as compared to the control group. Furthermore, the biochemical ratios which are used to evaluate the effectiveness of an antioxidant system on oxidative stress could be described in this model. Conclusions: The correlations between the behavioral patterns and biochemical oxidative stress features could suggest that this may be a complex model, which can successfully mimic IBS symptomatology further providing evidence of a strong connection between the digestive system, enteric nervous system, and the central nervous system.

Gut Microbial Dysbiosis in the Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of Case-Control Studies

BACKGROUND

Irritable bowel syndrome (IBS) is the most common functional digestive condition in the industrialized world. The gut microbiota plays a key role in disease pathogenesis.

OBJECTIVE

A systematic review and meta-analysis on case-control studies was conducted to determine whether there is gut microbial dysbiosis in participants with IBS in comparison with healthy controls and, if so, whether the dysbiosis pattern differs among IBS subtypes and geographic regions.

METHODS

This review was conducted and reported according to the MOOSE (Meta-Analysis of Observational Studies in Epidemiology) 2000 and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2009 guidelines. Research articles published up to May 9, 2018 were identified through MEDLINE (PubMed), Cochrane Central Register of Controlled Trials (Cochrane Library), ClinicalTrials.gov, EMBASE, and Web of Science. Study quality was assessed using the Newcastle-Ottawa Scale. Case-control studies of participants with IBS who had undergone quantitative gut microbial stool analysis were included. The primary exposure measure of interest is log₁₀ bacterial counts per gram of stool. Meta-analyses were performed to estimate the mean difference (MD) in gut microbiota between participants with IBS and healthy controls using the random-effects model with inverse variance in Revman 5.3 and R 3.5.1. Publication bias was assessed with funnel plots and Egger's test. Between-study heterogeneity was analyzed using Higgins I² statistic with 95% CIs.

RESULTS

There were 6,333 unique articles identified; 52 qualified for full-text screening. Of these, 23 studies were included for analysis (n=1,340 participants from North America, Europe, and Asia). Overall, the studies were moderate in quality. Comparing participants with IBS to healthy controls, lower fecal Lactobacillus (MD= -0.57 log₁₀ colony-forming unit [CFU]/g; P<0.01) and Bifidobacterium (MD= -1.04 log₁₀CFU/g; P<0.01), higher Escherichia coli (MD=0.60 log₁₀CFU/g; P<0.01), and marginally higher Enterobacter (MD=0.74 log₁₀CFU/g; P=0.05). No difference was found between participants with IBS and healthy controls in fecal Bacteroides and Enterococcus (P=0.18 and 0.68, respectively). Publication bias was not observed except in Bifidobacterium (P=0.015). Subgroup analyses on participants with diarrhea-predominant and constipation-predominant IBS showed consistent results with the primary results. A subgroup analysis of Chinese studies was consistent with the primary results, except for fecal Bacteroides, which was increased in participants with IBS vs healthy controls (MD=0.29; 95% CI 0.13 to 0.46; P<0.01). Although substantial heterogeneity was detected (I²>75%) in most comparisons, the direction of the effect estimates is relatively consistent across studies.

CONCLUSIONS

IBS is characterized by gut microbial dysbiosis. Prospective, large-scale studies are needed to delineate how gut microbial profiles can be used to guide targeted therapies in this challenging patient population.

Diet in Irritable Bowel Syndrome (IBS): Interaction with Gut Microbiota and Gut Hormones

Diet plays an important role not only in the pathophysiology of irritable bowel syndrome (IBS), but also as a tool that improves symptoms and quality of life. The effects of diet seem to be a result of an interaction with the gut bacteria and the gut endocrine cells. The density of gut endocrine cells is low in IBS patients, and it is believed that this abnormality is the direct cause of the symptoms seen in IBS patients. The low density of gut endocrine cells is probably caused by a low number of stem cells and low differentiation progeny toward endocrine cells. A low fermentable oligo-, di-, monosaccharide, and polyol (FODMAP) diet and fecal microbiota transplantation (FMT) restore the gut endocrine cells to the level of healthy subjects. It has been suggested that our diet acts as a prebiotic that favors the growth of a certain types of bacteria. Diet also acts as a substrate for gut bacteria fermentation, which results in several by-products. These by-products might act on the stem cells in such a way that the gut stem cells decrease, and consequently, endocrine cell numbers decrease. Changing to a low-FODMAP diet or changing the gut bacteria through FMT improves IBS symptoms and restores the density of endocrine cells.

Reduction in IBS symptom severity is not paralleled by improvement in quality of life in patients with irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a brain-gut disorder, of which the natural course varies between patients and is difficult to predict. This study aimed to evaluate symptom evolution over a 5-year follow-up period and to identify baseline predictors for symptom severity and quality of life (QoL) at follow-up.

METHODS

Maastricht IBS cohort participants completed questionnaires upon inclusion regarding demographics and lifestyle, gastrointestinal (GI) symptoms, anxiety and depression, and QoL. The same questionnaires, in addition to others, were completed after 5 years. Rome criteria were confirmed face-to-face at initial enrollment and through telephonic interviews at follow-up.

KEY RESULTS

At a mean follow-up of 4.7 years, 379 patients were approached of whom 203 (53.7%) responded. Of these, 161 were reached by telephone and analyzed; 49 (30.4%) did not fulfill the Rome III criteria at follow-up and had lower levels of GI symptoms and GI-specific anxiety compared to those remaining Rome III-positive (P < 0.001). However, Rome III-negative patients had comparable levels of QoL and life satisfaction, comorbid anxiety and depression, work absenteeism, and impaired productivity. No baseline predictors were found for being Rome III-positive or Rome III-negative. However, greater age and lower baseline physical QoL predicted lower physical QoL at follow-up (P < 0.005 and P < 0.01, respectively), while lower baseline mental QoL predicted lower mental QoL at follow-up (P = 0.005). Additionally, higher anxiety and depression scores at follow-up were associated with lower QoL and life satisfaction at follow-up (P < 0.001).

CONCLUSIONS AND INFERENCES

Long-term QoL and general well-being might depend on concurrent psychological symptoms, rather than GI symptom improvement.

A Dietary Intervention with Reduction of Starch and Sucrose Leads to Reduced Gastrointestinal and Extra-Intestinal Symptoms in IBS Patients

Patients with irritable bowel syndrome (IBS) exhibit low-grade inflammation and increased gut permeability. Dietary sugar has been shown to contribute to low-grade inflammation and increased gut permeability, and to correlate with gastrointestinal (GI) symptoms. The aim of the present study was to examine the effect of a starch- and sucrose-reduced diet (SSRD) on gastrointestinal (GI) and extra-intestinal symptoms in IBS. One hundred and five IBS patients (82 women, 46.06 ± 13.11 years), with irritable bowel syndrome-symptom severity scale (IBS-SSS) > 175, were randomized to SSRD for 4 weeks or continued ordinary eating habits. The visual analog scale for irritable bowel syndrome (VAS-IBS), IBS-SSS, and 4-day food diaries were collected at baseline and after 2 and 4 weeks. After the intervention, one-third of the patients did not fulfill the criteria for IBS/functional gastrointestinal disorder. Half of the participants changed from moderate/severe disease to no/mild disease according to IBS-SSS. Comparisons between the groups showed decreased weight and sweet cravings, and parallel decreases in total IBS-SSS and extra-intestinal IBS-SSS scores, in the intervention group compared to controls (p < 0.001 for all). When calculating separate extra-intestinal symptoms, belching (p = 0.001), muscle/joint pain (p = 0.029), urinary urgency (p = 0.017), and tiredness (p = 0.011) were decreased after introduction of SSRD compared to controls. In conclusion, SSRD improves both GI and extra-intestinal symptoms in IBS.

Effects of a Cod Protein Hydrolysate Supplement on Symptoms, Gut Integrity Markers and Fecal Fermentation in Patients with Irritable Bowel Syndrome

Peptides from fish may beneficially affect several metabolic outcomes, including gut health and inflammation. The effect of fish peptides in subjects with irritable bowel syndrome (IBS) has not previously been investigated, hence this study aimed to evaluate the effect of a cod protein hydrolysate (CPH) supplement on symptom severity, gut integrity markers and fecal fermentation in IBS-patients. A double-blind, randomized parallel-intervention with six weeks of supplementation with 2.5 g CPH (n = 13) or placebo (n = 15) was conducted. The outcomes were evaluated at baseline and the end of the study. The primary outcomes were symptom severity evaluated by the IBS severity scoring system (IBS-SSS) and quality of life. The secondary outcomes included gut integrity markers and pro-inflammatory cytokines in serum, fecal fermentation measured by concentration of short-chain fatty acids (SCFAs) and fecal calprotectin. The groups were comparable at baseline. The total IBS-SSS-scores were reduced in both the CPH-group (298 ± 69 to 236 ± 106, p = 0.081) and the placebo-group (295 ± 107 to 202 ± 103, p = 0.005), but the end of study-scores did not differ (p = 0.395). The concentrations of serum markers and SCFAs did not change for any of the groups. The baseline measures for the whole group showed that the total SCFA concentrations were inversely correlated with the total IBS-SSS-score (r = −0.527, p = 0.004). Our study showed that a low dose of CPH taken daily by IBS-patients for six weeks did not affect symptom severity, gut integrity markers or fecal fermentation when compared to the placebo group.

Increasing the Dose and/or Repeating Faecal Microbiota Transplantation (FMT) Increases the Response in Patients with Irritable Bowel Syndrome (IBS)

BACKGROUND

Faecal microbiome transplantation (FMT) appears to be an effective method for treating irritable bowel syndrome (IBS) patients. However, it is not clear if a high transplant dose and/or repeating FMT are/is needed to ensure a response. The present study was undertaken to clarify this matter.

METHODS

Ten IBS patients who did not respond to a 30-g transplant subsequently received a 60-g transplant into the duodenum via a gastroscope. The patients provided faecal samples before and 1 month after FMT. They completed five questionnaires measuring symptoms, fatigue and quality of life at baseline and then at 2 weeks, 1 month and 3 months after FMT. The dysbiosis index (DI) was measured using the GA-map Dysbiosis Test®.

RESULTS

Seven patients (70%) responded to the 60-g transplant, with significant clinical improvements in the abdominal symptoms, fatigue and quality of life in 57%, 80% and 67% of these patients. The 60-g transplant also reduced the DI.

CONCLUSION

FMT is an effective treatment for IBS. A high-dose transplant and/or repeated FMT increase the response rate and the intensity of the effects of FMT.

Overlapping of irritable bowel syndrome with erosive esophagitis and the performance of Rome criteria in diagnosing IBS in a clinical setting

Irritable bowel syndrome (IBS) and gastroesophageal reflux disease (GERD) overlap. It is not clear whether GERD is caused by non-erosive esophagitis, or erosive esophagitis. The Rome criteria are not widely used for the diagnosis of IBS in the clinic. In total, 1,489 IBS patients without red flags were included in the present retrospective study. They comprised of 1,331 females and 158 males with a mean age of 51 years. The diagnosis of IBS was verified by endoscopic and histopathological examinations. Whereas erosive esophagitis occurred in 97% of patients, only 66% had GERD symptoms. Endoscopy and histopathological examinations revealed that 1.4% of the IBS patients with diarrhea as the predominant symptom had other organic gastrointestinal diseases: 0.3% with celiac disease, 0.2% with Crohn's disease, 0.07% with ulcerative colitis, 0.6% with microscopic colitis, and 0.2% with colon cancer. Applying the Rome III criteria produced a sensitivity of 100% [95% confidence intervals (CI)=99.8–100.0%] a specificity of 98.7% (95% CI=98.0–99.2%), a positive likelihood ratio of 76.9%, and a negative likelihood ratio of 0%. IBS is associated with erosive esophagitis. Applying Rome III criteria without red flags and history, was effective in diagnosing IBS. Celiac disease and microscopic colitis should be considered as alternative diagnoses.

The potential probiotic Lactobacillus rhamnosus CNCM I-3690 strain protects the intestinal barrier by stimulating both mucus production and cytoprotective response

The gut barrier plays an important role in human health. When barrier function is impaired, altered permeability and barrier dysfunction can occur, leading to inflammatory bowel diseases, irritable bowel syndrome or obesity. Several bacteria, including pathogens and commensals, have been found to directly or indirectly modulate intestinal barrier function. The use of probiotic strains could be an important landmark in the management of gut dysfunction with a clear impact on the general population. Previously, we found that Lactobacillus rhamnosus CNCM I-3690 can protect intestinal barrier functions in mice inflammation model. Here, we investigated its mechanism of action. Our results show that CNCM I-3690 can (i) physically maintain modulated goblet cells and the mucus layer and (ii) counteract changes in local and systemic lymphocytes. Furthermore, mice colonic transcriptome analysis revealed that CNCM I-3690 enhances the expression of genes related to healthy gut permeability: motility and absorption, cell proliferation; and protective functions by inhibiting endogenous proteases. Finally, SpaFED pili are clearly important effectors since an L. rhamnosus ΔspaF mutant failed to provide the same benefits as the wild type strain. Taken together, our data suggest that CNCM I-3690 restores impaired intestinal barrier functions via anti-inflammatory and cytoprotective responses.

Clinical and Microbiological Effect of a Multispecies Probiotic Supplementation in Celiac Patients With Persistent IBS-type Symptoms: A Randomized, Double-Blind, Placebo-controlled, Multicenter Trial

GOALS

The goals of this study were to evaluate the efficacy and safety of a probiotic mixture in patients with celiac disease (CD) with irritable bowel syndrome (IBS)-type symptoms despite a strict gluten-free diet (GFD).

BACKGROUND

About 30% of patients with CD adherent to a GFD suffer from IBS-type symptoms; a possible cause resides in the imbalances of the intestinal microbiota in CD. Probiotics may represent a potential treatment.

STUDY

CD patients with IBS-type symptoms entered a prospective, double-blind, randomized placebo-controlled study. A 6-week treatment period was preceded by a 2-week run-in and followed by a 6-week follow-up phase. Clinical data were monitored throughout the study by validated questionnaires: IBS Severity Scoring System (IBS-SSS); Gastrointestinal Symptom Rating Scale (GSRS); Bristol Stool Form Scale (BSFS); and IBS Quality of Life Questionnaire (IBS-QOL). The fecal microbiota were assayed using plate counts and 16S rRNA gene-based analysis.

RESULTS

In total, 109 patients were randomized to probiotics (n=54) or placebo (n=55). IBS-SSS and GSRS decreased significantly in probiotics, as compared with placebo [(-15.9%±14.8% vs. 8.2%±25.9%; P<0.001) and (-19.8%±16.6% vs. 12.9%±31.6%; P<0.001)], respectively. Treatment success was significantly higher in patients receiving probiotics, as compared with placebo (15.3% vs. 3.8%; P<0.04). Presumptive lactic acid bacteria, Staphylococcus and Bifidobacterium, increased in patients receiving probiotic treatment. No adverse events were reported.

CONCLUSIONS

A 6-week probiotic treatment is effective in improving the severity of IBS-type symptoms, in CD patients on strict GFD, and is associated with a modification of gut microbiota, characterized by an increase of bifidobacteria.

Contribution of ghrelin to functional gastrointestinal disorders' pathogenesis

Functional gastrointestinal disorders (FGID) are heterogeneous disorders with a variety of clinical manifestations, primarily defined by signs and symptoms rather than a definite underlying cause. Their pathophysiology remains obscure and, although it is expected to differ according to the specific FGID, disruptions in the brain-gut axis are now thought to be a common denominator in their pathogenesis. The hormone ghrelin is an important component of this axis, exerting a wide repertoire of physiological actions, including regulation of gastrointestinal motility and protection of mucosal tissue. Ghrelin's gene shows genetic polymorphism, while its protein product undergoes complex regulation and metabolism in the human body. Numerous studies have studied ghrelin's relation to the emergence of FGIDs, its potential value as an index of disease severity and as a predictive marker for symptom relief during attempted treatment. Despite the mixed results currently available in scientific literature, the plethora of statistically significant findings shows that disruptions in ghrelin genetics and expression are plausibly related to FGID pathogenesis. The aim of this paper is to review current literature studying these associations, in an effort to uncover certain patterns of alterations in both genetics and expression, which could delineate its true contribution to FGID emergence, either as a causative agent or as a pathogenetic intermediate.