Modulation of the gut microbiota: a focus on treatments for irritable bowel syndrome

Bile acids and FXR in functional gastrointestinal disorders

Functional gastrointestinal disorders (FGIDs), such as irritable bowel syndrome (IBS) and chronic constipation (CC), are commonly diagnosed conditions in clinical practice which create a substantial global burden. Since the farnesoid X receptor (FXR) and bile acids (BAs) are responsible for maintaining homeostasis in the GI tract, any disturbances in the expression of FXR or the composition of BAs may contribute to the development of the GI symptoms. Alterations in the mechanism of action of FXR directly affect the BAs pool and account for increased intestinal permeability and changes in abundance and diversity of gut microbiota leading to intestinal dysmotility. Current review focuses on the correlation between the FXR, BAs and the composition of gut microbiota and its influence on the occurrence of GI symptoms in FGIDs.

Risk of psychiatric disorders in irritable bowel syndrome-A nationwide, population-based, cohort study

AIMS

This cohort study aimed to investigate the association between irritable bowel syndrome (IBS) and the risk of developing psychiatric disorders.

METHODS

Utilizing the National Health Insurance Research Database (NHIRD) of Taiwan, IBS patients were identified and compared with age, sex, and index year-matched controls (1:3).

RESULTS

Of the IBS subjects, 3934 in 22 356 (17.60%, or 1533.68 per 100 000 person-years) developed psychiatric disorders when compared with 6127 in 67 068 (9.14%, or 802 per 100 000 person-years) in the non-IBS control group. Fine and Gray's survival analysis revealed that the study subjects were more likely to develop psychiatric disorders. The crude hazard ratio (HR) is 3.767 (95% CI: 3.614-3.925, P < .001), and the adjusted HR is 3.598 (95% CI: 3.452-3.752, P < .001) in the risk of developing psychiatric disorders after being adjusted for age, sex, comorbidities, geographical area of residence, urbanisation level of residence, and monthly insurance premiums. The cohort study revealed that IBS subjects were associated with an increased risk of anxiety, depression, bipolar, and sleep disorders.

CONCLUSIONS

This cohort study, using NHIRD, shows evidence support that patients with IBS have a 3.6-fold risk of developing psychiatric disorders. Other large or national datasets should be done to explore to underlying mechanisms.

Effects of Alkaline-Reduced Drinking Water on Irritable Bowel Syndrome with Diarrhea: A Randomized Double-Blind, Placebo-Controlled Pilot Study

Objectives

The purpose of this study was to investigate whether the ingestion of alkaline-reduced water (ARW) is helpful in improving the symptoms of diarrhea-predominant irritable bowel syndrome (IBS).

Methods

Twenty-seven patients (male, 25.9%; mean, 41.7 years old) with diarrhea-predominant IBS were randomly allocated to two groups. For eight weeks, the ARW group (n = 13) ingested at least 2 liters/day of ARW, while the control group (n = 14) ingested placebo water. IBS symptom scores (quality-of-life, abdominal pain/discomfort), stool form, and frequency were assessed before and after treatment via questionnaires.

Results

Eight patients (61.5%) in the ARW group and six patients (42.9%) in the control group indicated that their symptoms had improved in more than four out of the eight weeks of treatment (p = 0.449). The IBS quality-of-life score significantly improved from 57.2 to 30.8 in the ARW group; this improvement was significantly greater than the slight improvement from 48.7 to 42.2 observed in the control group (p = 0.029). The abdominal pain score improved from 1.8 to 0.9 in the ARW group and from 1.8 to 1.1 in the control group, with no significant group difference (p = 0.232).

Conclusions

Drinking ARW for eight weeks improves the quality of life in patients with diarrhea-predominant IBS.