Functional constipation and the effect of prebiotics on the gut microbiota: a review

Microbiota treatment of functional constipation: Current status and future prospects

Functional constipation (FC) is a common disorder that is characterized by difficult stool passage, infrequent bowel movement, or both. FC is highly prevalent, recurs often, accompanies severe diseases, and affects quality of life; therefore, safe and effective therapy with long-term benefits is urgently needed. Microbiota treatment has potential value for FC treatment. Microbiota treatments include modulators such as probiotics, prebiotics, synbiotics, postbiotics, and fecal microbiota transplantation (FMT). Some probiotics and prebiotics have been adopted, and the efficacy of other microbiota modulators is being explored. FMT is considered an emerging field because of its curative effects; nevertheless, substantial work must be performed before clinical implementation.

Efficacy and mechanism of acupuncture for functional constipation in older adults: study protocol for a randomized controlled trial

Introduction

Functional constipation (FC) is a common functional gastrointestinal disorder in clinical practice, with the prevalence of which increasing with age. With the increasing aging of the population worldwide, this problem is bound to become more prominent. Acupuncture is effective and recommended for the treatment of FC. However, little is known about how acupuncture affects the gut microbiota and inflammatory cytokines and thus improves gut function. Meanwhile, there are few high-quality clinical trials specifically focusing on acupuncture in treating FC in older people. The objective of this study is to assess the efficacy and safety of acupuncture in treating FC in older people. Additionally, the research aims to explore the mechanism of action of acupuncture in treating FC in older people by affecting intestinal microbiota and inflammation cytokines.

Methods and analysis

This study is designed as a single-center, randomized, sham-controlled clinical trial. A total of 98 eligible FC patients will be randomized in a 1:1 ratio into an acupuncture group and a sham acupuncture group. Both groups will receive 24 treatments over 8 weeks with a 12-week follow-up. The primary outcome of the study is the treatment response rate, which is the proportion of participants with ≥3 mean weekly Complete Spontaneous Bowel Movements (CSBMs) over weeks 3-8. The secondary outcomes will include the proportion of participants with ≥3 mean weekly CSBMs during other assessment periods; the percentage of patients with ≥1 increase in mean weekly CSBMs from baseline; the average changes in CSBMs; Patient Assessment of Constipation-Symptoms (PAC-SYM), Bristol Stool Scale, Patient Assessment of Constipation Quality of Life Questionnaire (PAC-QOL), Self-rating Anxiety Scale (SAS), Self-rating Depression Scale (SDS) and weekly usage of emergency bowel medications. Adverse events will be recorded throughout the study. Data for the outcomes will be collected at Week 0 (baseline), Week 4 (the intervention period), Week 8 (the post-treatment), Week 12 (the follow-up period) and Week 20 (the follow-up period). In addition, changes in intestinal microbiota will be analyzed using 16S rRNA high-throughput detection, and the concentration of relevant inflammatory cytokines in serum will be measured by ELISA based on blood samples. The intention-to-treat analysis will be performed in this study.Clinical trial registration: [https://www.chictr.org.cn/], identifier [ChiCTR2300070735].

Effects of a prebiotic formulation on the composition of the faecal microbiota of people with functional constipation

PURPOSE

Prebiotics are defined as substances which selectively promote beneficial gut microbes leading to a health benefit for the host. Limited trials have been carried out investigating their effect on the microbiota composition of individuals afflicted by functional constipation with equivocal outcomes. In a 21-day randomised, controlled clinical trial involving 61 adults with functional constipation, a prebiotic formulation with partially hydrolysed guar gum and acacia gum as its main ingredients, significantly increased complete spontaneous bowel motions in the treatment group. This follow-up exploratory analysis investigated whether the prebiotic was associated with changes to the composition, richness, and diversity of the faecal microbiota.

METHODS

Participants provided a faecal specimen at baseline and on day 21 of the intervention period. Whole genome metagenomic shotgun sequencing comprehensively assessed taxonomic and functional composition of the microbiota.

RESULTS

Linear mixed effects regression models adjusted for potential confounders showed a significant reduction in species richness of 28.15 species (95% CI - 49.86, - 6.43) and Shannon diversity of 0.29 units (95% CI - 0.56, - 0.02) over the trial period in the prebiotic group. These changes were not observed in the control group, and functional composition was unchanged in both groups.

CONCLUSION

In adults with functional constipation, the intake of a prebiotic formulation was associated with a decline of species richness and Shannon diversity. Further research regarding the associations between prebiotics and the composition and function of the gut microbiota is warranted.

Flavonoids in Amomum tsaoko Crevost et Lemarie Ameliorate Loperamide-Induced Constipation in Mice by Regulating Gut Microbiota and Related Metabolites

Amomum tsaoko (AT) is a dietary botanical with laxative properties; however, the active ingredients and mechanisms are still unclear. The active fraction of AT aqueous extract (ATAE) for promoting defecation in slow transit constipation mice is the ethanol-soluble part (ATES). The total flavonoids of ATES (ATTF) were the main active component. ATTF significantly increased the abundance of Lactobacillus and Bacillus and reduced the dominant commensals, such as Lachnospiraceae, thereby changing the gut microbiota structure and composition. Meanwhile, ATTF changed the gut metabolites mainly enriched in pathways such as the serotonergic synapse. In addition, ATTF increased the serum serotonin (5-HT) content and mRNA expression of 5-hydroxytryptamine receptor 2A (5-HT_2A), Phospholipase A2 (PLA2), and Cyclooxygenase-2 (COX2), which are involved in the serotonergic synaptic pathway. ATTF increased Transient receptor potential A1 (TRPA1), which promotes the release of 5-HT, and Myosin light chain 3(MLC3), which promotes smooth muscle motility. Notably, we established a network between gut microbiota, gut metabolites, and host parameters. The dominant gut microbiota Lactobacillus and Bacillus, prostaglandin J2 (PGJ2) and laxative phenotypes showed the most significant associations. The above results suggest that ATTF may relieve constipation by regulating the gut microbiota and serotonergic synaptic pathway and has great potential for laxative drug development in the future.