Efficacy and Safety of High Specific Volume Polysaccharide-A New Type of Dietary Fiber for Treatment of Functional Constipation and IBS-C

A Combination of Xyloglucan, Pea Protein and Chia Seed Ameliorates Intestinal Barrier Integrity and Mucosa Functionality in a Rat Model of Constipation-Predominant Irritable Bowel Syndrome

Irritable Bowel Syndrome is a gastrointestinal disorder that affects the large intestine, which encompasses several symptoms including, but not limited to, abdominal pain, bloating and dysmotility. In particular, IBS associated with constipation (IBS-C) is characterized by hard and dry stools and inadequate evacuation and difficulty in defecation. Although several drugs ameliorate intestinal modifications and constipation-associated features, management of IBS is still a challenge. Natural compounds including Xyloglucan and pea protein (XP) and Chia seed powder (CS) are widely known to possess beneficial effects in counteracting several gastrointestinal disorders. Here, we aimed to assess the combined effects of XP and CS to treat constipation-related alterations in an IBS-C rat model. IBS-C was induced by gastric instillation of 2 mL of cold water (0-4 °C) for 14 days and Xiloglucan, Pea protein and Chia seeds (XP + CS) treatment was orally administered for 7 days. On day 22, colon tissues were collected for histological analysis. Our results showed that XP + CS administration attenuated constipation-related parameters by increasing body weight and food and water intake. Upon XP + CS treatment, from day 14 to 22, stool moisture content was restored to physiological level. Colonic tissues from IBS-C rats depicted a disruption of the organ architecture accompanied by edema. Loss of colonic structure was reflected by the marked reduction of tight junction protein expression, Occludin and zona occludens-1 (ZO-1). Administration of XP + CS treatment in IBS-C rats significantly ameliorated the colonic histological parameters and exerted a positive effect on barrier integrity by restoring the expression of Occludin and zona occludens-1 (ZO-1). Our findings demonstrated that the efficacy of XP and CS in managing constipation in rats is due to the ability of these compounds to form a protective barrier fortifying intestinal integrity and gut functionality.

Efficacy of High Specific Volume Polysaccharide - A New Type of Dietary Fiber - On Molecular Mechanism of Intestinal Water Metabolism in Rats With Constipation

Background

The aim of this study was to evaluate the effects of a new type of dietary fiber – high specific volume polysaccharide (HSVP) – on fecal properties, serum vasoactive intestinal peptide (VIP) concentration, intestinal flora count, and expression of the VIP-cAMP-PKA-AQP3 signaling pathway.

Marerial/Methods

Compound diphenoxylate was used in 48 healthy Wistar rats to establish a constipation model. Rats were divided into a normal control group, a constipation model group, an HSVP low-dose group, an HSVP medium-dose group, an HSVP high-dose group, and a fructose control group. We used colony count method, ELISA, WB, and RT-PCR to determine fecal moisture content, fecal hardness, fecal passage time, serum VIP concentration, number of intestinal bacteria, and VIP-cAMP-PKA-AQP3 signal pathway protein expression.

Results

The constipation model was established successfully. HSVP (the medium dose was 10% and the high dose was 15%) improved fecal moisture content, reduced hardness, shortened fecal emptying time, increased intestinal bacteria, reduced serum VIP concentration, downregulated cAMP and PKAm RNA transcription, reduced protein expression, and reduced intestinal AQP3 expression.

Conclusions

HSVP improved constipation, increased the number of intestinal bacteria, and elevated expression of the VIP-cAMP-PKA-AQP3 signaling pathway. The mechanism of HSVP in regulating intestinal water metabolism in constipated rats may occur through the VIP-cAMP-PKA-AQP3 signaling pathway, and be closely related to changes in intestinal bacteria. The important role of the brain-gut-microbiome axis in the pathogenesis of constipation has been confirmed in this study.