Plasma Concentrations of GLP-1 and PYY in Rats Fed Dietary Fiber Depend on the Fermentability of Dietary Fiber and Respond to an Altered Diet

Ryoko Shimada,Kiyoshi Ebihara,Kaori Murakami,Miki Yoshimura

doi:10.15344/2456-8171/2015/103

Abstract

Background: It was reported to be associated with intake of dietary fiber and gut hormone. We compared the effect of dietary fiber on the plasma concentration of glucagon-like peptide-1 (GLP-1) and peptide YY (PYY). Methods: Firstly, male Wistar rats (10 wk old) were fed a fiber-free diet (FF diet, AIN-93G-based diet without cellulose) or one of nine FF diets with 5% dietary fiber for 21 days. Cellulose, guar gam (GG), partially hydrolyzed guar gum (PHGG), sugar beet fiber (BF), konjac mannnan (KM), raffinose (RF), hydroxypropyl starch (HPS), hydroxypropyl distarch phosphate (HPDP) and Akamoku (AK) were used as dietary fiber sources. Secondly, we then determined whether the concentrations of GLP-1 and PYY in portal and aorta plasma and microbiota in cecal contents responded to an altered diet. Male Wistar rats (10 wk old) were fed the PHGG diet for 20 days before being changed to the FF diet. Results: The amount of short chain fatty acids (SCFA) in the cecal contents markedly increased in rats fed the GG, PHGG, BF, KM, RF, HPS or HPDP diets compared with SCFA in rats fed the FF, CL or AK diets. The concentrations of GLP-1 and PYY in portal plasma positively correlated with the concentration of SCFA in the cecal contents and cecal tissue weight. The concentrations of GLP-1 and PYY, in the altered diet group decreased to the same concentration as that measured in the FF group. However, it was low the similarities in the cecal bacteria population. Conclusion: The plasma concentrations of GLP-1 and PYY increased with increasing the amounts of SCFA, the products of DF fermentation, in the cecal contents. GLP-1 and PYY plasma concentrations and SCFA concentrations in the cecal contents rapidly responded to the altered diet, but the cecal bacteria population did not.

Highlights

Introduction amount and type ofDietary fiber (DF) and RS consumed has dramatic effects onA recent animal study showed that short-chain fatty acids (SCFA) produced by bacterial fermentation in the gut can directly influence L-cells to enhance the release of peptides such as glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY) [1].The effect of SCFA in stimulating PYY and GLP-1 secretion from L-cells has been demonstrated in humans[2]
The plasma concentrations of GLP-1 and PYY increased with increasing the amounts of SCFA, the products of DF fermentation, in the cecal contents
GLP-1 and PYY plasma concentrations and SCFA concentrations in the cecal contents rapidly responded to the altered diet, but the cecal bacteria population did not

Summary

Introduction

A recent animal study showed that short-chain fatty acids (SCFA) produced by bacterial fermentation in the gut can directly influence L-cells to enhance the release of peptides such as glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY) [1].The effect of SCFA in stimulating PYY and GLP-1 secretion from L-cells has been demonstrated in humans[2]. GLP-1and PYY are cosecreted from endocrine L-cells that are found primarily in the distal gastrointestinal tract [3,4]. GLP-1 causes reduced appetite and increases the release of insulin [5]. PYY acts to reduce appetite [6]. PYY acts in the stomach and intestine to slow down the movement of food through the digestive tract. Resistant the composition of the intestinal microbiota and on the type and amount of SCFA produced.

Methods

Results

Conclusion