Dietary Propolis Ameliorates Dextran Sulfate Sodium-Induced Colitis and Modulates the Gut Microbiota in Rats Fed a Western Diet.

Kai Wang,Liming Wu,David Topping,Fuliang Hu,Michael Conlon,Wenli Tian,Mengmeng You,Xiaolu Jin,Richard Leu

doi:10.3390/nu9080875

Abstract

Propolis is an important hive product and considered beneficial to health. However, evidence of its potential for improving gut health is still lacking. Here we use rats to examine whether dietary supplementation with propolis could be used as a therapy for ulcerative colitis. Rats were fed with a Western style diet alone (controls) or supplemented with different amounts of Chinese propolis (0.1%, 0.2%, and 0.3%) to examine effects on acute colitis induced by 3% dextran sulphate sodium (DSS) in drinking water. Propolis at 0.3%, but not lower levels, significantly improved colitis symptoms compared with the control group, with a less pronounced disease activity index (DAI) (p < 0.001), a significant increase in colon length/weight ratio (p < 0.05) and an improved distal colon tissue structure as assessed by histology. Although short chain fatty acid levels in digesta were not altered by propolis supplementation, 16S rRNA phylogenetic sequencing revealed a significant increase in gut microbial diversity after 21 days of 0.3% propolis supplementation compared with controls including a significant increase in bacteria belonging to the Proteobacteria and Acidobacteria phyla. This is the first study to demonstrate that propolis can attenuate DSS-induced colitis and provides new insight into diet-microbiota interactions during inflammatory bowel disease.

Highlights

Inflammatory bowel disease (IBD), which includes Crohn’s disease (CD) and ulcerative colitis (UC), is a chronic disorder of the gastrointestinal tract characterized by inflammation
We describe a study to determine whether the addition of a Chinese propolis extract to a Western style diet can reduce the severity of colitis induced by dextran sulphate sodium (DSS) in rats and using this model to examine the contribution that the gut microbiota may play in this protection
The experimental diets were a modification of the AIN 93G diet in which protein and fat levels were increased to 25% and 20%, respectively, to approximate a Western style diet (Table 1) which was supplemented with 0%, 0.1%, 0.2%, or 0.3% of a Chinese propolis extract

Summary

Introduction

Inflammatory bowel disease (IBD), which includes Crohn’s disease (CD) and ulcerative colitis (UC), is a chronic disorder of the gastrointestinal tract characterized by inflammation. UC typically suffer with recurrent inflammation of the colon whereas in CD patients the inflammatory responses can occur in the terminal ileum and colon [1]. The precise aetiology of IBD still remains unknown, and there are some cases reporting genetic susceptibility of some individuals, a dysbiosis of the gut microbiota remains a consistent underlying feature [2]. Environmental factors, diet and lifestyle have been widely recognized as potential triggers for IBD. Recent rapid increases in the incidence of IBD in developing countries have occurred along with considerable shifts toward. Dietary intervention is being considered as a means of IBD

Methods

Results

Conclusion