Protection of Galacto-Oligosaccharide against E. coli O157 Colonization through Enhancing Gut Barrier Function and Modulating Gut Microbiota

Yan Zou,Huan Lv,Shuo Wang,Bo Peng,Yuanyifei Wang,Bowei Zhang,Jingmin Liu,Jin Wang

doi:10.3390/foods9111710

Abstract

Galacto-oligosaccharide (GOS) has been added to infant formula as prebiotics and can bring many benefits to human health. This study proved the effect of GOS in prevention and alleviation against E. coli O157 invasion and colonization and the mechanism behind this was explored in a mice model. The results showed that the expression of Muc2 and Occlaudin were both significantly down-regulated (p < 0.05) by E. coli O157 infection, while GOS alleviated this phenomenon, which means that GOS can reduce the colonization of E. coli O157 by enhancing the gut barrier function. Through the determination of inflammatory cytokines, we found that GOS can relieve inflammation caused by pathogens. At the same time, GOS can promote the growth of probiotics such as Akkermansia, Ruminococcaceae and Bacteroides, thus modulating microorganism environments and improving short chain fatty acid (SCFA) levels in the intestine. This study provides an explanation for the mechanism behind the protection of GOS against pathogen infection.

Highlights

Enterohemorrhagic Escherichia coli O157:H7 (E. coli O157) is a leading food-borne pathogen of intestinal infection
In order to study the correlation between intestinal microflora and other sample indicators, we introduced environmental factor analysis and established the correspondence analysis (CCA) model of microbial community samples along with four main factors, including the total amount of short chain fatty acid (SCFA), the relative expression of
Enterohemorrhagic E. coli O157 mainly enters the intestine through the oral route, passes the mucus layer and reaches epithelial cells

Summary

Introduction

Enterohemorrhagic Escherichia coli O157:H7 (E. coli O157) is a leading food-borne pathogen of intestinal infection. It is commonly seen in meat, dairy and many other products, and can cause diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome worldwide [1,2]. The pathogenic site of E. coli O157 is mainly the colon and ileum. Antibiotics are mainly used to deal with the infection. When it comes to pathogen infection, antibiotic usage might bring many adverse effects, such as disturbance to the intestinal microenvironment, allergy and drug resistance. The results of this research indicate that GOS can effectively protect against the infection of E. coli O157 in mice

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