Lysozyme-like Protein Produced by Bifidobacterium longum Regulates Human Gut Microbiota Using In Vitro Models.

Mingzhu Du,Ying Li,Tong Jiang,Longyan Li,Jumei Zhang,Qingping Wu,Wei Chen,Xinqiang Xie,Shuanghong Yang,Yunxiao Huang,Juan Yang

doi:10.3390/molecules26216480

Abstract

The extracellular secreted protein of Bifidobacterium longum (B. longum) plays an important role in maintaining the homeostasis of the human intestinal microenvironment. However, the mechanism(s) of interaction remain unclear. Lysozyme is a kind of antibacterial peptide. In this study, the amino acid sequence of a lysozyme-like protein of B. longum based on whole-genome data of an isolate from human gut feces was found. We further predicted functional domains from the amino acid sequence, purified the protein, and verified its bioactivity. The growth of some bacteria were significantly delayed by the 020402_LYZ M1 protein. In addition, the gut microbiota was analyzed via high-throughput sequencing of 16S rRNA genes and an in vitro fermentation model, and the fluctuations in the gut microbiota under the treatment of 020402_LYZ M1 protein were characterized. The 020402_LYZ M1 protein affected the composition of human gut microbiota significantly, implying that the protein is able to communicate with intestinal microbes as a regulatory factor.

Highlights

Each area of the human gut represents a habitat with unique structure, chemical [1], and biological components [2], which is similar to the river system to some extent [3]
The protein modulated the composition of the human gut microbiome, which better understood the specific mechanisms that B. longum involved in gut microbiota modulation
B. longum based on whole-genome data of an isolate from human gut feces

Summary

Introduction

Each area of the human gut represents a habitat with unique structure, chemical [1], and biological components [2], which is similar to the river system to some extent [3]. B. longum were purported to exert various promoting effects in intestinal dynamic balance and host health [11,12,13], but the specific mechanism is still obscure. These studies uncovered various molecules that act as important mediators for the establishment of a Bifidobacteria—host communication, such as pili [14], extracellular polysaccharides [15], serpins, TagA [16], BopA [17], etc

Objectives

Methods

Results

Conclusion