The chicken gut metagenome and the modulatory effects of plant-derived benzylisoquinoline alkaloids

Peng Huang,Yisong Liu,Wei Fan,Conghui Liu,Zhixing Qing,Cheng Zeng,Xi He,Nan-Xi Hu ,Dan Liu,Sanwen Huang,Fan Jiang,Kangpeng Xiao,Dazhi Tang,Hua Liu,Yuming Guo,Long Yun,Li Lin,Jialu Huang,Bo Liu,Yingxue Ren ,Qian Lin,Xiubin Liu,Jing Yuan ,Lei Yin ,Hengchao Wang,Xiaogang Su,Yan Zhang,Hong Cao ,Jianguo Zeng

doi:10.1186/s40168-018-0590-5

Abstract

BackgroundSub-therapeutic antibiotics are widely used as growth promoters in the poultry industry; however, the resulting antibiotic resistance threatens public health. A plant-derived growth promoter, Macleaya cordata extract (MCE), with effective ingredients of benzylisoquinoline alkaloids, is a potential alternative to antibiotic growth promoters. Altered intestinal microbiota play important roles in growth promotion, but the underlying mechanism remains unknown.ResultsWe generated 1.64 terabases of metagenomic data from 495 chicken intestinal digesta samples and constructed a comprehensive chicken gut microbial gene catalog (9.04 million genes), which is also the first gene catalog of an animal’s gut microbiome that covers all intestinal compartments. Then, we identified the distinctive characteristics and temporal changes in the foregut and hindgut microbiota. Next, we assessed the impact of MCE on chickens and gut microbiota. Chickens fed with MCE had improved growth performance, and major microbial changes were confined to the foregut, with the predominant role of Lactobacillus being enhanced, and the amino acids, vitamins, and secondary bile acids biosynthesis pathways being upregulated, but lacked the accumulation of antibiotic-resistance genes. In comparison, treatment with chlortetracycline similarly enriched some biosynthesis pathways of nutrients in the foregut microbiota, but elicited an increase in antibiotic-producing bacteria and antibiotic-resistance genes.ConclusionThe reference gene catalog of the chicken gut microbiome is an important supplement to animal gut metagenomes. Metagenomic analysis provides insights into the growth-promoting mechanism of MCE, and underscored the importance of utilizing safe and effective growth promoters.

Highlights

Sub-therapeutic antibiotics are widely used as growth promoters in the poultry industry; the resulting antibiotic resistance threatens public health
Sub-therapeutic antibiotics have been widely used as growth promoters (AGPs) in livestock to maintain health and enhance productivity, the resulting antibiotic resistance has become a major threat to public health [1]
A comprehensive chicken gut microbial gene catalog and its comparison with the human and pig catalogs We collected 495 digesta samples from the five intestinal compartments of chickens raised in 7 different farms in China

Summary

Introduction

Sub-therapeutic antibiotics are widely used as growth promoters in the poultry industry; the resulting antibiotic resistance threatens public health. Sub-therapeutic antibiotics have been widely used as growth promoters (AGPs) in livestock to maintain health and enhance productivity, the resulting antibiotic resistance has become a major threat to public health [1]. The effects of AGPs are generally thought to be through inhibition of sub-clinical infections, reduction of growth-depressing metabolites from gut microbiota, reduction of nutrients available for pathogens, and so forth [5]. It is still unclear how sub-therapeutic antibiotics could efficiently prevent infection and promote growth, and further studies are needed to advance our understanding of AGPs

Methods

Results

Conclusion