Profound perturbation induced by triclosan exposure in mouse gut microbiome: a less resilient microbial community with elevated antibiotic and metal resistomes

Bei Gao,Liang Chi,Kun Lu,Pengcheng Tu,Hongyu Ru,Xiaoming Bian

doi:10.1186/s40360-017-0150-9

Abstract

BackgroundEnvironmental chemical-induced perturbations of gut microbiome are associated with a series of adverse health outcomes. The effects of triclosan on human health have been controversial in recent years. The purpose of this study is to investigate the functional impact of triclosan on the mouse gut microbiome and the link between triclosan exposure and resistomes in gut bacteria.MethodsWe combined 16S rRNA gene sequencing and shotgun metagenomics sequencing to examine the compositional and functional impact of triclosan exposure on the gut microbiota of C57BL/6 mice.Results16S rRNA sequencing results revealed that 13-week triclosan exposure in drinking water induced significant perturbations in mouse gut bacterial assemblages with distinct trajectories compared to controls. Metagenomics sequencing results indicated a remarkable enrichment of gut bacterial genes related to triclosan resistance, stress response, antibiotic resistance and heavy metal resistance.ConclusionsTriclosan exposure has a profound impact on the mouse gut microbiome by inducing perturbations at both compositional and functional levels. To our best knowledge, this is the first evidence regarding the functional alterations of gut microbiome induced by triclosan exposure, which may provide novel mechanistic insights into triclosan exposure and associated diseases.

Highlights

Environmental chemical-induced perturbations of gut microbiome are associated with a series of adverse health outcomes
Controversy exists regarding a causal relationship between antibiotic resistance and triclosan exposure, considering the cross-resistance due to shared resistance mechanisms and the growing threat that antibiotic resistance poses, there is a necessity to examine triclosan resistance as well as antibiotics resistome in the gut microbiome with triclosan exposure
Triclosan exposure significantly changed the gut microbiome composition To investigate the triclosan-induced change of the composition in mouse gut microbiome, we compared the abundance of gut bacteria between the treatment and control groups after 13-week triclosan exposure. 13-week exposure substantially altered the microbial community manifested by a series of shifted bacterial families

Summary

Introduction

Environmental chemical-induced perturbations of gut microbiome are associated with a series of adverse health outcomes. The effects of triclosan on human health have been controversial in recent years. The purpose of this study is to investigate the functional impact of triclosan on the mouse gut microbiome and the link between triclosan exposure and resistomes in gut bacteria. A properly-functioning immune system from birth is inseparable from the communications with gut bacteria [2]. This relationship can be readily affected by various endogenous (e.g. genetics) and exogenous factors (e.g. diet) [3]. Most recent studies observed that triclosan exposure was able to induce gut microbiome perturbations in animal models. Controversy exists regarding a causal relationship between antibiotic resistance and triclosan exposure, considering the cross-resistance due to shared resistance mechanisms and the growing threat that antibiotic resistance poses, there is a necessity to examine triclosan resistance as well as antibiotics resistome in the gut microbiome with triclosan exposure

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