Hexachlorocyclohexane exposure alters the microbiome of colostrum in Chinese breastfeeding mothers

Mengling Tang; Chenye Xu; Kun Chen; Qi Yan; Weihua Mao; Weiping Liu; Beate Ritz

doi:10.1016/j.envpol.2019.07.068

Hexachlorocyclohexane exposure alters the microbiome of colostrum in Chinese breastfeeding mothers

Environ Pollut. 2019 Nov;254(Pt A):112900. doi: 10.1016/j.envpol.2019.07.068. Epub 2019 Jul 18.

Authors

Mengling Tang¹, Chenye Xu², Kun Chen³, Qi Yan⁴, Weihua Mao⁵, Weiping Liu⁶, Beate Ritz⁴

Affiliations

¹ Department of Epidemiology and Biostatistics, Zhejiang University School of Public Health, Hangzhou, Zhejiang, China; Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles (UCLA), Los Angeles, CA, USA.
² Ministry of Education Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China.
³ Department of Epidemiology and Biostatistics, Zhejiang University School of Public Health, Hangzhou, Zhejiang, China.
⁴ Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles (UCLA), Los Angeles, CA, USA.
⁵ Analysis Center of Agrobiology and Environmental Sciences, Zhejiang University, Hangzhou, Zhejiang, China.
⁶ Ministry of Education Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China. Electronic address: wliu@zju.edu.cn.

PMID: 31394347
DOI: 10.1016/j.envpol.2019.07.068

Abstract

Breast milk, especially colostrum, is not just a source of nutrients and immune factors for the newborn, but also accumulates environmental persistent pollutants and its diverse microbes affect the early colonization of the newborn's gut. Little is known about associations between environmental pollutants and the microbial composition of human colostrum. We assessed the influence of hexachlorocyclohexane (HCH), a persistent organic pollutant (POP), in colostrums on the microbial composition of human colostrum samples. HCH concentrations in 89 colostrum samples collected from a population living on the easternmost island of China were measured via gas chromatography equipped with mass spectrometer (GC-MS), HCH exposure risks for infants via dietary intake of breast milk were assessed, and for 29 colostrum samples the microbiota were profiled using 16S rRNA gene pyrosequencing to assess the association with HCH exposure levels. Our study confirmed high colostrum exposure levels of total HCHs (12.19 ± 13.68 μg L^-1) in this Chinese population. We predominantly identified Proteobacteria (67.6%) and Firmicutes (25.1%) in colostrum and microbial diversity at the genus level differed between samples with different HCH levels; e.g., Pseudomonas which contains several HCH degrading strains was found in significantly higher abundance in γ-HCH rich samples. Also, microbes that were statistically significantly associated with HCH levels were also highly correlated with each other (false discovery rate (FDR)＜0.01) and clustered in network analysis. Microbial diversity is associated with HCH levels in human colostrum and these associations might be attributable to their HCH degrading ability. These finding provide first insights into the role that environmental persistent pollutants may play in the microbial composition of human colostrum and the colonization of the infant gut.

Keywords: Breast milk microbiota; Colostrum; Hexachlorocyclohexane; Microbiome; Pollution exposure.

MeSH terms

Breast Feeding
China
Colostrum / chemistry
Colostrum / metabolism
Colostrum / microbiology*
Environmental Pollutants / analysis
Environmental Pollutants / toxicity*
Female
Hexachlorocyclohexane / toxicity*
Humans
Infant
Infant, Newborn
Maternal Exposure
Microbiota / drug effects*
Milk, Human / chemistry
Mothers
Pregnancy
RNA, Ribosomal, 16S

Substances

Environmental Pollutants
RNA, Ribosomal, 16S
Hexachlorocyclohexane