125 - Inorganic arsenic exposure and gut microbiota with respective folate functional pathway in children aged 4 years

Poster Number: 125
Publication Number: 125.108

Tsung-Lin Tsai, National Health Research Institutes, Zhunan, Miaoli, Taiwan (Republic of China); Chin-Chi Kuo, Big Data Center, China Medical University Hospital, Taichung City, Taichung, Taiwan (Republic of China); Yu-Chieh Liao, National Health Research Institutes, Zhunan Town, Miaoli, Taiwan (Republic of China); Chieh Hua Lin, National Health Research Institutes, Zhunan Township, Miaoli, Taiwan (Republic of China); Shu-Li Wang, National Health Research Institutes, Zhunan, Miaoli, Taiwan (Republic of China)

Background: Increasing evidence supports the association between composition and abundance of gut bacteria and human diseases (such as obesity and type 2 diabetes). Studies showed inorganic arsenic (iAs), widely in drinking water and air pollutants, may alter the equilibrium and diversity of human gut microbiota. In return, gut microbiota might affect iAs metabolism such as from iAs to methyl- and dimethyl- arsenic acids. Folate-mediated one-carbon metabolism is crucial in fetal and children’s development and health.
 

Objective: This study aimed to investigate the associations between iAs exposure and gut microbiota with respective of folate-related pathways in children.

Design/Methods: One hundred and eighteen children previously recruited in a birth cohort from central Taiwan (2012–2014) were followed in 2015–2017. We used a structured questionnaire for the interview and collected urinary samples and feces specimens in children aged 3‒4 years. We quantified children’s urinary concentration of iAs and extracted DNA from feces specimens. The composition (species) and abundance of gut microbiota, and microbial functional profiles were sequenced by whole metagenome shotgun sequencing. The folate-related pathways or the corresponding protein sequences were defined through the Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologous genes, and we listed the top 20 species that contributed to the folate pathways.

Results: After adjustment for sex, environmental tobacco smoke, BMI, and antibiotics and probiotics use, urinary total iAs concentration significantly associated with decreased abundance of Bacteroides ovatus (β = -1.27) and Parabacteroides distasonis (β = -1.26). However, iAs associated with the increased abundance of Eggerthella lenta (β = 2.28), Bacteroides fragilis (β = 1.86), and Roseburia intestinalis (β = 3.45). We also observed a significant association between increased urinary total iAs concentration with the decreased functional pathway of folate transformations III (β = -0.03) and decreased gene expression of 11 folate-function-related species (β from -0.03 to -0.46) in the full-adjusted model.Conclusion(s): Childhood iAs exposure may alter the abundance of gut microbiota and have negative associations with species of folate functional pathways. Future work is needed to investigate the potential effects of the reduced folate biosynthesis in relation to microbiota and the consequent one-carbon metabolism of the host.