Arsenic Exposure Alters the Microbiome of Larval Zebrafish: A Metagenomic Analysis

Drinking water contaminated with arsenic presents a global concern, affecting upwards of 75 million people in Bangladesh and India alone. Arsenic poisoning can result in several disease including diabetes, keratosis and cardiovascular disease. In addition, arsenic interacts with microbial communities through processes including microbial resistance and energy-production mechanisms. Host-symbiont microbial communities, called microbiomes, are vast and diverse communities of microorganisms. Microbiomes are critical to maintaining host-health and provide key services in immune function, metabolism, energy-production, development and so on. Microbiomes’ ability to maintain host-health relies on complex dynamics such as specific organisms abundance and overall diversity. These dynamics, however, can be affected by external factors, including environmental toxins. To determine whether arsenic perturbs host microbiomes, I exposed larval zebrafish to low, medium and high doses of sodium meta-arsenite for 20-days and conducted a targeted 16S rRNA metagenomic analysis of their microbiomes. The data shows that the presence of arsenic caused significant perturbations in the overall composition and diversity of the zebrafish microbiome. In addition, I have revealed key operational taxonomic units (OTUs) in the arsenic treatments with previously described arsenic resistance mechanisms and another that was identified as an opportunistic pathogen. Observing changes in taxonomy and diversity is only the first step in understanding how arsenic affects microbiomes. Future studies should integrate more omics’ approaches to develop an understanding of the mechanisms underlying microbial survival in the presence of arsenic and these surviving microbes’ implications for host-health