ICMGP - Conference Presentation

Abstract Information :

Methylmercury is a potent neurotoxin that bioaccumulates in individual organisms and biomagnifies up the food chain. This toxin is found in lakes and rivers worldwide, and climate change is expected to increase its concentration in these environments. This poses a significant risk for those who rely on methylmercury-contaminated sources of predatory fish for food. Although methylmercury metabolism has been studied extensively, it remains unknown why the half-life of methylmercury can range from 120 days in the body across individuals after ingestion. The gut microbiome is a topic of rising interest in the field of toxicology, particularly its impact on the metabolism of ingested environmental contaminants. Individuals? gut microbiomes can vary greatly depending on environmental factors, and these differences may contribute to the wide range methylmercury half-lives observed in humans.

Here we present strong evidence that the human gut microbiome contributes to the metabolism/demethylation of methylmercury. Using batch incubations of healthy individuals? fecal samples with methylmercury, we observed large variations in the ability of the microbiomes to degrade/demethylate the toxin. Some microbiomes degraded virtually all methylmercury present, others only half. The degradation phenotype appears to be associated with i) fermentation capacity of the microbiome and ii) the nutrient profile of the assay medium. Alteration of metabolism with changes in nutrient profiles have implications for the effect of diet on neurotoxin transformation. This work offers a novel perspective on the role of human microbiomes in altering neurotoxin exposure and highlights the importance of gut health to an individual?s overall well-being.