We study how exposure to environmental contaminants affects microbiome of the test organisms in ecotoxicological assays and whether variations in the microbiota are causing variability in the estimated toxicity. Appreciation of the host-microbiome interactions can improve reproducibility and reliability of the standard ecotoxicity testing, and we hope that our findings will offer insights for how to include microbiome response and host-bacteria interactions in practical ecotoxicology as well as promote research on animals' coexistence with microorganisms at large.
Microbial communities associated with multicellular animals and their collective genetic capacity (microbiome) perform key metabolic functions, support essential physiological processes, and metabolize toxic substances. Therefore, animal tolerance to xenobiotics and environmental stressors is a function of the animal and its microbiome tolerances. In (eco)toxicological context, it is becoming increasingly evident that variations in the microbiota can have significant effects on animal models and their expressed phenotypes, adding a complex and important variable into the assessment.