The microbiomes of wildlife and chemical pollution: Status, knowledge gaps and challenges

The effect of chemical pollution on the microbiomes of wildlife has been given little attention. A new concept is emerging where microbiomes are vital to host animal or plant health, and for ecosystems. Data are mainly on mammals, birds, and fish. Changing environmental conditions (e.g., salinity, pH, season) and exposure to chemicals alter the composition of gill, gut and skin microbiomes. Gut microbiomes are also modulated by diet, and exposure to chemicals including metals, nanomaterials, fungicides or microplastics. However, a change in the microbiome does not necessarily infer adverse effects on the host, with some evidence of co-adaptation. Environmental risk assessment for biocides and new nanomaterials should be revisited in context with microbiome-host interactions, to better protect wildlife and ecosystems.