Application of intestinal microbiota in marine fish for assessing the toxicity of typical pollutants: a literature review.

The widespread diffusion and dilution of pollutants in the ocean lead to prolonged exposure of marine organisms to low-concentration contaminated environments, raising growing concerns about the potential risks associated with chronic low-level pollution. The gut microbiota of fish plays a pivotal role in essential physiological processes, which are critical for host health. Therefore, the key microbes in the gut could serve as valuable biomarkers for assessing the toxic effects of pollutants. This article systematically reviews the structure and functions of marine fish gut microbiota, outlines the primary methodologies for assessing gut microbiota, and highlights the impacts of typical pollutants (including petroleum hydrocarbons, antibiotics, heavy metals, and microplastic) on the composition, functionality, and metabolic activities of marine fish gut microbiota. In the future, integrating multi-technology approaches to investigate the toxic mechanisms of pollutants on gut microbiota and their biodegradation pathways will represent a pivotal direction in marine ecotoxicology research.