Capabilities of bio-binding, antioxidant and intestinal environmental repair jointly determine the ability of lactic acid bacteria to mitigate perfluorooctane sulfonate toxicity.

Perfluorooctane sulfonate (PFOS) is a novel environmental contaminant that can be enriched in humans through the food chain, causing liver diseases, neurotoxicity and metabolic disorders. Lactic acid bacteria (LAB) are safe food-grade microorganisms that exhibit high antioxidant activity and bio-binding capacity towards toxins. Here, strains of LAB with different PFOS binding capacities and antioxidant activities were selected and analyzed for their ability in mitigating the toxic effects of PFOS. The results showed that the PFOS binding capacity and antioxidant activity of LAB largely influenced their ability in alleviating the toxic effects of PFOS. Notably, the individual LAB strains with low PFOS binding capacities and antioxidant activities also attenuated the toxic effects of PFOS, which was shown to up-regulate the contents of short-chain fatty acids (SCFAs) in the cecum and of tight junction proteins in the intestines of mice. Therefore, the mitigation pathway of PFOS-induced toxic damage by LAB is not limited to bio-binding and antioxidant. Repairing the gut environment damaged by PFOS is also essential for LAB to alleviate the toxic damage due to PFOS and may be partly independent of the bio-binding and antioxidant. Therefore, LAB as an alternative pathway for alleviating PFOS toxicity is suggested.