Lactic acid bacteria alleviate di-(2-ethylhexyl) phthalate-induced liver and testis toxicity via their bio-binding capacity, antioxidant capacity and regulation of the gut microbiota.

Di-(2-ethylhexyl) phthalate (DEHP) is a plasticiser that, if absorbed into the human body, can cause various adverse effects including reproductive toxicity, liver toxicity and gut microbiota dysbiosis. So far, some studies have proved that the toxicity of DEHP can be reduced by using antioxidants. However, these candidates all show potential side effects and cannot prevent the accumulation of DEHP in the body, making them unable to be used as a daily dietary supplement to relieve the toxic effects of DEHP. Lactic acid bacteria (LAB) have antioxidant capacity and the ability to adsorb harmful substances. Herein, we investigated the protective effects of five strains of LAB, selected based on our in vitro assessments on antioxidant capacities or bio-binding capacities, against the adverse effects of DEHP exposure in rats. Our results showed that LAB strains with outstanding DEHP/MEHP binding capacities, Lactococcus lactis subsp. lactis CCFM1018 and Lactobacillus plantarum CCFM1019, possess the ability to facilitate the elimination of DEHP and its metabolite mono-(2-ethylhexyl) phthalate (MEHP) with the faeces, decrease DEHP and MEHP level in serum further. Meanwhile, DEHP-induced liver and testicular injuries were effectively alleviated by CCFM1018 and CCFM1019. In addition, CCFM1018 effectively alleviated the DEHP-induced oxidative stress with its strong antioxidant ability. Furthermore, both CCFM1018 and CCFM1019 modulated the gut microbiota, which in turn increased the concentrations of faecal propionate and butyrate and regulated the pathways related to host metabolism. Correlation analysis indicate that DEHP/MEHP bio-binding capacity of LAB plays a crucial role in protecting the body from DEHP exposure, and its antioxidant capacity and the ability to alleviate the gut microbiota dysbiosis are also involved in the alleviation of damage. Thus, LAB with powerful bio-binding capacity of DEHP and MEHP can be considered as a potential therapeutic dietary strategy against DEHP exposure.