Biological detoxification of ochratoxin A in-food systems using probiotic and Bacillus strains

Ochratoxin A (OTA) is a widespread mycotoxin found in food and feed, posing serious risks to human and animal health due to its nephrotoxic, immunotoxic, and carcinogenic effects. Strategies to reduce OTA exposure are therefore essential, and biological approaches based on probiotic microorganisms have gained increasing attention. The objective of this study was to identify probiotic bacteria suitable as food and feed additives capable of mitigating the effects of the mycotoxin OTA in the gastrointestinal tract, either through adsorption or metabolic degradation. A total of twenty probiotic bacterial strains belonging to eight different genera were evaluated. The experimental design included an initial screening phase in which the bacterial strains (n = 20) were cultivated in appropriate media. Based on their performance, three strains were selected for a subsequent in vitro digestion assay. OTA and its potential degradation product, ochratoxin α (OTα), were quantified using high-performance liquid chromatography with fluorescence detection (HPLC-FLD). To gain insights into the metabolic capacity of the bacteria, a proteolytic activity test was performed in parallel, followed by the analysis of OTα formation during both the screening and digestion phases. Among the tested bacterial genera, Pediococcus, Lactiplantibacillus, and Limosilactobacillus showed greater potential than Bacillus, Priestia, and Cytobacillus, with the highest efficacy observed for P. pentosaceus 4, Lactiplantibacillus plantarum 5, and Limosilactobacillus fermentum 8. However, all strains exhibited lower detoxification rates under in vitro digestion conditions compared to the screening phase. Although further validation is required, these findings suggest that the evaluated probiotic bacteria represent a promising strategy for OTA mitigation in food and feed, even if complete detoxification has not yet been achieved.