Mycotoxins are important food contaminants that commonly co-occur with modified mycotoxins such as mycotoxin-glucosides in contaminated cereal grains. These masked mycotoxins are less toxic, but their breakdown and release of unconjugated mycotoxins has been shown by mixed gut microbiota of humans and animals. The role of different bacteria in hydrolysing mycotoxin-glucosides is unknown, and this study therefore investigated fourteen strains of human gut bacteria for their ability to break down masked mycotoxins. Individual bacterial strains were incubated anaerobically with masked mycotoxins (deoxynivalenol-3-β-glucoside, DON-Glc; nivalenol-3-β-glucoside, NIV-Glc; HT-2-β-glucoside, HT-2-Glc; diacetoxyscirpenol-α-glucoside, DAS-Glc), or unconjugated mycotoxins (DON, NIV, HT-2, T-2, and DAS) for up to 48 h. Bacterial growth, hydrolysis of mycotoxin-glucosides and further metabolism of mycotoxins were assessed. We found no impact of any mycotoxin on bacterial growth. We have demonstrated that Butyrivibrio fibrisolvens, Roseburia intestinalis and Eubacterium rectale hydrolyse DON-Glc, HT-2 Glc, and NIV-Glc efficiently and have confirmed this activity in Bifidobacterium adolescentis and Lactiplantibacillus plantarum (DON-Glc only). Prevotella copri and B. fibrisolvens efficiently de-acetylated T-2 and DAS, but none of the bacteria were capable of de-epoxydation or hydrolysis of α-glucosides. In summary we have identified key bacteria involved in hydrolysing mycotoxin-glucosides and de-acetylating type A trichothecenes in the human gut.
Bibliographical noteFunding: This study was supported by the Scottish Government Rural and Environment Science and Analytical Services division (RESAS). N.D. was supported by an Elphinstone PhD scholarship from the University of Aberdeen.
Acknowledgments: Susan McCormick and Mark Busman at the USDA-Agricultural Research Service in Peoria, IL, USA, are acknowledged for providing the standard solutions of T-2-Glc and HT-2-Glc used in this study. We acknowledge Saima Khalid, who worked with the team when planning this study.
- gut microbiota
- GEN. NOV.
- BUTYRATE-PRODUCING BACTERIA
- FUSARIUM TOXINS
- T-2 TOXIN
- Gut microbiota