Prevalent Human Gut Bacteria Hydrolyse and Metabolise Important Food-Derived Mycotoxins and Masked Mycotoxins

• Published in: Toxins Vol. 12; no. 10; p. 654
• Main Authors: Daud, Noshin, Currie, Valerie, Duncan, Gary, Farquharson, Freda, Yoshinari, Tomoya, Louis, Petra, Gratz, Silvia
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 13-10-2020; MDPI
• Subjects: Bacteria; Cereals; Colon; Contaminants; de-acetylation; Deoxynivalenol; Experiments; Food contamination; Glucosides; gut microbiota; Hydrolysis; Intestinal microflora; Metabolism; Metabolites; microbiome; Microbiota; mycotoxin-glucosides; Mycotoxins; Nivalenol; release; Strains (organisms); Trichothecenes; de-acetylation; mycotoxin-glucosides; trichothecenes; microbiome; release; gut microbiota
• ISSN: 2072-6651; 2072-6651
• DOI: 10.3390/toxins12100654

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
,
and
hydrolyse DON-Glc, HT-2 Glc, and NIV-Glc efficiently and have confirmed this activity in
and
(DON-Glc only).
and
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.