Abstract
Abstract: Background and objectives: Deoxynivalenol (DON) is a potent mycotoxin produced by Fusarium moulds and affects nutrient absorption and intestinal barrier function. Free DON and the plant metabolite DON-3-glucoside (D3G) are frequently found in cereals including wheat and maize. Aim of this work is to assess the metabolism of DON and D3G by human faecal microbiota and to study the intestinal absorption of DON metabolites in humans using urinary exposure biomarkers.
Method: Fresh faecal samples from ten volunteers were prepared into faecal slurries using M2 culture medium, spiked with DON or D3G and incubated anaerobically for up to 7 days. Mycotoxins were extracted into acetonitrile and detected using LC-MS/MS. Spot urine samples were collected from the same volunteers, cleaned through immunoaffinity columns and mycotoxins were detected using LC-MS/MS.
Results: We found that faecal microbiota from all ten volunteers efficiently cleaved D3G and released free DON, with hydrolysis peaking after 4-6 hours of incubation. Faecal microbiota of two out of ten volunteers detoxified DON to DOM-1. This is the first evidence of DON detoxification by human faecal microbiota. DON was detectable in all urine samples tested. Additionally, DOM-1 was detectable in urine samples of the same two volunteers who harbour the detoxifying microbiota at ratios of 1.5 – 16% of urinary DON. D3G was not detectable in urine.
Conclusion: Our results indicated that DON is readily absorbed in the intestinal tract of humans. D3G is not absorbed but hydrolysed by colonic microbiota hence exposing the colon to free DON and increasing the toxic burden to exposed individuals. Some individuals also harbour microbiota capable of detoxifying DON to DOM-1, which could lead to a modest protection against potential DON toxicities in the large intestine. Future dietary intervention studies will assess DON exposure from different cereal products.
Method: Fresh faecal samples from ten volunteers were prepared into faecal slurries using M2 culture medium, spiked with DON or D3G and incubated anaerobically for up to 7 days. Mycotoxins were extracted into acetonitrile and detected using LC-MS/MS. Spot urine samples were collected from the same volunteers, cleaned through immunoaffinity columns and mycotoxins were detected using LC-MS/MS.
Results: We found that faecal microbiota from all ten volunteers efficiently cleaved D3G and released free DON, with hydrolysis peaking after 4-6 hours of incubation. Faecal microbiota of two out of ten volunteers detoxified DON to DOM-1. This is the first evidence of DON detoxification by human faecal microbiota. DON was detectable in all urine samples tested. Additionally, DOM-1 was detectable in urine samples of the same two volunteers who harbour the detoxifying microbiota at ratios of 1.5 – 16% of urinary DON. D3G was not detectable in urine.
Conclusion: Our results indicated that DON is readily absorbed in the intestinal tract of humans. D3G is not absorbed but hydrolysed by colonic microbiota hence exposing the colon to free DON and increasing the toxic burden to exposed individuals. Some individuals also harbour microbiota capable of detoxifying DON to DOM-1, which could lead to a modest protection against potential DON toxicities in the large intestine. Future dietary intervention studies will assess DON exposure from different cereal products.
| Original language | English |
|---|---|
| Article number | P03190 |
| Pages (from-to) | 1806 |
| Number of pages | 1 |
| Journal | Annals of Nutrition & Metabolism |
| Volume | 63 |
| Issue number | Suppl 1 |
| Publication status | Published - Sept 2013 |
Keywords
- Mycotoxin
- deoxynivalenol
- metabolism
- microbiota
- human