Mycotoxin Interactions along the Gastrointestinal Tract: In Vitro Semi-Dynamic Digestion and Static Colonic Fermentation of a Contaminated Meal

• Published in: Toxins 2022-01, Vol.14 (1), p.28
• Main Authors: Sobral, Maria Madalena Costa, Gonçalves, Tiago, Martins, Zita E, Bäuerl, Christine, Cortés-Macías, Erika, Collado, Maria Carmen, Ferreira, Isabel M P L V O
• Format: Article
• Language: English
• Subjects: Acidification; Aflatoxin B1; Aflatoxin B1 - metabolism; Aflatoxins; Bacteria; Bioavailability; Cell viability; Cereals; Colon - drug effects; Digestion; Digestion - drug effects; Digestive system; Dynamic models; Exposure; Fermentation; Fermentation - drug effects; Food Contamination; Food contamination & poisoning; Food products; Gastric emptying; Gastrointestinal Microbiome - drug effects; Gastrointestinal system; Gastrointestinal tract; Gastrointestinal Tract - chemistry; Gene expression; gut microbiota; Immune system; in vitro models; inflammation; Intestinal microflora; Intestine; Meals; Microbiota; Mycotoxins; Mycotoxins - chemistry; Mycotoxins - metabolism; NF-κB protein; Ochratoxin A; Ochratoxins - metabolism; Oral administration; Physiology; Poisons - metabolism; Portugal; Probiotics; Small intestine; Stomach; Toxicity
• ISSN: 2072-6651; 2072-6651
• DOI: 10.3390/toxins14010028

Aflatoxin B1 (AFB1) and ochratoxin A (OTA) naturally co-occur in several foods, but no studies have followed the fate of mycotoxins' interactions along the gastrointestinal tract using in vitro digestion models. This study used a novel semi-dynamic model that mimics gradual acidification and gastric emptying, coupled with a static colonic fermentation phase, in order to monitor mycotoxins' bioaccessibility by the oral route. AFB1 and OTA bioaccessibility patterns differed in single or co-exposed scenarios. When co-exposed (MIX meal), AFB1 bioaccessibility at the intestinal level increased by ~16%, while OTA bioaccessibility decreased by ~20%. Additionally, a significant increase was observed in both intestinal cell viability and NO production. With regard to mycotoxin-probiotic interactions, the MIX meal showed a null effect on and strain growth, while isolated AFB1 reduced bacterial growth parameters. These results were confirmed at phylum and family levels using a gut microbiota approach. After colonic fermentation, the fecal supernatant did not trigger the NF-kB activation pathway, indicating reduced toxicity of mycotoxins. In conclusion, if single exposed, AFB1 will have a significant impact on intestinal viability and probiotic growth, while OTA will mostly trigger NO production; in a co-exposure situation, both intestinal viability and inflammation will be affected, but the impact on probiotic growth will be neglected.