In vivo study of chronic AFB1 exposure on gut villi in the presence of probiotic S. cerevisiae RC016 strain

DOGI C.A; CRISTOFOLINI, ANDREA; FOCHESATO, A; ARMANDO, MR; DALCERO A.M.; CAVAGLIERI L.R.

Simposio; 7th Conference of The World Mycotoxin Forum® and the XIIIth IUPAC International Symposium on Mycotoxins and Phycotoxins; 2012

Aflatoxin contamination is a worldwide problem that compromises the safety of food and feed and represents a serious hazard to humans and animals. Low level chronic AFB1 exposure is linked to the development of occult conditions such as impaired growth and immune function and chronic diseases.Previous studies have demonstrated that Saccharomyces cerevisiae RC016 has beneficial properties and mycotoxin binding abilities in vitro. The aim of the present work was to study in vivo the toxic effect of chronic moderate AFB1 exposure on gut villi in the presence of probiotic S. cerevisiae RC016 strain. A total of 36 female Wistar rats were divided into six different groups: 1) commercial diet and PBS (1ml) orally administered; 2) control diet and S. cerevisiae (1x109 cells/ml in PBS) orally administered; 3) commercial diet with AFB1 40 ppb; 4) commercial diet with AFB1 100 ppb; 5) commercial diet with AFB1 40 ppb and S. cerevisiae(1x109 cells/ml in PBS) and 6) animals received commercial diet with AFB1 100 ppb and S. cerevisiae (1x109 cells/ml in PBS). The assay was carried out during 60 days. At the end of the experiment rats were killed and the small intestines were recovered and subject to histological studies. The morphometric parameters included length of villi, width of villi, intestinal crypt depth and quantification of goblet cells. Apoptosis was determined by Tunels technique. The results showed apoptotic index in rats that received the yeast (T2), even higher than the determined in the T3. The same trend was observed for all the morphometric parameters evaluated and the yeast strain seemed to exert its beneficial effect only in the presence of the high toxin concentrations. In concordance, previous in vitro studies, demonstrated that the amount of AFB1 removed increased with increasing AFB1 concentration. Apoptosis plays a fundamental role in cellular remodeling to maintain tissue homeostasis. The results obtained shown that S. cerevisiae RC016 would favor this tissue remodeling. The presence of the toxin inhibits tissue remodeling leading to atrophy or at least not allow adequate remodeling.S. cerevisiae RC016 would reverts this deleterious effect of the toxin, allowing gut remodel their cells and thereby improves tissue homeostasis.