STUDY OF THE PROBIOTIC PROPERTIES OF YEASTS ISOLATED FROM KEFIR

ROMANIN, DAVID E.; BENGOA, ANA A.; PENDÓN, MARÍA DOLORES; RUMBO, MARTIN; GARROTE, GRACIELA L.

Bariloche

Simposio; 34º INTERNATIONAL SPECIALIZED SYMPOSIUM ON YEASTS; 2018

The term probiotic describes live microorganisms that are supplemented to the diet to improve the health of those who consume them. Lactic acid bacteria and bifidobacteria are the most frequently used in the field of probiotics, although some yeasts also have beneficial properties, being the genus Saccharomyces the most documented. Kefir is a fermented beverage that is obtained by milk fermentation with kefir grains where coexists in sympbiotic association lactic acid bacteria and yeasts. There are numerous reports about the beneficial health properties attributed to the consumption of kefir. Our aim was to study of the probiotic potential of the yeasts from kefir.Among 35 strains analyzed, 20 showed a survival greater than 50% after being subjected for 2 h and 37 °C at pH 2.5 and hight bile resistance. Viable K. marxianus CIDCA 8154 was also recovered after passage of gastrointestinal tract of both BALB/c mice and hamsters confirming the behavior observed in vitro. Selected strains showed adherence to intestinal epithelial cell line Caco-2 cells. Different kefir yeast strains inhibited the activation of innate immunre response triggered on Caco-2 cells with flagellin (FliC), both in a reporter system (Caco-2 ccl20: luciferase), as on the mRNA expression of CCL20, CXCL-8 and CXCL-2. We analyzed the anti-inflammatory capacity of the strain K. marxianus CIDCA 8154 in different models, demostrating reduction of intracellular levels of reactive oxygen species upon pretreatment of the epithelial cells with yeast. Likewise, K. marxianus CIDCA 8154 administered orally protects from histopathological damage and rise of serum IL-6 triggered by TNBS in an acute model of colitis.Results indicate that kefir yeasts are able to modulate the intestinal epithelial inflammatory response that could explain some of the benefical properties of kefir and lead to formulation of novel functional food for patients with an increased gastrointestinal inflammatory status.