HELTH PROMOTING PROPERTIES OF KEFIR: RELEVANCE OF THE NON BACTERIAL FRACTION

HAMET M F; GARROTE G L,; IRAPORDA C; RUMBO M; MEDRANO M.; PEREZ P; ABRAHAM A G

San Miguel de Tucumán

Simposio; SIBAL 2016 - V Simposio Internacional de Bacterias Lácticas.; 2016

CERELA

Kefir is a traditional beverage obtained by fermentation of milk with kefir grains that contain a wide diversity of lactic and acetic acid bacteria and yeasts. The health benefit associated to kefir consumption may be exerted by the presence of the microorganisms themselves and/or by containing different bioactive components such as the metabolites produced during fermentation, products coming from the hydrolysis of the components of the food matrix, or changes in the microbiota induced by any of these factors. Among the components of the non-bacterial fraction of kefir it can be mentioned lactic and acetic acid and the exopolysaccharide kefiran.Lactate was identified as the component responsible of the capacity to modulate innate epithelial response. At the concentrations found in fermented milk it can inhibit the innate response activation of intestinal epithelial cells triggered by IL-1β, TNF-α or flagellin. Lactate treatment abrogates NF-kB signaling on the epithelial cells, which could be responsible of the observed modulation of inflammatory activation. Kefiran, orally administered to BALB/c mice, is able to change intestinal and faecal microbiota by increasing the number of bifidobacteria populations. These findings are probably due to the competitive success of Bifidobacterium sp. in the intestinal lumen of kefiran-administered mice. Oral administration of kefiran in animal models also produces a significant increment in the number of goblet cells and IgA producing cells in the intestine. Taking into account the above mentioned results, it is tempting to speculate that the biological response elicited in vivo by kefiran could be ascribed, at less in part, to the bifidogenic effect. However kefiran interaction with human enterocytes should not be ruled out as a relevant step for the biological effect. The study of the non-bacterial fraction of this fermented product is interesting in order to improve the understanding of its biological activity. In the light of the accumulated evidence kefiran itself or by its bifidogenic effect, or lactate as food component itself or as a bioactive metabolite generated in situ on the intestinal mucosa may contribute to health promoting-properties of kefir fermented milk.