Characterization of yeasts isolated from kefir as a probiotic and its synergic interaction with the wine byproduct grape seed flour/extract

Few studies have assessed the probiotic characteristics and antioxidant activity of the kefir-derived yeast, Kluyveromyces marxianus, and its synergistic interactions with polyphenol-rich grape seed flour (GSF)/extract (GSE). We examined several probiotic characteristics (gastric resistance, intestinal resistance, cholesterol reduction, adhesiveness to intestinal cells) of four K. marxianus strains. Each of the yeasts showed 5-25% greater intestinal cell adhesiveness than that of Lactobacillus acidophilus. Among the four yeast strains, K. marxianus KU140723-02 (KM2) exhibited the greatest antioxidant activity. When incubated with GSF/GSE, its antioxidant activity was synergistically increased by two-fold. In conclusion, a combination of kefir-derived yeast KM2 and GSF/GSEs may be a novel functional food ingredient with antioxidant properties targeting gut health.