Ingredients from integral valorization of Isabel grape to formulate goat yogurt with stimulatory effects on probiotics and beneficial impacts on human colonic microbiota in vitro

Isabel grape(IG)products have high contents of phenolic compounds and fiber recognized for their positive impacts on microorganisms associated with health benefits to host.This study evaluated the effects of goat yogurts formulated with ingredients from IG integral valorization on the growth and metabolism of different probiotic strains,as well as on the population of selected bacterial groups and metabolic activity of human colonic microbiota in vitro.Goat yogurts with IG ingredients(IGI)stimulated the growth of tested Lactobacillus and Bifidobacterium probiotic strains during a 48-h cultivation,as well as decreased the pH values and enhanced the organic acid production.Goat yogurts with IGI increased the population of Lactobacillus spp.and Bifidobacterium spp.during a 24-h in vitro colonic fermentation.A stable Firmicutes:Bacteroidetes ratio close to 1 was found in media with goat yogurt formulations during the colonic fermentation,being similar to the effect caused by fructooligosaccharides.Goat yogurt formulations with IGI caused increased production of short-chain fatty acids and sugar consumption during colonic fermentation.Goat yogurts with IGI should be a valuable strategy for development of novel added-value foods with beneficial effects on gut microbiota and human health.

Effects of chitosan oligosaccharide-nisin conjugates formed by Maillard reaction on the intestinal microbiota of high-fat diet-induced obesity mice model

Objectives:The goal of this study was to evaluate the modulatory effect of chitosan oligosaccharide-nisin conjugate(CON-C)on intestinal microbiota of human flora-associated(HFA)mice and also reveal its effect towards the high-fat diet(HFD)-induced obesity.Both Chitosan oligosaccharides and nisin showed great potential in modulating the intestinal microbiota,so it is worth to explore whether the modulation effect of chitosan oligosaccharide could be improved by covalently binding with nisin.Materials and Methods:CON-C was prepared by heating the mixed solution of chitosan oligosaccharide and nisin at 80℃ and pH 2.0 for 24h.The structure of CON-C were analyzed by Fourier transform-infrared spectroscopy(FT-IR)and X-ray diffraction(XRD).The CON-C’s anti-obesity effect and modulatory effect toward intestinal microbiota were analyzed using human flora-associated(HFA)mice model.Results:CON-C could alleviated HFD-induced gut dysbiosis,by significantly decreasing the numbers of Bifidobacterium and Lactobacillus/Enterococcus spp.,and increasing the numbers of Bacteroides-Prevotella and Clostridium groups.CON-C could also enriched the most differentially expressed genes through KEGG pathways of biosynthesis of amino acids,two-component system,and ATP binding cassette(ABC)transporters.Conclusions:The improved therapeutic effect of CON-C against HFD-induced obesity has been approved,and hence,CON-C has a great potential to be utilized as a functional food ingredient in reducing body weight.