Preparation of fermented oat milk and evaluation of its modulatory effect on antigen-specific immune responses in ovalbumin-sensitized mice

ABSTRACT A growing number of people choose plant-based milk products to replace dairy for health reasons or veganism. Since fermentation is a promising method to improve the nutritional value of plant-based milk, this study aimed to establish the process of oat milk fermentation and to evaluate the effect of fermented oat milk (FOM) on modulating antigen-specific immune response in ovalbumin (OVA)-sensitized mice. The FOM was prepared by fermentation of oat milk with Streptococcus thermophilus, Lactobacillus bulgaricus and proteolytic L. rhamnosus. Addition of 1% glucose improved the process of fermentation. FOM was stable while stored at 4°C within seven days. Oral administration with FOM (0.4 and 2 g/kg body weight) did not alter the serum level of OVA-specific IgG and spleen index. However, FOM had comparable potency with commercial dairy yogurt to lower stimulation index, IL-2, IFN-γ and IL-4 production and to promote TGF-β and IL-10 secretion by OVA-stimulated splenocytes.