Effects of different probiotics on the flavor nutritional profile, and immune modulation of soy whey carrot beverage in mice

In this study, a probiotic fermented beverage was prepared from soy whey and carrot (unfermented, single-strain, double-strain, and triple-strain fermented), and its antioxidant and immunomodulatory activities were investigated. Gas chromatography-mass spectrometry(GC–MS) and amino acid analysis revealed that ester content increased from 1.60 × 10 −4 μg/mL to 3.34 × 10 −4 μg/mL after fermentation with three bacterial strains, compared to the unfermented control. The •OH scavenging capacity increased from 28 % to 92 %. Mouse experiments showed that the fermented beverages significantly affected immune cell levels, with each bacterial strain inducing distinct immunomodulatory effects. Short-term stimulation of cytotoxicity and helper T-cell proliferation was observed after ingestion, along with long-term increases in natural killer cells and memory T-cell counts. This study addressed critical knowledge gaps regarding the efficacy of fermented beverages and provides a theoretical and technical foundation for the high-value utilization of soy by-products. • Soy whey carrot enzyme beverage fermented by probiotics can reduce the bad flavor of soy whey. • To investigate the promoting effect of compound probiotic enzyme on immune function in mice. • Probiotic fermentation group has significant immunomodulatory effect and may boost body immunity.