A probiotic Lacticaseibacillus paracacei isolate from traditional Chinese fermented mung bean juice capable of alleviating oxidative stress in colorectal cells

Traditional fermented mung bean juice (FMJ) has hundreds of years' consumption history in North China with known health benefits, and thus could be a valuable source for uncovering novel probiotics. In this study, we discovered a probiotic isolate with good antioxidant bioactivity from FMJ. First, we conducted 16 S rRNA amplicon analysis on 14 samples of two types of FMJ, Douzhir and Fenjiang, collected from Beijing and Henan Province, respectively. The dominant genera were Lactobacillus, Lactococcus, Weissella and Streptococcus, and the abundance of Weissella was significantly higher in Fenjiang than in Douzhir. Based on rank-sum ratio evaluation of 21 selected isolates, seven isolates identified as Lacticaseibacillus fermentum (Lactobacillus fermentum), Lactiplantibacillus plantarum (Lactobacillus plantarum), Limosilactobacillus paracasei (Lactobacillus paracasei), Lentilactobacillus parabuchneri (Lactobacillus parabuchneri) and Levilactobacillus brevis (Lactobacillus brevis), exhibited good tolerance to acid (pH 2.5) and bile salt (0.3%), high cell surface hydrophobicity and auto-aggregation, and ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and DPPH (2,2-Diphenyl-1-picrylhydrazyl) scavenging rates, without antibiotic resistance or hemolytic activity, and were further tested in cell assays. The cell-free extract of L. paracacei D1-10 showed significant protective effects on HT29 colon cell viability under 300–600 μM H2O2 treatments. These findings suggested FMJ is a valuable source for probiotic exploration, and D1-10 might be a promising probiotic strain with good antioxidant potential.

Duke Scholars

Author Zhen-Ming Pei Biology