Evaluation of the Probiotic Potential of Lactobacillus delbrueckii ssp. indicus WDS-7 Isolated from Chinese Traditional Fermented Buffalo Milk In Vitro

Abstract

The present study aimed to evaluate the probiotic potential of lactic acid bacteria (LAB) isolated from Chinese traditional fermented buffalo milk. Out of 22 isolates, 11 were putatively identified as LAB preliminarily. A total of six LAB strains displayed strong adhesion to HT-29 cells and all these strains showed preferable tolerance to artificially simulated gastrointestinal juices. WDS-4, WDS-7, and WDS-18 exhibited excellent antioxidant capacities, including DPPH radical, ABTS+ radical, and superoxide anion scavenging activities. Compared with the other two LAB strains, WDS-7 had a stronger inhibition effect on four pathogens. Based on the 16S rRNA gene sequencing and phylogenetic analysis, WDS-7 was identified as Lactobacillus delbrueckii ssp. indicus and selected to assess the potential and safety of probiotics further. The results revealed that WDS-7 strain had a strong capacity for acid production and good thermal stability. WDS-7 strain also possessed bile salt hydrolase (BSH) activity. Compared to LGG, WDS-7 was a greater biofilm producer on the plastic surface and exhibited a better EPS production ability (1.94 mg/ml as a glucose equivalent). WDS-7 was proved to be sensitive in the majority of tested antibiotics and absence of hemolytic activity. Moreover, no production of biogenic amines and β-glucuronidase was observed in WDS-7. The findings of this work indicated that L. delbrueckii ssp. indicus WDS-7 fulfilled the probiotic criteria in vitro and could be exploited for further evaluation in vivo.

TEM Experiment and Complete Genome Sequencing with Comparative Genomic Analysis to Uncover Potential Probiotic Features of IsolatedLactobacillus delbrueckiisubsp.indicusTY-11

“…This is consistent with the biochemical character of Lactobacillus delbrueckii ssp. indicus WDS-7 [5].…”

“…indicus TY-11. The subspecies indicus was reported previously by two different studies, where phenotypic and genotypic traits were observed by DNA–DNA hybridization, multilocus sequence typing (MLST), 16S rRNA gene sequencing, and biochemical tests [4, 5]. From the past two studies it was confirmed that subspecies indicus strains were potential probiotics, which fermented lactose constitutively like subspecies bulgaricus.…”

“…Although some research suggested that it may also be found in other nutrient-rich settings, such as yogurts [5], this reflects the environment that it can live in the gut, where it may absorb peptides and amino acids from its surrounding environment. One of the most well-known probiotics, Lactobacillus delbrueckii subsp.…”

“…In the previous studies, this information was not covered for the described strains of subspecies indicus . Functional genes and comparative genomic information from whole genome sequences of subspecies indicus was not studied in previous studies [4, 5]. Therefore, the aim of this study was to isolate and identify a potential strain of L. delbrueckii subsp.…”

Lactobacillus paracasei CNCM I-5220-derived postbiotic protects from the leaky-gut

“…Thus, their functional properties and low toxicity pose postbiotics as a novel approach for re-establishing host-microbe homeostasis, without risking potentially harmful bacterial translocation. Since it is very well known the beneficial effect of different bacterial strains on the host organism ( Simeoli et al, 2015 ; Hossain et al, 2022 ; Wu et al, 2022 ), we sought to determine if probiotic-derived metabolites, or postbiotics, could also enhance the well-being of the host. Maintenance of the IEB integrity and function requires a fine-tuned balance among different specialized cells to ensure the physiological and protective crosstalk between intestinal microbes and host immune response.…”