Construction of R16F and D19L mutations in the loop I of bile salt hydrolase (BSH) enzyme fromLactobacillus plantarumB14 and structural and functional analysis of the mutant BSHs

Effects of Synbiotic Lacticaseibacillus paracasei, Bifidobacterium breve, and Prebiotics on the Growth Stimulation of Beneficial Gut Microbiota

The gut microbiota is a complex community of microorganisms that plays a vital role in maintaining overall health, and is comprised of Lactobacillus and Bifidobacterium. The probiotic efficacy and safety of Lacticaseibacillus paracasei and Bifidobacterium breve for consumption were confirmed by in vitro experiments. The survival rate of the probiotics showed a significant decline in in vitro gut tract simulation; however, the survival rate was more than 50%. Also, the probiotics could adhere to Caco-2 cell lines by more than 90%, inhibit the pathogenic growths, deconjugate glycocholic acid and taurodeoxycholic acid through activity of bile salt hydrolase (BSH) proteins, and lower cholesterol levels by over 46%. Regarding safety assessment, L. paracasei and B. breve showed susceptibility to some antibiotics but resistance to vancomycin and were examined as γ-hemolytic strains. Anti-inflammatory properties of B. breve with Caco-2 epithelial cell lines showed the significantly highest value (p < 0.05) for interleukin-10. Furthermore, probiotics and prebiotics (inulin, fructooligosaccharides, and galactooligosaccharides) comprise synbiotics, which have potential effects on the increased abundance of beneficial microbiota, but do not affect the growth of harmful bacteria in feces samples. Moreover, the highest concentration of short chain fatty acid was of acetic acid, followed by propionic and butyric acid.