Newly characterized Lactiplantibacillus plantarum strains isolated from raw goat milk as probiotic cultures with potent cholesterol-lowering activity

Abstract

One of the most promising aspects of lactic acid bacteria (LAB) in foodstuffs with probiotic characteristics is cholesterol-lowering action. This study aimed to examine the bile salt hydrolase (BSH) positive strains; out of 50 LAB isolates, Lactiplantibacillus plantarum Lpb01 and Lpb02 were selected. Both Lpb01 and Lpb02 were more bile-tolerant strains, surviving in 1% bile for 3 h at up to 7.27 and 7.14 log CFU/mL, respectively. Lactiplantibacillus plantarum Lpb01 and Lpb02 deconjugated considerably more sodium glycocholate, releasing 5.50 ± 0.12 mM and 5.23 ± 0.41 mM cholic acid, respectively, compared with 4.32 ± 0.17 mM cholic acid released by ATCC 8014. In addition, Lpb. plantarum Lpb01 and Lpb02 deconjugated a considerably higher quantity of sodium glycocholate than ATCC 8014. Compared to ATCC 8014, Lactiplantibacillus plantarum Lpb01 and Lpb02 demonstrated a higher level of BSH activity. The tested strains Lactiplantibacillus plantarum Lpb01 and Lpb02 resulted in a 63–68% reduction in the cholesterol level in broth media, whereas the commercial strain Lpb. plantarum ATCC 8014 showed a 51% reduction. In the case of survivability during in vitro gastrointestinal digestion, they did not lyse in the presence of lysozyme, and they survived more than 96% of the time when exposed to pepsin and low acidity (pH 3) for 1.5 h. Finally, the LAB strains were resistant to bile salts and pancreatin, with an overall viability rate of 94.0–99.4% after exposure to small intestinal conditions. This suggests that the isolates can live in the GI tract's severe environment. As a result, these strains with demonstrated in vitro capabilities are promising candidates for novel probiotic-containing formulations and could be incorporated into functional dairy foods. • The Lactiplantibacillus plantarum Lpb01and Lpb02 strains have shown high bile salt hydrolase activity. • The strains Lpb01 and Lpb02 resulted in remarkably higher cholesterol reductions of 63 and 68%, respectively. • The evaluated strains have a cholesterol removal ability of 12–17% higher than commercial strain ATCC 8014. • Biomimetic digestion model assessed that both strains had more than 96% survivability.