In Vitro and In Vivo Cholesterol Reducing Ability and Safety of Probiotic Candidates Isolated from Korean Fermented Soya Beans.

Hypercholesterolemia is a risk factor for cardiovascular diseases, and hence, reducing serum cholesterol levels could reduce the incidence. In this study, we ascertained the cholesterol-reducing potential of lactic acid bacteria (LAB) isolated from Korean fermented soybean paste. Live, resting, and dead cells of all the bacteria reduced cholesterol in liquid media in a strain-dependent manner. Live cells of Weissella cibaria SCCB2306, Pediococcus acidilactici SDL1402, P. acidilactici SDL1406, and Lactobacillus rhamnosus JDFM6 reduced the most cholesterol in liquid media by 78 ± 3%, 72 ± 3%, 76 ± 3%, 75 ± 5%, and 79 ± 2%, respectively. As the cholesterol levels in the media reduced, cell membrane lipids of P. acidilactici SDL1402, P. acidilactici SDL1406, and L. rhamnosus JDFM6 increased by 23.36 mg/mL, 6.53 mg/mL, and 8.14 mg/mL, respectively, indicating that cholesterol was incorporated into the bacteria cell membranes. All the bacteria displayed bile salt hydrolase activities in a strain-dependent manner. Though all four LAB significantly reduced cholesterol levels in Caenorhabditis elegans irrespective of the order of feeding, L. rhamnosus JDFM6 reduced the most cholesterol in vivo (up to 40% of ingested cholesterol). None of the four LAB hydrolyzed mucin or gelatin and none was toxic to C. elegans. The concentrations of phenylethylamine, putrescine, cadaverine, histamine, and tyramine produced by the LAB were below the toxic limits of biogenic amines set by the European Food Safety Authority. Taken together, our results demonstrate that Weissella cibaria SCCB2306, P. acidilactici SDL1402, P. acidilactici SDL1405, and L. rhamnosus JDFM6 could be safe cholesterol-reducing probiotic candidates for preventing or managing hypercholesterolemia.