Bile Salt Hydrolase Activity of Cholesterol-Lowering Probiotic Lactic Acid Bacteria Isolated from Indigenous Fermented Foods

The main risk factor for cardiovascular diseases is hypercholesterolaemia (elevated blood cholesterol levels). Many cholesterol-lowering drugs exist, but not without adverse side effects. Consequently, a natural dietary approach with little or no side effects is needed. This study aimed to isolate, characterise and identify probiotic lactic acid bacteria with cholesterol-lowering abilities in vitro and their bile salt hydrolase activity. Fifty-two isolates of lactic acid bacteria were isolated from indigenous fermented food products (ugba, ogi, ogiri, raw cow milk and yoghurt), of which 22 isolates were considered presumptive LAB after Gram staining and biochemical tests. The antimicrobial activity of the isolates was evaluated, and out of 22 LAB isolates, only six showed broad-spectrum antagonistic effects on test bacteria pathogens and good bile and acid tolerance. The six isolates had in vitro cholesterol assimilation between 19.34% and 53.60% and bile salt hydrolase activity between 2.52±0.21 and 6.67±0.21 activity/ml/min. The two most promising LAB isolates were selected based on cholesterol assimilation over 40.0% and bile salt hydrolase activity above 6.00 ml/min. The isolates were identified using API 50 CHL kits and medium and 16S rRNA gene sequencing. After genotypic identification, the two promising LAB isolates were identified as Pediococcus acidilactici MTA463550.1 and Pediococcus acidilactici MN994318.1. These data demonstrated the bile salt hydrolase activity and cholesterol-lowering effects of Pediococcus acidilactici MTA463550.1 and Pediococcus acidilactici MN994318.1. They can, therefore, be used as probiotic supplements in foods to help reduce the risks of cardiovascular diseases and improve heart health.