Development and properties evaluation of multi-strain probiotic with cholesterol-lowering potential in vitro

Probiotics have a cholesterol-lowering effect. Multi-strain probiotics (MSPs) outperformed single-strain probiotics due to the interaction of strains. Hence, we expect to develop a high-efficiency MSP for lowering cholesterol. Three strains, including Lactobacillus caseiS1, Enterococcus faeciumS4, and L. harbinensisS6, were used to develop the MSPs. To evaluate their effect, gastrointestinal tolerance, bile salt hydrolase (BSH) activity, cholesterol-lowering rate, antioxidant ability, gamma-aminobutyric acid (GABA) production, and antibiotic sensitivity were determined. The triple lactic acid bacteria probiotic (TLP) was the most efficient one. After 24 h treatment with artificial gastric fluid, 47.88% of TLP survived. TLP exhibited the highest BSH activity (149.40 U·ml-1) and cholesterol-lowering rate (75.05%) in vitro, with co-precipitation reducing the majority of cholesterol. The reducing power and superoxide radical scavenging rate of the cell-free supernatant and the hydroxyl radical scavenging rate in viable cells were 1.52, 85.03%, and 89.66%, respectively, and the GABA production was 0.67 mg·ml-1, which enhanced the health benefit effects. By fuzzy mathematical analysis, TLP was the optimal probiotic and was competitive with commercial probiotics. The three strains were susceptible to 13 antibiotics. Therefore, TLP has the potential to develop into a cholesterol-lowering probiotic preparation.