Lacticaseibacillus rhamnosus FM9 and Limosilactobacillus fermentum Y57 Are as Effective as Statins at Improving Blood Lipid Profile in High Cholesterol, High-Fat Diet Model in Male Wistar Rats

Abstract

Elevated serum cholesterol is a major risk factor for coronary heart diseases. Some <i>Lactobacillus</i> strains with cholesterol-lowering potential have been isolated from artisanal food products. The purpose of this study was to isolate probiotic <i>Lactobacillus</i> strains from traditional yoghurt (dahi) and yogurt milk (lassi) and investigate the impact of these strains on the blood lipid profile and anti-obesity effect in a high cholesterol high fat diet model in Wistar rats. Eight candidate probiotic strains were chosen based on in vitro probiotic features and cholesterol reduction ability. By 16S rDNA sequencing, these strains were identified as <i>Limosilactibacillus fermentum</i> FM6, <i>L. fermentum</i> FM16, <i>L. fermentum</i> FM12, <i>Lacticaseibacillus rhamnosus</i> FM9, <i>L. fermentum</i> Y55, <i>L. fermentum</i> Y57, L. <i>rhamnosus</i> Y59, and <i>L. fermentum</i> Y63. The safety of these strains was investigated by feeding 2 × 10⁸ CFU/mL in saline water for 28 days in a Wistar rat model. No bacterial translocation or any other adverse effects were observed in animals after administration of strains in water, which indicates the safety of strains. The cholesterol-lowering profile of these probiotics was evaluated in male Wistar rats using a high-fat, high-cholesterol diet (HFCD) model. For 30 days, animals were fed probiotic strains in water with 2 × 10⁸ CFU/mL/rat/day, in addition to a high fat, high cholesterol diet. The cholesterol-lowering effects of various probiotic strains were compared to those of statin. All strains showed improvement in total cholesterol, LDL, HDL, triglycerides, and weight gain. Serum cholesterol levels were reduced by 9% and 8% for <i>L. rhamnosus</i> FM9 and <i>L. fermentum</i> Y57, respectively, compared to 5% for the statin-treated group. HDL levels significantly improved by 46 and 44% for <i>L. rhamnosus</i> FM9 and <i>L. fermentum</i> Y57, respectively, compared to 46% for the statin-treated group. Compared to the statin-treated group, FM9 and Y57 significantly reduced LDL levels by almost twofold. These findings show that these strains can improve blood lipid profiles as effectively as statins in male Wistar rats. Furthermore, probiotic-fed groups helped weight control in animals on HFCD, indicating the possible anti-obesity potential of these strains. These strains can be used to develop food products and supplements to treat ischemic heart diseases and weight management. Clinical trials, however, are required to validate these findings.