Effect of supplementation of probiotics and phytosterols alone or in combination on serum and hepatic lipid profiles and thyroid hormones of hypercholesterolemic rats

Probiotic bacteria and phytosterols are natural hypocholesterolemic agents with potential cardiovascular benefits. Accordingly, the present study was conducted to evaluate the effect of supplementation of probiotics and phytosterols alone or in combination on serum and hepatic lipid profiles and thyroid hormones of hypercholesterolemic rats. Mixed probiotics treatment consisted of 8 probiotic strains: 2 strains of each of Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus gasseri, and Lactobacillus reuteri. The rats were fed for 8 wk with the given treatments in addition to a high-fat-high-cholesterol basal diet to induce hypercholesterolemia. Results showed that supplementation significantly reduced serum total cholesterol, low-density-lipoprotein cholesterol (LDL-C), high-density-lipoprotein cholesterol, and triglycerides compared with the controls. The symbiotic treatment was more effective in lowering LDL-C, whereas mixed probiotics treatment more effectively lowered serum total cholesterol and LDL-C than the phytosterol-containing treatment. The phytosterol-containing treatments induced the increased activity of thyroid glands, as evident by elevated levels of serum total thyroxine, total triiodothyronine, and free triiodothyronine. In conclusion, the lipid profile can effectively be reduced to lower the incidence of cardiovascular disease using combinations of Lactobacillus-based probiotics and phytosterols in functional foods.