Hamsters Are a Better Model System than Rats for Evaluating the Hypocholesterolemic Efficacy of Potential Probiotic Strains

Dietary supplements: clinical cholesterol-lowering efficacy and potential mechanisms of action

This review aims to analyse the efficacy of dietary supplements in reducing plasma cholesterol levels. Focusing on evidence from meta-analyses of randomised controlled clinical trials, with an emphasis on potential mechanisms of action as supported by human, animal, and cell studies. Certain dietary supplements including phytosterols, berberine, viscous soluble dietary fibres, garlic supplements, soy protein, specific probiotic strains, and certain polyphenol extracts could significantly reduce plasma total and low-density lipoprotein (LDL) cholesterol levels by 3-25% in hypercholesterolemic patients depending on the type of supplement. They tended to be more effective in reducing plasma LDL cholesterol level in hypercholesterolemic individuals than in normocholesterolemic individuals. These supplements worked by various mechanisms, such as enhancing the excretion of bile acids, inhibiting the absorption of cholesterol in the intestines, increasing the expression of hepatic LDL receptors, suppressing the activity of enzymes involved in cholesterol synthesis, and activating the adenosine monophosphate-activated protein kinase signalling pathway.

Cholesterol-lowering effect of bile salt hydrolase from a Lactobacillus johnsonii strain mediated by FXR pathway regulation

Hypercholesterolemia is a major risk factor for cardiovascular diseases worldwide.

Probiotic Effects of Lactobacillus fermentum ZJUIDS06 and Lactobacillus plantarum ZY08 on Hypercholesteremic Golden Hamsters

Hypercholesteremia or high cholesterol is one of the important factors leading to atherosclerosis and other cardiovascular diseases. The application of probiotics with cholesterol-lowering characteristics has become increasingly popular over the past decade due to their contribution to human health. This study aimed to evaluate the probiotic effects of Lactobacillus fermentum ZJUIDS06 and Lactobacillus plantarum ZY08 on hyperlipidemic golden hamsters. A hyperlipidemic model was established through a high cholesterol diet in golden hamsters, after which lyophilized Lactobacillus fermentum ZJUIDS06 and Lactobacillus plantarum ZY08 were orally administered individually for 8 weeks. The physiological characteristics of golden hamsters and short chain fatty acid (SCFA) in the colon were assessed by automatic Biochemical Analyzer and gas choromatograph, respectively. A MiSeq sequencing-based analysis of the bacterial 16S rRNA gene (V3–V4 region) in the cecum content was performed to analyze the cecum microbiota. Correlations between sets of these variables were also investigated using the R package “corrplot.” Results showed that neither Lactobacillus fermentum ZJUIDS06 nor Lactobacillus plantarum ZY08 inhibited body weight increase. However, supplementation with Lactobacillus fermentum ZJUIDS06 for 8 weeks increased colon SCFA levels (P < 0.05), decreased serum low-density lipoprotein, total cholesterol, and triglycerides levels, and also induced changes in the cecum microbiota of hyperlipidemic golden hamsters. Remarkably, oral administration of Lactobacillus fermentum ZJUIDS06 increased the relative abundance of Parabacteroides in the cecum, which served as a biomarker for colon SCFA production and improvement of serum cholesterol levels. In a word, Lactobacillus fermentum ZJUIDS06 improved hyperlipidemia in golden hamsters, which correlated with an increase in SCFA levels and relative abundance of Parabacteroides, indicating its potential importance in functional foods that can help lower cholesterol.

Screening for Cholesterol-Lowering Probiotics from Lactic Acid Bacteria Isolated from Corn Silage Based on Three Hypothesized Pathways

A total of 85 strains of lactic acid bacteria were isolated from corn silage in this study and analyzed in vitro for their cholesterol removal, NPC1L1 protein down-regulation and bile salt deconjugation ability, respectively. Nineteen strains were selected for further analysis for their probiotic potential. Finally, 3 strains showing better probiotic potential were evaluated for their cholesterol-lowering activity in hamsters. The strains showing the greater cholesterol removal and NPC1L1 protein down-regulation activity had no significant effects on serum and hepatic cholesterol levels in hamsters (p > 0.05). However, Lactobacillus plantarum CAAS 18008 (1 × 10⁹ CFU/d) showing the greater bile salt deconjugation ability significantly reduced serum low-density lipoprotein cholesterol, total cholesterol, and hepatic total cholesterol levels by 28.8%, 21.7%, and 30.9%, respectively (p < 0.05). The cholesterol-lowering mechanism was attributed to its bile salt hydrolase activity, which enhanced daily fecal bile acid excretion levels and thereby accelerated new bile acid synthesis from cholesterol in liver. This study demonstrated that the strains showing greater cholesterol removal and NPC1L1 protein down-regulation activity in vitro hardly reveal cholesterol-lowering activity in vivo, whereas the strains showing greater bile salt deconjugation ability in vitro has large potential to decrease serum cholesterol levels in vivo.