Lactobacillus paracasei DTA81, a cholesterol-lowering strain having immunomodulatory activity, reveals gut microbiota regulation capability in BALB/c mice receiving high-fat diet

Aims: In-vitro/In-vivo evaluation of cholesterol-lowering probiotic strain Lactobacillus paracasei DTA81 and the possible connection with the gut microbiota modulation. Methods and Results: In the present study, strain DTA81 has been evaluated for the possible influence on blood lipid and glucose concentrations, modulation of the immune system, gastrointestinal survivability and modulation of gut microbiota in BALB/c mice receiving a high-fat diet. After 6 weeks of treatment, a significant reduction of total cholesterol and fasting blood sugar (FBS) among animals treated with L. paracasei DTA81 has been recorded. Comparison of colon tissue levels of different cytokines revealed a significant reduction of the inflammatory cytokine interleukin-6. The comparison of gut microbiota using the 16S rRNA approach indicated that the treatment with L. paracasei DTA81 significantly increased the taxa Bacteroidetes and Coprococcus. Moreover, the genome of DTA81 was sequenced for the in-silico assessment, and the analysis indicated the presence of cholesterol assimilation-related genes as well as the absence of negative traits such as transmissible antibiotic resistance genes, plasmids and prophage regions. Conclusion: The outcome of this study revealed the in-vitro and in-vivo properties of L. paracasei DTA81 and the possible mechanism between consumption of this strain, the abundance of Bacteriodetes/Coprococcus taxa, immunomodulatory activity and the subsequent reduction of cholesterol/FBS in BALB/c mice. Significance and Impact of the Study: Lactobacillus paracasei DTA81 as a non-pharmacological potential probiotic supplement can influence metabolic homeostasis in individuals, particularly those adopting high-fat diets, and it can contribute to reduce coronary heart disease.