Lactobacillus fermentum is often found in the human gastrointestinal tract and is considered a safe probiotic. Specific strains have been linked to reduction in cholesterol.
One mechanism of this is through the absorption of cholesterol, which accelerates cholesterol metabolism. L. fermentum is also hypothesized to incorporate cholesterol in the host body into cell membranes or walls, ultimately increasing the bacterial resistance to environmental factors. In addition, it may cause the body to consume more cholesterol, interfering with bile salt recycling and aiding in its removal, increasing the demand for bile salt through cholesterol production.
Studies have also linked L. fermentum with improvements in antioxidant enzyme function, immune response, and increased resistance to bacterial infections like E. coli.
Tomaro-Duchesneau, C., et al. “Lactobacillus fermentum NCIMB 5221 and NCIMB 2797 as cholesterol-lowering probiotic biotherapeutics: in vitro analysis. Beneficial Microbes. Wageningen Academic Publishers. 2015. 861-869. doi: http://dx.doi.org/10.3920/BM2015.0021