Optimization of cholesterol reduction by Lactobacillus plantarum through central composite design for hypercholesterolemia

Probiotics derived from milk and milk products have cholesterol reduction potential. The main objective of this study was to evaluate the cholesterol reduction ability of lactic acid bacterial species isolated from dairy milk and milk products. Two bacterial species were isolated, characterized, and their cholesterol reduction potential was evaluated. Maximum cholesterol reduction levels were about 15.3 and 13.91% observed on the 4th day of incubation by bio-therapeutic bacterial strains Lactobacillus plantarum and Lactobacillus acidophilus, respectively. The cholesterol reduction potential of a former bio-therapeutic bacterial strain with maximum cholesterol reduction potential was further optimized by using a central composite design of response surface methodology under the same experimental conditions. Maximized cholesterol reduction of 21.91% was achieved after optimization. This increase of 43% in cholesterol reduction was achieved while optimizing three factors, including bacterial inoculum (log CFU/mL)/inoculum size, substrate concentration (mg/mL), and incubation time (days) by using central composite design and response surface methodology. From the results obtained, it has been suggested that optimization of parameters by applying response surface methodology showed more significant results (P < 0.05) in a short time with a smaller number of experiments, instead of the conventional and established “one factor at a time” approach.