Reduction of Cholesterol by Lactobacillus acidophilus in Culture Broth

Abstract

Cholesterol reducing abilities of six strains of Lactobacillus acidophilus including ATCC 4356, B, E, Farr, LA-1 and N-1 were investigated in vitro. All these strains were able to reduce cholesterol at various levels in the broth system used in this study. Among the strains tested, L. acidophilus ATCC 4356 demonstrated the best cholesterol reducing ability at 57 and 71% in the presence of oxgall and cholic acid, respectively, in the broth. Results from the acid tolerance and growth in oxgall studies demonstrated that these L. acidophilus strains would likely survive in the human gastrointestinal tract, where acid and oxgall are present in the stomach and small intestine. Coprecipitation, which was observed in the presence of cholic acid, of cholesterol with deconjugated bile at acidic pH contributed to the reduction of cholesterol in vitro. However, coprecipitation is not likely to take place in vivo since the pH in the small intestine is higher than neutral. Results from this study indicate that the in vivo hypocholesteremic ability is likely due to the assimilation of cholesterol by L. acidophilus cells or/and attachment of cholesterol to the surface of L. acidophilus cells.