Abstract:
Elevated serum cholesterol is an important risk factor associated with atherosclerosis and
coronary heart disease. Several studies have reported a decrease in serum cholesterol during the
consumption of high doses of fermented dairy products or Lactobacillus strains. The aim of the
present study was to isolate potential probiotic Lactobacillus strains from indigenous yogurt
(dahi) samples and their ability to survive gastrointestinal conditions in vitro. The most tolerant
strains were further tested for their ability to reduce cholesterol in vitro. Lactobacillus
ferementum Y55, Lactobacillus ferementum Y57, Lactobacillus rhamnosus Y59, Lactobacillus
ferementum Y63 and Y52 were selected for in vivo trials as their percentage cholesterol
assimilation in vitro was 37%, 41%, 38%, 37% and 38% respectively. The safety profile of the
best strains was evaluated in rat model followed by the in vivo cholesterol reducing potential of
these strains. In vivo safety assessment was carried out and all the strains turned out to be safe
for consumption. The strains showed a significant decrease in serum cholesterol when
administered with high fat diet in rats. The increase in cholesterol level of group fed with high fat
diet only was 31% whereas the decrease in cholesterol levels of groups fed with high fat diet
along with probiotic dosage of Lactobacillus ferementum Y55, Lactobacillus ferementum Y57,
Lactobacillus rhamnosus Y59 and Lactobacillus ferementum Y63 was 8%, 6%, 5% and 3%
respectively. A significant increase in HDL levels and decrease in LDL levels was also observed
in the test groups whereas Lactobacillus ferementum Y57 showed better reduction in serum
cholesterol than statins.
