effect of lactobacillus plantarum a7 (kc355240.1) on cholesterol-level in vitro

background: although lowering of food cholesterol is an effective way to reduce blood cholesterol, but recently some effective health and bioactivity characteristics of the milk fat components have been identified, so by decreasing the use of milk fat, an important source of fat-soluble vitamins and bioactive components of milk is limited. recent studies have shown that the growth of lactic acid bacteria in milk can be effective in reducing the harmful fat in milk. before introduction of lactobacillus plantarum a7 (which has different probiotic properties) as a native species with the ability to reduce cholesterol level, it was necessary to know its mechanism of action. methods: the strain was cultured in mrs medium and whole milk containing 70 to 100 µg/ml of water-soluble cholesterol. by isolating the bacteria from the culture medium or milk by centrifugation, isolation of non-fat saponify part of milk and cholesterol spectrophotometric measurement were performed. findings: the results indicated that the difference in standard cholesterol can be effective on measuring method. cholesterol concentration did not change during the growth of bacteria in the media and properties of the bacterium in significant reduction of serum cholesterol and triglycerides in mice were not coordinated with activity of bacteria in the extracellular environment and its absorption, digestion or strong binding to the bacterium surface. conclusion: this study showed that the method used in studies for measuring cholesterol in the medium is not entirely accurate and if the difference between the tested strains’ ability to reduce cholesterol is less than 10 to 20 mg per liter, this method can hardly select the best strains. probably other mechanisms such as production of short chain fatty acids, which can cause interference on cholesterol metabolism in the body, were the main cause of the effectiveness of this strain in laboratory rats.