Clinical Microbiology: Open Access

Abstract

Cholesterol Lowering Capability of some Lactobacillus Strains and its Effect on Mice Fed a High Cholesterol Diet

Mohamed Abd El Helim, Shabaan Hashem, Tamer Essam and Mohamed Omar

Elevated blood 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 large doses of fermented dairy products or Lactobacillus strains. Based on literature, in vitro cholesterol removal of lactic acid bacteria (LAB) has been accounted for their in vivo cholesterol reduction. But recently it has been proposed that such in vitro characteristic may not be directly relevant to their in vivo activity. The objective of this study was to find how much in vitro cholesterol reducing capability from bacterial culture media contain Lactobacillus reutri (ATCC 23272) and Lactobacillus casei (ATCC 393), As well as under vivo conditions. Bacteria used are a native strains isolated from a human and cheese origin respectively reflects its in vivo efficiency. Here, we investigate whether the given strains are capable of in vitro cholesterol assimilation or consumption using a colorimetric method. The proposed mechanism for this effect is the removal or assimilation of intestinal cholesterol by the bacteria, reducing cholesterol absorption. Although this effect was demonstrated in vitro, its relevance in vivo is still controversial. Furthermore, few studies have investigated the role of lactobacilli in atherogenesis Lactobacillus reutri (LA7) previously showed serum cholesterol reducing capability in mice subjected to fatty diet. Our in-vivo study was held as twenty male Swiss albino mice aged 4-6 weeks and weighing 25-30 g were orally ingested by L. casei and L. reutri. They were kept under a 12 hr light/dark cycle at 22-26°C and a relative humidity of 50%, in Cages (15 × 25 cm), three mice used as a control group. Samples are taken in eppendorf tubes and tested for total serum cholesterol concentration. However, more clinical evidence is needed to strengthen these proposals