Dual Effects of Lactobacilli as a Cholesterol Assimilator and an Inhibitor of Gastrointestinal Pathogenic Bacteria

Abstract

Background: Probiotics are live microbial supplements which can improve the healthy intestinal microbial balance. Lactobacilli are a group of lactic acid producing bacteria (LAB) that are known as natural probiotics found in the dairy products. Objectives: In this study, we aimed to detect the most potent Lactobacillus isolates of the Fars province local dairy products in cholesterol removal and investigate their antibacterial properties against some gastrointestinal pathogens. Materials and Methods: Fifteen locally produced yogurt samples of the Fars province were collected and characterized with routine microbiology methods. Cholesterol removal ability of the Lactobacilli isolates were determined, and their growth inhibitory effect on some standard pathogenic strains pathogen was evaluated using the well-diffusion method. Results: In this study, five common strains of Lactobacilli including L. acidophilus, L. casei, L. fermentum, L. lactis, and L. bulgaricuswere identified in the samples obtained from the locally produced yogurt in the Fars province. L. lactis and L. acidophilus were determined as the two most active strains with the maximum rate of cholesterol assimilation (5.6 and 4.5 mg/mL, respectively) in the process of cholesterol removal. In the antibacterial activity assay, the two mentioned strains had significant inhibitory effect on all of the tested bacteria except for B. subtilis. Conclusions: Cholesterol removal ability had a direct relation with bacterial growth, so it is suggested to use the probiotic bacteria in the growth phase to achieve better results.

Dual function of Lactobacillus kefiri DH5 in preventing high‐fat‐diet‐induced obesity: direct reduction of cholesterol and upregulation of PPAR‐α in adipose tissue

“…Since the prevalence of overweight and obesity is increasing, many researchers have actively developed anti‐obesity agents . In these processes, various in vitro screening assays are employed to select anti‐obesity probiotics, including the measurement of bile salt hydrolase activity, cholesterol‐reducing activity, inhibition of lipid accumulation in 3T3‐L1 cells, and triacylglycerol lipase assay . In this study, we measured the cholesterol‐reducing activity of isolates, as this activity is directly related to the prevention and treatment of HFD‐induced obesity .…”

“…For example, Lactobacillus amylovorus CP1563, which showed excellent hepatic and adipose PPAR‐α ‐agonistic activity in a mouse model of HFD‐induced obesity, decreased the adiposity and plasma cholesterol levels in a clinical trial . In addition, the in vitro cholesterol‐reducing activity of lactic acid bacterium (LAB) strains has been generally tested for screening probiotics with anti‐obesity activity . Unfortunately, many of the selected strains did not demonstrate anti‐obesity activity in vivo .…”

Cholesterol-lowering effects of a putative probiotic strain Lactobacillus plantarum EM isolated from kimchi

“…However, direct investigation of the chemical and structural properties of the L. plantarum EM cell wall that promote binding to cholesterol is required. Cholesterol removal by dead cells of LAB strains has been reported previously, even though the degree of removal is significantly less compared to that of growing cells (Emami & Bazargani, 2014;Liong & Shah, 2005;Mahdieh, Hamid, & Naheed, 2014;Sirilun, Chaiyasut, Kantachote, & Luxananil, 2010;Zeng, Pan, & Guo, 2010). Further, cholesterol removal by dead cells due to cholesterol attachment to the cellular membrane has been investigated based on scanning electron microscopic observation of cholesterol binding to growing cells (Lye et al, 2010a;Ooi & Liong, 2010).…”