ABSTRACT:
Probiotic bacteria have shown the capacity to reduce cholesterol levels through a variety of processes, including cholesterol assimilation, bile salt hydrolase action, and cell outer layer buildup. The goal of the research was to pinpoint three hypocholesterolemic processes in the Lactobacillus reuteri strain, using the multifactorial statistical Plackett-Burman Design (PBD) to improve cholesterol uptake conditions. The PBD was used to investigate the effects of five parameters on cholesterol assimilation. The results demonstrated that the greatest level of cholesterol assimilation (97%) occurred at the level of cholesterol 100 mg/dl, incubation time 24 hours, bill salt concentrations 0.5%, pH 6.5, and inoculum size 200 µl at 30 oC in MRS broth. Bile salt hydrolase (BSH) efficiency was assessed using both qualitative and quantitative methods. The activity of the BSH enzyme was assessed qualitatively by examining zones of precipitation on the growing medium. Additionally, a quantitative assessment was performed at 570 nm using a UV-vis spectrophotometer. The diameter of the precipitation zones was (2, 4, 6, 6 and 9 mm) for bile salt levels of (0.1, 0.2, 0.3, 0.4, and 0.5%). The quantitative values of BSH enzyme activity were found to be 18.83 U/mL for sodium thioglycocholate substrate. Scanning electron microscope images (SEM) confirmed that cholesterol had adhered to the bacterial cell wall. Referring to the SEM results of probiotic strains, In the cholesterol-containing medium made for this experiment, Lactobacillus reuteri had a nearly empty and smooth morphology. The findings suggested that lactobacilli might eliminate cholesterol in vitro via a variety of pathways and may have similar hypocholesterolemic effects in vivo.