Abstract
BackgroundElevated serum cholesterol level is generally considered to be a risk factor for the development of cardiovascular diseases which seriously threaten human health. The cholesterol-lowering effects of lactic acid bacteria have recently become an area of great interest and controversy for many researchers. In this study, we investigated the effects of two NS lactobacillus strains, Lactobacillus plantarum NS5 and Lactobacillus delbrueckii subsp. bulgaricus NS12, on lipid metabolism of rats fed a high cholesterol diet.MethodsThirty-two SD rats were assigned to four groups and fed either a normal or a high-cholesterol diet. The NS lactobacillus treated groups received the high-cholesterol diet supplemented with Lactobacillus plantarum NS5 or Lactobacillus delbrueckii subsp. bulgaricus NS12 in drinking water. The rats were sacrificed after a 6-week feeding period. Body weights, visceral organ and fat weights, serum and liver cholesterol and lipid levels, intestinal microbiota and liver mRNA expression levels related to cholesterol metabolism were analyzed. Liver lipid deposition and adipocyte size were evaluated histologically.ResultsCompared with rats fed a high cholesterol diet, serum total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B and free fatty acids levels were decreased and apolipoprotein A-I level was increased in NS5 or NS12 strain treated rats, and with no significant change in high-density lipoprotein cholesterol level. Liver cholesterol and triglyceride levels were also significantly decreased in NS lactobacillus strains treated groups. Meanwhile, the NS lactobacillus strains obviously alleviated hepatic injuries, decreased liver lipid deposition and reduced adipocyte size of high cholesterol diet fed rats. NS lactobacillus strains restored the changes in intestinal microbiota compositions, such as the increase in Bacteroides and the decrease in Clostridium. NS lactobacillus strains also regulated the mRNA expression levels of liver enzymes related to cholesterol metabolism, including the down regulation of acyl-CoA:cholesterol acyltransferase (ACAT) and the upregulation of cholesterol 7α-hydroxylase (CYP7A1).ConclusionThis study suggested that the two NS lactobacillus strains may affect lipid metabolism and have cholesterol-lowering effects in rats fed a high cholesterol diet.
Highlights
The incidence of hypercholesterolemia is increasing rapidly with the improvements of people’s living standards and alterations of lifestyles
Lactobacillus strains on serum and liver lipid levels in high-cholesterol diet fed male standard deviations (SD) rats, and explored the possible mechanisms from the aspects of intestinal microbiota compositions and mRNA expression levels of liver enzymes related to cholesterol metabolism
Adding 108 CFU/ml of Lactobacillus plantarum NS5 (HC + NS5 group) or Lactobacillus delbrueckii subsp. bulgaricus NS12 (HC + NS12 group) in drinking water, they showed a slight decrease in final body weight compared with High cholesterol (HC) group, and without significant difference (Table 2)
Summary
The incidence of hypercholesterolemia is increasing rapidly with the improvements of people’s living standards and alterations of lifestyles. The level of cholesterol in conventionally raised mice was lower than that of germ-free mice [6]. These facts indicated the existence of the relationship between intestinal microbiota and hypercholesterolemia. Effective interventions in intestinal microbiota may be able to achieve the purpose of reducing serum cholesterol level. Based on the biological feature of LAB in intestine, we proposed other new possibility that LAB display the cholesterol-lowering effects by means of modulating the compositions of intestinal microbiota. Elevated serum cholesterol level is generally considered to be a risk factor for the development of cardiovascular diseases which seriously threaten human health. We investigated the effects of two NS lactobacillus strains, Lactobacillus plantarum NS5 and Lactobacillus delbrueckii subsp. bulgaricus NS12, on lipid metabolism of rats fed a high cholesterol diet
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
