Isolation and identification of cholesterol-degrading intestinal bacteria by culturomics and evaluation of their functions.

Yeshi HE; Zhiyuan Pan; Ni Han; Yan GE; Yuxiao Chang; Wenting Wei; Yuejiao Liu; Qianwen Zhang; Ruifu Yang; Yujing BI

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Isolation and identification of cholesterol-degrading intestinal bacteria by culturomics and evaluation of their functions.

Author: Yeshi HE ¹ ; Zhiyuan PAN ¹ ; Ni HAN ¹ ; Yan GE ¹ ; Yuxiao CHANG ¹ ; Wenting WEI ¹ ; Yuejiao LIU ¹ ; Qianwen ZHANG ¹ ; Ruifu YANG ¹ ; Yujing BI ¹
Author Information

1. State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing 100071, China.
Publication Type:Journal Article
Keywords: bile acid; cholesterol; culturomics; intestinal bacteria; triglyceride
MeSH: Animals; Cattle; Cholesterol; Gammaproteobacteria; Humans; Proteus mirabilis; Providencia
From: Chinese Journal of Biotechnology 2021;37(11):3734-3744
CountryChina
Language:Chinese
Abstract: High cholesterol is one of the important factors inducing cardiovascular and cerebrovascular diseases. Drug therapy is the main method for reducing cholesterol, but has the disadvantages such as high cost and side effects. Studies have shown that intestinal bacteria play important roles in cholesterol metabolism. However, there are few reports on the screening and functional evaluation of cholesterol-lowering intestinal bacteria. In this study, 36 bile-tolerant bacteria were screened from healthy people stool through culturomics using bovine bile acid or artificial mixed bile acids as substrates. Taking Lactobacillus rhamnosus GG (LGG) as a positive control, three bile acid concentration groups (0 g/L, 0.3 g/L, 3 g/L) were set up to evaluate the cholesterol-lowering ability of bile-tolerant bacteria in vitro. Ten bacteria (including Proteus mirabilis, Providencia stuartii, Proteus vulgaris et al) were identified as the dominant cholesterol-lowering bacteria. Six of the above bacteria, Proteus mirabilis, Providencia stuartii, Proteus vulgaris, Proteus penneri, Wohlfahrtiimonas chitiniclastica, Providencia rettger, were evaluated for their ability to reduce triglycerides in vitro and tolerance to artificial gastric juice. Comparing with strain LGG, the six bacteria showed better triglyceride-lowering ability in vitro. With the decrease of pH value of artificial gastric juice and the increase of treatment time, the survival rate of six bacteria decreased. The above screening experiments and functional evaluation provide a basis for further development of potential cholesterol-lowering bacterial products.