scholarly journals Bile salt hydrolases: Gatekeepers of bile acid metabolism and host-microbiome crosstalk in the gastrointestinal tract

2019 ◽  
Vol 15 (3) ◽  
pp. e1007581 ◽  
Author(s):  
Matthew H. Foley ◽  
Sarah O’Flaherty ◽  
Rodolphe Barrangou ◽  
Casey M. Theriot
2017 ◽  
Vol 7 (11) ◽  
pp. 849
Author(s):  
Yosuke Saito ◽  
Hiroyuki Nishimiya ◽  
Yasue Kondo ◽  
Toyoaki Sagae

Background: Probiotics is used as a promising approach in the prevention and treatment of hypercholesterolemia. Modification of bile acid metabolism through the deconjugation of bile salts by microbial bile salt hydrolase (BSH) is considered to be the core mechanism of the hypocholesterolemic effects of probiotics. Nevertheless, BSH activity is reported to be detrimental to the human host due to the generation of toxic secondary bile acids. Thus, the influence of probiotic intake on bile acid metabolism needs to be elucidated. We analyzed the bile acid levels and microbiota in human fecal samples after probiotic supplementation to assess the influence of probiotic intake on fecal bile acid levels. Two patients hospitalized for schizophrenia and dyslipidemia, receiving an atypical antipsychotic drug, were enrolled in this study (Subjects A and B). Both subjects received Lactobacillus rhamnosus GG (LGG) for 4 weeks, and no probiotics for the following 4 weeks. Fecal samples were collected at baseline and after 4 and 8 weeks.Results: Conjugated bile acids may be modified by indigenous intestinal bacteria into unconjugated bile acids and secondary bile acids through deconjugation reactions by BSH activity and the subsequent 7a-dehydroxylation pathway, respectively. In the fecal microbiota from Subject A, the relative abundance of Bifidobacterium increased after LGG supplementation (30%–49%). Most Bifidobacterium and Lactobacillus strains that colonize mammalian intestines may report BSH activity, and in general bifidobacteria reveals a higher BSH activity than lactobacilli. The fecal unconjugated bile acid and secondary bile acid levels in Subject A increased after the LGG supplementation (0.36–1.79 and 1.82–16.19 mmol/g respectively). Although the LGG supplementation appears to promote bile acid deconjugation, most of the unconjugated bile acids in Subject A appear to have been modified into secondary bile acids. Alternatively, in Subject B there were no significant changes throughout the study.Conclusion: We observed a significant increase in the fecal secondary bile acid levels after probiotic administration in one of our cases. Further studies are needed to elucidate the factors affecting 7a-dehydroxylation of bile acids to confirm the safety of using probiotics.Keywords: bile salt hydrolase; BSH; dihydroxylation; Bifidobacterium


2018 ◽  
Vol 56 (01) ◽  
pp. E2-E89
Author(s):  
F Glaser ◽  
C John ◽  
B Engel ◽  
B Höh ◽  
S Weidemann ◽  
...  

2021 ◽  
Author(s):  
Ming-zhi Zhu ◽  
Fang Zhou ◽  
Jian Ouyang ◽  
Qi-ye Wang ◽  
Yi-long Li ◽  
...  

Combined use of epigallocatechin-3-gallate (EGCG) and caffeine in low doses exhibits marked anti-obesity synergy. The synergistic effect may be attributed to regulation of gut microbiota and BA metabolism.


1942 ◽  
Vol 143 (3) ◽  
pp. 771-783
Author(s):  
L.H. Schmidt ◽  
Hettie B. Hughes

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