Bile salt hydrolases deplete conjugated bile acids and erode gut barrier integrity in non-alcoholic steatohepatitis

Background & Aims: While altered host-microbe interactions are implicated in non-alcoholic fatty liver disease/non-alcoholic steatohepatitis (NAFLD/NASH), specific contributions of microbially derived metabolites remain obscure. We investigated the impact of altered bile acid (BA) populations on intestinal and hepatic phenotypes in a rodent model of NAFLD/NASH. Methods: Wistar rats fed a choline-deficient high-fat diet (CDAHFD) were assessed for altered intestinal permeability after dietary intervention. Cecal and portal venous BA composition were assessed via mass spectrometry. BA-mediated effects on epithelial permeability were assessed using Caco2 epithelial monolayers. Micelle formation was assessed using fluorescent probes and electron microscopy. Bile salt hydrolase (BSH) activity was inhibited with a gut-restricted small molecule in CDAHFD-fed rats and intestinal and hepatic phenotypes were assessed. Results: Increased intestinal permeability and reduced intestinal conjugated BAs were early phenotypes of CDAHFD-fed rats preceding hepatic disease development. Similar intestinal BA pool changes were observed in rats and human NAFLD/NASH patients with progressive disease. Conjugated BAs protected epithelial layers from unconjugated BA-induced damage via mixed micelle formation. The decrease in intestinal conjugated BAs was mediated by increased activity of bacterial BSHs and inhibition of BSH activity prevented the development of pathologic intestinal permeability and hepatic inflammation in the NAFLD/NASH model. Conclusions: Conjugated BAs are important for the maintenance of intestinal barrier function by sequestering unconjugated BAs in mixed micelles. Increased BSH activity reduces intestinal conjugated BA abundance, in turn increasing intestinal permeability and susceptibility to the development of NAFLD/NASH. These findings suggest that interventions that shift the intestinal bile acid pool toward conjugated BAs could be developed as therapies for NAFLD/NASH.

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Cholesterol-Lowering Potentials of Lactic Acid Bacteria Based on Bile-Salt Hydrolase Activity and Effect of Potent Strains on Cholesterol MetabolismIn VitroandIn Vivo

The Scientific World JOURNAL ◽

10.1155/2014/690752 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10 ◽

Cited By ~ 30

Author(s):

Cheng-Chih Tsai ◽

Pei-Pei Lin ◽

You-Miin Hsieh ◽

Zi-yi Zhang ◽

Hui-Ching Wu ◽

...

Keyword(s):

Lactic Acid ◽

Bile Acid ◽

Lactic Acid Bacteria ◽

Bile Salt ◽

Hepg2 Cells ◽

Bile Salt Hydrolase ◽

Apo B ◽

Probiotic Strains ◽

Bile Salt Hydrolase Activity ◽

Bsh Activity

This study collected different probiotic isolates from animal and plant sources to evaluate the bile-salt hydrolase activity of probioticsin vitro. The deconjugation potential of bile acid was determined using high-performance liquid chromatography. HepG2 cells were cultured with probiotic strains with high BSH activity. The triglyceride (TG) and apolipoprotein B (apo B) secretion by HepG2 cells were evaluated. Our results show that the BSH activity and bile-acid deconjugation abilities ofPediococcus acidilacticiNBHK002,Bifidobacterium adolescentisNBHK006,Lactobacillus rhamnosusNBHK007, andLactobacillus acidophilusNBHK008 were higher than those of the other probiotic strains. The cholesterol concentration in cholesterol micelles was reduced within 24 h. NBHK007 reduced the TG secretion by 100% after 48 h of incubation. NBHK002, NBHK006, and NBHK007 could reduce apo B secretion by 33%, 38%, and 39%, respectively, after 24 h of incubation. The product PROBIO S-23 produced a greater decrease in the total concentration of cholesterol, low-density lipoprotein, TG, and thiobarbituric acid reactive substance in the serum or livers of hamsters with hypercholesterolemia compared with that of hamsters fed with a high-fat and high-cholesterol diet. These results show that the three probiotic strains of lactic acid bacteria are better candidates for reducing the risk of cardiovascular disease.

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Development of a Covalent Inhibitor of Gut Bacterial Bile Salt Hydrolases

10.1101/640086 ◽

2019 ◽

Author(s):

Arijit A. Adhikari ◽

Tom C. Seegar ◽

Scott B. Ficarro ◽

Megan D. McCurry ◽

Deepti Ramachandran ◽

...

Keyword(s):

Bile Acid ◽

Bile Salt ◽

Bile Acids ◽

Unmet Need ◽

Cysteine Residue ◽

Gut Bacteria ◽

Bile Salt Hydrolase ◽

Secondary Bile Acid ◽

Bsh Activity

AbstractBile salt hydrolase (BSH) enzymes are widely expressed by human gut bacteria and catalyze the gateway reaction leading to secondary bile acid formation. Bile acids regulate key metabolic and immune processes by binding to host receptors. There is an unmet need for a potent tool to inhibit BSHs across all gut bacteria in order to study the effects of bile acids on host physiology. Here, we report the development of a covalent pan-inhibitor of gut bacterial BSH. From a rationally designed candidate library, we identified a lead compound bearing an alpha-fluoromethyl ketone warhead that modifies BSH at the catalytic cysteine residue. Strikingly, this inhibitor abolished BSH activity in conventional mouse feces. Mice gavaged with a single dose of this compound displayed decreased BSH activity and decreased deconjugated bile acid levels in feces. Our studies demonstrate the potential of a covalent BSH inhibitor to modulate bile acid composition in vivo.

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A gut-restricted lithocholic acid analog as an inhibitor of gut bacterial bile salt hydrolases

10.1101/2021.03.15.435552 ◽

2021 ◽

Cited By ~ 1

Author(s):

Arijit A. Adhikari ◽

Deepti Ramachandran ◽

Snehal N. Chaudhari ◽

Chelsea E. Powell ◽

Megan D. McCurry ◽

...

Keyword(s):

Bile Acid ◽

Bile Salt ◽

Bile Acids ◽

Mammalian Cells ◽

Lithocholic Acid ◽

Bile Salt Hydrolase ◽

Host Physiology ◽

Secondary Bile Acids ◽

Bsh Activity

AbstractBile acids play crucial roles in host physiology by acting as both detergents that aid in digestion and as signaling molecules that bind to host receptors. Gut bacterial bile salt hydrolase (BSH) enzymes perform the gateway reaction leading to the conversion of host-produced primary bile acids into bacterially modified secondary bile acids. Small molecule probes that target BSHs will help elucidate the causal roles of these metabolites in host physiology. We previously reported the development of a covalent BSH inhibitor with low gut permeability. Here, we build on our previous findings and describe the development of a second-generation gut-restricted BSH inhibitor with enhanced potency, reduced off-target effects, and durable in vivo efficacy. SAR studies focused on the bile acid core identified a compound, AAA-10, containing a C3-sulfonated lithocholic acid scaffold and an alpha-fluoromethyl ketone warhead as a potent pan-BSH inhibitor. This compound inhibits BSH activity in conventional mouse fecal slurries, bacterial cultures, and purified BSH proteins and displays reduced toxicity against mammalian cells compared to first generation compounds. Oral administration of AAA-10 to wild-type mice for 5 days resulted in a decrease in the abundance of the secondary bile acids deoxycholic acid (DCA) and lithocholic acid (LCA) in the mouse GI tract with low systemic exposure of AAA-10, demonstrating that AAA-10 is an effective tool for inhibiting BSH activity and modulating bile acid pool composition in vivo.

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The influence of probiotics on individual fecal secondary bile acid levels: a two-case study of schizophrenic patients receiving an atypical antipsychotic drug

Functional Foods in Health and Disease ◽

10.31989/ffhd.v7i11.384 ◽

2017 ◽

Vol 7 (11) ◽

pp. 849

Author(s):

Yosuke Saito ◽

Hiroyuki Nishimiya ◽

Yasue Kondo ◽

Toyoaki Sagae

Keyword(s):

Bile Acid ◽

Bile Salt ◽

Bile Acids ◽

Acid Metabolism ◽

Bile Acid Metabolism ◽

Bile Salt Hydrolase ◽

Atypical Antipsychotic Drug ◽

Secondary Bile Acid ◽

Secondary Bile Acids ◽

Bsh Activity

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

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In VitroStudy of Bile Salt Hydrolase (BSH) Activity of BSH IsogenicLactobacillus plantarum80 Strains and Estimation of Cholesterol Lowering through Enhanced BSH Activity

Microbial Ecology in Health and Disease ◽

10.3402/mehd.v7i6.8306 ◽

1994 ◽

Vol 7 (6) ◽

Author(s):

I. De Smet ◽

L. Van Hoorde ◽

N. De Saeyer ◽

M. Vande Woestyne ◽

W. Verstraete

Keyword(s):

Bile Salt ◽

Bile Salt Hydrolase ◽

Cholesterol Lowering ◽

Bsh Activity

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In Vitro Bile Salt Hydrolase (BSH) Activity Screening of Different Probiotic Microorganisms

Foods ◽

10.3390/foods10030674 ◽

2021 ◽

Vol 10 (3) ◽

pp. 674

Author(s):

Jimmy G. Hernández-Gómez ◽

Argelia López-Bonilla ◽

Gabriela Trejo-Tapia ◽

Sandra V. Ávila-Reyes ◽

Antonio R. Jiménez-Aparicio ◽

...

Keyword(s):

Bile Salt ◽

High Performance ◽

Probiotic Strain ◽

Saccharomyces Boulardii ◽

Bile Salt Hydrolase ◽

Sodium Glycocholate ◽

Probiotic Yeast ◽

Probiotic Strains ◽

Bsh Activity

Bile salt hydrolase (BSH) activity in probiotic strains is usually correlated with the ability to lower serum cholesterol levels in hypercholesterolemic patients. The objective of this study was the evaluation of BSH in five probiotic strains of lactic acid bacteria (LAB) and a probiotic yeast. The activity was assessed using a qualitative direct plate test and a quantitative high-performance thin- layer chromatography assay. The six strains differed in their BSH substrate preference and activity. Lactobacillus plantarum DGIA1, a potentially probiotic strain isolated from a double cream cheese from Chiapas, Mexico, showed excellent deconjugation activities in the four tested bile acids (69, 100, 81, and 92% for sodium glycocholate, glycodeoxycholate, taurocholate, and taurodeoxycholate, respectively). In the case of the commercial probiotic yeast Saccharomyces boulardii, the deconjugation activities were good against sodium glycodeoxycholate, taurocholate, and taurodeoxycholate (100, 57, and 63%, respectively). These last two results are part of the novelty of the work. A weak deconjugative activity (5%) was observed in the case of sodium glycocholate. This is the first time that the BSH activity has been detected in this yeast.

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Compact Miniaturized Bioluminescence Sensor Based on Continuous Air-Segmented Flow for Real-Time Monitoring: Application to Bile Salt Hydrolase (BSH) Activity and ATP Detection in Biological Fluids

Chemosensors ◽

10.3390/chemosensors9060122 ◽

2021 ◽

Vol 9 (6) ◽

pp. 122

Author(s):

Aldo Roda ◽

Pierpaolo Greco ◽

Patrizia Simoni ◽

Valentina Marassi ◽

Giada Moroni ◽

...

Keyword(s):

Bile Salt ◽

Light Emission ◽

Ex Vivo ◽

Biological Fluids ◽

Low Cost ◽

Bile Salt Hydrolase ◽

Segmented Flow ◽

Active Substrate ◽

Flat Spiral ◽

Bsh Activity

A simple and versatile continuous air-segmented flow sensor using immobilized luciferase was designed as a general miniaturized platform based on sensitive biochemiluminescence detection. The device uses miniaturized microperistaltic pumps to deliver flows and compact sensitive light imaging detectors based on BI-CMOS (smartphone camera) or CCD technology. The low-cost components and power supply make it suitable as out-lab device at point of need to monitor kinetic-related processes or ex vivo dynamic events. A nylon6 flat spiral carrying immobilized luciferase was placed in front of the detector in lensless mode using a fiber optic tapered faceplate. ATP was measured in samples collected by microdialysis from rat brain with detecting levels as low as 0.4 fmoles. The same immobilized luciferase was also used for the evaluation of bile salt hydrolase (BSH) activity in intestinal microbiota. An aminoluciferin was conjugatated with chenodeoxycholic acid forming the amide derivative aLuc-CDCA. The hydrolysis of the aLuc-CDCA probe by BSH releases free uncaged aminoluciferin which is the active substrate for luciferase leading to light emission. This method can detect as low as 0.5 mM of aLuc-CDCA, so it can be used on real faecal human samples to study BSH activity and its modulation by diseases and drugs.

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Non-alcoholic fatty liver disease after liver transplantation in patients with non-alcoholic steatohepatitis and cryptogenic cirrhosis: the impact of pre-transplant graft steatosis

HPB ◽

10.1016/j.hpb.2019.07.015 ◽

2020 ◽

Vol 22 (4) ◽

pp. 521-528

Author(s):

Ahad Eshraghian ◽

Saman Nikeghbalian ◽

Kourosh Kazemi ◽

Alireza Shamsaeefar ◽

Bita Geramizadeh ◽

...

Keyword(s):

Liver Transplantation ◽

Liver Disease ◽

Fatty Liver ◽

Fatty Liver Disease ◽

Alcoholic Fatty Liver ◽

Cryptogenic Cirrhosis ◽

Alcoholic Steatohepatitis ◽

The Impact ◽

Alcoholic Fatty Liver Disease

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Functional Analysis of Four Bile Salt Hydrolase and Penicillin Acylase Family Members in Lactobacillus plantarum WCFS1

Applied and Environmental Microbiology ◽

10.1128/aem.00137-08 ◽

2008 ◽

Vol 74 (15) ◽

pp. 4719-4726 ◽

Cited By ~ 105

Author(s):

Jolanda M. Lambert ◽

Roger S. Bongers ◽

Willem M. de Vos ◽

Michiel Kleerebezem

Keyword(s):

Bile Salt ◽

Lactobacillus Plantarum ◽

Bile Salts ◽

Natural Habitat ◽

Penicillin Acylase ◽

Exponential Growth Phase ◽

Bile Salt Hydrolase ◽

Intestinal Microbes ◽

Bsh Activity

ABSTRACT Bile salts play an important role in the digestion of lipids in vertebrates and are synthesized and conjugated to either glycine or taurine in the liver. Following secretion of bile salts into the small intestine, intestinal microbes are capable of deconjugating the glycine or taurine from the bile salts, using an enzyme called bile salt hydrolase (Bsh). Intestinal lactobacilli are regarded as major contributors to bile salt hydrolysis in vivo. Since the bile salt-hydrolyzing strain Lactobacillus plantarum WCFS1 was predicted to carry four bsh genes (bsh1, bsh2, bsh3, and bsh4), the functionality of these bsh genes was explored using Lactococcus lactis heterologous overexpression and multiple bsh deletion strains. Thus, Bsh1 was shown to be responsible for the majority of Bsh activity in L. plantarum WCFS1. In addition, bsh1 of L. plantarum WCFS1 was shown to be involved in conferring tolerance to specific bile salts (i.e., glycocholic acid). Northern blot analysis established that bsh1, bsh2, bsh3, and bsh4 are all expressed in L. plantarum WCFS1 during the exponential growth phase. Following biodiversity analysis, bsh1 appeared to be the only bsh homologue that was variable among L. plantarum strains; furthermore, the presence of bsh1 correlated with the presence of Bsh activity, suggesting that Bsh1 is commonly responsible for Bsh activity in L. plantarum strains. The fact that bsh2, bsh3, and bsh4 genes appeared to be conserved among L. plantarum strains suggests an important role of these genes in the physiology and lifestyle of the species L. plantarum. Analysis of these additional bsh-like genes in L. plantarum WCFS1 suggests that they might encode penicillin acylase rather than Bsh activity, indicating their implication in the conversion of substrates other than bile acids in the natural habitat.

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