scholarly journals Development of a Covalent Inhibitor of Gut Bacterial Bile Salt Hydrolases

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.

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

2021 ◽  
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.

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

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

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

2008 ◽  
Vol 74 (15) ◽  
pp. 4719-4726 ◽  
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.

scholarly journals Human gut bacteria produce TH17-modulating bile acid metabolites

2021 ◽  
Author(s):  
Donggi Paik ◽  
Lina Yao ◽  
Yancong Zhang ◽  
Sena Bae ◽  
Gabriel D. D'Agostino ◽  
...  
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Lithocholic Acid ◽  
Retinoic Acid Receptor ◽  
Gut Bacteria ◽  
Orphan Nuclear Receptor ◽  
Human Gut ◽  
Secondary Bile Acid ◽  
Bowel Diseases ◽  
And Function

The microbiota plays a pivotal role in gut immune homeostasis. Bacteria influence the development and function of host immune cells, including T helper cells expressing interleukin-17a (TH17 cells). We previously reported that the bile acid metabolite 3-oxolithocholic acid (3-oxoLCA) inhibits TH17 cell differentiation. While it was suggested that gut-residing bacteria produce 3-oxoLCA, the identity of such bacteria was unknown. Furthermore, it was not clear whether 3-oxoLCA and other immunomodulatory bile acids are associated with gut inflammatory pathologies in humans. Using a high-throughput screen, we identified human gut bacteria and corresponding enzymes that convert the secondary bile acid lithocholic acid into 3-oxoLCA as well as the abundant gut metabolite isolithocholic acid (isoLCA). Like 3-oxoLCA, isoLCA suppressed TH17 differentiation by inhibiting RORγt (retinoic acid receptor-related orphan nuclear receptor γt), a key TH17 cell-promoting transcription factor. Levels of both 3-oxoLCA and isoLCA and the 3α-hydroxysteroid dehydrogenase (3α-HSDH) genes required for their biosynthesis were significantly reduced in patients with inflammatory bowel diseases (IBD). Moreover, levels of these bile acids were inversely correlated with expression of TH17 cell-associated genes. Overall, our data suggest that bacterially produced TH17 cell-inhibitory bile acids may reduce the risk of autoimmune and inflammatory disorders such as IBD.

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

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
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.

scholarly journals Dissection of Catalytic Site in Crucial Gut Microbiome Enzyme: Bile Salt Hydrolase

2019 ◽  
Author(s):  
Yashpal Yadav ◽  
Mrityunjay K. Tiwari ◽  
Deepak Chand ◽  
Debjoyati Boral ◽  
Archana Pundle ◽  
...  
Keyword(s):  
Bile Salt ◽  
Bile Acids ◽  
Active Sites ◽  
Electrostatic Force ◽  
Enteric Bacteria ◽  
Significant Loss ◽  
Bile Salt Hydrolase ◽  
Hydrolysis Of ◽  
Determining Factor ◽  
Bsh Activity

AbstractBile Salt Hydrolases (BSHs) are enzymes from enteric bacteria that catalyze the hydrolysis of Bile Acids and consequently promote the reduction of cholesterol level in the mammalian body. Out of several reported BSHs, the Enterococcus faecalis BSH (EfBSH) has been reported to have the highest enzymatic activity. Herein, we have investigated the mechanistic details of the EfBSH activity. The study was carried out employing two mutants of EfBSH: E269A and R207A, which shows differential catalytic activity. The mutant E269A exhibits significant loss in the BSH activity with an increased affinity towards the substrate as compared to R207A mutant. Further, R207A was found to be involved in allostery with an increased EfBSH activity towards tauro-conjugated bile acids. The structural and electrostatic force analyses of the active sites of the E269A mutant and the wild type EfBSH (wt EfBSH) revealed that the interaction between Glu21 and Arg207 is the determining factor in maintaining the dynamic allostery and high activity of EfBSH.

scholarly journals Noninvasive imaging and quantification of bile salt hydrolase activity: From bacteria to humans

2021 ◽  
Vol 7 (6) ◽  
pp. eaaz9857
Author(s):  
Pavlo V. Khodakivskyi ◽  
Christian L. Lauber ◽  
Aleksey Yevtodiyenko ◽  
Arkadiy A. Bazhin ◽  
Stephen Bruce ◽  
...  
Keyword(s):  
Bile Salt ◽  
Noninvasive Imaging ◽  
Clinical Status ◽  
Cost Effective ◽  
Bile Salt Hydrolase ◽  
Inflammatory Bowel ◽  
Bile Salt Hydrolase Activity ◽  
Bsh Activity ◽  
Entire Gastrointestinal Tract

The microbiome-produced enzyme bile salt hydrolase (BSH) plays a central role in human health, but its function remains unclear due to the lack of suitable methods for measuring its activity. Here, we have developed a novel optical tool based on ultrasensitive bioluminescent imaging and demonstrated that this assay can be used for quick and cost-effective quantification of BSH activity across a broad range of biological settings including pure enzymes and bacteria, intact fecal slurries, and noninvasive imaging in live animals, as well as for the assessment of BSH activity in the entire gastrointestinal tract of mice and humans. Using this assay, we showed that certain types of prebiotics are capable of increasing BSH activity of the gut microbiota in vivo and successfully demonstrated potential application of this assay as a noninvasive diagnostic test to predict the clinical status of inflammatory bowel disease (IBD) patients.

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

2021 ◽  
Author(s):  
Darrick K. Li ◽  
Snehal N. Chaudhari ◽  
Mozhdeh Sojoodi ◽  
Yoojin Li ◽  
Arijit A. Adhikari ◽  
...  
Keyword(s):  
Bile Acid ◽  
Bile Salt ◽  
Intestinal Permeability ◽  
Micelle Formation ◽  
Intestinal Barrier Function ◽  
Bile Salt Hydrolase ◽  
Alcoholic Fatty Liver ◽  
Alcoholic Steatohepatitis ◽  
The Impact ◽  
Bsh Activity

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.

scholarly journals Aryl hydrocarbon receptor (AhR) activation by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) dose-dependently shifts the gut microbiome consistent with the progression of steatosis to steatohepatitis with fibrosis

2021 ◽  
Author(s):  
Russell R Fling ◽  
Tim Zacharewski
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Acid Metabolism ◽  
Lactobacillus Species ◽  
Bile Acid Metabolism ◽  
Bile Salt Hydrolase ◽  
Metagenomic Sequencing ◽  
Secondary Bile Acid ◽  
Alcoholic Fatty Liver ◽  
Dose Dependent

Gut dysbiosis with disrupted enterohepatic bile acid metabolism is commonly associated with non-alcoholic fatty liver disease (NAFLD) and recapitulated in a NAFLD-phenotype elicited by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in mice. TCDD induces hepatic fat accumulation and increases levels of secondary bile acids including taurolithocholic acid and deoxycholic acid, microbial modified bile acids involved in host bile acid regulation signaling pathways. To investigate the effects of TCDD on the gut microbiota, cecum contents of male C57BL/6 mice orally gavaged with sesame oil vehicle or 0.3, 3, or 30 µg/kg TCDD were examined using shotgun metagenomic sequencing. Taxonomic analysis identified dose-dependent increases in Lactobacillus species (i.e., Lactobacillus reuteri). Increased species were also associated with dose-dependent increases in bile salt hydrolase sequences, responsible for deconjugation reactions in secondary bile acid metabolism. Increased L. reuteri levels were further associated with mevalonate-dependent isopentenyl diphosphate (IPP) biosynthesis and menaquinone biosynthesis genes. Analysis of gut microbiomes from cirrhosis patients identified increased abundance of these pathways as identified in the mouse cecum metagenomic analysis. These results extend the association of lactobacilli with the AhR/intestinal axis in NAFLD progression and highlight the similarities between TCDD-elicited phenotypes in mice to human NAFLD.

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