Bile Salt Metabolism Research Articles

Clostridioides difficile colonization is not mediated by bile salts and requires Stickland fermentation of proline in an in vitro model of infection.

Treatment with antibiotics is a major risk factor for Clostridioides difficile infection, likely due to depletion of the gastrointestinal microbiota. Two microbiota-mediated mechanisms thought to limit C. difficile colonization include conversion of conjugated primary bile salts into secondary bile salts toxic to C. difficile growth, and competition between the microbiota and C. difficile for limiting nutrients. Using a continuous flow model of the distal colon, we investigated how treatment with six clinically-used antibiotics influenced susceptibility to C. difficile infection in 12 different microbial communities cultivated from healthy individuals. Antibiotic treatment reduced microbial richness; disruption varied by antibiotic class and microbiota composition, but did not correlate with C. difficile susceptibility. Antibiotic treatment also disrupted microbial bile salt metabolism, increasing levels of the primary bile salt, cholate, and decreasing levels of the secondary bile salt, deoxycholate. However, decreased levels of deoxycholate did not correlate with increased C. difficile susceptibility. Further, bile salts were not required to inhibit C. difficile colonization. We tested whether amino acid fermentation contributed to persistence of C. difficile in antibiotic-treated communities. C. difficile mutants unable to use proline as an electron acceptor in Stickland fermentation due to disruption of proline reductase (ΔprdB) had significantly lower levels of colonization than wild-type strains in four of six antibiotic-treated communities tested. This data provides further support for the importance of bile salt-independent mechanisms in regulating colonization of C. difficile.

Unveiling the Impact of Lactic Acid Bacteria on Blood Lipid Regulation for Cardiovascular Health

Lactic acid bacteria (LAB) are a group of microorganisms which are beneficial and well-characterized with respect to the flavor and texture of food products via fermentation. The accumulated literature has suggested that dietary intake of fermented foods rich in LAB is related to different health-promoting benefits; however, in recent years, emerging evidence suggests a contribution of LAB to blood lipid regulation and cardiovascular health via certain mechanisms. Different potential mechanisms for the lipid regulatory effects of LAB may include the interaction of hydroxymethylglutaryl-CoA (HMG-CoA) reductase and bile salt hydrolase activity and bile salt metabolism; gut microbiome modulation; and regulation of mRNA expression of genes related to fat metabolism in animal models and human studies. This review comprehensively aims to answer whether/how LAB influence blood lipids in both animal models and human studies while also uncovering the underlying mechanisms linking LAB to lipid metabolism.

Modulation of gut microbiota and intestinal immune response in gilthead seabream (Sparus aurata) by dietary bile salt supplementation.

Given their role in lipid digestion, feed supplementation with bile salts could be an economic and sustainable solution to alterations in adiposity and intestinal inflammation generated by some strategies currently used in aquaculture. An important part of the metabolism of bile salts takes place in the intestine, where the microbiota transforms them into more toxic forms. Consequently, we aimed to evaluate the gut immune response and microbial populations in gilthead seabream (Sparus aurata) fed a diet supplemented with a blend of bile salts with proven background as a regulator of lipid metabolism and fat content. After the 90-day feeding trial, a differential modulation of the microbiota between the anterior and posterior intestine was observed. While in the anterior intestine the relative abundance of Desulfobacterota doubled, in the posterior intestine, the levels of Firmicutes increased and Proteobacteria, Actinobacteriota, and Campylobacterota were reduced when supplementing the diet with bile salts. Even so, only in the anterior intestine, there was a decrease in estimated richness (Chao1 and ACE indices) in presence of dietary bile salts. No significant differences were displayed in alpha (Shannon and Simpson indices) nor beta-diversity, showing that bile sales did not have a great impact on the intestinal microbiota. Regarding the gene expression profile in 2 h postprandial-fish, several changes were observed in the analyzed biomarkers of epithelial integrity, nutrient transport, mucus production, interleukins, cell markers, immunoglobulin production and pathogen recognition receptors. These results may indicate the development of an intestinal immune-protective status to tackle future threats. This work also suggests that this immune response is not only regulated by the presence of the dietary bile salts in the intestine, but also by the microbial populations that are in turn modulated by bile salts. After a fasting period of 2 days, the overall gene expression profile was stabilized with respect to fish fed the unsupplemented diet, indicating that the effect of bile salts was transient after short periods of fasting. On the balance, bile salts can be used as a dietary supplement to enhance S. aurata farming and production without compromising their intestinal health.

Long-Term Lactulose Administration Improves Dysbiosis Induced by Antibiotic and C. difficile in the PathoGutTM SHIME Model.

Clostridioides difficile infection (CDI) is the leading cause of antibiotic-associated diarrhea and an important nosocomial infection with different severity degrees. Disruption of the gut microbiota by broad-spectrum antibiotics creates a proper environment for C. difficile colonization, proliferation, and clinical disease onset. Restoration of the gut microbial ecosystem through prebiotic interventions can constitute an effective complementary treatment of CDI. Using an adapted simulator of the human gut microbial ecosystem, the PathoGutTM SHIME, the effect of different long-term and repeated dose lactulose treatments was tested on C. difficile germination and growth in antibiotic-induced dysbiotic gut microbiota environments. The results showed that lactulose reduced the growth of viable C. difficile cells following clindamycin treatment, shifted the antibiotic-induced dysbiotic microbial community, and stimulated the production of health-promoting metabolites (especially butyrate). Recovery of the gut microenvironment by long-term lactulose administration following CDI was also linked to lactate production, decrease in pH and modulation of bile salt metabolism. At a structural level, lactulose showed a significant bifidogenic potential and restored key commensal members of the gut ecosystem such as Lactobacillaceae, Veillonellaceae and Lachnospiraceae. These results support further human intervention studies aiming to validate the in vitro beneficial effects of lactulose on gut microbiome recovery during antibiotic exposure and CDI.

Drug candidates and potential targets of Curculigo spp. compounds for treating diabetes mellitus based on network pharmacology, molecular docking and molecular dynamics simulation

Curculigo spp. is a herb that is commonly used in Indonesia to treat diabetes mellitus (DM) . The main active components of Curculigo spp. were identified through our previous metabolomic study and online database platform. However, the biological mechanisms underlying Curculigo spp. activity in treating DM remain unclear. Therefore, in this study, a network pharmacology was used to explore the active compounds of Curculigo spp. and their potential molecular mechanisms for treating DM. Oral bioavailability and drug-likeness from the compounds of Curculigo spp. were screened using Lipinski’s rule of five, BBB, HIA + and Caco-2 permeability criteria. A network of compound–target–disease–pathway was then constructed using Cytoscape. The highest degree compounds and targets were then confirmed by molecular docking and molecular dynamics (MD) simulations. The human body can absorb 33 compounds derived from Curculigo spp. In addition, 58 nodes and 62 edges generated a network analysis with the DM target. The highest degree of the compound–target–disease pathway was for orcinol glucoside, AKR1B1, autoimmune diabetes, bile acid and bile salt metabolism. Furthermore, the computational docking method on Curculigo spp. compounds with the highest degree revealed that orcinol glucoside interacted with PTPN1 through a hydrogen bond and resulted in a binding energy of −7.2 kcal mol−1. Through hydrogen bonds, orcinol glucoside in PTPN1 regulates multiple signaling pathways via the adherens junction pathway, which may play a therapeutic role in DM (type 2 diabetes: obesity). In addition, MD simulation confirmed that orcinol glucoside, is suitable for DM treatment by interacting with PTPN1. Communicated by Ramaswamy H. Sarma

Engineering probiotics to inhibit Clostridioides difficile infection by dynamic regulation of intestinal metabolism

Clostridioides difficile infection (CDI) results in significant morbidity and mortality in hospitalised patients. The pathogenesis of CDI is intrinsically related to the ability of C. difficile to shuffle between active vegetative cells and dormant endospores through the processes of germination and sporulation. Here, we hypothesise that dysregulation of microbiome-mediated bile salt metabolism contributes to CDI and that its alleviation can limit the pathogenesis of CDI. We engineer a genetic circuit harbouring a genetically encoded sensor, amplifier and actuator in probiotics to restore intestinal bile salt metabolism in response to antibiotic-induced microbiome dysbiosis. We demonstrate that the engineered probiotics limited the germination of endospores and the growth of vegetative cells of C. difficile in vitro and further significantly reduced CDI in model mice, as evidenced by a 100% survival rate and improved clinical outcomes. Our work presents an antimicrobial strategy that harnesses the host-pathogen microenvironment as the intervention target to limit the pathogenesis of infection.

TCF7L2 transcriptionally regulates Fgf15 to maintain bile acid and lipid homeostasis through gut-liver crosstalk.

FGF19/FGF15 is an endocrine regulator of hepatic bile salt and lipid metabolism, which has shown promising effects in the treatment of NASH in clinical trials. FGF19/15 is transcribed and released from enterocytes of the small intestine into enterohepatic circulation in response to bile-induced FXR activation. Previously, the TSS of FGF19 was identified to bind Wnt-regulated TCF7L2/encoded transcription factor TCF4 in colorectal cancer cells. Impaired Wnt signaling and specifical loss of function of its coreceptor LRP6have been associated with NASH. We, therefore, examined if TCF7L2/TCF4 upregulates Fgf19 in the small intestine and restrains NASH through gut-liver crosstalk. We examined the mice globally overexpressing, haploinsufficient, and conditional knockout models of TCF7L2 in the intestinal epithelium. The TCF7L2+/- mice exhibited increased plasma bile salts and lipids and developed diet-induced fatty liver disease while mice globally overexpressing TCF7L2 were protected against these traits. Comprehensive in vivo analysis revealed that TCF7L2 transcriptionally upregulates FGF15 in the gut, leading to reduced bile synthesis and diminished intestinal lipid uptake. Accordingly, VilinCreert2 ; Tcf7L2fl/fl mice showed reduced Fgf19 in the ileum, and increased plasma bile. The global overexpression of TCF7L2 in mice with metabolic syndrome-linked LRP6R611C substitution rescued the fatty liver and fibrosis in the latter. Strikingly, the hepatic levels of TCF4 were reduced and CYP7a1 was increased in human NASH, indicating the relevance of TCF4-dependent regulation of bile synthesis to human disease. These studies identify the critical role of TCF4 as an upstream regulator of the FGF15-mediated gut-liver crosstalk that maintains bile and liver triglyceride homeostasis.

Abstract PO-127: Proteome profiling of pancreatic Ductal Adenocarcinoma (PDAC) primary tumors in Caucasian, African Americans and Latinx patients

Abstract The clinical management of pancreatic ductal adenocarcinoma (PDAC) faces difficult challenges due to its aggressive metastatic potential, complex microenvironment, and lack of targeted therapies. Health disparities also exacerbate these challenges. For instance, Black and African American (AA) patients have higher incidence rates and worse clinical outcomes than White patients even when socioeconomic and tumor stages are controlled. To advance the understanding of the biological differences across the racial groups, PDAC primary tumors collected from 30 Caucasian, 12 African American (AA) and 3 Latinx patients were analyzed by quantitative proteomics. In collaboration with the IDeA National Resource for Quantitative Proteomics, 5820 proteins were identified and quantified using data-independent acquisition (DIA) in the tumor proteome. Comparing the Latinx and the Caucasian tumor proteome, 120 and 95 proteins were found up- and down-regulated in the Latinx proteome, respectively. Proteins involved in the fatty acid metabolism, urea cycle, bile acid and bile salt metabolism were found enriched among the upregulated proteins. 108 and 75 proteins were found up- and down-regulated in African American tumor proteome over the Caucasians, respectively. The 108 upregulated proteins were submitted for Reactome Pathway Analysis. Pathways such as the complement cascade, extracellular matrix (ECM) organization and ECM proteoglycans were found enriched. Haptoglobin-related protein (HPR) was one of the 108 upregulated proteins in the AA tumor proteome, which is also observed at the transcript level in the The Cancer Genome Atlas data. The HPR is known for its trypanolytic function and gene amplifications are observed in those of African descent. HPR works with haptoglobin to clear the free hemoglobin in blood to prevent oxidative damage. We believe that the proteins overexpressed, and the biological processes activated are contributing to the PDAC disparities observed in the African descendants. Therefore, the characterization of the PDAC proteome is a valuable method to delineate the underlying molecular signatures that may contribute to the health disparities. Citation Format: Henry C.-H. Law, Andrea N. Riner, Jose G. Trevino, Nicholas T. Woods. Proteome profiling of pancreatic Ductal Adenocarcinoma (PDAC) primary tumors in Caucasian, African Americans and Latinx patients [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-127.

Risk of gallstones based on ABCG8 rs11887534 single nucleotide polymorphism among Taiwanese men and women

BackgroundGallstones are abnormal masses caused by impaired metabolism of cholesterol, bilirubin, or bile salts in the gallbladder or biliary tract. ATP-binding cassette subfamily G member 8 (ABCG8) is a protein that regulates cholesterol efflux from the liver. Genome-wide association studies (GWAS) and meta-analyses of GWAS revealed the ABCG8 rs11887534 variant as the most common genetic determinant of gallstones in humans. These findings have not been extensively replicated in Taiwanese. Therefore, we appraised the relationship between gallstones and rs11887534 in a relatively large Taiwanese sample.MethodsWe retrieved data collected through questionnaires, physical and biochemical tests from the Taiwan Biobank Bank (TWB). The study participants comprised 7388 men and 13,880 women who voluntarily enrolled in the Taiwan Biobank project between 2008 and 2019. Gallstones were self-reported.ResultsThe overall sample size was 21,268 comprising 938 gallstone patients and 20,330 non-gallstone individuals. Among the participants, 20,640 had the GG and 628 had the GC + CC genotype. At p-value < 0.05, the baseline genotypes and gallstone status between men and women were not significantly different. The risk of gallstones was higher in participants having the GC + CC compared to the GG genotype: odds ratio (OR); 95% confidence interval (CI) = 1.698; 1.240–2.325), but was lower in men compared to women (OR = 0.763; 95% CI = 0.638–0.913). Compared to men with the rs11887534 GG genotype, women with the GG and GC + CC genotypes had a higher risk of gallstone (OR; 95% CI = 1.304; 1.087–1.565 for GG and 2.291; 1.514–3.467 for GC + CC). The positive association between GC + CC and gallstones was retained after we restricted the analysis to the female participants (OR; 95% CI = 1.789 = 1.208–2.648). Hormone use was associated with an elevated risk of gallstones (OR; 95% CI = 1.359; 1.107–1.668). Relative to GG and no hormone use, we found a significantly high risk among hormone users with the GC + CC genotype (OR; 95% CI = 3.596; 1.495–8.650).ConclusionsThe rs11887534 GC + CC genotype was independently associated with a higher risk of gallstones. This risk was much higher among women, especially those who used hormones for various gynecological purposes.

Abstract PO-005: Proteome profiling of pancreatic ductal adenocarcinoma (PDAC) primary tumors in Caucasian, African American and Latinx patients

Abstract The clinical management of pancreatic ductal adenocarcinoma (PDAC) faces difficult challenges due to its aggressive metastatic potential, complex microenvironment, and lack of targeted therapies. Health disparities also exacerbate these challenges. For instance, African and African Americans have higher incidence rates and worse clinical outcomes than Whites even when socioeconomic and tumor stages are controlled. To advance the understanding of the biological differences across the racial groups, the PDAC primary tumors collected from 30 Caucasian, 12 African American (AA) and 3 Latinx patients were analyzed by quantitative proteomics. In collaboration with the IDeA National Resource for Quantitative Proteomics, 5820 proteins were identified and quantified using data-independent acquisition (DIA) in the tumor proteome. Comparing the Latinx and the Caucasian tumor proteome, 120 and 95 proteins were found up- and down-regulated in the Latinx proteome. Proteins involved in the fatty acid metabolism, urea cycle, bile acid and bile salt metabolism were found enriched among the upregulated proteins. 108 and 75 proteins were found up- and down-regulated in African American tumor proteome over the Caucasians. The 108 upregulated proteins were submitted for Reactome Pathway Analysis. Pathways such as the complement cascade, extracellular matrix organization and ECM proteoglycans were found enriched. Haptoglobin-related protein (HPR) was one of the 108 upregulated proteins in the AA tumor proteome, which is also observed at the transcript level in the TCGA data. The HPR is known for its trypanolytic function and gene amplifications are observed in those of African descent. HPR works with haptoglobin (HP) to clear the free hemoglobin in blood to prevent oxidative damage. We believe that the proteins overexpressed, and the biological processes activated are contributing to the PDAC disparities observed in the African descendants. Therefore, the characterization of the PDAC proteome is a valuable method to delineate the underlying molecular signatures that may contribute to the health disparities. Citation Format: Henry C. H. Law, Andrea N. Riner, Jose G. Trevino, Nicholas T. Woods. Proteome profiling of pancreatic ductal adenocarcinoma (PDAC) primary tumors in Caucasian, African American and Latinx patients [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-005.

Metabolome and exposome profiling of the biospecimens from COVID-19 patients in India

Introduction. COVID-19 has become a global impediment by bringing everything to a halt starting from January 2020. India underwent the lockdown starting from 22nd March 2020 with the sudden spike in the number of COVID-19 patients in major cities and states. This study focused on how metabolites play a crucial role in SARSCoV-2 prognosis.Materials and methods. Metabolome profiling of 106 plasma samples and 24 swab samples from symptomatic patients in the Indian population of the Mumbai region was done. COVID-19 positive samples were further segregated under the non-severe COVID-19 and severe COVID-19 patient cohort for both plasma and swab.Results. After analyzing the raw files, total 7,949 and 12,871 metabolites in plasma and swab were found. 11 and 35 significantly altered metabolites were found in COVID-19 positive compared to COVID-19 negative plasma and swab samples, respectively. Also, 9 and 23 significantly altered metabolites were found in severe COVID-19 positive to non-severe COVID-19 positive plasma and swab samples, respectively. The majorly affected pathways in COVID-19 patients were found to be the amino acid metabolism pathway, sphingosine metabolism pathway, and bile salt metabolism pathway.Conclusion. This study facilitates identification of potential metabolite-based biomarker candidates for rapid diagnosis and prognosis for clinical applications.

Fxr signaling and microbial metabolism of bile salts in the zebrafish intestine.

Bile salt synthesis, secretion into the intestinal lumen, and resorption in the ileum occur in all vertebrate classes. In mammals, bile salt composition is determined by host and microbial enzymes, affecting signaling through the bile salt-binding transcription factor farnesoid X receptor (Fxr). However, these processes in other vertebrate classes remain poorly understood. We show that key components of hepatic bile salt synthesis and ileal transport pathways are conserved and under control of Fxr in zebrafish. Zebrafish bile salts consist primarily of a C27 bile alcohol and a C24 bile acid that undergo multiple microbial modifications including bile acid deconjugation that augments Fxr activity. Using single-cell RNA sequencing, we provide a cellular atlas of the zebrafish intestinal epithelium and uncover roles for Fxr in transcriptional and differentiation programs in ileal and other cell types. These results establish zebrafish as a nonmammalian vertebrate model for studying bile salt metabolism and Fxr signaling.

Activity-Based Protein Profiling of Bile Salt Hydrolysis in the Human Gut Microbiome with Beta-Lactam or Acrylamide-Based Probes.

Microbial bile salt hydrolases (BSHs) found in the intestine catalyze the deconjugation of taurine- and glycine-linked bile salts produced in the liver. The resulting bile salts are biological detergents and are critical in aiding lipophilic nutrient digestion. Therefore, the activity of BSHs in the gut microbiome is directly linked to human metabolism and overall health. Bile salt metabolism has also been associated with disease phenotypes such as liver and colorectal cancer. In order to reshape the gut microbiome to optimize bile salt metabolism, tools to characterize and quantify these processes must exist to enable a much-improved understanding of how metabolism goes awry in the face of disease, and how it can be improved through an altered lifestyle and environment. Furthermore, it is necessary to attribute metabolic activity to specific members and BSHs within the microbiome. To this end, we have developed activity-based probes with two different reactive groups to target bile salt hydrolases. These probes bind similarly to the authentic bile salt substrates, and we demonstrate enzyme labeling of active bile salt hydrolases by using purified protein, cell lysates, and in human stool.

Impaired cholesterol metabolism in the mouse model of cystic fibrosis. A preliminary study.

This study aims to investigate cholesterol metabolism in a mouse model with cystic fibrosis (CF) by the comparison of affected homozygous versus wild type (WT) mice. In particular, we evaluated the effects of a diet enriched with cholesterol in both mice groups in comparison with the normal diet. To this purpose, beyond serum and liver cholesterol, we analyzed serum phytosterols as indirect markers of intestinal absorption of cholesterol, liver lathosterol as indirect marker of de novo cholesterol synthesis, liver cholestanol (a catabolite of bile salts synthesis) and the liver mRNA levels of LDL receptor (LDLR), 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoAR), acyl CoA:cholesterol acyl transferase 2 (ACAT2), cytochrome P450 7A1 (CYP7A1) and tumor necrosis factor alpha (TNFα). CF mice showed lower intestinal absorption and higher liver synthesis of cholesterol than WT mice. In WT mice, the cholesterol supplementation inhibits the synthesis of liver cholesterol and enhances its catabolism, while in CF mice we did not observe a reduction of LDLR and HMG-CoAR expression (probably due to an altered feed-back), causing an increase of intracellular cholesterol. In addition, we observed a further increase (5-fold) in TNFα mRNA levels. This preliminary study suggests that in CF mice there is a vicious circle in which the altered synthesis/secretion of bile salts may reduce the digestion/absorption of cholesterol. As a result, the liver increases the biosynthesis of cholesterol that accumulates in the cells, triggering inflammation and further compromising the metabolism of bile salts.

Simple Analysis of Primary and Secondary Bile Salt Hydrolysis in Mouse and Human Gut Microbiome Samples by Using Fluorogenic Substrates

Animals produce bile to act as an antibacterial agent and to maximize the absorption of lipophilic nutrients in the gut. The physical properties of bile are largely dictated by amphipathic bile salt molecules, which also participate in signaling pathways by modulating physiological processes upon binding host receptors. Upon excretion of bile salts from the gall bladder into the intestine, the gut microbiota can create metabolites with modified signaling capabilities. The category and magnitude of bile salt metabolism can have positive or negative effects on the host. A key modification is bile salt hydrolysis, which is a prerequisite for all additional microbial transformations. We have synthesized five different fluorogenic bile salts for simple and continuous reporting of hydrolysis in both murine and human fecal samples. Our data demonstrate that most gut microbiomes have the highest capacity for hydrolysis of host-produced primary bile salts, but some microbially modified secondary bile salts also display significant turnover.

Gut Microbes Take It to the Next Level? First Insights Into Farnesoid X Receptor Agonists of Microbial Origin.

The intestinal microbiome and its metabolites contribute to host (patho)physiology through signaling via host bile salt receptors(1) . To assess the overall chemical effects of the microbiome at the level of an entire animal, Quinn et al. conducted untargeted metabolome analysis of 29 different organs of germ-free and specific pathogen-free (SPF) mice. [Quinn RA, Melnik AV, Vrbanac A et al. Global chemical effects of the microbiome include new bile-acid conjugations. Nature 2020;579:123-129] Unique microbial and metabolome profiles were evident along the GI tract.

Nudix hydrolase 1 is a prognostic biomarker in hepatocellular carcinoma.

We investigated the prognostic significance of Nudix hydrolase 1 (NUDT1) in hepatocellular carcinoma (HCC). NUDT1 mRNA and protein levels were significantly higher in HCC tissues than normal liver tissues. The level of NUDT1 expression correlated with tumor grade, stage, size, differentiation, degree of vascular invasion, overall survival (OS), and disease-free survival (DFS) in HCC patients. Multivariate analysis showed that NUDT1 expression was an independent prognostic factor for OS and DFS in HCC patients. We constructed a prognostic nomogram with NUDT1 expression, AFP levels, vascular invasion, Child–Pugh classification, age, sex, AJCC staging, and tumor differentiation as variables. This nomogram was highly accurate in predicting the 5-year OS of HCC patients (c-index= 0.709; AUC= 0.740). NUDT1 silencing in HCC cells significantly reduced their survival, colony formation, migration, and invasiveness. Gene set enrichment analysis showed that biological pathways related to cell cycle, fatty acid metabolism, bile acid and bile salt metabolism, and PLK1 signaling were associated with NUDT1, as were the gene ontology terms “DNA binding transcription activator activity,” “RNA polymerase II,” “nuclear division,” and “transmembrane transporter activity.” Our study thus demonstrates that NUDT1 is a prognostic biomarker with therapeutic potential in HCC patients.

Bile salt metabolism is not the only factor contributing to Clostridioides (Clostridium) difficile disease severity in the murine model of disease

ABSTRACT Susceptibility of patients to antibiotic-associated C. difficile disease is intimately associated with specific changes to gut microbiome composition. In particular, loss of microbes that modify bile salt acids (BSA) play a central role; primary bile acids stimulate spore germination whilst secondary bile acids limit C. difficile vegetative growth. To determine the relative contribution of bile salt (BS) metabolism on C. difficile disease severity, we treated mice with three combinations of antibiotics prior to infection. Mice given clindamycin alone became colonized but displayed no tissue pathology while severe disease, exemplified by weight loss and inflammatory tissue damage occurred in animals given a combination of five antibiotics and clindamycin. Animals given only the five antibiotic cocktails showed only transient colonization and no disease. C. difficile colonization was associated with a reduction in bacterial diversity, an inability to amplify bile salt hydrolase (BSH) sequences from fecal DNA and a relative increase in primary bile acids (pBA) in cecal lavages from infected mice. Further, the link between BSA modification and the microbiome was confirmed by the isolation of strains of Lactobacillus murinus that modified primary bile acids in vitro, thus preventing C. difficile germination. Interestingly, BSH activity did not correlate with disease severity which appeared linked to alternations in mucin, which may indirectly lead to increased exposure of the epithelial surface to inflammatory signals. These data confirm the role of microbial metabolic activity in protection of the gut and highlights the need for greater understanding the function of bacterial communities in disease prevention.

Gut Microbiome Modulation Based on Probiotic Application for Anti-Obesity: A Review on Efficacy and Validation.

The growing prevalence of obesity has become an important problem worldwide as obesity has several health risks. Notably, factors such as excessive food consumption, a sedentary way of life, high sugar consumption, a fat-rich diet, and a certain genetic profile may lead to obesity. The present review brings together recent advances regarding the significance of interventions involving intestinal gut bacteria and host metabolic phenotypes. We assess important biological molecular mechanisms underlying the impact of gut microbiota on hosts including bile salt metabolism, short-chain fatty acids, and metabolic endotoxemia. Some previous studies have shown a link between microbiota and obesity, and associated disease reports have been documented. Thus, this review focuses on obesity and gut microbiota interactions and further develops the mechanism of the gut microbiome approach related to human obesity. Specifically, we highlight several alternative diet treatments including dietary changes and supplementation with probiotics. The future direction or comparative significance of fecal transplantation, synbiotics, and metabolomics as an approach to the modulation of intestinal microbes is also discussed.

Distribution of the ATP-binding cassette transporter ABCG8 IVS1-2A>G genotype and clinical characteristics of gallbladder patients in Northeastern Mexico: A pilot study.

Biliary lithiasis is a multifactorial pathology determined by the interaction of genes and the environment, characterized by alterations in cholesterol homeostasis and in the metabolism of bile salts. A number of gene polymorphisms and mutations have been identified in the ATP-dependent cholesterol transporter (ABCG8) associated with lithiasis disease. The aim of the present study was to evaluate the association of the ABCG8 gene mutation IVS1-2A>G with cholecystolithiasis in patients from Northeast Mexico. This was a pilot study including 90 Mexican subjects diagnosed by ultrasonography, 57.8% of which presented gallstones. The studied parameters included: Lipid profile, total protein in plasma and polymerase chain reaction-restriction fragment length polymorphism genotyping. Significant differences were identified in total plasma protein, weight and BMI values, with these being these higher in subjects with gallstones (P<0.05). The presence of the mutant allele IVS1-2G was not detected, and the IVS1-2A wild-type allele was present in 100% of the population. Therefore, no association was apparent between the presence of the splice site mutation in ABCG8 (IVS1-2A>G) and the presence of gallstones in the evaluated subjects.