Concentrations Of Deoxycholic Acid Research Articles

Vertical Sleeve Gastrectomy Reduces Gut Luminal Deoxycholic Acid Concentrations in Mice.

Bariatric surgery alters bile acid metabolism, which contributes to post-operative improvements in metabolic health. However, the mechanisms by which bariatric surgery alters bile acid metabolism are incompletely defined. In particular, the role of the gut microbiome in the effects of bariatric surgery on bile acid metabolism is incompletely understood. Therefore, we sought to define the changes in gut luminal bile acid composition after vertical sleeve gastrectomy (VSG). Bile acid profile was determined by UPLC-MS/MS in serum and gut luminal samples from VSG and sham-operated mice. Sham-operated mice were divided into two groups: one was fed ad libitum, while the other was food-restricted to match their body weight to the VSG-operated mice. VSG decreased gut luminal secondary bile acids, which was driven by a decrease in gut luminal deoxycholic acid concentrations and abundance. However, gut luminal cholic acid (precursor for deoxycholic acid) concentration and abundance did not differ between groups. Therefore, the observed decrease in gut luminal deoxycholic acid abundance after VSG was not due to a reduction in substrate availability. VSG decreased gut luminal deoxycholic acid abundance independently of body weight, which may be driven by a decrease in gut bacterial bile acid metabolism.

Smooth muscle contractile responses to bile acids in mouse ileum require TGR5 but not ASBT.

Many disorders of gut-brain interaction (DGBIs) are more prevalent in women than men and feature alterations in gastrointestinal motility and bile acid homeostasis. Mechanisms by which bile acids regulate gastrointestinal motility are poorly characterized. We recently validated an adapted tissue bath technique using everted mouse ileum, which revealed differential contractile responses to ursodeoxycholic acid (UDCA) and deoxycholic acid (DCA). Here, we aimed to determine whether these responses are dependent on host sex, the plasma membrane bile acid receptor TGR5, or the apical sodium-dependent bile acid transporter ASBT. Ileal segments from male and female mice were everted and suspended in tissue baths. Contractile responses to physiologic concentrations of UDCA and DCA were quantified with or without TGR5 or ASBT inhibitors. Phosphorylation of extracellular signal-regulated kinase (ERK) and myosin light chain (MLC), markers of TGR5 activation and smooth muscle contraction, respectively, were assessed with western blot. There were no sex differences in the dose-dependent contractile responses to bile acids. At 100 μmol/L, UDCA but not DCA increased MLC phosphorylation and increased contractility. TGR5 inhibition decreased ERK phosphorylation and led to decreases in contractility, phosphorylated MLC, and surprisingly, total MLC. ASBT inhibition did not affect contractile responses. Differential effects of UDCA and DCA on ileal smooth muscle contractility are not dependent on host sex or ASBT-mediated transport. Bile acids signal through mucosal TGR5, which regulates smooth muscle contractility by complex mechanisms. Understanding how bile acids differentially regulate gastrointestinal motility could facilitate new therapeutic options for specific DGBIs.

Investigation of Effects of Novel Bifidobacterium longum ssp. longum on Gastrointestinal Microbiota and Blood Serum Parameters in a Conventional Mouse Model.

Representatives of the genus Bifidobacterium are widely used as probiotics to modulate the gut microbiome and alleviate various health conditions. The action mechanisms of probiotics rely on their direct effect on the gut microbiota and the local and systemic effect of its metabolites. The main purpose of this animal experiment was to assess the biosafety of the Bifidobacterium longum strain BIOCC1719. Additional aims were to characterise the influence of the strain on the intestinal microbiota and the effect on several health parameters of the host during 15- and 30-day oral administration of the strain to mice. The strain altered the gut microbial community, thereby altering luminal short-chain fatty acid metabolism, resulting in a shift in the proportions of acetic, butyric, and propionic acids in the faeces and serum of the test group mice. Targeted metabolic profiling of serum revealed the possible ability of the strain to positively affect the hosts' amino acids and bile acids metabolism, as the cholic acid, deoxycholic acid, aspartate, and glutamate concentration were significantly higher in the test group. The tendency to increase anti-inflammatory polyamines (spermidine, putrescine) and neuroprotective 3-indolepropionic acid metabolism and to lower uremic toxins (P-cresol-SO4, indoxyl-SO4) was registered. Thus, B. longum BIOCC1719 may exert health-promoting effects on the host through modulation of the gut microbiome and the host metabolome via inducing the production of health-promoting bioactive compounds. The health effects of the strain need to be confirmed in clinical trials with human volunteers.

Downregulation of ABCC3 activates MAPK signaling through accumulation of deoxycholic acid in colorectal cancer cells.

ABCC3 (also known as MRP3) is an ATP binding cassette transporter for bile acids, whose expression is downregulated in colorectal cancer through the Wnt/β-catenin signaling pathway. However, it remained unclear how downregulation of ABCC3 expression contributes to colorectal carcinogenesis. We explored the role of ABCC3 in the progression of colorectal cancer-in particular, focusing on the regulation of bile acid export. Gene expression analysis of colorectal adenoma isolated from familial adenomatous polyposis patients revealed that genes related to bile acid secretion including ABCC3 were downregulated as early as at the stage of adenoma formation. Knockdown or overexpression of ABCC3 increased or decreased intracellular concentration of deoxycholic acid, a secondary bile acid, respectively, in colorectal cancer cells. Forced expression of ABCC3 suppressed deoxycholic acid-induced activation of MAPK signaling. Finally, we found that nonsteroidal anti-inflammatory drugs increased ABCC3 expression in colorectal cancer cells, suggesting that ABCC3 could be one of the targets for therapeutic intervention of familial adenomatous polyposis. Our data thus suggest that downregulation of ABCC3 expression contributes to colorectal carcinogenesis through the regulation of intracellular accumulation of bile acids and activity of MAPK signaling.

Abstract 1479: ABCC3 (MRP3)-mediated export of deoxycholic acid regulates MAPK signaling in colorectal adenoma and adenocarcinoma

Abstract ABCC3 (also known as MRP3) is an ATP binding cassette transporter and it works as a bile acids transporter. We previously elucidated that ABCC3 expression is downregulated in colorectal cancer through the Wnt/β-catenin signaling pathway. However, it remained unclear how downregulation of ABCC3 expression contributes to colorectal carcinogenesis. We here explored the role of ABCC3 in the progression of colorectal cancer-in particular, focusing on the regulation of bile acid export. First, we performed experiments with clinical samples of familial adenomatous polyposis (FAP) patients to confirm whether ABCC3 expression is already downregulated in colorectal adenomas. Next, we investigated the effect of ABCC3 expression on intracellular bile acid concentrations using ABCC3 knockdown and overexpression colorectal cancer cell lines (HT-29, SW620). The intracellular concentration of deoxycholic acid, which is known to have carcinogenic effects, was verified with fluorescently labeled deoxycholic acid. Then, we tested whether activation of oncogenic signaling by deoxycholic acid is affected by ABCC3 expression changes. Finally, we examined the effect of nonsteroidal anti-inflammatory drugs (NSAIDs), which have been suggested to inhibit the carcinogenesis of FAP, on the expression of ABCC3 in experiments with colorectal cancer cell lines. Gene and protein expression analysis of colorectal adenomas isolated from FAP patients revealed that ABCC3 were downregulated as early as at the stage of adenoma formation, and many other genes related to bile acid efflux were also downregulated. Knockdown or overexpression of ABCC3 increased or decreased intracellular concentration of deoxycholic acid in colorectal cancer cells, respectively. Forced expression of ABCC3 suppressed deoxycholic acid-induced activation of MAPK signaling. Finally, we found that several NSAIDs increased ABCC3 expression in colorectal cancer cells, suggesting that ABCC3 could be one of the targets for therapeutic intervention of FAP. Our data thus suggest that downregulation of ABCC3 expression contributes to colorectal carcinogenesis through the regulation of intracellular accumulation of bile acids and activity of MAPK signaling. Citation Format: Yukihiro Sato, Minoru Kobayashi, Masahiro Ohira, Ryo Funayama, Masamitsu Maekawa, Hideaki Karasawa, Shinobu Ohnuma, Michiaki Unno, Keiko Nakayama. ABCC3 (MRP3)-mediated export of deoxycholic acid regulates MAPK signaling in colorectal adenoma and adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1479.

Bile acids modified by the intestinal microbiota promote colorectal cancer growth by suppressing CD8+ T cell effector functions

Concentrations of the secondary bile acid, deoxycholic acid (DCA), are aberrantly elevated in colorectal cancer (CRC) patients, but the consequences remain poorly understood. Here, we screened a library of gut microbiota-derived metabolites and identified DCA as a negative regulator for CD8+ Tcell effector function. Mechanistically, DCA suppressed CD8+ Tcell responses by targeting plasma membrane Ca2+ ATPase (PMCA) to inhibit Ca2+-nuclear factor of activated T cells (NFAT)2 signaling. In CRC patients, CD8+ Tcell effector function negatively correlated with both DCA concentration and expression of a bacterial DCA biosynthetic gene. Bacteria harboring DCA biosynthetic genes suppressed CD8+ Tcells effector function and promoted tumor growth in mice. This effect was abolished by disrupting bile acid metabolism via bile acid chelation, genetic ablation of bacterial DCA biosynthetic pathway, or specific bacteriophage. Our study demonstrated causation between microbial DCA metabolism and anti-tumor CD8+ Tcell response in CRC, suggesting potential directions for anti-tumor therapy.

Bile acid profiles and mRNA abundance of bile acid-related genes in adipose tissue of dairy cows with high versus normal body condition

Besides their lipid-digestive role, bile acids (BA) influence overall energy homeostasis, such as glucose and lipid metabolism. We hypothesized that BA along with their receptors, regulatory enzymes, and transporters are present in subcutaneous adipose tissue (scAT). In addition, we hypothesized that their mRNA abundance varies with the body condition of dairy cows around calving. Therefore, we analyzed BA in serum and scAT as well as the mRNA abundance of BA -related enzymes, transporters, and receptors in scAT during the transition period in cows with different body conditions around calving. In a previously established animal model, 38 German Holstein cows were divided into either a high (HBCS; n = 19) or normal BCS (NBCS; n = 19) group based on their body condition score (BCS) and back fat thickness (BFT). Cows were fed different diets to achieve the targeted differences in BCS and BFT (NBCS: BCS <3.5, BFT <1.2 cm; HBCS: BCS >3.75, BFT >1.4 cm) until dry-off at 7 wk ante partum. During the dry period and subsequent lactation, both groups were fed the same diets regarding their demands. Using a targeted metabolomics approach via LC-ESI-MS /MS, BA were analyzed in serum and scAT at wk -7, 1, 3, and 12 relative to parturition. In serum, 15 BA (cholic acid (CA), chenodeoxycholic acid (CDCA), glycocholic acid (GCA), taurocholic acid (TCA), glycochenodeoxycholic acid (GCDCA), taurochenodeoxycholic acid (TCDCA), deoxycholic acid (DCA), lithocholic acid (LCA), glycodeoxycholic acid (GDCA), glycolithocholic acid (GLCA), taurodeoxycholic acid (TDCA), taurolithocholic acid (TLCA), β-muricholic acid (MCA(b)), tauromuricholic acid (sum of α and β) (TMCA (a+b)), glycoursodeoxycholic acid (GUDCA)) were observed, whereas in scAT 7 BA (CA, GCA, TCA, GCDCA, TCDCA, GDCA, TDCA) were detected. In serum and scAT samples, the primary BA CA and its conjugate GCA were predominantly detected. Increasing serum concentrations of CA, CDCA, TCA, GCA, GCDCA, DCA, and MCA(b) with the onset of lactation might be related to the increasing DMI after parturition. Furthermore, serum concentrations of CA, CDCA, GCA, DCA, GCDCA, TCA, LCA, and GDCA were lower in HBCS cows compared with NBCS cows, concomitant with increased lipolysis in HBCS cows. The correlation between CA in serum and scAT may point to the transport of CA across cell membranes. Overall, the findings of the present study suggest a potential role of BA in lipid metabolism depending on the body condition of periparturient dairy cows.

Deoxycholic Acid, a Secondary Bile Acid, Increases Cardiac Output and Blood Pressure in Rats.

Deoxycholic acid (DCA) is a secondary bile acid produced by gut bacteria. Elevated serum concentrations of DCA are observed in cardiovascular disease (CVD). We hypothesized that DCA might influence hemodynamic parameters in rats. The concentration of DCA in systemic blood was measured with liquid chromatography coupled with mass spectrometry. Arterial blood pressure (BP), heart rate (HR) and echocardiographic parameters were evaluated in anesthetized, male, 3-4-month-old Sprague-Dawley rats administered intravenously (IV) or intracerebroventricularly (ICV) with investigated compounds. Mesenteric artery (MA) reactivity was tested ex vivo. The baseline plasma concentration of DCA was 0.24 ± 0.03 mg/L. The oral antibiotic treatment produced a large decrease in the concentration. Administered IV, the compound increased BP and HR in a dose-dependent manner. DCA also increased heart contractility and cardiac output. None of the tested compounds-prazosin (an alpha-blocker), propranolol (beta-adrenolytic), atropine (muscarinic receptor antagonist), glibenclamide (K-ATP inhibitor) or DY 268 (FXR antagonist), glycyrrhetinic acid (11HSD2 inhibitor)-significantly diminished the DCA-induced pressor effect. ICV infusion did not exert significant HR or BP changes. DCA relaxed MAs. Systemic vascular resistance did not change significantly. DCA elevates BP primarily by augmenting cardiac output. As a metabolite derived from gut bacteria, DCA potentially serves as a mediator in the interaction between the gut microbiota and the host's circulatory system.

Rosiglitazone induces hepatocyte injury by increasing DCA accumulation through OATP1A4 inhibiting in mice

Rosiglitazone (RL), a second-generation thiazolidinedione (TZD), is an oral antidiabetic agent that is reportedly associated with hepatotoxicity. However, the molecular mechanism of Rosiglitazone induced hepatotoxicity has not been reported yet. To minimize clinical risk, in the present study, toxicity was evaluated initially in C57BL/6 mice to confirm the hepatotoxicity of Rosiglitazone. Subsequently, the transcription of genes, the up-regulated expression of proteins and changes of metabolite spectrum in bile acid system in accordance with system pharmacology and multi-omics profiling strategy were investigated to reveal its toxic mechanism. Results show an obvious Rosiglitazone induced hepatocyte injury in our experiment. Changes in bile acid profiles revealed that Rosiglitazone administration increased the concentration of deoxycholic acid (DCA) in the liver, but decreased those of other bile acids. Transcriptomic and proteomic data showed that while the expression of efflux transporters ABCC3, ABCC4 and ABCB11 was upregulated following Rosiglitazone treatment, the expression of two hepatic uptake transporters, OATP1A1 and OATP1A4, which were negatively associated with DCA accumulation, were significantly downregulated. These results indicated that cholestasis, especially the accumulation of DCA in the liver, is the primary factors responsible for Rosiglitazone induced hepatocyte injury. The mechanism of Rosiglitazone induced DCA accumulation in the liver may be the result of stimulated intestinal permeability and increased biosynthesis and uptake of DCA and weakening of DCA amidation to reduce DCA efflux due to the inhibition of OATP1A1 and OATP1A4 expression in the liver.

The pro- and antineoplastic effects of deoxycholic acid in pancreatic adenocarcinoma cell models

BackgroundCommensal bacteria secrete metabolites that reach distant cancer cells through the circulation and influence cancer behavior. Deoxycholic acid (DCA), a hormone-like metabolite, is a secondary bile acid specifically synthesized by intestinal microbes. DCA may have both pro- and antineoplastic effects in cancers.Methods and resultsThe pancreatic adenocarcinoma cell lines, Capan-2 and BxPC-3, were treated with 0.7 µM DCA, which corresponds to the reference concentration of DCA in human serum. DCA influenced the expression of epithelial to mesenchymal transition (EMT)-related genes, significantly decreased the expression level of the mesenchymal markers, transcription factor 7- like 2 (TCF7L2), snail family transcriptional repressor 2 (SLUG), CLAUDIN-1, and increased the expression of the epithelial genes, zona occludens 1 (ZO-1) and E-CADHERIN, as shown by real-time PCR and Western blotting. Consequently, DCA reduced the invasion capacity of pancreatic adenocarcinoma cells in Boyden chamber experiments. DCA induced the protein expression of oxidative/nitrosative stress markers. Moreover, DCA reduced aldehyde dehydrogenase 1 (ALDH1) activity in an Aldefluor assay and ALDH1 protein level, suggesting that DCA reduced stemness in pancreatic adenocarcinoma. In Seahorse experiments, DCA induced all fractions of mitochondrial respiration and glycolytic flux. The ratio of mitochondrial oxidation and glycolysis did not change after DCA treatment, suggesting that cells became hypermetabolic.ConclusionDCA induced antineoplastic effects in pancreatic adenocarcinoma cells by inhibiting EMT, reducing cancer stemness, and inducing oxidative/nitrosative stress and procarcinogenic effects such as hypermetabolic bioenergetics.

Bile acid alterations associated with indolent course of inflammatory bowel disease

Background The indolent course of treatment-naive patients with inflammatory bowel disease (IBD) is confirmed predictable based on clinical characteristics. Current evidences supported that bile acids (BAs) alteration might be promising biomarkers in the field of IBD. We aimed to analyze the alterations of BAs as the disease progresses and explore their predictive value for indolent course of IBD. Methods The indolent course of IBD was defined as a disease course without need for strict interventions throughout the entire follow-up. A targeted metabolomics method was used to detect the concentration of 27 BAs from serum sample in treatment-naive patients with IBD (Crohn’s disease [CD], n = 27; ulcerative colitis [UC], n = 50). Patients with CD and UC were individually divided into two groups for further study according to the median time of indolent course. The overall BAs profile and the clinical value of BAs in predicting indolent course of IBD were identified between different groups. Results For CD, the levels of deoxycholic acid, glycodeoxycholic acid, taurodeoxycholic acid, glycolithocholic acid-3-sulfate disodium salt and iso-lithocholic acid were significantly increased in patients with indolent course > 18 M (p < 0.05). These five BAs owned 83.5% accuracy for predicting indolent course over 18 months in CD. For UC, the concentration of deoxycholic acid and glycodeoxycholic acid were significantly higher, while dehydrocholic acid were lower in patients with indolent course > 48 M (p < 0.05). These three BAs predicted indolent course over 48 months of 69.8% accuracy in UC. Conclusion The specific BAs alterations might be potential biomarkers in predicting disease course of IBD patients.

Ingesting a fermented milk product reduces liver triacylglycerol accumulation and normalizes gut permeability in rats even under a cholic acid-fed condition

We investigated whether a diet containing fermented milk products (FMP) improves hepatic lipid accumulation and gut permeability induced by cholic acid (CA) supplementation. After acclimation, male Slc:Wistar rats were fed diets supplemented with a combination of FMP and/or CA (0.5 g/kg diet) for four weeks. FMP was used as a protein source. The FMP-containing diet reduced the total food intake and hepatic triacylglycerol levels without altering the body weight. Enhanced in vivo gut permeability induced by CA was inhibited by the FMP diet. The FMP diet also enhanced the excretion of fecal triacylglycerol and the fecal concentration of non-12-hydroxylated BAs. Multiple regression analysis revealed that total food intake, fecal deoxycholic acid concentration, and fecal triacylglycerol excretion were predictors of hepatic triacylglycerol concentration. A negative correlation was observed between fecal non-12-hydroxylated BAs and hepatic triacylglycerol concentration. These results imply that FMP contributes to reduced hepatic lipid accumulation and normalised gut permeability.

Maternal antibiotic treatment during pregnancy attenuates the transport and absorption of maternal antibody IgG through TLR4 and TLR2 receptor.

Maternal antibody IgG, the main antibody in colostrum, plays an important role in neonates protection. Commensal microbiota is closely related to host antibody repertoire. However, there are few reports on how maternal gut microbiota affects maternal antibody IgG transfer. In the present study, we investigated the effects of altering the gut microbiota (treated with antibiotics during pregnancy) on maternal IgG transportation and offspring absorption and explored its underlying mechanisms. Results showed that antibiotic treatment during pregnancy significantly decreased maternal cecal microbial richness (Chao1 and Obesrved species) and diversity (Shannon and Simpson). Plasma metabolome enriched significant changes in the process of bile acid secretion pathway, and the concentration of deoxycholic acid, a secondary metabolite of microorganisms was lowered. Flow cytometry analysis indicated that antibiotic treatment promoted the number of B cells and abated the number of T, DC and M1 cells in intestinal lamina propria of dams. Surprisingly, the serum IgG level in antibiotic treated dams was significantly increased, while IgG contents in colostrum was decreased. Moreover, pregnancy antibiotic treatment in dams was reduced the expression of FcRn, TLR4 and TLR2 in breast of dams and in duodenum and jejunum of neonates. Furthermore, TLR4-/- and TLR2-/- knock-out mice showed a lower FcRn expression in breast of dams and in duodenum and jejunum of neonates. These findings suggest that maternal intestine bacteria may affect the maternal IgG transfer through regulating the breast TLR4 and TLR2 of dams.

Intestinal Stem Cells Damaged by Deoxycholic Acid via AHR Pathway Contributes to Mucosal Barrier Dysfunction in High-Fat Feeding Mice

High-fat exposure leads to impaired intestinal barrier function by disrupting the function of intestinal stem cells (ISCs); however, the exact mechanism of this phenomenon is still not known. We hypothesize that high concentrations of deoxycholic acid (DCA) in response to a high-fat diet (HFD) affect aryl hydrocarbon receptor (AHR) signalling in ISCs and the intestinal barrier. For this purpose, C57BL/6J mice feeding on a low-fat diet (LFD), an HFD, an HFD with the bile acid binder cholestyramine, and a LFD with the DCA were studied. We found that high-fat feeding induced an increase in faecal DCA concentrations. An HFD or DCA diet disrupted the differentiation function of ISCs by downregulating AHR signalling, which resulted in decreased goblet cells (GCs) and MUC2, and these changes were reversed by cholestyramine. In vitro experiments showed that DCA downregulated the differentiation function of ISCs, which was reversed by the AHR agonist 6-formylindolo [3,2-b]carbazole (FICZ). Mechanistically, DCA caused a reduction in indoleamine 2,3-dioxygenase 1 (IDO1) in Paneth cells, resulting in paracrine deficiency of the AHR ligand kynurenine in crypts. We demonstrated for the first time that DCA disrupts intestinal mucosal barrier function by interfering with AHR signalling in ISCs. Supplementation with AHR ligands may be a new therapeutic target for HFD-related impaired intestinal barrier function.

Mouse precision-cut liver slices as an ex vivo model to study drug-induced cholestasis

Drugs are often withdrawn from the market due to the manifestation of drug-induced liver injury (DILI) in patients. Drug-induced cholestasis (DIC), defined as obstruction of hepatic bile flow due to medication, is one form of DILI. Because DILI is idiosyncratic, and the resulting cholestasis complex, there is no suitable in vitro model for early DIC detection during drug development. Our goal was to develop a mouse precision-cut liver slice (mPCLS) model to study DIC and to assess cholestasis development using conventional molecular biology and analytical chemistry methods. Cholestasis was induced in mPCLS through a 48-h-incubation with three drugs known to induce cholestasis in humans, namely chlorpromazine (15, 20, and 30 µM), cyclosporin A (1, 3, and 6 µM) or glibenclamide (25, 50, and 65 µM). A bile-acid mixture (16 µM) that is physiologically representative of the human bile-acid pool was added to the incubation medium with drug, and results were compared to incubations with no added bile acids. Treatment of PCLS with cholestatic drugs increased the intracellular bile-acid concentration of deoxycholic acid and modulated bile-transporter genes. Chlorpromazine led to the most pronounced cholestasis in 48 h, observed as increased toxicity; decreased protein and gene expression of the bile salt export pump; increased gene expression of multidrug resistance-associated protein 4; and accumulation of intracellular bile acids. Moreover, chlorpromazine-induced cholestasis exhibited some transition into fibrosis, evidenced by increased gene expression of collagen 1A1 and heatshock protein 47. In conclusion, we demonstrate that mPCLS can be used to study human DIC onset and progression in a 48 h period. We thus propose this model is suited for other similar studies of human DIC.

The Effect of Deoxycholic Acid on Chitosan-Enabled Matrices for Tissue Scaffolding and Injectable Nanogels.

The pathophysiology of a multitude of diseases is influenced by bioenergetic dysfunction. Healthy mitochondria are presented as essential for the regulation and function of multiple cell types, including the cells of relevance for this research: pancreatic beta cells, muscle cells, and liver cells. Hence, effects of hydrogels (particularly nanogels) on bioenergetics needs to be taken into account when designing optimum delivery matrices. Several polymers have been suggested for use in hydrogels and nanogels, with focus on chitosan due to its range of beneficial properties. Bile acids have emerged as beneficial excipients, including deoxycholic acid, which can increase membrane permeability of cells. Nanogels were manufactured containing various concentrations of chitosan and deoxycholic acid in addition to the staple sodium alginate. Nanogels then underwent an array of analysis including rheological studies and in vitro cell work assessing viability, hypoxia, and the bioenergetic profiles. Overall, deoxycholic acid showed enhanced gel strength although this resulted in slightly lower cell viability and impacted bioenergetic profiles. Results from this study showed the benefits of deoxycholic acid; however, this was found to be less suitable for cell delivery matrices and is perhaps more beneficial for drug-delivery systems.

Deoxycholic and Ursodeoxycholic Acid Differentially Impact Cellular Steatosis and Lipid Peroxidation in Cultured Hepatoma Cells

Background: Bile acids (BAs) are the major lipid components of bile. They are synthesized from cholesterol in the liver and stored in the gallbladder. BAs have gained attention as drug candidates to control obesity and/or diabetic condition due to their role in lipid and glucose metabolism. Objective: This study aimed to evaluate the antisteatotic and antioxidant potential of deoxycholic ac-id (DCA) and ursodeoxycholic acid (UDCA), two BAs with opposite physico-chemical features. Methods: Different concentrations of DCA and UDCA in the micromolar range were tested on cul-tured hepatoma cells after loading with an excess of fatty acids to mimic non-alcoholic fatty liver disease (NAFLD) in vitro. Experimental analyses included cell viability, lipid accumulation and li-pid peroxidation in steatotic hepatocytes before and after exposure to either DCA or UDCA. Results: Both UDCA and DCA improved lipid dysmetabolism and oxidative stress conditions in the steatotic hepatocytes. However, while UDCA was more effective as lipid lowering agent, DCA showed a greater antioxidant effect. Conclusions: UDCA seems to have better protective and beneficial potential than DCA, as it is able to both alleviate lipid accumulation in the steatotic liver cells, but also to play antioxidant effect.

Development of Alcohol-Associated Hepatitis Is Associated With Specific Changes in Gut-Modified Bile Acids.

The perturbations in bile acids (BAs) in alcohol‐associated hepatitis (AH) and its relationship to disease severity is not well defined. The aims of this study were to define (1) the effects of heavy alcohol consumption on BAs and related microbiome, (2) the additional changes with AH, and (3) the relationship of these changes to disease severity. In this multicenter study, plasma and fecal BAs and related microbiome were interrogated in healthy individuals, heavy drinking controls (HDCs) without overt liver disease, and AH. Compared to healthy controls, HDCs had increased glycine‐conjugated 7α and 27α primary BAs and increased secondary BA glycocholenic sulfate (multiple‐comparison adjusted P < 0.05 for all). Plasma‐conjugated cholic and chenodeoxycholic acid increased in AH along with the secondary BAs ursodeoxycholic and lithocholic acid (P < 0.001 for all), whereas deoxycholic acid decreased; however fecal concentrations of both deoxycholic acid and lithocholic acid were decreased. Glycocholenic acid further increased significantly from HDCs to AH. HDCs and AH had distinct plasma and fecal BA profiles (area under the curve, 0.99 and 0.93, respectively). Plasma taurochenodeoxycholic acid and tauroursodeoxycholic acid were directly related to disease severity, whereas fecal ursodeoxycholic acid was inversely related. The fecal abundance of multiple taxa involved in formation of secondary BAs, especially deoxycholic acid (Clostridium cluster XIVa) was decreased in AH. Multiple genera containing taxa expressing 3α, 3β, 7α, and 7β epimerases were decreased with concordant changes in fecal BAs that required these functions for formation. Conclusion: There are distinct changes in BA‐transforming microbiota and corresponding BAs in AH that are related to disease severity.

Non-absorbable antibiotic treatment inhibits colorectal cancer liver metastasis by modulating deoxycholic acid metabolism by intestinal microbes

Emerging evidence suggests that intestinal microbes influence the occurrence and development of colorectal cancer (CRC). However, few studies have examined the relationship between gut bacteria and liver metastasis of CRC. In this study, we found that administration of non-absorbable antibiotics inhibited liver metastasis of CRC in a mouse model compared with a control group. To elucidate the underlying mechanism, immune cell infiltration analysis, 16S rRNA sequencing, and metabolomics were performed. Differential analysis revealed that non-absorbable antibiotic treatment significantly altered gut microbial diversity and decreased the concentration of deoxycholic acid (DCA) in feces and liver tissues. Furthermore, we verified that bacteria capable of converting cholic acid (CA) to DCA via 7α-dehydroxylation were reduced in mice treated with non-absorbable antibiotics. Finally, in vitro and in vivo experiments confirmed that DCA accelerated the proliferation and metastasis of CRC cells.

1039. Rapid Restoration of Bile Acid Compositions After Treatment with RBX2660 for Recurrent Clostridioides difficile Infection—Results from the PUNCH CD3 Phase 3 Trial

BackgroundMicrobiota-based treatments are increasingly evaluated as a strategy to reduce recurrence of Clostridioides difficile infection (rCDI), and their proposed mechanisms include restoration of the microbiota and microbiota-mediated functions, including bile acid metabolism. RBX2660—a broad-consortium investigational live biotherapeutic—has been evaluated in >600 participants in 6 clinical trials, with consistent reduction of rCDI recurrence. Here we report that fecal bile acid compositions were significantly restored in treatment-responsive participants in PUNCH CD3—a Phase 3 randomized, double-blinded, placebo-controlled trial of RBX2660.MethodsPUNCH CD3 participants received a single dose of RBX2660 or placebo between 24 to 72 hours after completing rCDI antibiotic treatment. Clinical response was the absence of CDI recurrence at eight weeks after treatment. Participants voluntarily submitted stool samples prior to blinded study treatment (baseline), 1, 4 and 8 weeks, 3 and 6 months after receiving study treatment. A liquid chromatography tandem mass spectrometry method was developed to extract and quantify 33 bile acids from all participant fecal samples received up to the 8-week time point. Mean bile acid compositions were fit to a Dirichlet multinomial distribution and compared across time points and between RBX2660- and placebo-treated participants.ResultsClinically, RBX2660 demonstrated superior efficacy versus placebo (70.4% versus 58.1%). RBX2660-treated clinical responders’ bile acid compositions shifted significantly from before to after treatment. Specifically, primary bile acids predominated before treatment, whereas secondary bile acids predominated after treatment (Figure 1A). These changes trended higher among RBX2660 responders compared to placebo responders. Importantly, median levels of lithocholic acid (LCA) and deoxycholic acid (DCA) showed large, significant increases after treatment (Figure 1B). A. Bile acid compositions before (BL) and up to 8 weeks after RBX2660 treatment among treatment responders. Compositions are shown as the fraction of total bile acids classified as primary or secondary conjugated or deconjugated bile acids. B. Concentrations of lithocholic acid (LCA) and deoxycholic acid (DCA) among RBX2660 treatment responders, shown with individual samples and time point group median with interquartile ranges.ConclusionAmong PUNCH CD3 clinical responders, RBX2660 significantly restored bile acids from less to more healthy compositions. These clinically correlated bile acid shifts are highly consistent with results from a prior trial of RBX2660.Disclosures Romeo Papazyan, PhD, Ferring Research Institute (Employee) Bryan Fuchs, PhD, Ferring Pharmaceuticals (Employee) Ken Blount, PhD, Rebiotix Inc., a Ferring Company (Employee)