Concentration Of Cholic Acid Research Articles

Effects of Low-Dose Non-Caloric Sweetener Consumption on Gut Microbiota in Mice.

Non-caloric artificial sweeteners (NASs) provide sweet tastes to food without adding calories or glucose. NASs can be used as alternative sweeteners for controlling blood glucose levels and weight gain. Although the consumption of NASs has increased over the past decade in Japan and other countries, whether these sweeteners affect the composition of the gut microbiome is unclear. In the present study, we examined the effects of sucralose or acesulfame-K ingestion (at most the maximum acceptable daily intake (ADI) levels, 15 mg/kg body weight) on the gut microbiome in mice. Consumption of sucralose, but not acesulfame-K, for 8 weeks reduced the relative amount of Clostridium cluster XIVa in feces. Meanwhile, sucralose and acesulfame-K did not increase food intake, body weight gain or liver weight, or fat in the epididymis or cecum. Only sucralose intake increased the concentration of hepatic cholesterol and cholic acid. Moreover, the relative concentration of butyrate and the ratio of secondary/primary bile acids in luminal metabolites increased with sucralose consumption in a dose-dependent manner. These results suggest that daily intake of maximum ADI levels of sucralose, but not acesulfame-K, affected the relative amount of the Clostridium cluster XIVa in fecal microbiome and cholesterol bile acid metabolism in mice.

120d - Saccharomyces Boulardii CNCM I-745 Lowers Fecal Cholic Acid Concentrations During Antibiotherapy in Healthy Volunteers: A New Potential Mechanism in the Protection Against Clostridium Difficile Infection

120d - Saccharomyces Boulardii CNCM I-745 Lowers Fecal Cholic Acid Concentrations During Antibiotherapy in Healthy Volunteers: A New Potential Mechanism in the Protection Against Clostridium Difficile Infection

Dispersion of single-walled carbon nanotubes in dimethylacetamide and a dimethylacetamide–cholic acid mixture

A way of dispersing single-walled carbon nanotubes in preparing stable suspensions with high concentrations of individual nanotubes in amide solvents is described. The obtained suspensions are studied via Raman spectroscopy. The dependence of the degree of single-walled carbon nanotube (SWNT) dispersion in individual and mixed amide solvents on the type of solvent, the mass of nanotubes, and the concentration of cholic acid is established. A technique for processing spectral data to estimate the diameters and chiralities of individual nanotubes in suspension is described in detail.

A Simple and Novel Electrochemical Sensor Based on Phosphomolybdic‐Polypyrrole Film Modified Electrode for Highly Sensitive Detection of Cholic Acid

AbstractA simpe electrochemical sensor for detection of cholic acid (CA) was designed by modifying phosphomolybdate (PMo12) doped polypyrrole (PPy) film on glassy carbon electrode (PMo12‐PPy/GCE). The electrochemical behavior of CA on PMo12‐PPy/GCE was investigated by cyclic voltammetry and 0.5 order differential voltammetry. The results indicated that CA had high inhibitory activity toward the peak currents of PMo12‐PPy/GCE. The reduction peak currents were linearly related to the logarithmic value of the concentration of CA from 1.0×10−7 to 1.0×10−3 mol/L with a low detection limit of 1.0×10−8 mol/L. The developed sensor exhibited excellent sensitivity, selectivity and stability for detection of CA, and it could be successfully applied to detect the level of CA in the urine samples. Moreover, the response mechanism of CA on the PMo12‐PPy/GCE was discussed in detail.

Зовнішньосекреторна функція печінки щурів при дії корвітину

In acute experiments on rats with cannulated bile duct we studied the effect of Corvitin, water-soluble analogue of quercetin, on secretion of bile. Intraportal administration of the test compound at doses of 2,5; 5 and 10 mg/kg resulted in a significant increase in the volume of secreted bile by 20,9, 31,2 and 20,4%, respectively, as compared with the control. Using the method of thin layer chromatography it was established the mild stimulating effect of Corvitin on the processes of bile acids conjugation with taurine and glycine, especially when administered at a dose of 5 mg/kg. This flavonoid did not affect the concentration of glycocholic acid, however increased the content of glycochenodeoxycholic and glycodeoxycholic acids in the mixture between 15 to 35,1%. Regarding free bile acids, the concentration of cholic acid, chenodeoxycholic and deoxycholic acids in the mixture was increased significantly relative to control only after Corvitin application at dose 10 mg/ kg. In the first case – from 17,9 to 29,8%, in the second – from 25 to 65,4%. At the dose of 5 mg/kg, Corvitin significantly increased the ratio of bile cholates conjugation (maximum by 23,2%), whereas 10 mg/kg of the drug decreased this index by 27,0%. After administration of Corvitin, the hydroxylation ratio in all experimental groups differed little from the control: at the dose of 5 and 10 mg/kg this parameter decreased by 14%. Thus, Corvitin modulates exocrine function of the liver, causing an increase in bile secretion and concentration of different cholates, dose-dependently increasing or decreasing the effectiveness of multienzyme systems providing processes of bile acids conjugation in rats.

Liquid chromatography–mass spectroscopy as a tool in the rapid diagnosis of biliary atresia: a pilot study

IntroductionBiliary atresia (BA) is a neonatal obstructive cholangiopathy requiring rapid intervention to prevent end-stage liver failure and death. Low bile acid levels in stool, detectable with high-performance liquid chromatography–mass spectroscopy, may reflect extrahepatic biliary obstruction in cholestasis. HypothesisStool bile acid content can differentiate BA from non-BA forms of cholestasis. MethodsStool samples from four healthy and nine cholestatic patients were collected following internal review board approval. Bile acids were extracted and separated on a 4000-Q-Trap HPLC-MS system. ResultsTotal bile acid content was highest in samples from healthy relative to cholestatic patients: 3354.01 ± 2102.56, 1476.27 ± 1361.07, and 34.29 ± 10.30 μM/mg of stool in healthy, total parenteral nutrition-associated cholestasis, and BA samples, respectively. Mean cholic acid and chenodeoxycholic acid concentrations in healthy samples (2017.5 ± 1413.6 and 876.83 ± 660.60 μM/mg) were higher than in TPN cholestatic samples (93.99±131.55 and 232.34 ± 293.41 μM/mg). The most dramatic reduction in cholic acid and chenodeoxycholic acid was observed in BA samples (0.65 ± 0.47 and 1.22 ± 0.80 μM/mg). ConclusionBile acid content in stool is reduced in cholestatic patients relative to healthy patients with the most dramatic reduction observed in BA-patients.

Effects of Two Traditional Chinese Cooking Oils, Canola and Pork, on pH and Cholic Acid Content of Faeces and Colon Tumorigenesis in Kunming Mice.

Faecal pH and cholate are two important factors that can affect colon tumorigenesis, and can be modified by diet. In this study, the effects of two Chinese traditional cooking oils (pork oil and canola/rapeseed oil) on the pH and the cholic acid content in feces, in addition to colon tumorigenesis, were studied in mice. Kunming mice were randomized into various groups; negative control group (NCG), azoxymethane control group (ACG), pork oil group (POG), and canola oil Ggroup (COG). Mice in the ACG were fed a basic rodent chow; mice in POG and COG were given 10% cooking oil rodent chow with the respective oil type. All mice were given four weekly AOM (azoxymethane) i.p. injections (10 mg/kg). The pH and cholic acid of the feces were examined every two weeks. Colon tumors, aberrant crypt foci and organ weights were examined 32 weeks following the final AOM injection. The results showed that canola oil significantly decreased faecal pH in female mice (P<0.05), but had no influence on feces pH in male mice (P>0.05). Pork oil significantly increased the feces pH in both male and female mice (P<0.05). No significant change was found in feces cholic acid content when mice were fed 10% pork oil or canola oil compared with the ACG. Although Kunming mice were not susceptible to AOM-induced tumorigenesis in terms of colon tumor incidence, pork oil significantly increased the ACF number in male mice. Canola oil showed no influence on ACF in either male or female mice. Our results indicate that cooking oil effects faecal pH, but does not affect the faecal cholic acid content and thus AOM-induced colon neoplastic ACF is modified by dietary fat.

Dissolution of single-walled carbon nanotubes in alkanol-cholic acid mixtures

A procedure for dispersing the single-walled carbon nanotubes (SWCNTs) for preparing stable suspensions with high concentrations of individual nanotubes in various alcohols was described. The obtained suspensions were studied by Raman spectroscopy. The solubility of the single-walled carbon nanotubes in alcohols was found to depend on the concentration of cholic acid. The ethanol-surfactant mixture was shown to be the best solvent for all alkanol-cholic acid mixtures (0.018 mol/kg) under study used for preparing time-stable suspensions of single-walled carbon nanotubes. The dissolving ability of aliphatic alcohols was found to decrease in the series: ethanol-isopropanol-tert-butanol-butanol-propanol.

胆酸对人工细胞膜流动性的影响

以天然磷脂1,2-二-十四烷基磷脂酰胆碱(DMPC)和合成肽脂Ala制备人工细胞膜，向不同样品中分别加入10%、20%、30%的胆酸，以1,6-二苯基-1,3,5-己三烯(DPH)作为荧光试剂，利用荧光偏光法检测不同浓度胆酸对人工细胞膜的流动性的影响。结果表明，在实验设置的温度范围内，不同浓度的胆酸对DMPC囊泡的流动性影响不大。Ala囊泡在凝胶态温度下，随着胆酸浓度的增加，偏光值P值逐渐减小，流动性增大；而在液晶态温度下，不同浓度胆酸对Ala囊泡的流动性影响不大。本实验为阐明生物体内胆酸和细胞膜的相互作用机理提供了参考依据。 The natural phospholipid DMPC and Ala, a kind of synthetic peptide lipid, were used to prepare artificial cell membrane vesicles. 10%, 20% and 30% cholic acid were added into the samples, re-spectively. DPH was taken as the fluorescence reagent and the influences on the fluidity of two kinds of vesicle samples were examined by fluorescence polarization technology. The results showed that in the setting temperature range, cholic acid of different concentrations had little effect on the fluidity of DMPC vesicles. For Ala vesicles, in the temperature range of gel phase, polarization value decreased while the fluidity increased with the elevation of cholic acid concentrations. However, in the temperature range of liquid phase, cholic acid of different concentrations showed little effect. This research provides the theory basis on interaction mechanism of cholic acid and cell membrane in the natural organism.

Hydrophilic modification of PVDF microfiltration membranes by adsorption of facial amphiphile cholic acid

Amphiphilic molecules have been widely used in surface modification of polymeric materials. Bile acids are natural biological compounds and possess special facial amphiphilic structure with a unusual distribution of hydrophobic and hydrophilic regions. Based on the facial amphiphilicity, cholic acid (CA), one of the bile acids, was utilized for the hydrophilic modification of poly(vinylidene fluoride) (PVDF) microfiltration membranes via the hydrophobic interactions between the hydrophobic face of CA and the membrane surfaces. Ethanol, methanol, and water were respectively used as solvent during CA adsorption procedure. Their polarity affects the CA adsorption amount, as similar to CA concentration and adsorption time. There are no changes on the membrane surface morphology after CA adsorption. The hydrophilicity of PVDF membranes is greatly enhanced and the water drops permeates into the CA modified membranes quickly after modification. All these factors benefit to the permeation flux of membrane for water. When CA concentration is higher than 0.088M, the water permeation flux is doubled as compared with the nascent PVDF membrane and shows a good stability during filtration procedure. These results reveal the promising potential of facial amphiphilic bile acids for the surface modification of polymeric materials.

Intrahepatic cholestasis in pregnancy

Abnormal liver function tests occur in 3-5% of pregnancies, with many potential causes, including coincidental liver disease (most commonly viral hepatitis or gallstones) and underlying chronic liver disease. Pruritus in pregnancy is common, affecting 23% of pregnancies, of which a small proportion will have obstetric cholestasis. Intrahepatic cholestasis of pregnancy (ICP) is a cholestatic disorder characterized by pruritus with onset in the second or third trimester of pregnancy, elevated serum aminotransferases and bile acid levels, and spontaneous relief of signs and symptoms within two to three weeks after delivery. ICP is observed in 0.4-1% of pregnancies in most areas of Central and Western Europe and North America. Genetic and hormonal factors, but also environmental factors may contribute to the pathogenesis of ICP. Intrahepatic cholestasis of pregnancy increases the risk of preterm delivery (19­60%), meconium staining of amniotic fluid (27%), fetal bradycardia (14%), fetal distress (22-41%), and fetal loss (0.4-4.1%), particularly when associated with fasting serum bile acid levels >40 μmol/L. Important ICP-induced changes in serum profiles of amidated bile acids were observed, involving both a marked increase in cholic acid concentration and a shift towards a higher proportion of taurine-conjugated species. Ursodeoxycholic acid (10-20 mg/kg/d) is today regarded as the first line treatment for intrahepatic cholestasis of pregnancy. Delivery has been recommended in the 37-38th week when lung maturity has been established.

Bile acid-surfactant interactions at the liquid crystal/aqueous interface.

The interaction between bile acids and surfactants at interfaces plays an important role in fat digestion. In this paper, we study the competitive adsorption of cholic acid (CA) at the sodium dodecyl sulfate (SDS)-laden liquid crystal (LC)/aqueous interface formed with cyanobiphenyl (nCB, n = 5-8) and the mixture of 5CB with 4-(4-pentylcyclohexyl)benzonitrile (5PCH). We find that the critical concentration of CA required to displace SDS from the interface linearly decreases from 160 μM to 16 μM by reducing the alkyl chain length of nCB from n = 8 to n = 5 and from 16 μM to 1.5 μM by increasing the 5PCH concentration from 0 wt% to 19 wt% in the 5PCH-5CB binary mixture. Our results clearly demonstrate that the sensitivity of 5PCH-5CB mixtures for monitoring the interaction between CA and SDS at the LC/aqueous interface can be increased by one order of magnitude, compared to 5CB.

Critical Role of the Degree of Substitution in the Interaction of Biocompatible Cholic Acid-Modified Dextrans with Phosphatidylcholine Liposomes

The interaction between biocompatible cholic acid-modified dextrans with different pendent cholic acid groups' content and phosphatidylcholine liposomes was studied by a variety of techniques including isothermal titration calorimetry (ITC), differential scanning calorimetry (DSC), turbidity measurements, microscopy imaging (transmission electron microscopy (TEM), and cryo-scanning electron microscopy (cryo-SEM)). The variation of the interaction enthalpy with polymer concentration, as obtained by ITC, highlighted the formation of different aggregates. Complete phase modification, from vesicles covered with a few polymer chains to vesicle disintegration, was observed by turbidity measurements. DSC showed the effect of polymer addition to the liposome gel to liquid-crystalline phase transition, and microscopy images gave information about the size and morphology of the aggregates. The composition, structure, and morphology of polymer/liposome aggregates were found to be strongly influenced by the cholic acid content in the polymer (degree of substitution, DS). Along with a rather monotonous change in the polymer/liposome system's properties with increasing DS, a discontinuity in behavior could also be observed at DS = 4 mol %. For DS ≤ 4 mol %, the polymer/liposome interaction takes place mainly between individual components, and liposome disintegration occurs in a narrow concentration range, whereas for DS > 4 mol % extended physical networks are formed, which last over a wide concentration range. A mechanism of interaction, as a function of DS, is proposed and discussed in detail.

Phosphatidylcholine Attenuates Aggregation of Nonsteroidal Anti-Inflammatory Drugs with Bile Acid

Prolonged usage of nonsteroidal anti-inflammatory drugs (NSAIDs) causes gastrointestinal injury. Bile acids and phospholipids have been shown to exasperate and attenuate NSAIDs' toxicity, respectively. However, the molecular mechanisms underlying these effects remain undetermined. We have investigated the molecular interactions in various mixtures of indomethacin (Indo), a commonly used NSAID, and cholic acid (CA), a bile acid, in the presence and absence of palmitoyloleylphosphatidylcholine (POPC) lipids. We found that CA and Indo spontaneously form mixed micelles, with the hydrophobic face of CA and hydrophobic region of Indo forming the core. Increasing the Indo concentration resulted in more stable and larger aggregates that contain a progressively larger number of Indo molecules. More dynamic aggregates with a maximum size of 15 were obtained when the relative concentration of CA was higher. The mixture of CA, Indo, and POPC also led to ternary mixed micelles in which CA and Indo distribute almost uniformly on the surface such that intra-CA, intra-Indo, and CA/Indo interactions are minimized. A number of previous reports have shown that Indo perforates the cell membrane in the presence of bile acids (e.g., Petruzzelli et al., (2006) Dig. Dis. Sci., 51, 766-774). We propose that this may be related to the stable, highly charged, large CA/Indo binary micelles observed in our simulations. Similarly, the diminished ability of the CA/Indo mixture to aggregate in the presence of POPC may partly explain the lower toxicity of PC-conjugated NSAIDs.

Implication of intestinal VDR deficiency in inflammatory bowel disease

BackgroundTo investigate the function of the intestinal Vdr gene in inflammatory bowel disease (IBD), in conjunction with the discovery of possible metabolic markers for IBD using intestine-specific Vdr knockout mice. MethodsVdrΔIEpC mice were generated, phenotyped and treated with a time-course of 3% dextran sulfate sodium (DSS) to induce colitis. Colitis was diagnosed by evaluating clinical symptoms and intestinal histopathology. Gene expression analysis was carried out. In addition, metabolic markers of IBD were explored by metabolomics. ResultsVdrΔIEpC mice showed abnormal body size, colon structures and feces color. Calcium, collagen, and intestinal proliferation-related gene expression were all decreased, and serum alkaline phosphatase was highly increased. In the acute model which was treated with 3% DSS for six days, VdrΔIEpC mice showed a high score of IBD symptoms; enlarged mucosal layer and damaged muscularis layer. In the recovery experiment model, where mice were treated with 3% DSS for four days and water for three days, VdrΔIEpC mice showed a high score of IBD symptoms; severe damage of mucosal layer and increased expression of genes encoding proinflammatory cytokines. Feces metabolomics revealed decreased concentrations of taurine, taurocholic acid, taurodeoxycholic acid and cholic acid in VdrΔIEpC mice. ConclusionsDisruption of the intestinal Vdr gene showed phenotypical changes that may exacerbate IBD. These results suggest that VDR may play an important role in IBD.General significanceVDR function has been implicated in IBD. This is of value for understanding the etiology of IBD and for development of diagnostic biomarkers for IBD.

Changes in bile composition and liver ultrastructure after TPN alone and TPN with ultra-short bowel syndrome

Summary Background & aims Two of the factors that can influence bile acid (BA) metabolism and biliary poles are long intestinal resections leading to short bowel syndrome (SBS) and prolonged starvation in total parenteral nutrition (TPN). These can act directly (by altering absorption) and/or indirectly (bacterial translocation, alterations of the hepato-intestinal hormonal complex,…). Our aim was to study the effects on bile metabolism and hepatic structure of the conditions of TPN with and without SBS in an animal model. Methods We used 3 experimental groups of Dunkin-Hartley guinea pigs: group A (GA: 10 animals), subjected to anaesthesia and a sham laparotomy, and fed for 10 days by TPN; group B (GB: 10 animals), subjected to a jejuno-ileal resection, and fed for 10 days by TPN; and a control group (6 animals) subjected to a sham laparotomy, and fed orally. At the end of the experimental period, bile samples were taken from the hepatic duct to study the bile composition, and blood samples from the vena cava for blood biochemistry. Following liver perfusion, samples of hepatic tissue were taken for electron microscopy. Results In GA and GB, there were significant losses in weight and increases in glycaemia and serum triglycerides, but a decrease in plasma cholesterol only in GB. For the bile composition, the concentrations of cholic acid (ChA), ketolithocholic acid (KLChA), and total conjugated BA were lowered in both GA and GB, while bile phospholipids (BPh) and bile cholesterol (BCh) were raised in GB only. The electron microscopy showed microsteatosis and a major loss of microvilli in the biliary poles or canaliculi in GA and even more so in GB, with the latter group also showing signs of fibrogenesis. Conclusions TPN and SBS affect the BPh, BCh, and BA composition, potentially increasing the risk of biliary lithogenicity. This was especially so in the association of SBS and TPN, with affection of the biliary duct anatomy, and induction of fibrogenesis and cholangitis.

Bile-acid-mediated decrease in endoplasmic reticulum stress: a potential contributor to the metabolic benefits of ileal interposition surgery in UCD-T2DM rats

SUMMARYPost-operative increases in circulating bile acids have been suggested to contribute to the metabolic benefits of bariatric surgery; however, their mechanistic contributions remain undefined. We have previously reported that ileal interposition (IT) surgery delays the onset of type 2 diabetes in UCD-T2DM rats and increases circulating bile acids, independently of effects on energy intake or body weight. Therefore, we investigated potential mechanisms by which post-operative increases in circulating bile acids improve glucose homeostasis after IT surgery. IT, sham or no surgery was performed on 2-month-old weight-matched male UCD-T2DM rats. Animals underwent an oral fat tolerance test (OFTT) and serial oral glucose tolerance tests (OGTT). Tissues were collected at 1.5 and 4.5 months after surgery. Cell culture models were used to investigate interactions between bile acids and ER stress. IT-operated animals exhibited marked improvements in glucose and lipid metabolism, with concurrent increases in postprandial glucagon-like peptide-1 (GLP-1) secretion during the OFTT and OGTTs, independently of food intake and body weight. Measurement of circulating bile acid profiles revealed increases in circulating total bile acids in IT-operated animals, with a preferential increase in circulating cholic acid concentrations. Gut microbial populations were assessed as potential contributors to the increases in circulating bile acid concentrations, which revealed proportional increases in Gammaproteobacteria in IT-operated animals. Furthermore, IT surgery decreased all three sub-arms of ER stress signaling in liver, adipose and pancreas tissues. Amelioration of ER stress coincided with improved insulin signaling and preservation of β-cell mass in IT-operated animals. Incubation of hepatocyte, adipocyte and β-cell lines with cholic acid decreased ER stress. These results suggest that postoperative increases in circulating cholic acid concentration contribute to improvements in glucose homeostasis after IT surgery by ameliorating ER stress.

Cholic acid changes defense response to oxidative stress in soybean induced by Aspergillus niger

Abstract The oxidative stress and antioxidant systems in soybean leaves and roots infected with plant pathogen Aspergillus niger were studied following treatment with different concentrations of cholic acid. Several oxidative stress parameters were analyzed: production of superoxide (O2 ·−) and hydroxyl radicals (·OH), lipid peroxidation (LP), and superoxide dismutase (SOD; EC 1.15.1.1) activity, as well as the content of reduced glutathione (GSH). Results showed that inoculation with A. niger led to the increase of O2 ·− production and GSH quantities in leaves and ·OH in roots. The highest activity of SOD occured in infected plants treated with cholic acid in concentrations of 40 and 60 mg L−1 which ultimately led to a decrease in O2 ·− production. Inoculation with Aspergillus in combination with elevated cholic acid concentrations also increased ·OH production which is correlated with increased LP. These results may support the idea of using cholic acid as an elicitor to trigger hypersensitive response in plant cells. Use of cholic acid may also actively contribute to soybean plants defense response against pathogen attack.

Bile Acid Is a Host Factor That Regulates the Composition of the Cecal Microbiota in Rats

Alterations in the gastrointestinal microbiota have been associated with metabolic diseases. However, little is known about host factors that induce changes in gastrointestinal bacterial populations. We investigated the role of bile acids in this process because of their strong antimicrobial activities, specifically the effects of cholic acid administration on the composition of the gut microbiota in a rat model. Rats were fed diets supplemented with different concentrations of cholic acid for 10 days. We used 16S ribosomal RNA gene clone library sequencing and fluorescence in situ hybridization to characterize the composition of the cecal microbiota of the different diet groups. Bile acids in feces, organic acids in cecal contents, and some blood parameters were also analyzed. Administration of cholic acid induced phylum-level alterations in the composition of the gut microbiota; Firmicutes predominated at the expense of Bacteroidetes. Cholic acid feeding simplified the composition of the microbiota, with outgrowth of several bacteria in the classes Clostridia and Erysipelotrichi. Externally administered cholic acid was efficiently transformed into deoxycholic acid by a bacterial 7α-dehydroxylation reaction. Serum levels of adiponectin decreased significantly in rats given the cholic acid diet. Cholic acid regulates the composition of gut microbiota in rats, inducing similar changes to those induced by high-fat diets. These findings improve our understanding of the relationship between metabolic diseases and the composition of the gastrointestinal microbiota.

Intestinal steroid profiles and microbiota composition in colitic mice

Reduced gut microbiota diversity in conjunction with a bloom of few bacterial species is a common feature in inflammatory bowel disease (IBD) patients. However, the environmental changes caused by inflammation and their possible impact on the microbiota are largely unknown. Since IBD is associated with an impaired intestinal steroid metabolism, we hypothesized that changes in intestinal steroid and particularly bile acid (BA) concentrations affect microbial communities. We used Interleukin-10 deficient (IL-10-/-) mice as a model for chronic gut inflammation. Healthy wild-type mice served as controls. In these animals, intestinal steroid concentrations and gut microbial diversity were analyzed at 24 weeks of age. The IL 10-/- mice developed moderate inflammation in cecum and colon and colorectal tumor formation was observed in 55 % of the animals. Compared to the healthy conditions, gut inflammation was associated with higher intestinal cholesterol and cholic acid concentrations and a reduced microbial diversity. The latter was accompanied by a proliferation of Robinsoniella peoriensis, Clostridium innocuum, Escherichia coli, and Enterococcus gallinarum. All these species proved to be highly bile acid resistant. We concluded that chronic colitis in IL-10-/- mice is associated with changes in intestinal steroid profiles. These changes may be due to alterations in gut microbiota composition or vice versa. Whether the bacterial sterol and bile acid metabolism is implicated in colitis and colorectal carcinoma etiology remains to be clarified.