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PubMed2002

Changes in bile acid composition and effect on cytolytic activity of fecal water by ursodeoxycholic acid administration: a placebo-controlled cross-over intervention trial in healthy volunteers.

BACKGROUND: Ursodeoxycholic acid (UDCA) has been shown to affect membrane-damaging effects of bile acids in vitro and fecal bile acid composition in rats. This study evaluates the effect of UDCA on fecal bile acid composition and on cytolytic activity of fecal water in man to clarify the potential chemopreventive role of UDCA for colorectal cancer. METHODS: In this placebo-controlled crossover intervention trial, the effect of 900 mg/day UDCA orally in 15 healthy volunteers was studied. At the end of each 4-week period, 72 h feces were collected. Total and individual bile acids in feces were determined by gas chromatography and soluble bile acids were analyzed by high-performance liquid chromatography. Cytolytic activity of fecal water was measured using an erythrocyte lysis assay. RESULTS: In feces, the percentages of primary bile acids-cholic acid (CA) and chenodeoxycholic acid (CDCA)-and of secondary bile acid-deoxycholic acid (DCA) - decreased after supplementation with UDCA, whereas those of UDCA and LCA increased from 2.7 +/- 0.4% to 23.7 +/- 2.6%, P < 0.0001 and from 26.2 +/- 1.2% to 49.4 +/- 1.8%, P < 0.0001 respectively. The concentrations of these two bile acids in fecal water also increased after UDCA administration from 7.8 +/- 1.9 micromol/l to 47.0 +/- 6.7 micromol/l (UDCA), P < 0.0001 and from 2.5 +/- 0.6 micromol/l to 18.3 +/- 4.1 micromol/l (LCA), P < 0.002, respectively. Cytolytic activity of fecal water was not affected by UDCA. CONCLUSION: These results do not support a protective effect of UDCA supplementation against colorectal cancer in man.

Administration, Oral↗

PubMed2005

Characteristics of apoptosis in HCT116 colon cancer cells induced by deoxycholic acid.

Hydrophobic bile acids induce apoptosis in both colon cancer cells and hepatocytes. The mechanism by which colon cancer cells respond to bile acids is thought to be different from that of hepatocytes. Therefore, we investigated the characteristics of apoptosis in colon cancer cell line HCT116. Hydrophobic bile acids, i.e., deoxycholic acid (DCA), and chenodeoxycholic acid, induced apoptosis in HCT116 cells. Apoptotic indications were detectable at as early as 30 min and the extent increased in time- and concentration-dependent manners. SDS and a hydrophilic bile acid, cholic acid, did not induce apoptosis even at cytotoxic concentrations. Pretreatment with cycloheximide failed to inhibit apoptosis, suggesting that protein synthesis is not involved in the apoptotic response. Release of cytochrome c from mitochondria and activation of caspase-9 were detectable after 5 and 10 min, respectively, whereas remarkable activation of Bid was not detected. Ursodeoxycholic acid (UDCA) protected HCT116 cells from DCA-induced apoptosis but a preincubation period of > or =5 h was required. Nevertheless, UDCA did not inhibit cytochrome c release from mitochondria. Our results indicate that hydrophobic bile acids induce apoptosis in HCT116 cells by releasing cytochrome c from mitochondria via an undefined but specific mechanism, and that UDCA protects HCT116 cells by acting downstream of cytochrome c release.

Apoptosis↗

PubMed1987

Identification of new C27 and C24 bile acids in the bile of Alligator mississippiensis.

Biliary bile acids of Alligator mississippiensis were analyzed by gas-liquid chromatography-mass spectrometry after fractionation by silica gel column chromatography. It was shown that the alligator bile contained 12 C27 bile acids and 8 C24 bile acids. In addition to the C27 bile acids, such as 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid, 3 alpha,7 alpha,12 alpha-trihydroxy-5 alpha-cholestanoic acid, 3 alpha,7 alpha-dihydroxy-5 beta-cholestanoic acid, 3 alpha,12 alpha-dihydroxy-5 beta-cholestanoic acid, 7 alpha,12 alpha-dihydroxy-3-oxo-5 beta-cholestanoic acid, and 3 alpha,12 alpha-dihydroxy-7-oxo-5 beta-cholestanoic acid, identified previously in the bile of A. mississippiensis, 3 alpha,7 beta-dihydroxy-5 beta-cholestanoic acid, 3 alpha,7 beta,12 alpha-trihydroxy-5 beta-cholestanoic acid, 7 beta,12 alpha-dihydroxy-3-oxo-5 beta-cholestanoic acid, 3 alpha,7 alpha,12 alpha,24-tetrahydroxy-5 beta-cholestanoic acid, 3 alpha,7 alpha,12 alpha,26-tetrahydroxy-5 beta-cholestanoic acid, and 1 beta,3 alpha,7 alpha,12 alpha-tetrahydroxy-5 beta-cholestanoic acid were newly identified. And in addition to the C24 bile acids, such as chenodeoxycholic acid, ursodeoxycholic acid, cholic acid, and allocholic acid, identified previously, deoxycholic acid, 3 alpha,7 alpha-dihydroxy-5 beta-chol-22-enoic acid, 3 alpha,7 alpha,12 alpha-trihydroxy-5 alpha-chol-22-enoic acid, and 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-chol-22-enoic acid were newly identified.

Alligators and Crocodiles↗

PubMed1997

Digitoxinlike and digoxinlike immunoreactivitis in sera of patients with uremia and liver disease as measured by fluorescence polarization immunoassays: poor correlation between digitoxinlike and digoxinlike immunoreactivities.

Digoxinlike immunoreactive substances (DLIS) cross-react with antidigoxin antibodies and falsely elevante total digoxin levels. Cross-reactivity of DLIS with various immunoassays for digoxin has been extensively studied in the past. The digitoxin molecule differs from digoxin by having one extra hydroxyl group in the aglycone ring. Therefore, DLIS may also falsely elevate total digitoxin concentrations. However, in the past, limited studies have shown the presence of digitoxinlike immunoreactive substances (DTLIS) in cord blood and sera of neonates. We compared DLIS and DTLIS concentrations in sera of patients with uremia, liver disease, and hypoalbuminemia. We found measurable DLIS concentrations in 11 of 45 patients by the fluorescence polarization immunoassay (FPIA) for digoxin (range, 0.20-0.89 ng/ml digoxin equivalent). These patients did not receive any digoxin or digitoxin. Using the FPIA, we also found elevated DTLIS concentrations in 10 of these 45 patients (range, 2.88-21.24 ng/ml digitoxin equivalent). Given the narrow therapeutic range of digitoxin (15-30 ng/ml), this cross-reactivity is significant. Elevated concentrations of DTLIS in sera falsely elevated the measured concentrations of digitoxin (positive interference) when known amounts of digitoxin were added to such sera. Interestingly, we found a poor correlation between DLIS and DTLIS concentrations in sera of patients with liver disease and uremia (r = 0.58), with some patients having no measurable DLIS activity but measurable DTLIS activity and vice versa. Digoxin showed only 4-8% cross-reactivity against digitoxin antibody with a wide range of concentration. Some proposed DLIS compounds (nonesterified fatty acids, cholic acid, lysophospholipid, and DHEA-sulfate) did not show any cross-reactivity with the digitoxin assay at a concentrations much higher than the physiologic range. We conclude that DTLIS activity is present in patients with liver disease and uremia, and the correlation between DLIS activity and DTLIS activity is poor. Moreover, some proposed DLIS do not explain the DTLIS activity detected in serum.

Digitoxin↗

PubMed2005

Effect of tibolone on turnover of cholesterol to bile acids in ovariectomized rats.

OBJECTIVE: Tibolone is used in breast cancer therapy in women. The most important aspect of this therapy concerns its influence on bone and lipid metabolism. Several studies have reported the effect of tibolone on plasma lipids. Approximately 40% of total cholesterol removal occurs by its conversion to bile acids, a process that takes place in the liver. The aim of the study was to evaluate the influence of tibolone on the conversion of cholesterol to bile acids in estrogen-deficient rats. DESIGN: Thirty female Wistar rats were divided into three groups: sham-operated controls, ovariectomized controls, and ovariectomized rats treated with tibolone. After 42 days of drug administration, bile was collected under anesthesia after administration of radioactive 4-C cholesterol. Bile was assayed for total C radioactivity; C bile acids were determined after thin-layer chromatography separation by using the isotopic technique. RESULTS: The ovariectomy decreased the concentrations of C-radioactive bile, taurocholic acid, and cholic acid. The administration of tibolone significantly increased the excretion of C-radioactive bile and C-radioactive bile acids as compared with ovariectomized controls. Moreover, the therapy with tibolone significantly increased the concentrations of C taurocholic acid, C glycocholic acid, cholic acid, and taurochenodeoxycholic plus taurodeoxycholic acids. CONCLUSION: The results of the present study suggest that tibolone may increase the concentrations of cholesterol and trihydroxy bile acids in bile. These changes may be associated with an increased risk of gallstone generation.

Animals↗

PubMed2000

Identification and characterization of a bile acid 7alpha-dehydroxylation operon in Clostridium sp. strain TO-931, a highly active 7alpha-dehydroxylating strain isolated from human feces.

Clostridium sp. strain TO-931 can rapidly convert the primary bile acid cholic acid to a potentially toxic compound, deoxycholic acid. Mixed oligonucleotide probes were used to isolate a gene fragment encoding a putative bile acid transporter from Clostridium sp. strain TO-931. This DNA fragment had 60% nucleotide sequence identity to a known bile acid transporter gene from Eubacterium sp. strain VPI 12708, another bile acid-7alpha-dehydroxylating intestinal bacterium. The DNA (9.15 kb) surrounding the transporter gene was cloned from Clostridium sp. strain TO-931 and sequenced. Within this larger DNA fragment was a 7.9-kb region, containing six successive open reading frames (ORFs), that was encoded by a single 8.1-kb transcript, as determined by Northern blot analysis. The gene arrangement and DNA sequence of the Clostridium sp. strain TO-931 operon are similar to those of a Eubacterium sp. strain VPI 12708 bile acid-inducible operon containing nine ORFs. Several genes in the Eubacterium sp. strain VPI 12708 operon have been shown to encode products required for bile acid 7alpha-dehydroxylation. In Clostridium sp. strain TO-931, genes potentially encoding bile acid-coenzyme A (CoA) ligase, 3alpha-hydroxysteroid dehydrogenase, bile acid 7alpha-dehydratase, bile acid-CoA hydrolase, and a bile acid transporter were similar in size and exhibited amino acid homology to similar gene products from Eubacterium sp. strain VPI 12708 (encoded by baiB, baiA, baiE, baiF, and baiG, respectively). However, no genes similar to Eubacterium sp. strain VPI 12708 biaH or baiI were found in the Clostridium sp. strain TO-931 bai operon, and the two putative Eubacterium sp. strain VPI 12708 genes, baiC and baiD, were arranged in one continuous ORF in Clostridium sp. strain TO-931. Intergene regions showed no significant DNA sequence similarity, but primer extension analysis identified a region 115 bp upstream from the first ORF that exhibited 58% identity to a bai operator/promoter region identified in Eubacterium sp. strain VPI 12708. These results indicate that the gene organization, gene product amino acid sequences, and promoters of the bile acid-inducible operons of Clostridium sp. strain TO-931 and Eubacterium sp. strain VPI 12708 are highly conserved.

3-Hydroxysteroid Dehydrogenases↗

PubMed1981

Genetic and biochemical characterization of periplasmic-leaky mutants of Escherichia coli K-12.

Periplasmic-leaky mutants of Escherichia coli K-12 were isolated after nitrosoguanidine-induced mutagenesis. They released periplasmic enzymes into the extracellular medium. Excretion of alkaline phosphatase, which started immediately in the early exponential phase of growth, could reach up to 90% of the total enzyme production in the stationary phase. Leaky mutants were sensitive to ethylenediaminetetraacetic acid, cholic acid, and the antibiotics rifampin, chloramphenicol, mitomycin C, and ampicillin. Furthermore, they were resistant to colicin E1 and partially resistant to phage TuLa. Their genetic characterization showed that the lky mutations mapped between the suc and gal markers, near or in the tolPAB locus. A biochemical analysis of cell envelope components showed that periplasmic-leaky mutants contained reduced amounts of major outer membrane protein OmpF and increased amounts of a 16,000-dalton outer membrane protein.

Alkaline Phosphatase↗

PubMed1971

Colonic secretion of water and electrolytes induced by bile acids: perfusion studies in man.

Each of the three major bile acids of man was tested for its influence on electrolyte and water absorption in the human colon. Transport from isotonic solutions, with or without added bile acids, was compared in 35 studies on 20 healthy volunteers by colonic perfusions under steady-state conditions. Electrolytes and water were always absorbed from control solutions, but dihydroxy bile acid solutions induced continuous secretion or inhibition of sodium, potassium, and water absorption, which was reversible. Deoxycholic acid caused consistent secretion at 3 mm concentrations, whereas chenodeoxycholic acid did not induce secretion until the concentration was 5 mm. The trihydroxy bile acid (cholic acid) produced no significant change in absorption at 10 mm. Inhibition of absorption was also induced by mixtures of the glycine or taurine conjugated bile acids. Secretion of sodium and chloride, induced by bile acid perfusion, was linearly correlated with secretion of water; potassium secretion was relatively constant regardless of the volume of secretion. These results establish a striking influence of bile acids on colonic absorptive activity, provide an explanation in part for the diarrhea that frequently accompanies ileal disease or resection, and imply that diarrhea should occur in other disease states that produce elevated concentrations of dihydroxy bile acids in the colonic lumen.

Bicarbonates↗

PubMed2003

Presence of protein-bound unconjugated bile acids in the cytoplasmic fraction of rat brain.

Using liquid chromatography/electrospray ionization mass spectrometry, we have found three unconjugated bile acids [cholic acid (CA), chenodeoxycholic acid (CDCA), and deoxycholic acid (DCA)] in the rat brain cytoplasmic fraction. CDCA was detected only upon extraction with high concentrations of guanidine, indicating that it is bound noncovalently to protein in the brain. The most abundant of the three, it was present at a concentration of 1.6 nmol/g wet weight (approximately 15 mg of protein) of brain, corresponding to almost 30 times its serum concentration. CA and DCA were present at 1/30th the concentration of CDCA. Bile acids conjugated with amino acids, sulfuric acid, and glucuronic acid were not detected. These data clearly demonstrate that unconjugated CDCA and, to a lesser extent, CA and DCA, exists in the rat brain.

Animals↗

PubMed2003

Synthesis and anti-tumor activity of new steroidal nuclear analogues of aragusterol A.

3alpha,7alpha-Dihydroxy-5-epiaragusterol A (3) was synthesized from bile acid (cholic acid) as a new steroidal nuclear analogue of antitumor marine steroid aragusterol A. 7alpha-Hydroxyaragusterol A (4) was also derived from xestokerol B. The in vitro anti-proliferative activity of each of these analogues toward KB cells as well as in vivo anti-tumor activity of 5-epiaragusterol A (2) previously synthesized by the authors and 3 were assessed.

Animals↗

PubMed2005

Simultaneous determination of major bioactive components in Qingkailing injection by high-performance liquid chromatography with evaporative light scattering detection.

High-performance liquid chromatography with evaporative light scattering detection (HPLC/ELSD) was established for simultaneous determination of seven major bioactive components of Qingkailing injection including adenosine, geniposide, chlorogenic acid, baicalin, ursodeoxycholic acid, cholic acid, and hyodeoxycholic acid. The proposed method was applied to analyze ten various Qingkailing injections and produced data with acceptable linearity, repeatability, precision and accuracy having a limit of detection (LOD) of 10-50 ng. In comparison with UV detection, HPLC/ELSD permits the determination of non-chromophoric compounds without prior derivatization, and shows good compatibility to the multi-components of complex analytes. The proposed method is a useful alternative for routine analysis in the quality control of traditional Chinese medicine.

Chromatography, High Pressure Liquid↗

PubMed2007

Comparative study on major bioactive components in natural, artificial and in-vitro cultured Calculus Bovis.

Major bioactive components in various Calculus Bovis, including natural, artificial and in-vitro cultured Calculus Bovis, were comparatively studied. An approach of high-performance liquid chromatography coupled with ultraviolet and evaporative light scattering detections (HPLC/UV/ELSD) was established to simultaneously determinate six bioactive components thereof, including five bile acids (cholic acid, deoxycholic acid, ursodeoxycholic, chenodeoxycholic acid, hyodeoxycholic acid) and bilirubin. ELSD and UV detector were applied to detect bile acids and bilirubin respectively. The assay was performed on a C(18) column with water-acetonitrile gradient elution and the investigated constituents were authenticated by comparing retention times and mass spectra with those of reference compounds. The proposed method was applied to analyze twenty-one Calculus Bovis extraction samples, and produced data with acceptable linearity, precision, repeatability and accuracy. The result indicated the variations among Calculus Bovis samples under different developmental conditions. Artificial and in-vitro cultured Calculus Bovis, especially in-vitro cultured ones, which contain total bioactive constituents no less than natural products and have the best batch-to-batch uniformity, suffice to be used as substitutes of natural Calculus Bovis.

Chromatography, High Pressure Liquid↗

PubMed1984

The mechanism of diarrhoea resulting from pelvic and abdominal radiotherapy; a prospective study using selenium-75 labelled conjugated bile acid and cobalt-58 labelled cyanocobalamin.

An attempt was made to elucidate the mechanism of diarrhoea resulting from pelvic and abdominal radiotherapy in a prospective study of 10 patients undergoing treatment for curable pelvic malignant tumours using the synthetic trihydroxy 75Se-labelled conjugated bile acid, SeHcat and 58Co-labelled cyanocobalamin (58Co Vit B12). Evidence of malabsorption of vitamin B12 measured as a significant fall in whole body percentage retention of 58Co Vit B12 from baseline levels was found in all nine patients who developed diarrhoea during radiotherapy. Only four out of these nine patients also had malabsorption of the trihydroxy conjugated bile acid, cholic acid, measured as a significant fall in SeHcat whole body percentage retention and these patients had the most severe diarrhoea. The findings are discussed in the light of what is known about the pathophysiology of diarrhoea during pelvic and abdominal radiotherapy and lend support to previous work which implicated increased bowel motility in the pathogenesis of radiation-induced diarrhoea. The hypothesis that local neuroendocrine mechanisms in the gut may be involved is put forward, with possible implications for treatment.

Adult↗

PubMed2005

Effects of fatty acid bile acid conjugates (FABACs) on biliary lithogenesis: potential consequences for non-surgical treatment of gallstones.

Fatty acid bile acid conjugates (FABACs) are novel synthetic lipid molecules, which were designed for the treatment of cholesterol gallstones. The rationale was to combine a cholesterol solubilizing moiety (a saturated fatty acid) with a bile acid (cholic acid) as a vehicle to enable secretion into bile and entry into the enterohepatic circulation. An amide bond was used to provide stability against intestinal degradation. Initial in vitro studies showed that FABACs are indeed cholesterol solubilizers, able to prevent biliary cholesterol crystallization. Arachidyl-amido-cholanoic acid (Aramchol) was found to be the most potent FABAC in these studies. Animal studies revealed that Aramchol was absorbed after oral administration and could prevent cholesterol crystallization as well as dissolve preformed crystals in rodents fed a lithogenic diet. In gallstone susceptible mice, Aramchol prevented gallstone formation and dissolved gallstones. FABACs were found to be metabolically active substances, also able to decrease blood cholesterol, atherosclerotic plaques and fat accumulation in the liver in several animal species. The underlying mechanisms of action are under active investigation, and several effects, e.g. on cholesterol and bile salt metabolizing enzymes as well as cholesterol efflux from cells have been discovered. These findings are, however, only the beginning of our understanding of the metabolic actions as well as the potential of use of FABACs as therapeutic agents.

Animals↗

PubMed1986

Bile acid metabolism in patients with Crohn's disease in terminal ileum.

Bile acid metabolism was studied by means of the fractional turnover rate or orally ingested 14C-labeled taurocholic acid and by gas chromatographic determination of fecal excretion of the bile acids cholic acid (CA), chenodeoxycholic acid (CDCA), deoxycholic acid (DCA), and lithocholic acid (LCA). Thirty patients with Crohn's disease (CD) of the small bowel, of whom 19 had been operated on with limited ileal resections, were studied and compared with 11 healthy volunteers. The unoperated group of CD patients did not show significant increase in bile acid excretion in the stools in contrast to the CD patients with ileal resection. The fecal excretion consisted mostly of primary bile acids, and a significant correlation between length of resection and bile acid excretion was found (rs = 0.81, p less than 0.01). The fractional turnover rate of CA + DCA was significantly increased in both unoperated (0.21 l/day) and operated (0.44 l/day) patients compared with normal controls (0.06 l/day). The bile acid pool of CA + DCA, however, was normal in patients with ileal resections, indicating a compensatory increase in bile acid synthesis. In unoperated patients the bile acid pool of CA + DCA was slightly decreased (3.1 mmol) compared with operated patients (6.2 mmol) and normal controls (4.8 mmol). The pool size was not significantly correlated to mean transit time of dietary residue, feces excretion, loss of weight, or amount of fat in feces. The mean transit time of dietary residue was decreased in both operated and unoperated CD patients.

Adult↗

PubMed1984

Effect of chenodeoxycholic acid feeding during gestation in the rat on bile acid metabolism and liver morphology.

Chenodeoxycholic acid (CDCA) was fed to pregnant rats at the 0.25% level in the diet from Day 11 of gestation to delivery in order to evaluate the effects on (1) maternal tissue bile acid composition, (2) neonatal tissue bile acid composition and cholesterol-7 alpha-hydroxylase activity, and (3) maternal, neonatal, and postnatal liver morphology. Feeding CDCA increased maternal lithocholic acid while significantly decreasing deoxycholic acid, cholic acid, and total bile acids. Feeding CDCA resulted in a significantly higher chenodeoxycholic acid pool in the neonates while neonatal plasma cholesterol and the 7 alpha-hydroxylation of cholesterol was not significantly affected. Morphological examination of maternal, neonatal, and postnatal rat liver revealed no significant hepatotoxicity. This investigation has shown that (a) neonates of CDCA fed dams have a significantly greater pool of CDCA, suggesting maternal-to-fetal transfer of dihydroxy bile acids, (b) neonatal cholesterol-7 alpha-hydroxylase activity and total tissue bile acid pools are not significantly altered by increased pool of CDCA, and (c) no hepatotoxic effects on maternal, neonatal, and postnatal livers were evident with gestational feeding of CDCA at the 0.25% level in the rat.

Animals↗

PubMed1999

Human fasciolosis: a study on the relation of infection intensity and treatment to hepatobiliary affection.

Seventeen patients with established fasciolosis and ten normal controls were enrolled in the study. The Fasciola patients were divided according to infection intensity into two groups (four patients with high intensity and thirteen patients with low intensity) as assessed by egg counts coupled with ultrasonography for detection of worms in the biliary system. Aspartate and alanine aminotransferases (AST and ALT) levels were similar to those of the controls, within the accepted normal limits, before and after treatment denoting absence of hepatocellular injury. Total serum bile acids, individual bile acids: cholic acid (CA) and chenodeoxycholic acid (CDCA), gamma glutamyl transpeptidase (GGT) and serum alkaline phosphatase (SAP) were significantly higher among all patients as compared to the controls denoting a degree of cholestatic lesion in those patients. Patients with high infection intensity revealed higher parameters than those with low intensity. The difference was not significant. One month after treatment, there was a significant improvement in the cholestasis indicating parameters in all Fasciola cases compared to the pretreatment ones. This indicates the effective role of the drug on the hepatobiliary function. However, the levels were still different from the controls. In Fasciola infection, total and individual serum bile acids in conjunction with GGT and SAP evaluate the hepatobiliary status and detect any minor abnormalities especially in anicteric subjects. Studied after treatment, they can be useful indices for assessment of the improvement.

Adolescent↗

PubMed1991

Effect of starch malabsorption on fecal bile acids and neutral sterols in humans: possible implications for colonic carcinogenesis.

Epidemiological and experimental studies indicate a strong association between an elevated colon cancer risk and increased fecal excretion of secondary bile acids, neutral sterols, and prolonged gastrointestinal transit time. Starch malabsorption, on the other hand, has been reported to be a possible protective factor in colon carcinogenesis. To study the impact of starch malabsorption on these parameters, 12 healthy volunteers consumed a diet rich in starch for two 4-week periods. During a double-blind crossover trial they received the alpha-glucosidase inhibitor acarbose (BAY g 5421) in one of the study periods and placebo in the other. During acarbose treatment stool wet weight increased by 68%, stool dry weight by 57%, and gastrointestinal mean transit time by 30%. Fecal concentrations (mg/g dry weight) of the neutral sterols coprostanol, coprostanone, campesterol, 4-cholesten-3-one, and beta-sitosterol decreased by 36.8, 48.7, 42.1, 34.6, and 39.4%, respectively, under acarbose. Concentrations of the major secondary bile acids, deoxycholic and lithocholic acid, decreased by 59.9 and 52.2%, respectively. In spite of an increased stool weight, also daily excretion (mg/day) of these two bile acids was lower under acarbose (47.9 and 36.6%, respectively) compared to placebo, whereas excretion of the main primary bile acid, cholic acid, rose from 22.58 mg/day to 379.80 mg/day during the acarbose period. The changes in fecal bile acid and neutral sterol excretion found during acarbose treatment may explain a protective effect of starch malabsorption on colon cancer development.

Acarbose↗