Postprandial serum bile acids in healthy man. Evidence for differences in absorptive pattern between individual bile acids (original) (raw)
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Journal of Clinical Investigation
A B S T R A C T This investigation was undertaken in order to (a) characterize the postprandial inflow of individual bile acids to the liver and (b) determine if peripheral venous bile acid levels always adequately reflect the portal venous concentration, or if saturation of hepatic bile acid uptake can occur under physiological conditions. In five patients with uncomplicated cholesterol gallstone disease, the umbilical cord was cannulated during cholecystectomy, and a catheter was left in the left portal branch for 5 to 7 d. The serum concentrations of cholic acid, chenodeoxycholic acid, and deoxycholic acid in portal venous and systemic circulation were then determined at intervals of 15 to 30 min before and after a standardized meal.
Diagnostic value of serum primary bile acids in detecting bile acid malabsorption
Gut, 1982
Serum cholic and chenodeoxycholic acid conjugates were measured in fasting conditions and after meals in 14 patients with bile acid malabsorption due to ileal resection. Mean serum fasting levels of both primary bile acids did not differ from the controls. After meals, serum cholic acid peaks were lower in patients with ileal resection than in control subjects (p<O.OO1), while chenodeoxycholic acid peaks were reduced in colectomised patients (p<OO1). In the sera from patients with ileal resection, the glycine/glycine + taurine ratio for cholic and chenodeoxycholic acid increased (p<O.OO1) from morning to evening, and glycine/glycine + taurine ratio for chenodeoxycholic acid was significantly (p<OO1) different from the controls in the sera collected in the evening. The results are consistent with the concept of a better intestinal conservation of chenyl, mainly of the glycine conjugated form, than of cholylconjugates, in patients with ileal resection; this is probably because of passive absorption in the intestine. The postprandial peaks of serum cholic acid conjugates may therefore be regarded as a test of ileal dysfunction, while peaks of chenodeoxycholic acid conjugates suggest colonic impairment.
Hepatic Uptake of Bile Acids in Man
Journal of Clinical Investigation, 1982
is the recipient of a research fellowship from the Ernst Klenk Foundation. well as total bile acids were well correlated with those in portal venous serum. The results (a) give a quantitation of postprandial bile acid inflow to the liver and (b) indicate that the hepatic uptake system for bile acids in healthy man cannot be saturated during maximal inflow of endogenous bile acids. Measurement of peripheral serum bile acids can thus give important information on the status of the enterohepatic circulation. ' Abbreviations used in this paper: C, cholic acid; CD, chenodeoxycholic acid; D, deoxycholic acid.
Gut, 1976
Bile acid composition was determined in duodenal and jejunal aspirates obtained under fasting conditions in normolipidaemic controls and in patients with the type Ila and type IV lipoprotein patterns. In 17 out of the 22 subjects studied, the duodenal as compared with the jejunal aspirates contained proportionally more CD (chenodeoxycholic acid) than C (cholic acid). The two types of aspirates also differed slightly with regard to the D (deoxycholic acid): CD ratio, which was higher in samples drawn from the jejunum. These findings, compatible with an absorption of about 30 % of CD in the upper small intestine, were approximately the same in all groups of patients. As evidenced by additional experiments in two subjects, an oral intake of cream does not significantly influence the absorption of CD in the upper small intestine.
Determinants of postprandial plasma bile acid kinetics in human volunteers
American journal of physiology. Gastrointestinal and liver physiology, 2017
Bile acids (BA) are signaling molecules with a wide range of biological effects, also identified among the most responsive plasma metabolites in the postprandial state. We here describe this response to different dietary challenges and report on key determinants linked to its interindividual variability. Healthy men and women (n = 72, 62 ± 8 yr, mean ± SE) were enrolled into a 12-wk weight loss intervention. All subjects underwent an oral glucose tolerance test and a mixed-meal tolerance test before and after the intervention. BA were quantified in plasma by liquid chromatography-tandem mass spectrometry combined with whole genome exome sequencing and fecal microbiota profiling. Considering the average response of all 72 subjects, no effect of the successful weight loss intervention was found on plasma BA profiles. Fasting and postprandial BA profiles revealed high interindividual variability, and three main patterns in postprandial BA response were identified using multivariate ana...
Colonic absorption of unconjugated bile acids
Digestive Diseases and Sciences, 1979
Colonic absorption of three major unconjugated bile acids-cholate, chenodeoxycholate, and deoxycholate-was measured under steady-state conditions using a technique of co-Ionic perfusion in healthy volunleers. Aqueous solutions at pH 8.0 and varying in concentration from 1 mM to 10 mM were used. The rate of chenodeoxycholate absorption averaged nine times that of cholate absorption; deoxycholate absorption was somewhat less than that of chenodeoxycholate absorption, averaging six times that of cholate. At concentrations below 5 mM, the rate of absorption of bile acids was directly proportional to concentration, so that "clearance" could be calculated. Clearance values for a 1-mM solution (ml/min/colon, mean +_ SE) were: chenodeoxycholate, 9.84 +_ 1.0; deoxycholate, 7.0 +-1; and cholate, 0.82 +_ 0.10. Since absorption was proportional to concentration in the lumen, and was more rapid for the dihydroxy acids, the major mechanism of absorption was thought to be passive nonionic diffusion. Maximal rates of bile acid absorption were calculated from a l-mM solution and found to be as high as 4.2 g/day for chenodeoxycholate, 3.2 g/day for deoxycholate, and 0.5 g/day for cholate, and the rate would be still greater for more concentrated solutions. Colonic absorption may contribute significantly to conservation of the dihydroxy bile acid pool, especially in conditions of bile acid malabsorption. Bile acids secreted into the proximal intestine are conserved efficiently by active absorption in the ileum (2-5) augmented by passive absorption throughout the intestine (5-10). Previous experiments in man have quantitated passive bile acid absorption in the jejunum (8-10) and ileum (i0, 11) and have also provided evidence that bile acids can be absorbed from the colon (12, 13). To date, there
Bile acid metabolism by fresh human colonic contents: a comparison of caecal versus faecal samples
Gut, 2001
Background-Deoxycholic acid (DCA), implicated in the pathogenesis of gall stones and colorectal cancer, is mainly formed by bacterial deconjugation (cholylglycine hydrolase (CGH)) and 7dehydroxylation (7-dehydroxylase (7-DH)) of conjugated cholic acid (CA) in the caecum/proximal colon. Despite this, most previous studies of CGH and 7-DH have been in faeces rather than in caecal contents. In bacteria, CA increases 7-DH activity by substrate-enzyme induction but little is known about CA concentrations or CA/7-DH induction in the human colon. Aims and methods-Therefore, in fresh "faeces", and in caecal aspirates obtained during colonoscopy from 20 patients, we: (i) compared the activities of CGH and 7-DH, (ii) measured 7-DH in patients with "low" and "high" percentages of DCA in fasting serum (less than and greater than the median), (iii) studied CA concentrations in the right and left halves of the colon, and examined the relationships between (iv) 7-DH activity and CA concentration in caecal samples (evidence of substrate-enzyme induction), and (v) 7-DH and per cent DCA in serum. Results-Although mean CGH activity in the proximal colon (18.3 (SEM 4.40) ×10 −2 U/mg protein) was comparable with that in "faeces" (16.0 (4.10) ×10 − 2 U/mg protein) , mean 7-DH in the caecum (8.54 (1.08) ×10-4 U/mg protein) was higher (p<0.05) than that in the left colon (5.72 (0.85) ×10-4 U/mg protein). At both sites, 7-DH was significantly greater in the "high" than in the "low" serum DCA subgroups. CA concentrations in the right colon (0.94 (0.08) µmol/ml) were higher than those in the left (0.09 (0.03) µmol/ml; p<0.001) while in the caecum (but not in the faeces) there was a weak (r=0.58) but significant (p<0.005) linear relationship between 7-DH and CA concentration. At both sites, 7-DH was linearly related (p<0.005) to per cent DCA in serum. Interpretation/summary-These results: (i) confirm that there are marked regional diVerences in bile acid metabolism between the right and left halves of the colon, (ii) suggest that caecal and faecal 7-DH influence per cent DCA in serum (and, by inference, in bile), and (iii) show that the substrate CA induces the enzyme 7-DH in the caecum.
Post-prandial and interdigestive return of bile acids to the gallbladder in healthy subjects
Neurogastroenterology & Motility, 2008
The enterohepatic circulation o f a radioactive marked bile acid (7sSe-HCAT) was studied b y scintigraphy in the post-prandial period as well as after prolonged fasting in healthy young male volunteers in combination with a continuous pressure recording from the antroduodenal region. In a group of 8 subjects the radioactive marker was instilled into duodenum complex cycle was seen with a net filling during Phase 1 and a net emptying during Phase 11. In the study after prolonged fasting the number and duration of the spontaneous gallbladder emptyings in Phase 11 were not different from those in the post-prandial study. However, the amount emptied in per cent of the 75Se-HCAT pool was significantly higher in the group studied after prolonged fasting compared to the group studied in the postprandial period, and accounted for a median of 3.3% (2.0-16.5%) and (1.6&,.0%) of the 75Se-HCAT pool, respectively. This difference is most likely due to an increase in the concentration of gallbladder bile during fasting.
The Journal of Lipid Research
Bile acid production has been quantitated in seven subjects by methods that compare the results of two independent approaches, namely, quantitation of cholesterol side-chain oxidation and fecal bile acid excretion. Six hypertriglyceridemic (HT) subjects and one normolipidemic control were studied by both techniques. A further control subject was studied by the cholesterol side-chain oxidation method alone. Cholesterol sidechain oxidation was quantitated by measuring the appearance of 3H20 after intravenous administration of [24,25-3H]cholestero1, using multicompartmental analysis of plasma cholesterol and [ 'Hlwater specific activity. Body water kinetics were independently defined by use of oral D20. Two HT subjects were restudied while they were taking cholestyramine, 16 g/day. In all ten studies, multicompartmental analysis closely simulated the observed appearance of 'H20. Values obtained for bile acid production suggest that cholesterol oxidation, or bile acid input, was significantly greater than fecal bile acid output in the HT subjects (P < 0.05). Cholesterol side-chain oxidation rates in the tion. J. Lipid Rw. 1986. 27: 183-195.