1.
Changes in fasting bile acid profiles after Roux-en-Y gastric bypass and sleeve gastrectomy.
Zhang, C, Zhang, J, Zhou, Z
Medicine. 2021;(3):e23939
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Abstract
BACKGROUND Bile acid is an essential factor that plays a role in metabolic regulation, but how bile acid is regulated after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) remains unclear. This meta-analysis aimed to investigate changes in the levels of fasting bile acids following RYGB and SG. METHODS A systematic literature search of the PubMed, EMBASE, Cochrane Library and Web of Science databases through July 2020 was performed in accordance with the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The concentrations of bile acids were evaluated. RESULTS Thirteen studies with 289 patients were included. Our results showed that patients who underwent RYGB had increased levels of fasting total bile acids, primary bile acids, secondary bile acids, conjugated bile acids, and unconjugated bile acids, but no significant differences in all these bile acid levels were observed in patients who underwent SG. Furthermore, 12a-hydroxylated bile acid levels and the 12a-hydroxylated/non-12a-hydroxylated bile acid ratio also increased following RYGB. CONCLUSION In this study, we found that fasting bile acid levels, especially 12a-hydroxylated bile acids levels, were increased after RYGB. However, no differences in fasting bile acid levels were observed following SG.
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Unconjugated and secondary bile acid profiles in response to higher-fat, lower-carbohydrate diet and associated with related gut microbiota: A 6-month randomized controlled-feeding trial.
Wan, Y, Yuan, J, Li, J, Li, H, Zhang, J, Tang, J, Ni, Y, Huang, T, Wang, F, Zhao, F, et al
Clinical nutrition (Edinburgh, Scotland). 2020;(2):395-404
Abstract
BACKGROUND & AIMS Observational studies have shown that diets high in fat and low in dietary fiber, might have an unfavorable impact on bile acid (BA) profiles, which might further affect host cardiometabolic health. In the current study, we aimed to evaluate the effects of dietary fat content on BA profiles and associated gut microbiota, and their correlates with cardiometabolic risk factors. METHODS In a randomized controlled-feeding trial, healthy young adults were assigned to one of the three diets: a lower-fat diet (fat 20%, carbohydrate 66% and protein 14%), a moderate-fat diet (fat 30%, carbohydrate 56% and protein 14%) and a higher-fat diet (fat 40%, carbohydrate 46% and protein 14%) for 6 months. All the foods were provided during the entire intervention period. The BA profiles, associated gut microbiota and markers of cardiometabolic risk factors were determined before and after intervention. RESULTS The higher-fat diet resulted in an elevated concentration of total BAs (p < 0.001), and unconjugated BAs (p = 0.03) compared with lower-fat diet. Secondary BAs, such as deoxycholic acid (DCA), taurodeoxycholic acid (TDCA), 12ketolithocholic acid (12keto-LCA), 3β-DCA and taurolithocholic acid (TLCA) (p < 0.05 after FDR correction) were significantly increased in the higher-fat diet group after the 6-month intervention. Consistently, the abundances of gut bacteria (Bacteroides, Clostridium, Bifidobacterium and Lactobacillus) which affect bile salt hydrolase gene expression were significantly increased after higher-fat consumption. The change of DCA was positively associated with the relative abundance of Bacteroides (r = 0.31, p = 0.08 after FDR correction). In addition, the changes of fecal concentrations of DCA and 12keto-LCA were positively associated with serum total cholesterol (r > 0.3, p = 0.02 and p = 0.008 after FDR correction, respectively). In line with these findings, serum fibroblast growth factor 19 (FGF19) was marginally significantly elevated in the higher-fat group after intervention (p = 0.05). CONCLUSIONS The higher-fat diet resulted in an alteration of BAs, especially unconjugated BAs and secondary BAs, most likely through actions of gut microbiota. These alterations might confer potentially unfavorable impacts on colonic and host cardiometabolic health in healthy young adults. Clinical trial registry number: NCT02355795 listed on NIH website: ClinicalTrials.gov.
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Effect of oral consumption of probiotic Lactobacillus planatarum P-8 on fecal microbiota, SIgA, SCFAs, and TBAs of adults of different ages.
Wang, L, Zhang, J, Guo, Z, Kwok, L, Ma, C, Zhang, W, Lv, Q, Huang, W, Zhang, H
Nutrition (Burbank, Los Angeles County, Calif.). 2014;(7-8):776-83.e1
Abstract
OBJECTIVE Probiotics may improve intestinal health by modulating intestinal microbiota. However, the age-related variation in response to probiotic consumption is understudied. The aim of this study was to determine the effect of oral consumption of Lactobacillus plantarum P-8 (Lp-8) on human intestinal microflora, secretary immunoglobulin A (SIgA), total bile acids (TBAs), and short-chain fatty acids (SCFAs) of different aged adults. METHODS Thirty-three recruited individuals, including young (mean age 26 y), middle-aged (mean age 51 y), and elderly (mean age 76 y) volunteers, were given a single daily oral dose of Lp-8 (6 × 10(10) colony forming units) for 4 wk. Fecal samples were collected before starting, during, and after stopping Lp-8 intake. Polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis, quantitative PCR, high-performance liquid chromatography, and enzyme-linked immunosorbent assay were used to detect for fecal microflora, SIgA, TBAs, and SCFAs. RESULTS Results showed an increase in Bifidobacterium (P < 0.05) and other beneficial bacteria, whereas Desulfovibrio (P < 0.05) and other opportunistic pathogens decreased after taking Lp-8 for 4 wk. Lp-8 consumption also affected fecal levels of SIgA, TBAs, and SCFAs. CONCLUSIONS Lp-8 administration could improve human gastrointestinal health. However, some of these effects were transient and gradually disappeared once the intervention was discontinued. Moreover, the extent of these desirable effects was age-related.