TY - JOUR
T1 - Dietary Fiber from Oat and Rye Brans Ameliorate Western Diet–Induced Body Weight Gain and Hepatic Inflammation by the Modulation of Short-Chain Fatty Acids, Bile Acids, and Tryptophan Metabolism
AU - Kundi, Zuzanna Maria
AU - Lee, Jetty Chung Yung
AU - Pihlajamäki, Jussi
AU - Chan, Chi Bun
AU - Leung, Kin Sum
AU - So, Stephanie Sik Yu
AU - Nordlund, Emilia
AU - Kolehmainen, Marjukka
AU - El-Nezami, Hani
N1 - Funding Information:
The authors would like to thank Dr.?Outi Mattila from?VTT Technical Research Centre of Finland Ltd.?for preparing and providing rye fiber for the supplementation. The authors would also like to thank Yau Yu Fung from HKU for constructing the protocol and optimizing the conditions for SCFA analysis and Sanutha Shetty from RVCE for helping with laboratory experiments.
PY - 2021/1
Y1 - 2021/1
N2 - Scope: Dietary fiber (DF) induces changes in gut microbiota function and thus modulates the gut environment. How this modulation is associated with metabolic pathways related to the gut is largely unclear. This study aims to investigate differences in metabolites produced by the gut microbiota and their interactions with host metabolism in response to supplementation with two bran fibers. Methods and Results: Male C57BL/6N mice are fed a western diet (WD) for 17 weeks. Two groups of mice received a diet enriched with 10% w/w of either oat or rye bran, with each bran containing 50% DF. Microbial metabolites are assessed by measuring cecal short-chain fatty acids (SCFAs), ileal and fecal bile acids (BAs), and the expression of genes related to tryptophan (TRP) metabolism. Both brans lowered body weight gain and ameliorated WD-induced impaired glucose responses, hepatic inflammation, liver enzymes, and gut integrity markers associated with SCFA production, altered BA metabolism, and TRP diversion from the serotonin synthesis pathway to microbial indole production. Conclusions: Both brans develop a favorable environment in the gut by altering the composition of microbes and modulating produced metabolites. Changes induced in the gut environment by a fiber-enriched diet may explain the amelioration of metabolic disturbances related to WD.
AB - Scope: Dietary fiber (DF) induces changes in gut microbiota function and thus modulates the gut environment. How this modulation is associated with metabolic pathways related to the gut is largely unclear. This study aims to investigate differences in metabolites produced by the gut microbiota and their interactions with host metabolism in response to supplementation with two bran fibers. Methods and Results: Male C57BL/6N mice are fed a western diet (WD) for 17 weeks. Two groups of mice received a diet enriched with 10% w/w of either oat or rye bran, with each bran containing 50% DF. Microbial metabolites are assessed by measuring cecal short-chain fatty acids (SCFAs), ileal and fecal bile acids (BAs), and the expression of genes related to tryptophan (TRP) metabolism. Both brans lowered body weight gain and ameliorated WD-induced impaired glucose responses, hepatic inflammation, liver enzymes, and gut integrity markers associated with SCFA production, altered BA metabolism, and TRP diversion from the serotonin synthesis pathway to microbial indole production. Conclusions: Both brans develop a favorable environment in the gut by altering the composition of microbes and modulating produced metabolites. Changes induced in the gut environment by a fiber-enriched diet may explain the amelioration of metabolic disturbances related to WD.
KW - dietary fiber
KW - gut metabolism
KW - microbial metabolites
KW - obesity
KW - prebiotics
UR - http://www.scopus.com/inward/record.url?scp=85087116168&partnerID=8YFLogxK
U2 - 10.1002/mnfr.201900580
DO - 10.1002/mnfr.201900580
M3 - Article
AN - SCOPUS:85087116168
VL - 65
JO - Molecular Nutrition and Food Research
JF - Molecular Nutrition and Food Research
SN - 1613-4125
IS - 1
M1 - 1900580
ER -