Potential mechanistic pathways underlying intestinal and hepatic effects of kefir in high-fructose-fed rats.


Akar F., Sumlu E., Alçığır M. E. , Bostancı A., Sadi G.

Food research international (Ottawa, Ont.), vol.143, pp.110287, 2021 (Peer-Reviewed Journal) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 143
  • Publication Date: 2021
  • Doi Number: 10.1016/j.foodres.2021.110287
  • Journal Name: Food research international (Ottawa, Ont.)
  • Journal Indexes: Science Citation Index Expanded
  • Page Numbers: pp.110287
  • Keywords: Dietary fructose, Kefir, Microbiota, Permeability factors, Lipogenesis, Insulin signaling, NF-KAPPA-B, GUT MICROBIOTA, INSULIN-RESISTANCE, EXOPOLYSACCHARIDE KEFIRAN, DIET, MICE, EXPRESSION, STEATOSIS, LIPOGENESIS, MODULATION

Abstract

Excess intake of fructose may contribute to the high prevalence of metabolic disorder. In this study, we investigated the effects of kefir supplementation on the intestine-liver-adipose tissue axis in metabolic disorder induced by high-fructose diet in rats to describe mechanistic action and potential therapeutic value of kefir. Fructose was given to the rats as a 20% solution in drinking water for 15 weeks. Kefir was administrated by gastric gavage once a day during the final six weeks. Kefir supplementation improved metabolic parameters, including plasma triglyceride and insulin levels; hepatic weight, triglyceride content and fatty degeneration; omental fat mass in fructose-fed rats. Kefir supplementation decreased the ratio of Firmicutes/Bacteroidetes in feces, as well as necrotic degeneration, expression levels of nuclear factor-kappa B (NF-kappa B), and inducible nitric oxide synthase (iNOS), but increased expression of tight-junction proteins occludin and claudin-1, in the ileum of the fructose-fed rats. Kefir treatment also reduced the mRNA levels of key lipogenic genes sterol regulatory element-binding protein (SREBP-1c) and fatty acid synthase (FASN) together with a decline in expression of tumor necrosis factor-alpha (TNF-alpha), NF-kappa B, and glycosylated glycoprotein (CD68) in the liver. Moreover, kefir treatment improved insulin signaling at the level of insulin receptor substrate 1 (IRS-1) and phospho-endothelial nitric oxide synthase (peNOS) as well as fructose transporters (GLUT2 and GLUT5) in the liver, but not in the adipose tissue, of high-fructose-fed rats. Consequently, kefir supplementation suppresses hepatic lipogenesis and inflammatory status, but promotes insulin signaling, in association with a change of the fecal microbiota and attenuation of the intestinal permeability factors in high-fructose-fed rats. Thus, we propose that kefir has favorable effects on the hepatic and intestinal irregularities induced by fructose overconsumption.