The human milk oligosaccharide 2’-fucosyllactose alleviates liver steatosis and associated gut permeability, ER stress and insulin resistance by reducing hepatic diacylglycerols in obese Ldlr-/-.Leiden mice. The human milk oligosaccharide 2’-fucosyllactose alleviates liver steatosis and associated gut permeability, ER stress and insulin resistance by reducing hepatic diacylglycerols in obese Ldlr-/-.Leiden mice

Abstract: - Non-alcoholic fatty liver disease (NAFLD) is a complex multifactorial disorder that is associated with gut dysbiosis, enhanced gut permeability, adiposity and insulin resistance. Prebiotics such as human milk oligosaccharide 2’-fucosyllactose are thought to primarily improve gut health and it is uncertain whether they would affect more distant organs. This study investigates whether 2’-fucosyllactose can alleviate NAFLD development in manifest obesity. Obese hyperinsulinemic Ldlr-/-.Leiden mice, after an 8 week run-in on HFD, were treated with 2’-fucosyllactose by oral gavage until week 28 and compared to HFD-vehicle controls. 2’-fucosyllactose did not affect food intake, body weight, total fat mass or plasma lipids. 2’-fucosyllactose altered the fecal microbiota composition which was paralleled by a suppression of HFD-induced gut permeability at t=12 weeks. 2’-fucosyllactose significantly attenuated the development of NAFLD by reducing microvesicular steatosis. These hepatoprotective effects were supported by functional transcriptome analyses showing that 2’-fucosyllactose activated ACOX1 (involved in lipid catabolism), while deactivating SREBF1 (involved in lipogenesis). Furthermore, 2’-fucosyllactose suppressed ATF4, ATF6, ERN1, and NUPR1 all of which participate in ER stress. 2’-fucosyllactose reduced fasting insulin concentrations and HOMA-IR, which was corroborated by decreased intrahepatic diacylglycerols. - In conclusion, long-term prebiotic treatment with 2’-fucosyllactose can counteract the detrimental effects of HFD on gut dysbiosis and gut permeability and attenuates the development of liver steatosis. The observed reduction in intrahepatic diacylglycerols provides a mechanistic rationale for the improvement of hyperinsulinemia and supports the use of 2’-fucosyllactose to correct dysmetabolism and insulin resistance. Overall design: After a run-in of 8 weeks on HFD, obese hyperinsulinemic mice were treated with 2-fucosyllactose (2’-FL) by oral gavage twice daily (750 mg/kg/day) until week 28, and compared with vehicle control mice receiving saline (n=15/group). Mice on standard rodent chow were used as a reference.