A High-Fat High-Fructose Diet Dysregulates the Homeostatic Crosstalk Between Gut Microbiome, Metabolome, and Immunity in an Experimental Model of Obesity

Scope: Ample evidence supports the prominent role of gut-liver axis in perpetuating pathological networks of high-fat high-fructose (HFF) diet induced metabolic disorders, however, the molecular mechanisms are still not fully understood. Herein, this study aims to present a holistic delineation and scientific explanation for the crosstalk between the gut and liver, including the potential mediators involved in orchestrating the metabolic and immune systems. Methods and Results: An experimental obesity-associated metaflammation rat model is induced with a HFF diet. An integrative multi-omics analysis is then performed. Following the clues illustrated by the multi-omics discoveries, putative pathways are subsequently validated by RT-qPCR and Western blotting. HFF diet leads to obese phenotypes in rats, as well as histopathological changes. Integrated omics analysis shows that there exists a strong interdependence among gut microbiota composition, intestinal metabolites, and innate immunity regulation in the liver. Some carboxylic acids may contribute to gut-liver communication. Moreover, activation of the hepatic LPS-TLR4 pathway in obesity is confirmed. Conclusion: HFF-intake disturbs gut flora homeostasis. Crosstalk between gut microbiota and innate immune system mediates hepatic metaflammation in obese rats, associated with LPS-TLR4 signaling pathway activation. Moreover, alpha-hydroxyisobutyric acid and some other organic acids may play a role as messengers in the liver-gut axis.