Effects of Zeaxanthin on the Insulin Resistance and Gut Microbiota of High-Fat-Diet-Induced Obese Mice

Obesity-induced insulin resistance (IR) can precipitate metabolic disorders such as diabetes. Zeaxanthin, a crucial member of the carotenoid family, has been found to mitigate the damage caused by obesity. However, reports on the effects of zeaxanthin on obesity-induced IR are lacking. Our objective was to examine the metabolic regulatory impacts of zeaxanthin on mice subjected to a high-fat diet (HFD) that triggered IR and to explore their influence on gut microbiota regulation. This study constructed a mouse model of metabolic dysfunction caused by lipid-rich nutritional patterns to investigate physiological and biochemical indices, liver pathway expression, and the intestinal microbiota. The mechanisms by which zeaxanthin improved both IR and glucose metabolic disorders were elucidated. The results demonstrate that zeaxanthin effectively suppressed obesity. The fasting blood glucose, area under curve of oral glucose tolerance test and insulin tolerance test, and homeostatic model assessment-insulin resistance (HOMA-IR) indices in the HFDZEA group decreased by 14.9%, 25.2%, 28.9%, and 29.8%. Additionally, zeaxanthin improved the lipid metabolism and alleviated damage to the liver and pancreas while also activating the PI3K/Akt pathway, regulating hepatic gluconeogenesis and the glycogen metabolism. The number of OTUs in the HFDZEA group increased by 29.04%. Zeaxanthin improved the structure and profile of the gastrointestinal microbiome and enhanced its diversity, increasing probiotics abundance, decreasing pathogen abundance, and thereby ameliorating the dysbiosis of enteric microbial communities in rodents with obesity resulting from excessive fat consumption. The outcomes of our analysis provide a rational basis for advancing zeaxanthin-based nutritional products.