Fermented Red Ginseng Restores Age-Associated Insulin Homeostasis and Gut Microbiome Balance in Mice

Biological aging disrupts liver–gut intercommunication, resulting in the development of insulin resistance and type 2 diabetes, coupled with the imbalance of gut microbiome composition known as gut dysbiosis. Fermented red ginseng (FRG) is a renowned functional food substance showing its notable anti-inflammatory and anti-diabetic effects owing to its unique bioactive compounds known as ginsenosides. However, whether FRG could impact biological aging and age-related metabolic dysfunction is still unclear. The current study aimed to determine the health benefits of FRG in improving age-associated impaired insulin homeostasis and gut dysbiosis in 19-month-old male mice. Mice were fed with a normal chow diet (NCD) or NCD with FRG (300 mg/kg) for 14 weeks. FRG supplementation significantly improved insulin homeostasis by activating the hepatic protein kinase B (AKT) and proline-rich AKT substrate of 40 kDa (PRAS40). We also observed suppressed mRNA expression of proinflammatory cytokines and diminished inflammatory infiltrates in the liver of FRG-fed mice compared with NCD-only controls. Furthermore, alongside a decreased ratio of Firmicutes to Bacteroidetes, FRG administration enriched beneficial genera, including Muribaculaceae, Borkfalkiaceae, Parasutterella, and Clostridia vadin BB60 group, whereas FRG reduced the abundance of Erysipelotrichaceae and Dubosiella at the genus level. In summary, we suggest that FRG can be a potential anti-aging dietary supplement to manage age-driven dysregulation of insulin homeostasis and gut microbiota composition.