The impact of aging on the gut-liver axis in health and disease

Aging is a complex biological process characterized by gradual impairment of organ function and increased susceptibility to disease. Among the systems most affected, the gut and liver are particularly important because of their role in metabolism, detoxification, and immune regulation. These two organs are closely connected through the portal vein and bile ducts, enabling continuous, bidirectional communication that coordinates homeostasis. Understanding how gut-liver communication changes with age is therefore critical, as even subtle alterations over time can have widespread effects on overall physiology and the progression of age-related disorders. In this review, we examine current knowledge on how aging shapes gut and liver physiology, highlighting changes in microbial composition, barrier function, and hepatic metabolism. We then discuss how sex influences the gut-liver axis during aging. Finally, we explore how disruptions in the gut-liver axis contribute to the development of age-related conditions.