Gut microbiota alterations and health status in aging adults: From correlation to causation

The deterioration of tissue structure and decline in physiological function during aging are accompanied by alterations to the gut microbiota. The elderly has higher risks of various diseases and chronic diseases. However, inter‐individual differences are more apparent in elderly than younger, and a proportion of individuals have a delayed onset or even avoid developing chronic diseases. This difference in health status is influenced by both heredity and Lifestyle and environmental factors. During the process of aging, the gut microbiota is also affected by the external environment, and provides a buffer to external challenge, and thus the gut microbiota reflects an individual's personal experience. Moreover, the immune system undergoes a series of changes with age, which are related to chronic inflammation in the elderly. The formation, maturation and senescence of the intestinal immune system is closely related to the gut microbiota. Additionally, changes in the gut microbiota of elderly individuals may modulate the immune system, which may in turn affect health status. Herein, we summarize the correlations between the gut microbiota with individual health status in the elderly and explore the related mechanisms, which may provide a basis to maintain or enhance the health of the elderly though interventions targeting the gut microbiota.