A research group at Hokkaido University has clarified that the decrease in the amount of "α-defensin" secreted with aging is involved in the compositional change (transition) of the intestinal flora in the elderly.
It is well known that the composition of the intestinal flora changes from neonatal to old age, and that the transition of the intestinal flora is involved in increasing the risk of various diseases.However, the mechanism by which the intestinal flora transitions with age remains unclear.
So far, this group has clarified that α-defensin secreted by the panel cells of the small intestine regulates the composition of the intestinal flora and maintains the homeostasis of the intestinal environment.Therefore, we hypothesized that aging might affect the amount of α-defensin secreted, and investigated the relationship between aging-related α-defensin and the intestinal flora in detail.
As a result, it was first clarified that the older the person, the lower the amount of alpha defensin in the intestine, and in particular, it was found that the elderly over 70 years old had significantly lower alpha defensin than the middle-aged and elderly. Since α-defensins are the major agonists of innate immunity, this can be interpreted as immunosenescence in innate immunity.
Furthermore, detailed analysis of the composition revealed that the diversity of the intestinal flora was different in the elderly than in the middle-aged and elderly, and characteristic intestinal bacteria were observed.That is, it was suggested that the decrease in α-defensin, which controls intestinal bacteria, may be involved in the previously unknown transition mechanism of the intestinal flora with aging.
Since this study revealed the importance of α-defensin in the transition of the intestinal flora associated with increased disease risk, new disease prevention and treatment methods targeting the induction of α-defensin secretion will be used in the future. Progress is expected.
