Long-term supplementation of genistein improves immune homeostasis in the aged gut and extends the laying cycle of aged laying hens

Aging is associated with alterations in gut function, including intestinal inflammation, leaky gut, and impaired epithelial regeneration. Rejuvenating the aged gut is imperative to extend the laying cycle of aged laying hens. Genistein is known to have beneficial effects on age-related diseases, but its precise role in homeostasis of the aged gut of laying hens remains to be elucidated. In this study, 160 45-week-old Hyline Brown laying hens were continuously fed a basal diet or a diet supplemented with 40 mg/kg genistein until they reached 100 weeks of age. The results revealed that long-term genistein supplementation led to an improvement in the egg production rate and feed conversion ratio, as well as an increase in egg quality. Moreover, the expression levels of senescence markers, such as β-galactosidase, P16, and P21, were decreased in the gut of genistein-treated aged laying hens. Furthermore, genistein ameliorated gut dysfunctions, such as intestinal inflammation, leaky gut, and impaired epithelial regeneration. Treg cell-derived IL-10 plays a crucial role in the genistein-induced regulation of age-related intestinal inflammation. This study demonstrates that long-term consumption of genistein improves homeostasis in the aged gut and extends the laying cycle of aged laying hens. Moreover, the link between genistein and Treg cells provides a rationale for dietary intervention against age-associated gut dysfunction.