Systemic inflammatory and gut microbiota responses to fracture in young and middle-aged mice

In this study, we investigated the systemic cytokine and intestinal microbiome response to closed femur fracture in 3-month-old (young adult) and 15-month-old (middle-aged) female wild-type mice. Middle-aged mice had a serum cytokine profile that was distinct from young mice at days 10, 14, and 18 post-fracture. This was characterized by increased concentrations of IL-17a, IL-10, IL-6, MCP-1, EPO, and TNF α. We also observed changes in the community structure of the gut microbiota in both young and middle-aged mice that was evident as early as day 3 post-fracture. This included an Enterobacteriaceae bloom at day 3 post-fracture in middle-aged mice and an increase in the relative abundance of theMuribaculum genus. Moreover, we observed an increase in the relative abundance of the health-promotingBifidobacterium genus in young mice after fracture that did not occur in middle-aged mice. There were significant correlations between serum cytokines and specific genera, including a negative correlation betweenBifidobacterium and the highly induced cytokine IL-17a. Our study demonstrates that aging exacerbates the inflammatory response to fracture leading to high levels of pro-inflammatory cytokines and disruption of the intestinal microbiota.

Source: AGE - October 12, 2023 Category: Geriatrics Source Type: research