Wound healing is a complex multistep process that involves an inflammatory phase that conditions many of the subsequent stages of healing. Skin barrier rupture results in exposure to bacterial compounds suggesting a key role of the wound microbiome in the healing process.
We here aimed to systematically study the healing of skin excisional wounds in 72 different strains of mice from the collaborative cross to evaluate wound healing. In 30 strains we also evaluated associations between bacterial composition in normal and wounded skin at different time points and healing speed.
The healing speed of excisional wounds varied significantly across the 72 strains (P<0.0001) allowing their separation into fast and slow groups. 16S sequencing was performed on faeces and skin swabs and faeces prior to wounding and at D3 and D10 post-wounding in 150 mice from 30 strains. We observed significant changes in alpha diversity between strains (p=0.00024, ANOVA) and at different time points (p=0.00096) during healing.
Using multivariate partial least regression models integrating microbiome and wound healing data at various time points we further showed that skin microbial composition at D3 but not D10 tended to predict healing classification of strains. The gut microbiome composition at baseline allowed a better classification of the fastest healing strains.
In conclusions, wound microbial composition affects the healing of wounds across multiple murine strains. However this should be considered in the context of the background genetic of murine strains.