We know many many aspects of skin aging aren’t due to microbiome changes: UV exposure breaks down elastin fibers and disrupts the collagen network; fibroblasts

We know many many aspects of skin aging aren’t due to microbiome changes: UV exposure breaks down elastin fibers and disrupts the collagen network; fibroblasts are known to have age related changes; fat layers below the dermis thin with age; skin becomes less oily and thus more prone to dehydration. These independent aging factors would change the environment microbes inhabit and thus very likely have causative effects on the microbiome overall. One might argue that a changing microbiome could in turn have second order deleterious effects on the skin. I suspect this could be a reason L’Oreal is sponsoring the research. But this is speculative at this point, and a quick read of the Abstract and Discussion didn’t reveal any such findings.