Skin microbiome, specifically. Not the gut microbiome.<p>Microbiome is a hot topic, but the current hype has surpassed the science. Despite knowing about the microbiome's significant for decades, there are very few microbiome-specific treatments that have proven to have much significance. Those that have are limited to small scale studies that have been difficult to replicate. Probiotic supplements seem to do <i>something</i> in many people, but there are a growing number of case reports in the literature of strange adverse effects from probiotic supplementation in certain patients.<p>We need much larger datasets before we can really make progress. These skin microbiome studies are easy because skin microbiome is easy to measure.<p>The secondary challenge is that correlation only tells us so much. In this study, did the patients' skin microbiome change because their skin was dry? Or did they have dry skin because their microbiome changed? Could we reduce dry skin by changing the microbiome somehow? Or is something else causing both the dry skin and microbiome change? These questions aren't easy as they look from the outside.