VANCOUVER, CANADA — Exposure to ultraviolet rays may increase biodiversity of the gut microbiome in humans.<br /><br />Canadian researchers find that being under the sun could enrich gut flora and that a novel skin-gut axis may exist, according to a study published in Frontiers in Microbiology on October 24. <br /><br />The researchers say that 21 women volunteers were subjected to three full body exposures to UV rays over one week.<br /><br />Blood samples were tested for vitamin D levels and stool samples were tested for the biodiversity of their gut bacteria.<br /><br />Frontiers Science News reports that half of the participants who regularly took vitamin D supplements experienced no changes to their gut microbiome.<br /><br />However, women who did not take supplements saw increases to vitamin D levels, and their gut microbiome became as diverse as the supplemented group.<br /><br />The researchers state that multiple sclerosis and inflammatory bowel diseases are associated with the lack of sunlight, vitamin D, and unhealthy gut microbiota.<br /><br />The study indicates that there is a direct link between those factors, but it does not identify the causal mechanism.
