Participants who took #vitaminD supplements and use the narrowband had no improvement in microbiome diversity.
Participants who used narrowband uvb light only had significant improvements.
Bacteria from several families were enriched in the group that did not take prior vitamin D supplements.
This is the first study to show changes in intestinal microbiome in response to Narrowband-UVB skin exposure.
This evidence suggests the existence of a novel skin-gut axis that could be used to promote intestinal homeostasis and health.