Scientists have long been advocating for spending time in the sun to fulfil the need of Vitamin D, the sunshine vitamin, but new research now reveals that sunlight can be healthier for a person's gut as well, giving another reason to go sunbathing.
The new research found those who lived at higher latitudes, with less exposure to UV light and a greater chance of being vitamin D deficient, had a higher risk of developing diseases such as multiple sclerosis and inflammatory bowel disease (IBD) as our microbial passengers played a significant role in conditions like these.
The researchers from the University of British Columbia in Vancouver made the finding based on the assessment of vitamin D deficient female participants, who received three sessions of UVB exposure, and those with no vitamin D deficiency.
According to the findings published in Frontiers in Microbiology, the participants' gut microbiomes changed and bore the same hallmarks as those of volunteers who were not vitamin D deficient.
"UVB exposure boosted the richness and evenness of their microbiome" to levels indistinguishable from those with no vitamin D deficiency, noted study author Professor Bruce Vallance, adding that prior to UVB exposure, the women had a less diverse and balanced gut microbiome than others.
Ultraviolet B – a form of light that can cause sunburns or increase the risk of skin cancer -- triggers our bodies to make Vitamin D.
The vitamin D deficient volunteers experienced an increase in Firmicutes and Proteobacteria and a decrease in Bacteroidetes to bring their levels in line with the microbiomes of participants who were not deficient.
Author Else Bosman suggested "vitamin D production was the main diver of the shift in the microbiome", urging people exposed themselves to at least a few minutes of sunlight and taking vitamin D supplements in winters.
But Professor Vallance suggested vitamin D supplements might be more important for people with inflammatory diseases such as MS and IBD.
He continued a larger study was needed to confirm the findings as his study "made use of a very selective group of participants, including healthy, female, pale skin".
"It will be very interesting to repeat the study with participants having a lot more variety in ages, and to further test if the phototherapy is useful for people with intestinal inflammation to promote their gut health," Vallance concluded.
