Written by Joyce Smith, BS. Narrow Band Ultraviolet B (NB-UVB) light increases serum vitamin D levels and modulated the human intestinal microbiome in participants with insufficient vitamin D levels who were not supplementing with Vitamin D.
There is a worldwide increase in idiopathic and inflammatory diseases such as multiple sclerosis (MS) and inflammatory bowel disease (IBD). Decreased exposure to sunlight/UVB light and subsequent decrease in vitamin D production as well as dysbiosis (an imbalance in types of micro-organisms) in gut microbiome are thought to be contributing factors. Eighty percent of our vitamin D requirements can be met through exposure to UVB light from sunlight and in areas of the world where winter seasons are long, limited UVB exposure is an important environmental factor as well as diet and widespread antibiotic use, contributing to insufficient vitamin D levels and gut microbiome dysbiosis 1.
Vitamin D plays a significant role in maintaining the integrity of the intestinal barrier 2, It also suppresses pro-inflammatory responses through its influence on the innate and adaptive immune cells 3 which may exert a protective function against the development of gut dysbiosis 4. To add clarity to a possible direct link between UVB light and the gut microbiome, Valiance and team investigated whether skin exposure to a Narrow Band Ultraviolet B (NB-UVB) light would increase serum vitamin D levels and alter or modulate the makeup of the human intestinal microbiome to provide potential health benefits 5.
Twenty-one healthy Caucasian females (19-40 years of age) with a Fitzpatrick Skin Type of 1-111 (skin types with less melanin and more susceptibility to sunburn) were divided into two groups: VDS+ group (n=9) who took vitamin D supplements throughout winter prior to study commencement and most of whom had adequate vitamin D levels; and VDS- group (n=21) most of whom were deficient in vitamin D before trial commencement. The three-month study (February to April, 2018) took place in Vancouver BC (49°N) where no significant ambient UVB intensity was measured during that time. All participants received three one-minute sessions of full-body UVB exposure over the course of a week. At set time points before and after treatment, stool analysis to determination changes in gut bacterial diversity and serum blood analysis to measure blood levels of vitamin D were conducted.
After three NB-UVB light exposures within the same week, the serum 25(OH)D levels of participants increased an average of 7.3 nmol/L. Fecal microbiota composition analysis using 16S rRNA sequencing showed that exposure to NB-UVB significantly increased alpha and beta diversity in the VDS- group whereas there were no changes in the VDS+ group. After UVB exposure, bacteria from several families were enriched in the VDS- group including Lachnospiracheae, Rikenellaceae, Desulfobacteraceae, Clostridiales vadin BB60 group, Clostridia Family XIII, Coriobacteriaceae, Marinifilaceae, and Ruminococcus. The serum 25(OH)D concentrations showed a correlation with the relative abundance of the Lachnospiraceae (p=0.00425), specifically members of the Lachnopsi and Fusicatenibacter genera.
This is the first study to show that humans with low 25(OH)D serum levels demonstrate apparent changes in their intestinal microbiome in response to NB-UVB skin exposure and increases in 25(OH)D levels, suggesting the existence of a novel skin-gut axis that could be used to promote intestinal homeostasis and health. A larger cohort study utilizing both sexes and more skin types is recommended.
Source: Bosman, Else Susan, Arianne Y. Albert, Harvey Lui, Jan Peter DUTZ, and Bruce A. Vallance. “Skin exposure to Narrow Band Ultraviolet (UV) B light modulates the human intestinal microbiome.” Frontiers in Microbiology 10 (2019): 2410.
© 2019 Bosman, Albert, Lui, Dutz and Vallance. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
Click here to read the full text study.
Posted November 26, 2019.
Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.
References:
- Ter Horst R, Jaeger M, Smeekens SP, et al. Host and Environmental Factors Influencing Individual Human Cytokine Responses. Cell. 2016;167(4):1111-1124.e1113.
- Assa A, Vong L, Pinnell LJ, Avitzur N, Johnson-Henry KC, Sherman PM. Vitamin D deficiency promotes epithelial barrier dysfunction and intestinal inflammation. J Infect Dis. 2014;210(8):1296-1305.
- Clark A, Mach N. Role of Vitamin D in the Hygiene Hypothesis: The Interplay between Vitamin D, Vitamin D Receptors, Gut Microbiota, and Immune Response. Frontiers in immunology. 2016;7:627.
- Luthold RV, Fernandes GR, Franco-de-Moraes AC, Folchetti LG, Ferreira SR. Gut microbiota interactions with the immunomodulatory role of vitamin D in normal individuals. Metabolism. 2017;69:76-86.
- Bosman ES, Albert AY, Lui H, Dutz JP, Vallance BA. Skin Exposure to Narrow Band Ultraviolet (UVB) Light Modulates the Human Intestinal Microbiome. Front Microbiol. 2019;10:2410.
