Recent research suggests that the composition of your gut flora is influenced by your skin, a phenomenon that is further boosted by the beneficial effects of UVB exposure. Additionally, individuals who incorporate vitamin D supplements into their routine seem to have a potential advantage, as revealed by an unexpected study.
Intestinal inflammation and disturbances in the gut flora balance
Most studies are currently about the influences of your intestinal system on the skin. Inflammation and imbalance of various intestinal flora (dysbiosis) are associated with intestinal barrier disruption and have been linked to a number of diseases.
The passage of so-called antigens that alarm the immune system
It is thought that impaired intestinal barrier function allows the passage of antigens (substance that activates the immune system) from the gut, and stimulates the immune system to produce an inflammatory response in humans.
The positive influence of sunlight
A very recent study from Canada showed that the skin changes your intestinal flora under the influence of sunlight. The other way instead of gut influences on the skin.
What about sunlight and ultraviolet radiation?
The light from the sun consists of a number of elements: Ultraviolet A (UVA), Ultraviolet B (UVB), visible light and infrared (IR).
UVA rays are present with relatively equal intensity during all daylight hours throughout the year, and can penetrate clouds and glass. UVA rays make up the largest part of the ultraviolet radiation, so more than UVB. No vitamin D production.
Although the intensity of UVA rays is less than UVB, it penetrates deeper into the skin, even into the dermis.
They penetrate deeper into the skin
Free radicals are formed in the dermis by UV rays. This causes damage to elastin and collagen fibers in the dermis, which provide the elasticity of the skin and skin fibroblasts. Skin fibroblasts are responsible, among other things, for the synthesis of collagen and elastin
To clarify: UVA – A stands for aging, uva does not indicate spf filter.
UVB rays penetrates into the superficial epidermis and is responsible for our vitamin D production and for a slow and longer-lasting tan.
Vitamin D production, but also sunburn
Too much UVB causes redness, sunburn and eventually also skin aging and skin cancer. Unlike UVA, UVB does not penetrate glass. Unlike UVA, UVB radiation can be up to 1000x stronger than UVA rays and does not penetrate glass to cause damage to our hereditary material, DNA.VB. Sun Protection Factor (SPF) only protects against UVB and not against UVA.
To clarify, UVB – B stands for burn or sunburn, but also for tanning of the skin. The spf is linked to UV-B radiation.
Dermatologist Francis Wu writes a lot on BeautyJournaal about the role of our intestines in skin health
Canadian study: UV-B and intestinal flora
This study investigated whether exposure of the skin to Narrow Band Ultraviolet B (NB-UVB) light (311 nm) increases the vitamin D value in the blood and whether this can also change the composition of the human intestinal flora.
This study involved 21 healthy female volunteers. They each received three one-minute sessions of full UV-B exposure over a week.
The participants were divided into two groups: those who already took vitamin D supplements (VDS) before the start of the study (VDS with) and those who did not (VDS without).
After three NB-UVB light exposures within the same week, vitamin D levels in the blood increased. The composition of the intestinal bacteria was examined by means of faeces.
Increase in microbiome in those who did not take supplements
The results revealed a significant increase in alpha and beta microbiome diversity only in individuals who had not taken vitamin D supplements.
Diversity increased in those who previously had a less balanced intestinal flora
Prior to UV-B exposure, these women had less diverse and balanced gut bacteria than those taking regular vitamin D supplements.
At the level of the supplement users
UV-B exposure increased the diversity and evenness of their gut bacteria to levels indistinguishable from the vitamin D supplement group. The intestinal bacteria of the supplement users had not changed significantly under the influence of UV-B.
At least 1 good family of bacteria increased
The largest effect in the non-supplement group was an increase in the relative abundance of at least one “healthy” family of bacteria, Lachnospiraceae. This is associated with improved health status. Lachnospiraceae are less abundant in people with inflammatory diseases.
Through the skin to healthier intestines
It is likely that exposure to UV-B light somehow modifies the immune system locally in the skin, then in the blood and finally in turn favorably influences the biodiversity of gut bacteria.
So far, this is the first human study to discover a direct link between UV-B exposure in the skin and microbiome alternations in the gut. Bring on the winter sun!!
While you are here
The importance of your gut bacteria. A new way of looking is to look at the skin-gut axis. The influence of intestinal bacteria and the skin is receiving increasing attention. Gut bacteria react to your diet and an imbalance of good bacteria due to bad eating habits affects the immune system. This has consequences for your skin and intestines. More on skin diseases and leaky gut