The Gut-Skin-Microbiome Connection: Understanding Rosacea
Are those rosy cheeks more than just a post-workout glow?
According to the Canadian Dermatology Association, as many as 3 million Canadians may have rosacea, an inflammatory skin disorder that is linked to dysregulation of the immune, nervous and circulatory systems.
Rosacea is classified into four subtypes, depending on the presentation. Rosacea presents as persistent redness or flushing in the central regions of the face, that may include or progress to visible capillaries, acne-like bumps, dry skin and burning or stinging skin. It can affect the eyes or cause thickening of the skin of the nose in severe cases.
What causes rosacea?
Rosacea has a complex pathophysiology – or disease origin – that involves an interaction of genetics, inflammatory response, the microbiome, nervous and circulatory system. Interestingly, researchers have a genetic link (three HLA alleles) between rosacea and the auto-immune diseases Type 1 Diabetes and Celiac Disease. What’s more, those with rosacea are more likely than the average population to have allergies or gut disturbances, suggesting that inflammatory response is likely a critical key to unlocking the mystery.
One trial found increased prevalence of most digestive diseases like IBS, Crohn’s and SIBO in those with rosacea. I am very intrigued by the link between small intestinal bacterial overgrowth and rosacea although research is conflicting: one study found that H.pylori infection was more common in rosacea but not SIBO.
There is evidence that the nervous system within the skin is a key factor. UV exposure, stress, hormone imbalance and microbial triggers can all cause the nervous system to increase dilation of the blood vessels, bringing heat and redness to the skin. Researchers have found increased density of sensory neurons (nerve cells) in the skin, leading to excessive release of stimulatory neuropeptides like substance P.
What triggers rosacea?
Triggers in rosacea are individualized but there are consistencies in the literature:
Hot foods or drinks like soup or tea
Alcohol, especially red wine
Vigorous, intense exercise
Temperature extremes like hot or cold weather, or hot baths
Skin Barrier Function
I talk a lot about barrier function with respect to the gut, usually comparing it to the skin…so yep, your skin is a critical barrier and the function of that barrier is diminished in those with rosacea.
This barrier challenge comes from multiple places. The first may be the microbiota of the skin. There are multiple skin microbes that are thought to play a role in rosacea, such as Staphylococcus epidermis and Demodex folliculorum. Demodex is a mite appears to be increased in numbers in rosacea, but it is uncertain if it plays a causative role.
More than the mere presence of microbes, excessive response to those microbes could be diminishing barrier function. It is thought that TLR2, a Toll-like Receptor of the immune system, may be overexpressed in the skin of rosacea sufferers. This leads to higher production of an anti-microbial peptide called cathelicidin which is seen in increased numbers in rosacea. The inflammatory response may be causing damage to the skin barrier in multiple ways, including presence of reactive oxygen species (ROS). UV exposure can also increase ROS production in the skin, as well as causing stress in the Endoplasmic Reticulum (ER) of skin cells.
So, what about diet?
Most of the dietary research has focused on triggers; there isn’t a gold standard dietary therapy to target rosacea. However, given the connection between inflammation, digestive disease and rosacea, it is a logical progression to attempt dietary therapy. In fact, it is extremely common for rosacea sufferers to try a dietary approach and report improvements. Interestingly, I was able to find evidence of cinnamaldehyde-containing foods as potential triggers which I had not previously heard of. As it sounds, cinnamaldehyde is a flavonoid found in cinnamon, but also citrus, chocolate and tomatoes.
There is some interesting but paradoxical research suggesting more insulin resistance in those with rosacea. I have absolutely noticed that high glycemic foods tend to flush my skin and avoid them for the most part. In addition, unlike most auto-immune or digestive disease, those with rosacea may present with higher vitamin D levels. I would absolutely recommend using probiotics as a potential balm against microbiome disturbances triggering rosacea but evidence is limited. The evidence for omega 3 and zinc is limited for rosacea.
Without a doubt, my first line of defence in building a healthy lifestyle that supports healthy skin is an anti-inflammatory diet. Starting there makes sense because it is a healthy dietary strategy you can use for life that is associated with lower risk of chronic disease.
I will talk about my own struggles with my skin and my anti-inflammatory approach to rosacea in a couple of weeks. I am also going to talk a lot about this topic on my Instagram feed in April because it is rosacea awareness month…so stay tuned!