The Gut Skin Axis

How is gut health related to skin health?

Let’s start with what the skin and the gut have in common. Both the skin and gut have resident microbes. These are bacteria that live on the skin, or within the gut, that help to keep both systems healthy. They play a role in building the immune system, protecting against pathogens, ensuring a healthy barrier to the external environment exists, and they help to break down metabolites. Sometimes, the resident bacteria can be replaced by pathogenic bacteria, that is microorganisms that are not meant to be there and have taken over.

In skin disorders, like acne, dermatitis, psoriasis, rosacea, alopecia, dandruff, even skin cancer, the resident bacterium of the skin is typically altered. Research has also shown that in skin disorders, the resident microbiome of the gut is altered. This makes sense because the microbiome is a key player in the regulation of the immune systems.

The skin is the first-line defense against the outer environment, and the gut is the largest interface between host and environment. Both contain epithelial cells which form the barrier between you and the external environment (the actual environment and food that consumed). Both are served by a rich supply of blood and nerves. Both are highly responsive to stress and anxiety. Diseases such as inflammatory bowel disease and psoriasis consist of dysfunction in the epithelial cell barrier, with an increased rate in epithelial cell turnover, and imbalances in the healthy microbiome.

What lifestyle factors play a role?

Lifestyle factors like diet and hygiene are highly influential on the health of the gut and skin, and how the microbiome interacts with the external environment. It’s important to mention here that it’s not only about lifestyle factors, genetic makeup also plays a role in the health of the guts and skin.

Speaking of lifestyle related to diet, approximately 60 tons of food will pass through the gut in a human lifetime, all of which can have an incredibly large impact on health. The western diet (aka a high fat diet) for example has been associated with immune-related diseases such as rheumatoid arthritis, psoriasis, atopic dermatitis, and several diseases of the gut.

Related to hygiene, there is the hygiene hypothesis that estimates many diseases have arisen (like asthma for one), due to a reduced exposure to microbes from modern health and hygiene practices. It’s good to be hygienic, and research has shown that being overly hygienic can result in inflammatory diseases of both the skin and gut.

The skin-gut axis works in both directions as well. Research has shown that skin exposure to UV-B, and therefore indirectly to serum vitamin D increases the diversity and abundance of the gut microbiome in a positive way. It is also hypothesized that food allergies result from an impairment in the skin barrier.

Several nutrients are thought to play a role in supporting skin and gut health either directly or indirectly. Some of these include short chain fatty acids, vitamin D, polyphenols, and lycopene.

What's the bottom line?

The health of the skin and gut are intimately related, and directly affect each other. In order to achieve skin health or gut health, attention needs to be paid how much sun the skin is exposed to as well as nutrients, additives and preservatives consumed. And close attention must be paid to stress and anxiety levels felt daily. Adopting lifestyle habits such as mediative movement like Qigong and Taichi, yoga, meditation, sound bath therapy, grounding, and getting regular acupuncture treatments and massages are all ways you can support the health of your skin and gut.

References

Brett, J. (Ed). (2020). Clean Needle Technique Manual, 7th ed. US: Council of Colleges of Acupuncture and Oriental Medicine.

De Pessemier, B., Grine, L., Debaere, M., Maes, A., Paetzold, B., & Callewaert, C. (2021). Gut-Skin Axis: Current Knowledge of the Interrelationship between Microbial Dysbiosis and Skin Conditions. Microorganisms, 9, 353. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7916842/pdf/microorganisms-09-00353.pdf