Analyzing the Gut-Skin-Brain Axis

At the 2023 South Beach Symposium meeting in Miami Beach, Florida, Doris Day, MD, clinical associate professor of dermatology at the New York University Langone Medical Center, discussed the gut-skin-brain axis and how our gut’s microbiome plays a bigger role in our overall skin health than many may think.¹

Day began her presentation by noting that Hippocrates was the first person to hypothesize that “all diseases begin in the gut.” Currently, more than 70 million Americans are affected by one or more digestive disorders. Additionally, 1 in 4 Americans suffer from a skin condition like atopic dermatitis, psoriasis, or rosacea. A quarter of a billion people worldwide suffer from depression, which in many cases is related to the burden of persistent inflammatory diseases.

The skin microbiome is largely part of the gut-skin-brain axis, as the skin microbiome is made of bacteria, fungi, and viruses that cohabitate on the top layer of the skin, including follicles. Skin inflammation is often influenced by the gut-skin-brain axis. Reduced brain function, anxiety, stress, and poor dietary habits are known to upset the gastrointestinal system. The western diet commonly eaten by Americans consists of added sugars, processed food, red meat, and dairy products that all contribute to systemic inflammation and skin dysbiosis.

Day also mentioned the relationship between acne and atopic dermatitis related to the guy. “Patients with acne vulgaris have a distinct gut microbiota in comparison to healthy controls,” Day noted. In atopic dermatitis, gut microbiota is closely related to the development of the disease. Psychological stress can cause intestinal microbes to trigger neurotransmitter to release, leading to cytokines entering the bloodstream and causing systemic inflammation. Day posed the question of “could stress induced alterations to microbial flora increase the likelihood of intestinal permeability?”

The gut microbiome is known to play a significant role in skin health. Day pointed out that the gut houses over 100 trillion microbes, which is more than 10 times the number of cells in the human body. According to Day, we are technically made of more microbes than we are our own cells.

According to a study published in Nature², when participants switched from a meat-based to a plant-based diet, their microbiota makeup changed after just one day. The study found that fiber-rich (prebiotic) foods and fermented (probiotic) foods can stimulate the growth of resident bacteria and increase microbial biodiversity in the gut. Additionally, environmental exposure, antibiotics, inadequate sleep, and environmental toxins all modulate microbiotic environments.

Lastly, depression is an antioxidant defense system disorder, according to Day. Approximately 30% of patients with skin disorders suffer from a comorbid psychological condition such as depression or anxiety. Skin biopsies from patients with depression show higher levels of oxidative stress. There is no immediate fix between inflammatory diseases related to the gut and brain axis, but managing skin health holistically with more nutritious foods and decreasing stress provides a better path towards gut, skin, and brain health.

References

1. Day D. The gut-skin-brain axis- The secret life of skin. Presented at the 2023 South Beach Symposium Meeting; February 9-12, 2023; Miami Beach, FL.
2. David L, Maurice C, Carmody R, et al. Diet rapidly and reproducibly alters the human gut microbiome. Nature 505, 559–563 (2014). https://doi.org/10.1038/nature12820