The skin and gut both have a microbiome and are meant to have a good amount of good, necessary bacteria(1). Both skin and gut defend the body against bad bacteria, or pathogens. Most of the immune system is actually in the gut, though, and an unhealthy gut will cause problems throughout the body, possibly to the level of autoimmune issues. The skin is the big elimination point of wastes from bacterial “standoff”(2).
Gastrointestinal issues often cause skin issues, though acne and eczema may be caused by other issues as well(1). A lot of people who have chronic skin issues have candida yeast overgrowth. Out-of-control yeast breaks down intestinal walls, reaches into the bloodstream, and gives off nasty byproducts. Those toxic substances and “‘superantigens’” can especially worsen psoriasis. Nail fungus, eczema, and dandruff also result from fungal infections. Most gut bacteria is located in the colon and large intestine, aiding the processing and breaking down of food, but if it gets into the small intestine, it will cause rosacea-causing small intestinal bacterial overgrowth (SIBO)(2).
Carotenid nutrients are examples of substances from food that make their way to skin. Refined carbs increase insulin production, which stimulates oil glands and therefore acne(2). Various vitamins and minerals are good for the skin and a healthy gut will get them where needed. On the other hand, stress is yet another trigger for skin issues. Gut health has links to “anxiety, depression, and irritable bowel syndrome.”
Some ways of helping the gut are eliminating inflammatory foods, consuming probiotics and prebiotics, cracking down on chronic stress, and getting sleep (especially promoting proper circadian rhythm via turning off electronics a decent time before bed)(1).
Winderl, Amy Marturana. “There’s a Connection Between Your Gut and Skin (Hint: It’s the Key to Clear Skin).” Parsley Health. Parsley Health. 21 Jun. 2021. Web. 28 Mar. 2022. https://www.parsleyhealth.com/blog/how-to-get-clear-skin-gut-connection/.
Myers, Amy. “The Gut-Skin Connection.” Amy Myers MD. AMMD, LLC (AmyMyersMD.com). Updated 15 Jul. 2021. Web. 28 Mar. 2022. https://www.amymyersmd.com/article/gut-skin-connection/.