Old School: The Gut-Brain-Skin Axis
Skin problems and gut issues have a long history of connection. It’s been almost 80 years since dermatologists John Stokes and Donald Pillsbury first proposed a scientific connection between gut, skin, and emotional health. Stokes and Pillsbury stated that emotional states (like anxiety or depression) can alter the normal intestinal microflora, thereby increasing permeability of the intestinal wall and contributing to systemic inflammation .
This connection - nowadays dubbed as the “gut-brain-skin axis” — is getting a TON of recent attention. A fact that would have Stokes and Pillsbury likely shaking their heads saying we told you so! The gut-brain-skin axis is for sure nothing new; but sometimes we need to go back to the future in order to find a path forward. Learn how you can get your skin, digestion, and emotional wellness in balance by following a few simple steps.
The Gut-Brain-Skin Axis: What Is It?
Let’s start with your skin and gut (and by ‘gut’ I mean stomach, small intestine, and large intestine). Both your gut and the skin play key roles as defenders against pathogens invading from the outside environment. Additionally, they are large players in the brain’s hormonal messaging system, as both your skin and gut have nerves that send and receive signals from the brain with the ability to send messages to other parts of the body.
Another similarity is that your skin has its own collection of bacteria that is just as important to health as that of the naturally occurring bacteria in your gut. This bacteria provides acts as a barrier against potential issues; but it exists in a delicate balance. When ‘bad’ bacteria overpowers the beneficial ones (a condition known as dysbiosis) through antibiotics, poor diet, or stress, this delicate balance gets thrown out of whack. What results are skin disorders (such as acne, hives, and eczema) and digestion issues (such as leaky gut, poor digestion, and food allergies).
Your emotional state is just as relevant here. Way back in 1930 Stokes and Pillsbury connected emotional states —such as depression, worry and anxiety - to altered gastrointestinal tract function. This in turn caused alterations to the microbial flora, which they theorized, promotes local and systemic inflammation . This is why study after study notes a very strong correlation between skin and gastric conditions - those with acne are more likely to be constipated, have bad breath, and be bloated. 
Hence, we have the gut-brain-skin axis: a strong link exists between emotional wellness, digestive health, and skin conditions. When one part of this axis is out of balance, the other two invariably start to become unbalanced as well. Your overall health is highly dependent on the wellness of your skin, gut, and emotions.
Gut Permeability, Skin Problems, and Emotional Wellness
There are many skin disorders that are more common in those with gut issues. There is also a strong correlation between emotional stress and gut/skin health. I will discuss a few of these here:
GUT ISSUE: Constipation
There are several reasons someone can experience constipation. Regardless the reason, the longer stool sits in the colon, the greater the chance the intestine wall will become permeable, leaving the body exposed to endotoxins derived from gut microbes.
Skin implications: The majority of acne patients test positive to E. coli endotoxins compared to those with clear skin. This means that gut permeability and circulating endotoxins from gut microbes are common features of acne.
Emotional correlation: Systemic E. coli endotoxins have been shown to produce depression-like behavior and higher anxiety levels.
Gut Issue: SIBO (Small Intestine Bacteria Overgrowth)
SIBO occurs when excess bacteria in the small intestine successfully compete for nutrients, produce toxic metabolites, and cause direct injury to the small intestine’s ability to absorb nutrients properly. SIBO increases permeability of the intestinal wall and sets the stage for systemic and localized skin inflammation.
Skin implications: SIBO is 10 times more prevalent in those with rosacea, and over 66% of those suffering from acne have a compromised intestinal lining. Correction of SIBO leads to a marked improvement for rosacea sufferers.
Emotional correlation: Studies show that stress slows down intestinal transit time (i.e., the amount of time food spends in the small intestine). Slower transit times lead to overgrowth of bacteria, which thereby compromise the intestinal barrier. SIBO is also strongly associated with depression and anxiety, while eradication of SIBO improves emotional symptoms.
Treat the Brain + Gut For Radiant Skin
Whether you have a skin disorder like rosacea or eczema or simply want to prevent skin cancer and maintain a youthful appearance, it is beneficial to look to your gut. Dysbiosis or other gut problems might be the cause of the issue–or it might simply exacerbate it. You can work to get and keep your gut + brain healthy with the 5 R's: remove, replace, reinoculate, repair, and rebalance.
Take away anything that might be contributing to an unhealthy gut. This might include stress (as much as humanly possible), environmental toxins, or food allergens. One of the most common treatments for this stage is an elimination diet: remove all of the most common foods that trigger inflammation and gut reactions for a period of time and then reintroduce them slowly to determine what might be the cause of the issue.
Proper digestion and subsequent absorption require digestive enzymes, hydrochloric acid, and bile acids. In the replace step, these are supplemented, as needed, depending on the situation. Good choices include papaya enzymes or bromelain.
Add good bacteria into the gut by taking a strong probiotic. It is also beneficial to supplement with prebiotics, which are known to fuel the good bacteria in the gut and assist building a healthy microbiome.
At this stage, vitamins, minerals, and other nutrients are introduced to assist in repairing any damage to the gut, including any inflammation or leaky gut. This typically includes zinc, antioxidants, fish oil, and glutamine, an amino acid that is the gut lining’s major fuel source.
This step goes beyond diet; it incorporates elements from your lifestyle to determine if there are negative aspects affecting the gut, such as lack of sleep or excessive stress. From here, you can make positive changes to create habits that support of a healthy gut.
The gut-brain-skin axis is a delicate interplay between your emotions, digestive system, and skin. When one component is out of balance, problems are likely to show up in the other two ares. Gut microbes, and the integrity of the gastrointestinal tract itself, are contributing factors to how radiant your skin looks as well as how good you feel emotionally. By working to keep your gut healthy, you can reap many rewards both in how great your skin looks, but also in how you feel.
 Bowe WP, Logan AC. Acne vulgaris, probiotics and the gut-brain-skin axis - back to the future? Gut Pathogens. 2011;3:1. doi:10.1186/1757-4749-3-1.
 Zhang H, Liao W, Chao W, Chen Q, Zeng H, Wu C. et al. Risk factors for sebaceous gland diseases and their relationship to gastrointestinal dysfunction in Han adolescents. J Dermatol. 2008;35:555–61. doi: 10.1111/j.1346-8138.2008.00523.x