The Gut-Skin Axis

By Seppo | Cause

Image of gut and intestines

One cause of acne is about as far away from the skin as we can get: in the gut. There’s good reason to believe that the health of your skin depends on what happens in your gut.

We know from research that gut issues are more prevalent in people with skin conditions. And the same studies show that if you treat those gut issues you can expect your skin to clear faster.

On this post I want to talk about this hidden cause of acne – hidden because in most cases these gut issues don’t cause any noticeable symptoms. And hopefully make acne just a little bit less mysterious and arm you with another weapon against acne.

Primer on gut problems: dysbiosis and leaky gut

Gut issues can mean many things. So let’s first understand the problem.

Broadly speaking there are two types of bacteria living in the digestive system: the so-called good bacteria (probiotics) and the so-called bad guys. In pure numbers there are more bacteria in your gut than there are cells in your body. And when things are in balance these little guys are absolutely essential to your health. For example, they digest certain foods and manufacture vitamins for you to use.

But this can turn into a real problem if the bad guys take over, for example as a result of too much stress, bad diet or excessive antibiotic usage. This is a condition known as gut dysbiosis or small intestinal bacterial overgrowth (SIBO). The harmful bacteria can interfere with digestion and produce toxins.

Normally the gut wall keeps these things out of your body. Despite being just a few cells thick it’s a very effective barrier; nutrients can enter the body but keeps toxins and other harmful stuff out. SIBO can change this.

The harmful bacteria produce corrosive substances that attack the gut wall. After a while tiny, tiny cracks appear, and though these cracks molecules that normally would be kept out can enter the body. This is known as leaky gut syndrome or intestinal permeability.

The substances that can leak into the body include:

  • Bacteria, virus and fungi
  • Incompletely digested food
  • Toxins from bacterial metabolism

This is not without consequences:

  • Increased chronic inflammation. This is really bad for the skin as acne patients are already under heavy inflammatory load.
  • Can cause food allergies. The immune system treats incompletely digested food particles as invaders and attacks them. This can ‘teach’ the immune system to always attack specific foods and thus lead to food allergies.
  • Possibly increases stress and emotional problems. One study with 1641 patients with gut issues showed that anxiety and depression correlate strongly with SIBO. Another study showed that treating gut issues improved depression and emotional problems.
  • Discomfort and gas
  • Nutrient deficiencies as a result of incomplete digestion

No symptoms

Pinning down these gut issues is difficult because the vast majority of people never experience any overt symptoms. And what minor symptoms they may experience are often disregarded as just normal rumblings from the tummy. That’s why many acne patients never suspect gut as the origin of their skin problems.

Acne-gut link

This is not just theoretical speculation. Several studies have demonstrated a link between acne and gut issues. For example:

  • One study looked at 114 acne patients, or which 54% suffered from SIBO (much higher than population average). Then they divided the SIBO sufferers into two groups. One got ‘intestinal microflora-correcting agents’ and the other group didn’t. The treated group cleared twice as fast.
  • Then there was a Korean study that looked on the effect of Lactobacillus-fermented dairy beverage on acne. They found that the fermented beverage reduced inflammatory acne by 40% and total pimple count by 23% as compared to placebo.
  • One study showed that SIBO is 10 times more prevalent in rosacea acne sufferers than healthy controls. And treating SIBO with antibiotics completely cleared rosacea for 71% of the patients and improved another 22%. Though it’s not clear from this study if the improvement was because of improvement in SIBO or some other antibiotic effect.
  • Doctors have suspected a connection between gut and the skin for at least 50 years now. An older study showed that people with acne have a far stronger reaction against gut bacteria. This suggests that the bacteria have leaked from the gut and primer the immune system against them.

I could show you some other studies also, but I don’t want to turn this into a complete medical review of the topic.

And if we compare acne patients to people with clear skin

Acne Clear skin
SIBO More Less
Inflammation levels More Less
Antioxidants levels Less More
Food allergies More Less


Let’s summarize what we’ve learned so far:

  • Acne patients have higher levels of systemic (all over the body) inflammation than people with healthy skin. And acne seems to get worse with increased inflammation.
  • Gut issues are a major factor in systemic inflammation.
  • Studies show that we can clear or reduce acne by treating the gut issues.

I have to insert a disclaimer here before people jump into conclusions. Science is messy and studies often contradict each other. So while the studies all seem to indicate a link between acne and gut issues, it’s not enough to draw rock –solid conclusions. But we can say there’s more than enough reason to suspect gut issues play a role in acne formation.

What causes gut problems

Here are some things that can contribute to gut problems:

  • Excessive antibiotic usage. Antibiotics often kill both the good and the bad bacteria. And long-term antibiotic usage can wipe out a significant portion of the gut bacteria, and thus open the door for the harmful bacteria to take over. This is why it’s not a good idea to treat acne with oral antibiotics. They only offer a short-term solution and can cause long-term disaster.
  • Too much stress
  • Sleep deprivation
  • Low stomach acid
  • Eating processed foods
  • Lack of plant fiber and other pre-biotic foods

How to treat gut problems

Unfortunately we don’t have enough research to come up with clear treatment guidelines, and the Internet is full of contradicting advice. Still, here are some common sense things that should help:

  • Use antibiotics only when you absolutely need them. Also, you talk to your doctor and ask for an antibiotic with minimal effect on the probiotic bacteria.
  • Fermented foods and probiotic supplements.
  • Eat minimally processed food, and make sure you include plenty of plant fiber (fruits and vegetables) into your diet.
  • Do your best to manage stress.
  • Make sure you get enough sleep.

Summary and take-home messages

We now have good reason to suspect gut issues contribute to acne (and other skin problems). 1) Gut problems are much more prevalent among acne sufferers, and 2) treating gut issues usually also helps the skin. This is not a universal One True Cause for acne, but rather one more avenue to explore in your fight against acne.

For treatment the best options are avoiding excessive antibiotic usage and taking probiotics either in the form of fermented food or supplements. Stress management and overall healthy diet should also help.


About the Author

Seppo Puusa, a.k.a. AcneEinstein shares rational advice about natural and alternative acne treatments. Read more about me and my acne struggles at the page.

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