Do you suspect your gut health and acne are connected?

You’re probably right.

Scientists have been aware of a connection between gut health and acne for almost 100 years [1]. This ‘gut-skin axis’ was ignored for decades but—with the recent explosion of research into the gut microbiome—it’s once again in the spotlight. And what we know so far might surprise you.

So, if your acne seems to resist all the usual treatments (and especially if it’s come back after antibiotics or Roaccutane), it’s worth paying attention. This article delves into how various aspects of your gut health affect your skin, and how you can optimise your gut health to improve acne.


Gut health and acne: how are they connected?
Gut health and acne: your stomach
Gut health and acne: your small intestine
Gut health and acne: your large intestine
What causes dysbiosis?
5 steps to address gut health and acne
Bonus gut health tips
Takeaway points

Gut health and acne: how are they connected?

Let’s start with the basics: your skin and gut are one large, connected structure. Your skin runs over your face, into your mouth and down through your digestive system, before looping back out and round at the other end.

It’s an odd thought, right?

But once you understand that concept, it makes sense that your outer skin and your inner skin (aka your gut) are similar. They’re just different parts of the same whole. They both act as a barrier between you and the outside world. They both have a rich nerve and blood supply. They are both essential for immune and hormonal function [2].

Most important of all, they influence each other. That’s why issues at varying points of your gastrointestinal tract can drive imbalances in your skin, leading to acne. Let’s look at these points in more detail:

Gut health and acne: your stomach

In the 1930s, those early proponents of the gut-skin axis suggested that up to 40% of acne patients have low stomach acid [3,4]. Clues you have low stomach acid include bloating, muscle cramps and getting full quickly (especially after protein-rich meals) [5].

Low stomach acid is typically caused by advancing age or H. pylori infection [5,6]. It’s a problem for two reasons:

1. It prevents proper absorption of some skin-essential vitamins and minerals [7]

2. It has a knock-on effect on the next part of your gastrointestinal system.

Expanding on point ii)…

Gut health and acne: your small intestine

When you don’t produce enough stomach acid, the pH in your small intestine becomes less acidic [3]. So, forget everything you’ve ever heard about ‘alkalising’ your body because an acidic pH in your small intestine is a good thing. It encourages good digestion, and it helps to keep nasty bacteria at bay.

Without it, things start going awry. Tempted by the new, more comfortable living conditions provided by a higher pH, bacteria can migrate from your large intestine and set up home in the small intestine [8,9]. Here, they eat your nutrients, produce noxious substances and fill you with gas.

Signs of small intestine bacterial overgrowth (or SIBO for short) are bloating soon after eating, wind, diarrhoea, greasy stools and—surprise, surprise—skin lesions [3].

But the gut-skin connection doesn’t stop there…

Gut health and acne: your large intestine

The large intestine is home to your gut microbiome—and this is the Big Daddy of the gut-skin connection. As summed up in one peer-reviewed research paper:

With the understanding that the brain-gut-skin axis exists, it is now clear that intestinal microbes have significant effects on acne” [10].

Research shows that people with acne have a different gut microbiome than those without acne [11]. The specific findings vary from study to study, but they all agree that people with acne have lower levels of friendly bacteria and higher levels of pro-inflammatory bacteria [12,13]. This state of imbalance is known as ‘dysbiosis’.

What causes dysbiosis?

There are three main culprits:

Diet. The Western diet drives dysbiosis [14]. Its high levels of fat and sugar promote the growth of nasty bacteria, which then release pro-inflammatory compounds into your gut and blood circulation [13,15].

Antibiotics. Although sometimes necessary and life-saving, these medications reduce populations of good bacteria. This leaves space for pathogenic bacteria and fungi to thrive [16,17].

Stress. Prolonged stress reduces levels of friendly Lactobacillus and Bifidobacteria—two of the bacterial groups found to be low in acne patients [9].

Other factors, such as your age and physical activity level, can influence gut microbiome composition too [18,19].OK, so we know what disrupts your gut microbiome, but HOW does your gut microbiome influence your skin? Here’s where it gets really interesting:

1) Gut bacteria produce molecules that get into your blood circulation and affect your skin [2]. Some of these molecules can be beneficial, but many of them are harmful.

One example is the molecule P-cresol, which is released by the not-so-friendly bacterium Clostridium difficile. P-cresol travels to the skin, interfering with skin cell turnover [20,21].

2) Gut bacteria themselves can enter the blood circulation. This is because dysbiosis can lead to intestinal hyperpermeability, otherwise known as ‘leaky gut’ [22].

When you have a leaky gut, gut bacteria can slip through the gaps between your intestinal cells and run amok all around your body. DNA from gut bacteria, for example, has been found in psoriasis plaques [23].

Your liver plays a big role in helping to trap these bacteria before they can cause too much damage. If your liver functions less than optimally, it’s easier for gut bacteria and their molecules to spread around the body and get to your skin [2].

3) Gut bacteria affect your immune system. Certain gut bacteria can fire up cells that make your immune system more reactive [24]. This makes you more likely to react to certain foods and substances, leading to an acne-promoting state of inflammation [25].

Bringing this all together, preliminary research looking at stool (poop) samples from acne patients has found that acne patients are more likely to harbour H. pylori, Candida and protozoa [26]. These microbes indicate imbalances in the stomach, small intestine and large intestine respectively—clearly showing that gut health and acne are linked at all stages of the gastrointestinal tract.

So, to support clear skin, you need to optimise your gut health. The good news? There’s so much you can do to help!

5 steps to address gut health and acne

As well as promoting clear skin, improving your gut health can also encourage better digestion and an enhanced mood [27,28]. Here’s where to begin:

1) Eat a Mediterranean-style diet

What you eat daily has a profound effect on your gut microbiome [29]. So, for the sake of your gut health and your skin, cut down on sugary, fatty, processed foods—and instead embrace colourful fruits and vegetables, pulses, legumes, wholegrains, healthy fats, fish, and small amounts of mineral-rich meat.

 If you need more convincing, one study showed that eating a low-GL diet (like a Mediterranean-style diet) reduced acne in just 12 weeks [30]. This effect was replicated in another study too [31].

For more tips on eating for clear skin, check out Foods That Cause Acne: The Ultimate Guide and 7 Foods That Help Acne: Backed By Science.

2) Make fibre your friend

That’s fiber, for our American friends!

We can’t digest fibre, but our friendly gut bacteria can. It’s their ultimate treat meal. They have a good old chew on fibre-rich food, producing special substances called short-chain fatty acids—which support your gut health and skin health [32]. It’s a win-win situation for everyone.

Great sources of fibre include pulses, legumes, fruits, nuts, seeds, vegetables and wholegrains (see how it’s all part of a Mediterranean-style diet?). Every time you eat something, think, Where’s the fibre in this?

3) Load up on probiotics

In one of the coolest studies ever, mice taking probiotics grew thicker, shinier fur and developed a ‘glow of health’ [33].

Now, you are not a mouse. But studies in humans have also shown that taking probiotics can improve acne and boost skin appearance [34,35,36,37]. They likely achieve this effect through improving gut health and modulating the immune system [2].

You can eat probiotic-rich foods such as sauerkraut, kimchi, kefir, kombucha and natural yoghurt (if you tolerate dairy). You can also take probiotic supplements. To learn how to choose the best, head over to Do Probiotics Help Acne? How to Choose the Right Probiotic.

4) Take time to relax

We all know that stress makes acne worse [38,39]. But not everyone knows that stress may make acne worse because of the way it impairs your gut health [40].

Remember those scientists from the 1930s who first talked about the gut-skin axis? They hypothesised that feeling stressed would affect digestion, negatively changing the gut microbiome and inducing a pro-inflammatory, acne-driving state [9]. It turns out they were right.

We can’t eliminate stress from our lives, but we can influence how we react to it—and a huge part of that is giving yourself time to decompress. Relaxation is much more effective when it’s active rather than passive. So, instead of tuning out to Netflix, why not go for a walk with a friend? Do some painting? Read a book?

Find out what gets you into a state of ‘flow’—where time seems to disappear—and do that. Habitually.

5) Reduce your toxic load

You learnt above that your liver plays a vital role in mopping up nasty bacteria and their substances that escape from your intestines [2].

But it’s not just internal substances—your liver must deal with hundreds of external toxic substances too. When it’s overwhelmed, skin issues can crop up [41,42]. Case in point: a recent study showed that people with acne had higher levels of BPA in their blood [43]. BPA is a compound found in plastic water bottles, plastic food containers some canned goods’ linings—and your liver should capture it.

You can give your liver a helping hand by reducing your overall toxic load. That means drinking less alcohol, cutting down on your use of plastic, choosing more natural beauty products, drinking filtered water, and eating organic food when you can.

For further tips on supporting your liver, head over to Do you need to detox for acne?.

Bonus gut health tips

Have you got the essential five points covered? Next, add in these:

a) Take apple cider vinegar

Remember how low stomach acid can kickstart acne-driving issues in your gut? If you feel this applies to you, apple cider vinegar can help.

Although there is no published research confirming this, anecdotal evidence suggests that taking apple cider vinegar with each meal can help to acidify the stomach and promote good digestion. An effective dose is 2tbsp apple cider vinegar (either neat or diluted in water) in an effective dose.

b) Try prebiotics

Prebiotic powders are concentrated forms of fibre. They can be particularly helpful in acne because they increase Lactobacillus bacteria and Bifidobacteria—those friendly bacterial groups that are low in acne patients [44].

The best choices include FOS, GOS and acacia gum [45]. These come as flavourless white powders that you can easily add to drinks or meals.

3) Use herbal antimicrobials

If you have significant overgrowth of pathogenic gut bacteria or fungi (and especially if you have SIBO), herbal antimicrobials might be needed to restore balance.

Commonly used herbal extracts include oregano, garlic, caprylic acid, olive leaf and barberry. These can regulate the composition of the gut microbiome, reduce inflammation and clear up skin [46,47].

These supplements may be natural, but they’re potent. It’s best to work with a registered nutritionist who can advise you on the safest, most effective way to take them.Improving your gut health for acne isn’t difficult, but it does require consistency. Focus on the five key steps first, then add in the bonus tips as necessary—and be patient. Your skin should start to respond within a few weeks.

Takeaway points

Gut health and acne is a big topic. Let’s recap what we’ve learnt:

– Your skin and your gut are linked physically and through various biochemical pathways. This is known as the ‘gut-skin axis’.

– Imbalances at varying points of your gastrointestinal tract can drive acne. These imbalances include low stomach acid, small intestine bacterial overgrowth and dysbiosis in the large intestine.

Dysbiosis is the Big Daddy of the gut-skin connection. In a state of dysbiosis, gut bacteria and their substances can enter your circulation, induce an inflammatory reaction and irritate your skin.

– You can help to clear your skin by supporting your gut health. Key steps include:

– Eating a Mediterranean-style diet

– Upping your intake of fibre

– Loading up on probiotics

– Taking time to relax

– Reducing your toxic load

– You can also support your gut health by taking apple cider vinegar, trying prebiotics and using herbal antimicrobials. The latter is best done with the support of a registered nutritionist.

Fiona Lawson is a former national magazine editor turned registered nutritionist and skin specialist. She holds an MSc in Nutritional Medicine and a BANT-registered post-graduate qualification in Nutritional Therapy.

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Dr Thivi Maruthappu


Dr Thivi Maruthappu is the UK’s first and only dual-qualified Consultant Dermatologist and Nutritionist, and the pioneer of the (much-needed!) Nutritional Dermatology field. She runs busy NHS dermatology clinics, conducts academic research and delivers lectures worldwide. She’s also recently authored her first book, Skin Food, which aims to make holistic skincare accessible for everyone.



Porter magazine called her a ‘Global Skincare Expert’, and Caroline Hirons described her as ‘one of the best facialists in the world’. In the skincare industry, Marie Reynolds is in a league of her own. I had the privilege of experiencing one of Marie’s facials as a young journalist—and I can still remember every exquisite detail more than a decade later.

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