New to the series? Read part 1, part 2 and part 3 first.

Our obsession with gut health may seem new, but did you know we’ve been aware of a link between gut bacteria and acne for nearly a century?

In the 1930s, two pioneering dermatologists called Stokes and Pillsbury hypothesised that heightened emotional states could alter the gut microbiome. They believed that this could lead to inflammation and leaky gut, both of which contribute to acne.

Fast forward almost 90 years and it’s clear that they were on to something. We now know that the gut microbiome—the 2kg’s worth of bacteria, yeasts, viruses, archaea and other microbes that live in your gut—plays a role in mood, digestion and immune function [1]. And, as I explain in The Happy Skin Solution, all of these are involved in acne.

The gut microbiome and acne

Evidence suggests that the gut microbiome plays a more direct role in acne too. Let’s look at some research findings:

– Early research found that supplementing with Saccharomyces cerevisiae, a friendly type of yeast, could improve both constipation and acne [2].

– A more recent study found that more than half of acne sufferers have ‘dysbiosis’. That’s just a fancy way of saying ‘unbalanced gut bacteria’ [3].

– A further study found that drinking fermented milk (a source of friendly bacteria) significantly improved acne [4].

But let’s not jump ahead of ourselves. We know there’s a connection between the gut, its microbial environment and the skin, but we don’t yet know the nature of that connection. One theory is that an out-of-shape (dysbiotic) microbiome leads to inflammation, which is a key factor in the development of acne [5]. And there might be even more to the story, since some gut bacteria have been found to migrate to the skin [6].

Research uncovers more every day, which means we may even get to the point where we know exactly which strains of bacteria can help to make acne disappear. Until then, we know that improving gut health can improve skin health too.

Your gut bacteria and acne

To understand this, think about a flower growing in soil. If the flower didn’t grow well, you wouldn’t blame the flower—you’d look at the climate and the soil. Your body is no different. To bloom on the outside, you have to cultivate your inner environment.

Working on your gut health requires time and attention, but it can also be freeing. So often, people think their acne is down to a certain food, when actually it’s down to how their gut is able to handle that food. Once they improve their gut health, everything works better and they’re often able to enjoy a much broader diet.

In The Happy Skin Solution, I go through specific ways to optimise your gut microbiome. I also talk about the other aspects of digestion that can influence acne—such as stomach acid and intestinal permeability—and explain what to do about those too.

The good news is that none of this has to be difficult. To support both your gut bacteria and your skin, start with these five steps:

1) Eat fibre-rich foods

Not only do these help to keep you regular (an essential part of gut microbiome balance), they can provide fuel for the right types of bacteria to grow [7]. Good choices include asparagus, chickpeas, garlic, leeks, lentils, oats and onions.

If your diet is currently low in fibre, suddenly eating a large volume of fibrous foods can cause flatulence. Start with smaller portions and work your way up.

If you find that eating fibre-rich foods causes constipation or diarrhoea, it may be worth working with a registered nutritional therapist to investigate SIBO and other gut issues.

2) Embrace fermented foods

While fibre provides fuel for friendly bacteria, fermented foods can provide friendly bacteria themselves.

We once thought that these friendly bacteria colonised the gut, but we now know they work in much more subtle ways, such as training the immune system, strengthening the intestinal barrier and stopping one bacterium from taking precedence [8, 9, 10]. A rich, diverse microbiome is a healthy one.

Try eating a type of fermented food daily. Sauerkraut, kimchi, kombucha and kefir (if you can tolerate dairy) are all readily available options.

3) Aim for diversity

Plant foods contain polyphenols. These nutrient-like substances—which are what give plant foods their colour—can boost levels of friendly gut bacteria [11].

You want to eat as many plants as possible, as the polyphenols (and other plant nutrients) all work slightly differently. There are six main colour groups:

Red e.g. tomatoes

Orange e.g. sweet potatoes

Green e.g. kale

Yellow e.g. sweetcorn

Red/Black/Purple e.g. blueberries

White/Tan/Brown e.g. cauliflower

Aim to eat all six of these colour groups daily. If you can hit all of the colours by eating 30 different plant foods over the course of a week, even better.

4) Experiment with fasting

Picture a lawn. If you keep walking over the lawn, it will eventually wear down and become muddy. If you stop walking over the lawn, the grass has the chance to re-grow.

Your gut bacteria are the same. Continuous eating (walking over the lawn) can cause some bacteria to prosper at the detriment of others. Preliminary studies suggest that fasting can help all bacteria to prosper, increasing that all-important diversity [12].

Try to go 12 hours a day without eating anything. This is much easier than you think. In practice, it means having your last bite of dinner at 8pm and then not eating anything else until you have your first bite of breakfast at 8am.

Fasting can be a useful tool, but please be sensible. If you have a history of disordered eating or suffer from diabetes, it’s more important that you eat in a manner that keeps you emotionally and physically balanced.

5) Make time to relax

Stress reduces not only increases cortisol, but it also reduces the diversity of gut bacteria—both of which can drive acne [13].

Let’s be real: you can’t get rid of all sources of stress in your life. But you do have some control over how you react to them. Prioritising relaxation can help to boost resilience and make you less reactive, so that the same stresses don’t send you into such a spiral.

Relaxation is best when it’s active rather than passive. So, instead of slumping in front of the TV, why not go for a walk in nature? You could also pick up your favourite book, or listen to a meditation recording. The rule of thumb is that relaxation should leave you feeling lighter and brighter.

Start with whatever you can manage, but try and get into a state of relaxation for at least 15 minutes every day. Your gut and your complexion will thank you for it.

Interested to learn more? Pick up your copy of The Happy Skin Solution.