By Morgan Helmling, BHSc (Naturopathy), Living Holistic Health — what the evidence really shows about gut health and skin.
Humour me for a second, and think about your skin as a border.
It is the edge of you. Everything the world offers — weather, water, wool, sunlight, other people’s hands — meets you there first. It decides what comes in and what stays out, and it does that all day without being asked.
Now think about the other border. The one running quietly through the middle of you, from mouth to gut to everything after. It has the same job and it never gets seen. Roughly the surface area of a small flat, folded into your abdomen, sorting food from threat, minute after minute.
Two borders, then. One of them visible, and one of them not. Maybe it is not so strange that when one is struggling, the other so often is too.
This article is about that relationship. What is known, what is guessed at, and what any of it means if you are the one living inside the skin.
The gut health and skin connection, in plain language
Almost every week, someone tells me they have tried everything on their face. Creams, serums, facials, a fortnight without dairy. Nothing has held. Then, often as an afterthought, they mention their digestion has never been quite right either.
Two borders, one of them visible
Both surfaces host their own communities of bacteria. Both depend on an immune system that has to keep deciding what is friend and what is threat. Because they share that work, researchers have long suspected they are in conversation.
They appear to be. Gut bacteria ferment what you eat, and in doing so they make compounds that travel in your bloodstream. Some of those compounds reach the immune cells involved in skin inflammation. That route is real, and it is being mapped in more detail every year.
What the gut-skin axis means for your skin health
Here is the part I want to be careful about, because it is where most of the internet loses its footing.
A route existing is not the same as a route being the whole story. Your gut may be driving your skin. Alternatively, both may be answering to something further upstream — stress, sleep, hormones, what has been on your plate for the past decade. In my experience it is usually the second.
That is not a disappointing answer. Actually, it is a more useful one, because it gives you more than one place to start.
Tolle Causam: identifying the cause behind gut health and skin flares
Naturopathy has six principles underneath it, and the third one is Tolle Causam — identify and treat the cause. It is the one that shapes a skin consultation more than any other.
The surface is the last place to look
Skin is an output. It reports on what is happening elsewhere, in its own slow and stubborn language. Treating only the surface is a bit like wiping the window instead of finding the leak. Sometimes the window genuinely needs wiping, and I will say so. But if it keeps fogging up, something behind it is unresolved.
This is why persistent skin concerns so often return once a topical routine stops. Nothing underneath has changed.
Patterns I listen for
Before any test, I want the timeline. When did the skin change, and what else changed around then? Antibiotics, a house move, a pregnancy, a grief, a new job, a stretch of poor sleep.
Then I want the rhythm of it. Skin that flares before a period behaves differently to skin that flares in a stressful week. Similarly, a rash that eases on holiday is telling you something a rash that ignores holidays is not. These patterns are usually more informative than anything I could order from a laboratory.
Tolle Totum: treating the whole person, not the rash
The fifth principle is Tolle Totum, treat the whole person. In clinic I read that as a practical instruction rather than a philosophy. You are, as the old framing goes, greater than the sum of your parts, and your skin does not exist in a compartment of its own.
Where gut health and skin meet hormones
For a lot of women, the skin story and the cycle story are the same story. Androgens influence how much oil the skin makes. Insulin and blood sugar influence androgens. Meanwhile, the gut is part of how used hormones are cleared from the body.
So a flare that arrives reliably in the week before a period is not a coincidence, and it is not a character flaw. It is information.
Stress, sleep and the skin barrier
This is the piece people most often wave away, and it has some of the cleanest evidence in the whole field. When researchers disrupt the skin barrier slightly and then measure how fast it repairs, psychological stress and sleep deprivation both slow that repair down. Exercise stress does not.
In other words, your skin heals more slowly when you are running on empty. That is not a metaphor. It is measurable, and it is one of the few things in this article that does not depend on the gut at all.
Vis Medicatrix Naturae: what food does for gut health and skin
Vis Medicatrix Naturae is the healing power of nature — the principle that says the body already knows how to repair itself, and our job is mostly to remove what is in the way and supply what is missing.
Fibre is the quiet one
When gut bacteria ferment fibre, they produce short-chain fatty acids. Those compounds are involved in calming inflammation and in maintaining barrier tissue. Most Australians eat well under the fibre they need, and it is the least glamorous recommendation I make.
Grounding foods do a lot of this work quietly. Vegetables, legumes, wholegrains, a bit of everything and a lot of plants. Nothing about that is exciting, and it is still the foundation.
Sugar, and why it matters more than most people expect
The strongest dietary evidence in skin research concerns blood sugar. An Australian trial found that people eating a lower-glycaemic diet had greater reductions in acne lesions than a control group, alongside improved insulin sensitivity. Later trials have been less uniform, so I would not promise it works for everyone.
Still, it works often enough, and it improves other things at the same time. That makes it a reasonable place to begin.
Dairy: worth a trial, not a rule
Dairy is associated with acne across a lot of survey data. However, it has never been tested in a randomised trial, and plenty of people with skin problems have no relationship with it whatsoever. So I treat it as a short, structured personal experiment rather than a commandment. Two to four weeks, then reintroduce properly and watch.
Docere: what the research on gut health and skin actually shows
Docere means doctor as teacher. My job is not to hand you a protocol. It is to give you an accurate picture so you can make your own decisions about your own body.
What is well established
People with acne, eczema and psoriasis do tend to have a measurably different mix of gut bacteria to people without. That has been found repeatedly. Stress measurably slows skin repair. Blood sugar and androgens are genuinely linked to oil production. Low nutritional status shows up in skin quickly, because skin is expensive tissue to build.
What is still a hypothesis
The idea that gut bacteria cause skin disease is not established. Different studies name different bacteria, and when researchers apply methods designed to test cause rather than association, very little survives. Likewise, the notion that stress alters gut bacteria which then inflame the skin dates back to a 1930 proposal and remains, ninety-odd years on, a proposal.
I would rather tell you that than sell you certainty.
Probiotics, gut health and skin: the honest answer
I am asked about probiotics constantly, so here is the unvarnished version. For eczema specifically, the most rigorous review of the evidence concluded that probiotics probably make little or no difference to symptoms. For psoriasis and acne, some small trials look genuinely encouraging.
Effects are also strain-specific, which matters more than people realise. A supermarket capsule is not the same thing as the organism used in a trial.
Primum Non Nocere: doing no harm to gut health and skin
The first principle comes first for a reason. Primum Non Nocere — first, do no harm. In skin care this mostly means resisting the urge to do something dramatic.
Why I will not tell you to cut out food groups
Long, unsupervised elimination diets are the most common harm I see in this area. They narrow nutrition, they make eating stressful, and in children they carry a documented risk of losing tolerance to foods that were previously fine. The evidence that broad elimination helps skin is weak. The evidence that it costs something is not.
A short trial of one food, with a proper reintroduction and someone watching, is an entirely different thing. That I will happily support.
Working collaboratively with your GP
If you have been prescribed a treatment for your skin, keep taking it. Steroid creams in particular have a much better evidence base, and a much better safety record when used as directed, than their reputation online suggests. Nothing here replaces them.
Where pathology is warranted, I will refer you through your GP, and where something needs ruling out, I will say so early. Naturopathy is not an alternative to medical care, but it does support you alongside it. It is one of the oldest forms of care there is, and it works best alongside.
Praeventare: the long game for gut health and skin
The sixth principle is Praeventare, prevention. It is the least dramatic and probably the most valuable.
Living seasonally
Skin behaves differently across the year, and so do we. Winter brings drier air, hotter showers, less daylight and less vitamin D. Summer brings sweat, sunscreen and salt. Adjusting a little before each season turns, rather than reacting once the skin has already flared, tends to be gentler and cheaper.
Nature is nurture, and we are part of our environment rather than separate from it.
What a realistic timeframe looks like
Skin turns over slowly. Eight to twelve weeks is a fair window before judging whether something is working, although digestion often shifts sooner. If nothing at all has moved by three months, the plan needs changing rather than extending.
What happens in a consultation
Mostly, listening. A first appointment covers your current concerns and goals, relevant medical history, a proper look at diet and lifestyle, and then a plan built for you rather than for the condition.
What we look at
Whether the diet actually supplies enough fibre, protein, zinc and essential fats. How digestion is functioning, since low intake and poor absorption produce similar results. Sleep, stress and cycle patterns. Where testing genuinely adds something, we discuss it first, including what it will and will not tell you.
Obligation-free suggestions
Any herbal or nutritional suggestions are obligation-free. Some people leave with a supplement plan and some leave with a shopping list and a bedtime. Both are legitimate outcomes, and I would rather you spent money on food than on capsules you do not need.
When to see your doctor first
Some things need medical assessment before anything else. Please see a doctor promptly if a rash is spreading quickly, weeping or looks infected. The same applies if you are unwell with it, if a mole or lesion has changed, or if your skin is affecting your sleep or your mental health.
None of that is a failure of natural medicine. It is what ruling out red flags looks like.
Frequently asked questions about gut health and skin
Can a naturopath help with gut health and skin concerns?
Yes, by investigating the possible drivers of your symptoms — diet, nutritional status, digestion, hormones, stress and sleep — and building a personalised plan alongside any treatment your GP or dermatologist has prescribed. We work collaboratively rather than in competition with medical care.
How long does it take to see changes in gut health and skin?
Usually eight to twelve weeks for skin, and often sooner for digestion. Skin renews slowly, so early weeks can feel discouraging even when things are moving. If there is no change at all by three months, the plan needs revisiting.
Is leaky gut a real thing?
Intestinal permeability is real and measurable in research settings, and differences have been observed in people with some skin conditions. What is not established is that it causes those conditions, or that repairing it clears them. I treat it as one thread in a bigger picture rather than a diagnosis on its own.
Should I take a probiotic for my skin?
It depends entirely on the condition. For eczema, the best-quality review found little or no benefit for symptoms. For acne and psoriasis, some small trials are promising. Because the effects are strain-specific, it is worth choosing deliberately rather than grabbing whatever is on the shelf.
Do I need a gut microbiome test?
Often not, at least not first. A careful history usually tells us more, and it costs nothing. Where testing will genuinely change what we do, we will talk it through before ordering anything.
Do I have to give up dairy?
No. Some people find it makes a real difference and many find it makes none. Rather than cutting it out indefinitely, try a defined period and then reintroduce it properly, so you actually learn something either way.
Where to from here
If your skin has been unresolved for a long time, and nobody has yet asked you about your digestion, your cycle or your sleep, that conversation is probably overdue. You can read more about how we approach skin health and gut health, or book an appointment at our Geelong or Drysdale clinic, or by telehealth.
Related reading
- Probiotics for eczema: what the evidence shows
- Hormonal acne in adult women: naturopathic treatments and the evidence
- Foods that cause eczema in children: how to find out properly
Related: our Gut Issues and Food Allergies, Eczema and Psoriasis pages explain how we approach these conditions alongside your doctor.
References
Evidence on gut health and skin
- De Pessemier B, et al. Gut-skin axis: current knowledge of the interrelationship between microbial dysbiosis and skin conditions. Microorganisms. 2021. https://doi.org/10.3390/microorganisms9020353
- Mahmud MR, et al. Impact of gut microbiome on skin health. Gut Microbes. 2022. https://doi.org/10.1080/19490976.2022.2096995
- Todberg T, et al. Characterisation of the gut microbiota in patients with psoriasis. British Journal of Dermatology. 2022. https://doi.org/10.1111/bjd.21245
- Deng Y, et al. Patients with acne vulgaris have a distinct gut microbiota. Acta Dermato-Venereologica. 2018. https://doi.org/10.2340/00015555-2968
- Feng F, et al. Causal effects of gut microbiota on skin diseases: a Mendelian randomisation study. PLoS One. 2024. https://doi.org/10.1371/journal.pone.0298443
Evidence on food, stress and supplements
- Trompette A, et al. Dietary fiber confers protection against skin inflammation. Mucosal Immunology. 2022. https://doi.org/10.1038/s41385-022-00524-9
- Smith RN, et al. A low-glycemic-load diet improves symptoms in acne vulgaris patients. American Journal of Clinical Nutrition. 2007. https://doi.org/10.1093/ajcn/86.1.107
- Juhl CR, et al. Dairy intake and acne vulgaris: a meta-analysis. Nutrients. 2018. https://doi.org/10.3390/nu10081049
- Altemus M, et al. Stress-induced changes in skin barrier function. Journal of Investigative Dermatology. 2001. https://doi.org/10.1046/j.1523-1747.2001.01373.x
- Makrgeorgou A, et al. Probiotics for treating eczema. Cochrane Database of Systematic Reviews. 2018. https://doi.org/10.1002/14651858.CD006135.pub3
- Navarro-López V, et al. Efficacy and safety of oral probiotics in plaque psoriasis. Acta Dermato-Venereologica. 2019. https://doi.org/10.2340/00015555-3305
- Shields A, et al. Oral nutraceuticals for the treatment of acne. JAMA Dermatology. 2023. https://doi.org/10.1001/jamadermatol.2023.3949
- Oykhman P, et al. Dietary elimination for the treatment of atopic dermatitis. Journal of Allergy and Clinical Immunology: In Practice. 2022. https://doi.org/10.1016/j.jaip.2022.06.044
- Lax SJ, et al. Topical anti-inflammatory treatments for eczema: network meta-analysis. Cochrane Database of Systematic Reviews. 2024. https://doi.org/10.1002/14651858.CD015064.pub2
