The Gut Skin Axis: How Your Gut Affects Your Skin and Acne
- Renae Cinanni
- Jul 13
- 7 min read
Updated: Jul 26
Your skin and your gut can feel like completely separate parts of the body, but they are in constant conversation. This guide walks you through how that conversation works, what it means for acne, and how the food on your plate fits in.
Written by Clinical Nutritionist (BHSc) Renae Cinanni
What is the gut-skin axis?
The gut-skin axis is simply the two-way link between what is happening inside your digestive system and what shows up on your skin. It might seem surprising that an organ tucked deep inside you can influence the surface you see in the mirror, but the two share more in common than most people realise.
Both your gut lining and your skin are barrier organs. Their main job is to let the good things in, nutrients and moisture, while keeping unwanted things out. Both renew themselves constantly, and both are home to a microbiome, a busy community of bacteria and other microbes that help keep the whole system in balance.
The messengers travel through your bloodstream and immune system. As the bacteria in your gut break down the food you eat, particularly fibre, they release compounds. Some are anti-inflammatory and protective, like short-chain fatty acids. Because your gut has such a rich blood supply, these compounds can circulate around the body and reach the skin, where they help shape how calm or reactive it is.
When the gut microbiome becomes unbalanced, a state called dysbiosis, the signals travelling to your skin can shift in an unhelpful direction. Poor diet, stress, illness, low fibre intake and repeated courses of antibiotics can all nudge the gut this way.
You may also have heard the phrase leaky gut. Your gut lining is meant to be semi-permeable: it absorbs water and nutrients while holding larger, unwanted molecules back. If it becomes more permeable than it should be, inflammatory compounds can pass through more easily and add to the load reaching the rest of the body.
Acne and the gut
Acne is driven by a handful of things working together: hormones, oil (sebum) production, the skin's own microbes and inflammation. The gut sits quietly behind several of these. It is not the whole story, but it is a meaningful piece of the puzzle, and it happens to be one you can influence.
People with acne often have less diverse gut bacteria and fewer of the beneficial species that keep the gut lining strong and inflammation low. At the same time, the balance of skin microbes shifts, and one bacterium, Cutibacterium acnes, thrives inside blocked, oily pores, tipping a clogged pore over into a red, inflamed pustule.
A lot of acne comes back to two linked signals: insulin and a growth factor called IGF-1. When these run high, the skin produces more oil and skin cells turn over faster, and both make blockages and breakouts more likely. This is why what you eat can matter, because certain foods push insulin and IGF-1 up more than others.
Probiotics: some early studies suggest oral probiotics may help reduce acne severity, particularly certain Lactobacillus and Bifidobacterium strains, partly by calming inflammation. The evidence is still limited, and no probiotic has been shown to cure acne, but supporting a healthy, diverse gut is a sensible foundation.
Diet and your skin
Unlike your genes, your diet is something you can adjust. Here is an honest look at where the evidence sits.
Antioxidants
Antioxidants help neutralise the reactive molecules that build up in the body (oxidative stress) from inflammation, poor detoxification and from sun exposure which contribute to skin ageing and healing issues. A colourful, antioxidant-rich diet is one of the more reliably beneficial things you can do for your skin, alongside daily sunscreen.
Food sources: all fruits especially dark berries and cherries, plums, dark leafy greens, purple foods like purple carrots, cabbage and red onions, red and yellow capsicums, black beans, red kidney beans and lentils.
Aim for a variety of different coloured fruits and vegetables each week for an antioxidant rich diet.
Omega-3 fats
Omega-3s are naturally anti-inflammatory, and studies show that a diet high in omega-3s from fish, alongside essential fatty acid (EFA) supplements, can help lower testosterone and other androgens, which are part of what drives acne.
Aim for fatty fish around twice a week: salmon, tuna, barramundi, trout, mackerel, sardines and anchovies. Plant sources like linseeds (flaxseed), chia seeds, hemp seeds and walnuts are also high in omega-3s and help maintain the skin's barrier and hydration to prevent skin sensitivity which is common with acne.
Zinc
Zinc is one of the more reliably helpful nutrients for acne. It has been shown to significantly reduce inflammatory papules, and topical zinc is useful for moderate to severe acne. Lower zinc levels in the blood are consistently found in people with acne and tend to track with severity. It also has antibacterial effects against acne-causing bacteria and helps reduce inflammation.
Good food sources include oysters, lean red meat, poultry, pumpkin seeds, cashews (all other nuts and seeds), chickpeas, beans, lentils, eggs and wholegrains.
Green tea (EGCG)
The active compound in green tea, EGCG (epigallocatechin-3-gallate), is a potent antioxidant that reduces oxidative stress and inflammation, and it has been shown to slow acne progression.
Around one cup of pure loose-leaf green tea a day is a reasonable amount to aim for. A small amount of EGCG can also be found in cocoa and dark chocolate.
Spearmint tea
Two cups of spearmint loose-leaf tea a day has been shown to lower both total and free testosterone within about 30 days, along with a significant reduction in unwanted hair growth in women with PCOS. Since higher androgens feed into acne, it can be a gentle, tea-based way to support the hormonal side. Spearmint tea is used especially for women who have PMOS or PCOS who experience excess facial hair growth and is used successfuly for women experiencing androgen driven acne flares.
High GI foods
Sugary drinks, white bread, fast food and other foods that spike blood sugar quickly trigger a rise in insulin and IGF-1, which ramps up oil production. Lowering the glycaemic load of your diet has been shown to improve acne for some people.
Dairy
Recent research shows that drinking milk or eating milk products is associated with acne. The whey and casein in dairy raise IGF-1 and insulin, both of which play a role in how acne develops, largely by increasing oil (sebum) production and feeding the formation of pustules. Milk also contains compounds that act as precursors to dihydrotestosterone (DHT), which directly stimulates acne, and the IGF-1 in milk encourages the body to make more androgens.
If you suspect dairy is a trigger, it can be worth trialling a reduction thoughtfully, since dairy is also a useful source of protein and minerals.
How long after cutting dairy will my acne clear?
It can take up to a month for dairy proteins to fully filter out of your body, so when eliminating dairy it may take up to 3 - 4 months to see improvements in your skin as it takes time for the inflammation and raised IGF-1 to resolve.
The skins epidermis also takes around 4 - 8 weeks to turnover (depending on the maturity of your skin) which is why patience is so important when it comes to skin health.
Chocolate, oily and fatty foods
These tend to sit high on the glycaemic index, which pushes insulin up. That rise lifts androgens and IGF-1, and together they trigger acne by driving more oil production. The result is more blockages, more food for acne-causing bacteria, and more inflammation.
If getting rid of your chocolate is too much to bear, switch to at least 70% dark chocolate or more which generally have no dairy added, less sugar and are higher in antioxidants.
I love recommending Lindt dark chocolate. The 70%, 70% smooth blend, 85%, 90% and 95% dark chocolate bars are all dairy free. Pair with a small handful of almonds and some cherries and you have created yourself a high antioxidant snack!
Avoid the dark chocolates with flavors as they contain milk and lots of added sugars.
What to take from this
Your gut and skin are genuinely connected through the bloodstream and immune system, they are not separate stories.
A diverse, well-fed gut microbiome is one of the best foundations for calmer skin, and fibre is its favourite food.
Acne comes back to a few linked drivers: oil production, inflammation, skin and gut microbes, and the insulin and IGF-1 signal that diet can nudge up or down.
Include food sources of zinc, omega-3s, antioxidants and green tea to your diet daily. Be more aware about high-GI foods, dairy, chocolate and fatty foods, and personalise from there.
References
Aghasi, M., Golzarand, M., Shab-Bidar, S., Aminianfar, A., Omidian, M., & Taheri, F. (2019). Dairy intake and acne development: A meta-analysis of observational studies. Clinical Nutrition, 38(3), 1067–1075. https://doi.org/10.1016/j.clnu.2018.04.015
Australasian Journal of Dermatology, 66(4), 189–198. https://doi.org/10.1111/ajd.14447
Davidovici, B. B., & Wolf, R. (2010). The role of diet in acne: Facts and controversies. Clinics in Dermatology, 28(1), 12–16. https://doi.org/10.1016/j.clindermatol.2009.03.010
De Cruz, R., Nguyen, R., Chen, P., Kerob, D., Gebauer, K., Willems, A., Tong, P., & Lee, M. (2025). From monotherapy to adjunctive therapies: Application of dermocosmetics in acne management across Australia and New Zealand.
Kim, H. J., & Kim, Y. H. (2024). Exploring acne treatments: From pathophysiological mechanisms to emerging therapies. International Journal of Molecular Sciences, 25(10), 5302. https://doi.org/10.3390/ijms25105302
Maeda K. New Method of Measurement of Epidermal Turnover in Humans. Cosmetics. 2017; 4(4):47. https://doi.org/10.3390/cosmetics4040047
Owlstone Medical. (2024). The gut-skin axis [eBook]. OMED Health. https://www.owlstonemedical.com/wp-content/uploads/2024/11/Gut-Skin-eBook-OMED-Health.pdf
Disclaimer:
This handout is for general education only and is not a substitute for individual clinical advice. If you have a persistent, painful or worsening skin condition, or you are considering a significant change to your diet, please speak with your practitioner or GP first so any care can be tailored safely to you.
Perth Nutrition & Natural Health Clinic · Renae Cinanni, Clinical Nutritionist (BHSc) · perthnaturalhealthnutrition.com.au
