The Gut-Skin Connection

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Written by Elle Rizzo

How Your Digestive Health Impacts Your Complexion

When it comes to radiant, healthy skin, most people turn to topical creams and serums.

Photo by Sora Shimazaki

But glowing skin may actually begin much deeper – in your gut. The gut-skin connection is a fascinating, science-backed concept that explains how your digestive health can directly influence the appearance and condition of your skin, and is changing how we approach common skin issues like acne, eczema, rosacea, and even premature aging.

Understanding the Gut-Skin Axis

The gut-skin axis refers to the bidirectional communication between your digestive tract and your skin. This connection is regulated by the immune system, hormonal signals, the nervous system (including the vagus nerve), and most importantly, the gut microbiome—a vast ecosystem of bacteria, fungi, and other microbes that reside in your large intestine.

A healthy gut microbiome helps regulate inflammation, break down food into absorbable nutrients, produce short-chain fatty acids (which maintain gut integrity), and keep your immune system balanced. When this ecosystem is out of balance—a state called dysbiosis—it can trigger low-grade systemic inflammation and immune responses that show up on the skin’s surface.

Photo by Polina Tankilevitch

In fact, studies have shown that people with certain skin conditions, such as acne or rosacea, often have measurable differences in their gut microbiome compared to those without skin issues. This suggests a direct link between internal microbial health and external skin appearance.

Common Digestive Imbalances That Can Affect the Skin

Here are some of the most common digestive issues that may be secretly sabotaging your skin—and some typical causes.

1. Gut Dysbiosis

When the balance of good and bad bacteria in your gut is disrupted, it can lead to chronic inflammation and immune system overactivation. Harmful microbes can also produce toxins (called lipopolysaccharides or LPS) that increase intestinal permeability and inflammation, which can show up on the skin as acne, rosacea, or dermatitis.

Common causes:

  • A diet high in sugar, refined carbs, and processed foods
  • Overuse of antibiotics or acid-blocking medications
  • Chronic stress, which alters gut bacteria composition
  • Alcohol overconsumption
  • Infections or food poisoning (which can alter microbial diversity)

2. Leaky Gut (Intestinal Permeability)

A healthy gut lining acts like a barrier that controls what enters the bloodstream – normally allowing only nutrients from food to enter. When that lining becomes “leaky,” substances like undigested food particles, toxins, and bacteria can pass into the bloodstream, triggering immune reactions and skin flare-ups.

Leaky gut has been linked to skin issues such as eczema, psoriasis, and even hives.

Common causes:

  • Chronic inflammation from food sensitivities (e.g., gluten, dairy)
  • Alcohol and non-steroidal anti-inflammatory drugs (NSAIDs)
  • Gut infections like Candida or parasites
  • Low-fibre diets lacking prebiotics
  • Excessive stress, which weakens the intestinal barrier

3. Poor Digestion & Nutrient Malabsorption

If your stomach acid levels are low or your pancreas isn’t producing enough enzymes, your body may struggle to digest food properly. This can lead to nutrient deficiencies, particularly of skin-loving nutrients like vitamin A, zinc, biotin, and essential fatty acids.

Signs of poor digestion can include bloating, burping, undigested food in stool, and fatigue after meals.

Common causes:

  • Age-related decline in stomach acid and enzyme production
  • Frequent use of antacids or proton-pump inhibitors (PPIs)
  • Gallbladder issues or low bile flow
  • Eating too quickly or while stressed, which disrupts digestive signalling
  • H.Pylori infection

How to Test for Gut Imbalances

If you suspect your gut may be impacting your skin, there are several functional and clinical tests that can provide clarity:

  • Comprehensive stool testing: Assesses gut bacteria, parasites, yeast overgrowth, inflammation markers, and more.
  • Zonulin/leaky gut tests: Evaluate intestinal permeability (leaky gut).
  • Micronutrient testing: Checks for common vitamin and mineral deficiencies.
  • Food sensitivity testing: Helps identify specific foods triggering gut or immune responses.
Photo by Yaroslav Shuraev

These tests are usually ordered through a functional medicine practitioner, nutritionist, or integrative doctor and can help personalise your treatment plan.

Small Shifts, Big Results

You don’t have to overhaul your entire life to start seeing changes in your skin. You can start with some simple strategies, such as:

  • Adding fermented foods daily (like sauerkraut or kefir – start with tiny amounts and build from that).
  • Drinking more filtered water to support digestion.
  • Managing stress through practices like yoga, walking, or breathwork.
  • Avoiding restrictive diets, which can harm the gut microbiome and deplete friendly species.

Final Thoughts

Your gut and your skin are in constant communication. If you’ve tried every skincare product under the sun without results, it may be time to look inward. Supporting your gut with whole foods, mindful eating, and proper testing could be the missing piece in your skincare routine.

Photo by Yaroslav Shuraev

Healthy skin starts from the inside out. And the journey to a glowing complexion might just begin with your next bite.

References
  1. Salem, I., et al. (2018). The Gut Microbiome and the Role of Probiotics in Skin Health: A Review. Frontiers in Microbiology, 9, 1453. https://doi.org/10.3389/fmicb.2018.01453
  2. Burris, J., et al. (2014). Acne: The Role of Medical Nutrition Therapy. Journal of the Academy of Nutrition and Dietetics, 114(3), 416–430.
  3. Becattini, S., et al. (2016). How to exploit the microbiota for therapy. Nature Reviews Microbiology, 14(4), 248–262.
  4. Foster, J. A., & McVey Neufeld, K. A. (2013). Gut–brain axis: how the microbiome influences anxiety and depression. Trends in Neurosciences, 36(5), 305–312.
  5. Engen, P. A., et al. (2015). The gastrointestinal microbiome: alcohol effects on the composition of intestinal microbiota. Alcohol Research: Current Reviews, 37(2), 223–236.
  6. Szántó, M., & Dózsa, A. (2020). Gut–Skin Axis in the Development of Acne. Journal of Clinical Medicine, 9(8), 2392.
  7. Fasano, A. (2012). Leaky gut and autoimmune diseases. Clinical Reviews in Allergy & Immunology, 42(1), 71–78.
  8. de Meij, T. G., et al. (2015). Composition and diversity of the pediatric intestinal microbiome in health and disease. Journal of Pediatric Gastroenterology and Nutrition, 60(1), 16–24.
  9. O’Mahony, S. M., et al. (2011). Early life stress alters behavior, immunity, and microbiota in rats: implications for irritable bowel syndrome and psychiatric illnesses. Biological Psychiatry, 70(11), 1023–1030.
  10. Fasano, A. (2012). Intestinal permeability and its regulation by zonulin: diagnostic and therapeutic implications. Clinical Gastroenterology and Hepatology, 10(10), 1096–1100.
  11. Martinsen, T. C., et al. (2005). The role of pepsin and other proteolytic enzymes in the development of gastric ulcer. Scandinavian Journal of Gastroenterology, 40(10), 887–893.
  12. Fohl, A. L., & Regal, R. E. (2011). Proton pump inhibitor-associated pneumonia: Not a breath of fresh air after all? World Journal of Gastrointestinal Pharmacology and Therapeutics, 2(3), 17–26.
  13. Linus Pauling Institute. (2012). Micronutrients and skin health. Dermato-Endocrinology, 4(3), 234–244. https://doi.org/10.4161/derm.19852

Main – Photo by Andrea Piacquadio