SIBO and Skin Issues: Why SIBO Can Lead to Skin Irritations
Content
1. What is SIBO?
1.1 SIBO Diagnosis
1.2 SIBO Treatment
2. Bacteria steal nutrients
3. The Gut-Skin Axis
3.1 SIBO and Rosacea
3.2 SIBO and Acne
3.3 Microbiome and Psoriasis/Neurodermatitis
1. What is SIBO?
SIBO, or Small Intestinal Bacterial Overgrowth, is a common digestive disorder seen in many gastroenterology settings and gut clinics, particularly in major cities like London. It refers to the abnormal presence of bacteria in the small intestine, where normally only minimal bacteria should exist.
When bacteria overgrow, the digestive system can no longer manage the gases and toxins produced. This imbalance can cause a wide range of gut-related symptoms, including abdominal pain, bloating, diarrhea, constipation, belching, fullness, and heartburn.
SIBO is frequently misdiagnosed as IBS, due to the similarity in symptoms, which makes testing and accurate diagnosis essential—especially if you experience regular digestive discomfort.
1.1 SIBO Diagnosis
SIBO is typically diagnosed using a breath test, a standard method in gut-focused clinics. During the procedure, the patient consumes a sugar solution—commonly lactulose, glucose, lactose, or fructose(1)—which is then fermented by bacteria if present. The resulting gases (hydrogen or methane) pass into the bloodstream and are measured in the breath.
Because human cells do not produce these gases, a positive result indicates the presence of bacterial fermentation. Different test substances are used to reflect the fact that not all bacteria metabolize sugars the same way.
This type of test is widely used in gastroenterology clinics to help differentiate between SIBO, IBS, and other gut conditions.
1.2 SIBO Treatment
Once a positive result is confirmed, there are several low-risk treatment approaches available. These include a tailored SIBO diet, sometimes based on low-FODMAP principles, along with probiotics, proteins, and possibly herbal or conventional antibiotics (2).
Doctors specializing in gut health and gastroenterology clinics will typically personalize the therapy based on the type of gas (hydrogen, methane, or hydrogen sulfide), the severity of symptoms, and the patient’s individual condition. If you are being treated in a clinic in London or another specialized center, this may also include microbiome testing or dietary tracking.
2. Bacteria steal nutrients
The effects of SIBO-related bacterial overgrowth can be extensive. When excess bacteria colonize the small intestine, they compete with the human body for vital nutrients. While the small intestine is responsible for nutrient absorption, overgrown bacteria begin consuming large amounts of vitamins, minerals, and even protein, depriving the patient of essential resources.
This disruption doesn’t just affect the gut, but also weakens the immune system and contributes to other conditions. When nutrient supplies are low, bacteria may even attack the gut lining, resulting in leaky gut syndrome—a condition commonly recognized by gastroenterology doctors in clinic settings. Leaky gut increases intestinal permeability, allowing toxins, undigested food particles, and pathogens to enter the bloodstream.
This can cause systemic inflammation, food intolerances, abdominal symptoms, and even autoimmune reactions. It’s one reason why you may experience symptoms like bloating, diarrhea, or fatigue—especially if you have chronic IBS or unaddressed SIBO.
Another serious link between bacterial overgrowth and poor health is the release of bacterial toxins. When the intestinal barrier is compromised, these toxins enter the bloodstream more easily, triggering widespread gut-related conditions.
A deficiency in nutrients can lead to numerous symptoms and health conditions. Certain skin disorders are among the possible consequences. For example, a lack of zinc, selenium, and vitamin D has been associated with acne (3).
3. The Gut-Skin Axis
A growing body of research shows that gut inflammation caused by SIBO can influence skin health. This is referred to as the gut–skin axis, and it highlights how gut conditions may lead to common dermatological symptoms.
In patients with SIBO, toxins from the overgrown bacteria may trigger systemic immune reactions, which can manifest through inflammatory skin responses. This concept is especially important in functional gastroenterology clinics, where skin and gut symptoms are assessed together.
3.1 SIBO and Rosacea
One example of a skin condition associated with SIBO is rosacea (4,5). Rosacea is a common chronic inflammatory skin condition characterized by visible dilation of small blood vessels in the skin and mucous membranes. During inflammatory episodes, papules and pustules may appear on the face. While the exact cause of rosacea remains unclear (as of 2024), a link with an altered gut microbiome is likely.
SIBO is 13 times more common in rosacea patients compared to healthy individuals (6). Treating SIBO (for example, with specific antibiotics) can lead to an improvement in rosacea symptoms (7,8,9).
3.2 SIBO and Acne
SIBO can result in nutrient deficiencies that may negatively impact skin health and contribute to common skin conditions such as acne (3). These deficiencies—especially in zinc, selenium, and vitamin D—are frequently observed in patients with gut imbalances.
Beyond nutrition, the immune system plays a crucial role. Up to 80% of the body’s immune cells reside in the gut, and these cells are significantly influenced by the gut microbiome (10). When dysbiosis occurs—as is often the case with SIBO—it can trigger systemic inflammation, including skin-related flare-ups.
In gastroenterology clinics, especially in London, doctors are increasingly recognizing the link between gut health and acne.
3.3 Microbiome and Psoriasis/Neurodermatitis
An altered gut microbiome has also been associated with chronic inflammatory skin conditions such as psoriasis and neurodermatitis (11). These disorders are believed to be connected to gut-related immune responses, which are commonly evaluated in functional gastroenterology clinics.
When bacterial dysbiosis leads to intestinal inflammation, it can compromise the gut barrier—often referred to as leaky gut syndrome. This impaired barrier can no longer properly regulate what enters the bloodstream, allowing toxins, pathogens, and undigested food particles to pass through.
The resulting inflammation becomes systemic, and doctors have observed that this immune response can manifest on the skin. Patients with IBS, SIBO, or food sensitivities are at higher risk. In specialized clinics, the treatment plan may include gut-healing protocols, probiotics, and anti-inflammatory strategies tailored to both digestive and dermatological symptoms.
References
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- Ginnebaugh B, Chey WD, Saad R. Small Intestinal Bacterial Overgrowth: How to Diagnose and Treat (and Then Treat Again). Gastroenterol Clin North Am. 2020 Sep;49(3):571-587. doi: 10.1016/j.gtc.2020.04.010. Epub 2020 Jun 14. PMID: 32718571.
- Kazeminejad A, Hajheydari Z, Taghian SS, Gholizadeh N. Serum zinc, selenium, and vitamin D levels in patients with acne vulgaris: A case-control study. J Cosmet Dermatol. 2024 Jul 25. doi: 10.1111/jocd.16494. Epub ahead of print. PMID: 39051440.
- De Pessemier B, Grine L, Debaere M, Maes A, Paetzold B, Callewaert C. Gut-Skin Axis: Current Knowledge of the Interrelationship between Microbial Dysbiosis and Skin Conditions. Microorganisms. 2021 Feb 11;9(2):353. doi: 10.3390/microorganisms9020353. PMID: 33670115; PMCID: PMC7916842.
- Wang FY, Chi CC. Rosacea, Germs, and Bowels: A Review on Gastrointestinal Comorbidities and Gut-Skin Axis of Rosacea. Adv Ther. 2021 Mar;38(3):1415-1424. doi: 10.1007/s12325-021-01624-x. Epub 2021 Jan 28. PMID: 33507499; PMCID: PMC7932979.
- Drago F, De Col E, Agnoletti AF, Schiavetti I, Savarino V, Rebora A, Paolino S, Cozzani E, Parodi A. The role of small intestinal bacterial overgrowth in rosacea: A 3-year follow-up. J Am Acad Dermatol. 2016 Sep;75(3):e113-e115. doi: 10.1016/j.jaad.2016.01.059. PMID: 27543234.
- Agnoletti AF, DE Col E, Parodi A, Schiavetti I, Savarino V, Rebora A, Paolino S, Cozzani E, Drago F. Etiopathogenesis of rosacea: a prospective study with a three-year follow-up. G Ital Dermatol Venereol. 2017 Oct;152(5):418-423. doi: 10.23736/S0392-0488.16.05315-3. Epub 2016 Feb 18. PMID: 26889725.
- Weinstock LB, Steinhoff M. Rosacea and small intestinal bacterial overgrowth: prevalence and response to rifaximin. J Am Acad Dermatol. 2013 May;68(5):875-6. doi: 10.1016/j.jaad.2012.11.038. PMID: 23602178.
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- Chen M, Wang R, Wang T. Gut microbiota and skin pathologies: Mechanism of the gut-skin axis in atopic dermatitis and psoriasis. Int Immunopharmacol. 2024 Aug 12;141:112658. doi: 10.1016/j.intimp.2024.112658. Epub ahead of print. PMID: 39137625.
