Psoriasis is a chronic autoimmune condition primarily affecting the skin, characterized by an accelerated turnover of skin cells that results in thick, scaly patches. The gut microbiome, a complex community of microorganisms residing in the intestines, plays a significant role in overall health and immune function. Research increasingly explores a connection between the balance of this microbial environment and psoriasis, suggesting gut health may influence the condition’s course and severity.
The Gut-Skin Axis Explained
The “gut-skin axis” describes a bidirectional communication pathway between the digestive system and the skin, influenced by the gut microbiome. This connection involves inflammatory mediators and immune system regulation. An imbalance in the gut’s microbial community, known as gut dysbiosis, can impact skin health, contributing to inflammatory conditions like psoriasis.
Gut dysbiosis involves altered bacterial diversity and composition. Psoriasis patients often show reduced gut microbe diversity, with shifts in bacterial ratios, such as an increased Firmicutes-to-Bacteroidetes ratio. Beneficial bacteria like Faecalibacterium prausnitzii and Akkermansia muciniphila are found in lower amounts, while inflammatory bacteria such as Prevotella copri and Escherichia coli may be more prevalent. These microbial shifts promote heightened immune reactions in the intestinal lining, influencing the T helper 17 (Th17) cell response and contributing to systemic inflammation.
A compromised intestinal barrier, often called “leaky gut,” is another mechanism within the gut-skin axis. When tight junctions in the gut lining are disturbed, bacteria, toxins, and undigested food particles can pass into the bloodstream. This triggers systemic immune activation, leading to inflammation throughout the body, including the skin, potentially causing psoriasis flare-ups. Studies show individuals with psoriasis often have subclinical inflammation and increased intestinal permeability, even without overt gastrointestinal symptoms. Elevated levels of plasma claudin-3 and intestinal fatty acid-binding protein (I-FABP) support intestinal barrier dysfunction in psoriasis.
Dietary Strategies for Gut Health
Dietary modifications can support a healthy gut microbiome and influence psoriasis symptoms. Probiotic-rich foods introduce beneficial microorganisms directly into the gut. Examples include yogurt with live active cultures, kefir, kimchi, and fermented cheeses. Some probiotic strains, like Lactobacillus rhamnosus GG and Bifidobacterium infantis 35624, have shown promise in reducing inflammation and improving psoriasis symptoms.
Prebiotics, non-digestible fibers, nourish beneficial gut bacteria. Good sources include garlic, onions, bananas, artichokes, legumes, fruits, and whole grains. Anti-inflammatory foods also support gut health. Foods rich in omega-3 fatty acids, such as fatty fish (salmon, sardines), leafy green vegetables, berries, nuts, seeds, and olive oil, can reduce inflammation. The Mediterranean diet, focusing on whole, unprocessed foods, is known for its anti-inflammatory effects.
Limiting certain foods may also help manage psoriasis. Highly processed foods and those high in added sugars can negatively impact gut diversity and promote systemic inflammation. Red meat and dairy products contain compounds that may increase inflammatory responses, potentially worsening psoriasis. For individuals with gluten sensitivity or celiac disease, avoiding gluten-containing foods (wheat, barley, rye) may be helpful.
Other reported dietary triggers some individuals with psoriasis limit include nightshade vegetables (tomatoes, eggplants, white potatoes). Alcohol consumption has also been linked to increased inflammation and can trigger flare-ups. Dietary triggers are highly individual, requiring careful observation of personal responses.
Associated Inflammatory Conditions
Psoriasis often overlaps with other inflammatory conditions, highlighting the connection between gut health and systemic inflammation. Inflammatory bowel diseases (IBD), including Crohn’s disease and ulcerative colitis, frequently co-occur with psoriasis. Individuals with psoriasis have a 1.7 to 2.5 times greater risk of developing IBD. This association stems from shared inflammatory pathways, including similar immune cell responses (Th17 cells) and common genetic predispositions (IL23R and IL12B genes).
Celiac disease also has an increased prevalence among individuals with psoriasis. Studies show psoriasis patients are two to three times more likely to be diagnosed with celiac disease. This link is supported by shared genetic and inflammatory pathways. Over 16% of psoriasis patients exhibit higher levels of celiac disease antibodies, such as anti-gliadin IgA and anti-tissue transglutaminase IgA, even without overt gastrointestinal symptoms. These comorbidities show how gut disturbances can contribute to diverse inflammatory manifestations.
Collaborating with Healthcare Professionals
When considering dietary or lifestyle changes to support gut health for psoriasis, discuss these with a dermatologist or primary care physician. These strategies are intended to complement, rather than replace, any prescribed medical treatments. A healthcare professional can provide guidance tailored to an individual’s specific health profile and existing medical conditions.
A doctor can also help rule out or diagnose associated conditions like celiac disease or inflammatory bowel diseases, which often require specific medical management beyond dietary adjustments. Screening for celiac disease markers is often recommended for psoriasis patients, especially if they experience bowel issues. An integrated approach, combining medical treatments with supportive dietary and lifestyle strategies under professional supervision, offers a comprehensive path to managing psoriasis and overall well-being.