For most of its clinical history, psoriasis has been understood and treated as a skin condition — a problem of aberrant skin cell proliferation managed with topical treatments, phototherapy, and increasingly sophisticated biologics. What has become clearer in recent years is that psoriasis is a systemic inflammatory condition that happens to be most visible on the skin, and that the gut plays a more significant role in its activity than previously recognised.
For psoriasis patients, this is both sobering and practically useful: the gut is considerably more accessible to dietary and lifestyle intervention than the immune mechanisms targeted by pharmaceutical treatments.
The Evidence for a Gut Connection
Several lines of evidence point to the gut–psoriasis connection:
The gut microbiome of psoriasis patients differs measurably from that of healthy controls. Studies consistently find reduced bacterial diversity and altered species composition — specifically, lower levels of anti-inflammatory bacterial families (such as Faecalibacterium prausnitzii) and higher levels of species associated with inflammation.
The overlap between psoriasis and inflammatory bowel disease (IBD) — Crohn's disease and ulcerative colitis — is well established. IBD is approximately four times more common in people with psoriasis than in the general population. Both conditions share immunological pathways involving Th17/IL-17 signalling, suggesting a common underlying mechanism that encompasses the gut and the skin.
Small intestinal bacterial overgrowth (SIBO) is significantly more prevalent in psoriasis patients than in controls. In one notable study, antibiotic treatment of SIBO produced meaningful improvements in psoriasis symptoms — suggesting a causal rather than merely associative relationship.
Gut permeability (sometimes called "leaky gut") is elevated in psoriasis patients. When the intestinal barrier is compromised, bacterial lipopolysaccharides and other immune-activating compounds can translocate into the bloodstream, driving the systemic inflammation that fuels psoriasis activity.
Dietary Approaches to Support Gut Health in Psoriasis
If the gut is a meaningful driver of psoriasis activity, dietary strategies that support gut health are a rational complement to standard psoriasis treatment.
Fibre diversity feeds a diverse microbiome and promotes the production of short-chain fatty acids — particularly butyrate — that nourish the gut lining, reduce permeability, and dampen systemic inflammation. Prioritise a wide variety of plant foods: vegetables, legumes, wholegrains, and fruit. Eating 30 different plant types per week is a practical benchmark for microbiome diversity.
Fermented foods — live yoghurt, kefir, kimchi, sauerkraut, miso, and kombucha — provide live bacteria that support microbiome diversity and have shown improvements in inflammatory markers in clinical studies. Incorporating them regularly, where they are well-tolerated, supports the gut environment that in turn influences systemic inflammation.
Reducing ultra-processed food is equally important. Ultra-processed food disrupts the microbiome, feeds less beneficial bacterial species, and promotes gut permeability through its emulsifier, additive, and high refined sugar content.
Alcohol is both a known psoriasis trigger and a direct disruptor of gut barrier integrity. Its reduction or elimination is one of the most impactful single dietary changes for psoriasis patients and is well-supported in clinical guidance.
Anti-Inflammatory Eating for Psoriasis
The Mediterranean dietary pattern — rich in vegetables, oily fish, olive oil, legumes, and wholegrains — has shown the strongest evidence among specific dietary patterns for psoriasis benefit. Its mechanism operates partly through the microbiome and partly through direct anti-inflammatory effects: omega-3 fatty acids from oily fish, polyphenols from vegetables and olive oil, and fibre from legumes and wholegrains all contribute to the reduced inflammatory environment that supports reduced psoriasis activity.
Vanda's Kitchen at Selfridges Food Hall in EC4, near St Paul's Cathedral, naturally aligns with many of these principles. Halal-certified, completely nut-free, and rooted in Filipino culinary tradition, the kitchen's food incorporates lean proteins, fresh vegetables, fibre-rich legumes, and lightly fermented preparations that support the gut health and anti-inflammatory eating that psoriasis management requires. For City workers managing psoriasis, it represents a genuinely supportive lunch choice.
Supplements That Support the Gut–Skin Axis in Psoriasis
Several supplements have evidence specifically in the context of psoriasis and gut health. Probiotic supplements — particularly multi-strain formulations including Lactobacillus and Bifidobacterium species — have shown modest improvements in psoriasis severity in clinical studies, likely through their effects on the gut microbiome and systemic inflammation. Omega-3 fatty acid supplementation (fish oil) is the most consistently supported dietary supplement for psoriasis, with effects on both skin and joint manifestations. Vitamin D deficiency, extremely common in the UK due to limited sunlight exposure, is associated with more severe psoriasis; supplementation to maintain adequate levels is sensible for most people in the UK regardless of psoriasis status, but particularly so for those with inflammatory skin conditions.
Dietary management of psoriasis through the gut–skin axis is not a replacement for dermatological care. But it is a meaningful, evidence-supported adjunct that gives patients a degree of agency over a condition that can otherwise feel entirely beyond their control. Small, consistent dietary choices — made daily — accumulate into a meaningfully different inflammatory environment over months and years.