IMBALANCE in the gut’s microbiome, caused by a diet high in sugar and fats, may contribute to inflammatory skin diseases such as psoriasis, research from the University of California (UC) Davis Health, USA, has found. Researchers have shown that switching to a more balanced diet can restore the gut’s health and suppress inflammation. Senior author of the study, Sam T Hwang, Chair of Dermatology at UC Davis Health, explained that the study demonstrates that despite the powerful anti-inflammatory drugs available to treat the condition, simple changes in diet can also have significant impact on psoriasis symptoms.
Gut bacteria play a role in shaping inflammation within the body, and food is one of the major modifiable factors that can regulate the gut microbiome. A western diet, high in sugars and fats, can cause disruption in the microbial balance, known as dysbiosis. This dysbiosis can, in turn, contribute to inflammation. IL-23 is the protein generated by human cells that is responsible for these inflammatory, autoimmune reactions such as psoriasis. Hwang and his colleagues injected mice models with IL-23 mini-circle DNA, which induced responses mimicking psoriasis-like skin.
Researchers found that indulging in a western diet, even in the short-term, appears sufficient to cause microbial imbalance and enhance susceptibility to IL-23 mediated psoriasis inflammation.
The study subsequently investigated whether the effects of an unhealthy diet could be reversed. Mice were fed a western diet for 6 weeks before being given an IL-23 inducing agent to trigger psoriasis. They were then split into two study groups; one continued on the western diet and the other was switched to a balanced diet. The study found that the mice that switched to a balanced diet had less incidence of scaling of the skin and reduced ear thickness compared to the mice that maintained the western diet.
Zhenrui Shi, visiting Assistant Researcher at the UC Davis Department of Dermatology and author of the study, stated: “These findings reveal that patients with psoriatic skin and joint diseases should consider changing to a healthier dietary pattern.”