A Randomized, Double-Blind Clinical Trial of a Probiotic Nutritional Intervention in the Treatment of Mild to Moderate Non-Scalp Psoriasis

Abstract

Background The cellular immune system plays an important role in the pathogenesis of psoriasis. The digestive system (by virtue of the profile, number and species of bacteria present at any given time and nutritional factors) can influence the status of the immune system. Bacterial pathogens influence specific cytokine activity due to the activity of superantigens. Modulation of bacterial gut flora offers a potential target for psoriasis treatment. Methods Forty-two subjects with mild to moderate plaque-type psoriasis were enrolled in a 12-week, randomized, placebo-controlled trial of a lactobacillus nutritional supplement. The supplement or placebo was taken orally once daily for eight weeks. The primary outcome of this study was the change from baseline to week 12 (or end of treatment) in the composite score of the signs of psoriasis (erythema, scaling, plaque thickness) for target lesions. Other outcomes included Investigator's and Subject's Global Assessment of Response and change in pruritus score. Results Data were evaluable for 40 subjects (18 on the nutritional supplement and 22 on placebo). No significant improvement was found with the lactobacillus nutritional supplement compared to placebo-treated patients. Conclusion Patients commonly seek out alternative treatments for psoriasis. Nutritional supplementation is an intriguing way to manage the disease, offering the potential for a very safe treatment, however we found little to no benefit for lactobacillus nutritional supplement in this group of subjects with mild to moderate psoriasis.