Efficacy of prolonged ingestion of Lactobacillus acidophilus L-92 in adult patients with atopic dermatitis

To evaluate the safety and efficacy of prolonged ingestion of Lactobacillus acidophilus L-92 (L-92) on skin symptoms in adult atopic dermatitis (AD) patients, a placebo-controlled double-blinded parallel-group comparison study was performed. This included daily administration of heat-killed and dried L-92 or placebo for 24 wk in 50 AD patients who were 16 yr old or older. The severity of skin symptoms was evaluated at baseline and at 4, 8, 12, 16, 20, and 24 wk during the intervention using the investigator global assessment, eczema area and severity index, and scoring atopic dermatitis. Serum cytokine and blood marker levels were also measured at baseline and at 4, 8, 16, and 24 wk during the intervention. No adverse events were reported during the study period. Compared with the placebo group, the L-92 group showed significant decreases in investigator global assessment, eczema area and severity index, and scoring atopic dermatitis. Subjective symptoms in adult AD patients were reduced by intake of L-92. Furthermore, it was suggested that sustained ingestion of L-92 resulted in suppression of scratching behavior and maintenance of remission status of skin symptoms. Sixteen weeks after the study commenced, a significant decrease in lactate dehydrogenase and a significant increase in transforming growth factor-β were observed in the L-92 group compared with the placebo group. In the L-92 group, a significant elevation of IL-12 (p70) level at the end of treatment period compared with before the treatment was observed. This study suggested that L-92 suppresses type-2-helper-T-cell-dominant inflammation by activating regulatory T cells and type 1 helper T cells.