Effects of oral administration of Lactobacillus acidophilus L-92 on the symptoms and serum cytokines of atopic dermatitis in Japanese adults: a double-blind, randomized, clinical trial.

OBJECTIVES: Several studies on lactobacilli have demonstrated they are effective against atopic dermatitis (AD) in children, but there are very few reports of their effects in adults. We investigated the changes in AD symptoms in adults after the ingestion of the Lactobacillus acidophilus strain L-92 (L-92), which has been shown to have a curative effect on AD in children. METHODS: A double-blind, parallel-group, placebo-controlled comparison was performed on 49 AD patients aged ≥16 years using heat-killed L-92. Skin lesions were assessed using the SCORing AD (SCORAD) index before the start of L-92 ingestion and 4 and 8 weeks after ingestion. Serum cytokine and blood marker levels were measured 8 weeks after the start of L-92 ingestion. RESULTS: The group that ingested L-92 had lower SCORAD scores than the controls (p = 0.002). The L-92 group also had decreased ratios of change for eosinophil count (p = 0.03) and increased ratios of change for serum TGF-ß (p = 0.03). Ratios of change for serum TGF-ß rose significantly (p = 0.04) in patients showing mitigated symptoms with L-92 administration. CONCLUSIONS: Administration of heat-killed L-92 was effective for AD symptoms in adults. L-92 may contribute to the suppression of Th2-dominant inflammation. Our preliminary trial is the first to report the effects of L-92 on adult AD.

Decreased expression of semaphorin-3A, a neurite-collapsing factor, is associated with itch in psoriatic skin.

Pruritus is a common symptom of psoriasis, which affects quality of life. This symptom accompanies the hyper-innervation of sensory C-fibres in psoriatic lesions. Two extracellular molecules, nerve growth factor (NGF) and semaphorin-3A, regulate C-fibre extension. In this study, the expression levels of these 2 molecules in biopsy specimens from psoriatic and healthy skin were quantified by immunohistochemistry and quantitative reverse-transcription PCR. Semaphorin-3A expression was lower in the psoriatic samples compared with the healthy samples, whereas NGF was higher. C-fibre innervation in the epidermis was also increased in psoriatic skin. Semaphorin-3A mRNA expression was negatively correlated with itch intensity and severity of psoriasis. We propose that decreased semaphorin-3A and increased NGF expression levels may trigger the outgrowth of C-fibres, leading to pruritus.

Intranasal administration of semaphorin-3A alleviates sneezing and nasal rubbing in a murine model of allergic rhinitis.

Sneezing and persistent itching of the nasal mucosa are distressing symptoms of allergic rhinitis (AR). Recent studies have revealed that hyperinnervation of sensory neurons in the nasal turbinate is one of the underlying causes of sneezing and itching. Since Semaphorin-3A (Sema3A) has been previously shown to restrict innervation of sensory neurons, it is presumed that reduced Sema3A expression in the nasal mucosa might contribute to the hypersensitivity. Analysis of the mouse model of ovalbumin-sensitized AR demonstrated a decreased expression of Sema3A in the nasal epithelium, which was accompanied by an increased nerve fiber density in the lamina propria of the turbinate. In rescue experiments, intranasal administration of recombinant Sema3A in the AR model mice alleviated sneezing and nasal rubbing symptoms. In addition, histological examinations also revealed that nerve fiber density was decreased in the lamina propria of the Sema3A-treated nasal turbinate. These results suggest that the nasal hypersensitivity of AR may be attributed to reduction of Sema3A expression and intranasal administration of Sema3A may provide a novel approach to alleviate the allergic symptoms for AR treatment.