Oral Administration of β-Glucan and Alleviates Atopic Dermatitis-Like Symptoms.

Atopic dermatitis (AD) is a chronic inflammatory skin disease of mainly infants and children. Currently, the development of safe and effective treatments for AD is urgently required. The present study was conducted to investigate the immunomodulatory effects of yeast-extracted β-1,3/1,6-glucan and/or () LM1004 against AD-like symptoms. To purpose, β-1,3/1,6-glucan and/or LM1004 were orally administered to AD-induced animal models of rat (histamine-induced vasodilation) and mouse (pruritus and contact dermatitis) exhibiting different symptoms of AD. We then investigated the treatment effects on AD-like symptoms, gene expression of immune-related factors, and gut microbiomes. Oral administration of β-1,3/1,6-glucan (0.01 g/kg initial body weight) and/or 2 × 10 cells/g LM1004 (0.01 g/kg initial body weight) to ADinduced animal models showed significantly reduced vasodilation in the rat model, and pruritus, edema, and serum histamine in the mouse models ( < 0.05). Interestingly, β-1,3/1,6- glucan and/or LM1004 significantly decreased the mRNA levels of Th2 and Th17 cell transcription factors, while the transcription factors of Th1 and Treg cells, galactin-9, filaggrin increased, which are indicative of enhanced immunomodulation ( < 0.05). Moreover, in rats with no AD induction, the same treatments significantly increased the relative abundance of phylum and the genus . Furthermore, bacterial taxa associated with butyrate production such as, and at family, and at genus level were increased in the treated groups. These findings suggest that the dietary supplementation of β-1,3/1,6-glucan and/or LM1004 has a great potential for treatment of AD as well as obesity in humans through mechanisms that might involve modulation of host immune systems and gut microbiota.