BackgroundAtopic dermatitis (AD) is recently increasing among populations, but the underlying mechanisms remain controversial. Interactions between the gut microbiota and mucosal immunity are considered to be a crucial etiology. Fructooligosaccharide (FOS), prebiotics have been reported as activators of the gut microbiota. ObjectiveThe aim of this study was to investigate the effects of kestose, the smallest FOS and FOS on atopic dermatitis in mice. MethodsAn AD mouse model was developed by (ovalbumin) epidermal sensitization using BALB/c mice. Kestose (1%, 5%, and 10%) or FOS (5%, positive control) was orally administered throughout the study. ResultsIn comparison with the values observed for the control AD mice, transepidermal water loss (TEWL), clinical score, and skin inflammation on histopathology were significantly decreased by the oral administration of kestose. Total IgE, thymic stromal lymphopoietin (TSLP) in skin, and IL-4 were also suppressed by this administration. In addition, the population of CD4+Foxp3+ cells in mesenteric lymph nodes (MLNs) and acetate concentrations in feces were significantly increased by kestose treatment. ConclusionsThese findings suggest that kestose activates the gut immune system to induce the tolerance against allergic skin inflammations in AD.