AimsThe purpose of this study was to investigate the effect of Lactobacillus casei variety rhamnosus (LCR35) on Atopic dermatitis (AD)-like symptoms in mice. Methods and ResultsAD-like skin lesions in BALB/C mice were induced by sensitization and subsequent repeated challenges with trimellitic anhydride (TMA) for 10days. LCR35 was orally administered to the mice once daily throughout the study. In the TMA-induced AD model, orally administered LCR35 suppressed significantly irritant-related scratching behaviour and skin dehydration as well as apparent severity of AD. LCR35 also significantly decreased serum levels of IgE and IL-4, but not IFN-, implying the restoration of TMA-induced disruption of Th1/Th2 balance. Quantitative real-time PCR targeting hypervariable regions of 16S rDNA gene of faecal microbiota indicated that the LCR35 treatment increased the population of Bifidobacterium, Lactobacilli, Enterococcus and Bacteroides fragilis group, but decreased those of Clostridium coccoides group. ConclusionsLCR35 has the ability to suppress the development of AD in mice, possibly through the modulation of Th1/Th2 balance and gut microbiota. Significance and Impact of the StudyLCR35 has a strong potential as a probiotic for preventing AD.