2023 Volume 25 Issue 1 Pages 46-55
Abnormal immune response and disturbance of intestinal microbiome have been reported as the onset factors of atopic dermatitis (AD). Apple pectin has been reported to selectively stimulate proliferation of specific intestinal bacteria and to lower histamine levels in the blood, so it is expected to have preventive effects against allergic diseases. However, its efficacy in improving AD has not been clarified. In this study, we investigated the ameliorating effect of apple pectin on AD and its effect on microbiome.
To induce AD, a picryl chloride solution was applied to shaved back skin of male NC/Nga mice. Treatment groups of AD mice then received oral administration of an apple pectin solution (0.4％ or 4％) for 35 days.
Compared with untreated AD mice, both apple pectin-treated groups showed improvement in skin symptoms of AD. Apple pectin treatment reduced the expression of COX-2, as well as TSLP and IL-4 (p < 0.05). Additionally, increased expression of IFN-γ and Foxp3 were observed in the apple pectin-treated groups (p < 0.05). Regarding intestinal bacteria, the 4％ pectin group showed a tendency toward lower Firmicutes and a tendency toward higher Bacteroidetes compared to the AD group (p = 0.103).
Our findings suggest that ingestion of apple pectin impacted AD by improving the Th1/Th2 balance at the site of AD onset, suppressing skin inflammation, and changing composition of intestinal microbiome in the AD mouse model.
