Variations in early gut microbiome are associated with childhood eczema.
Zhang Y, Jin S, Wang J, Zhang L, Mu Y, Huang K, Zhao B, Zhang K, Cui Y, Li S
FEMS Microbiol Lett. Mar 2019
COMMENT: Gut microbiota plays an important role in human immunological processes, potentially affecting allergic diseases such as eczema. Eczema is the most common chronic inflammatory skin disorder in children and one of the strongest predictors of allergic diseases. In this paper, the authors investigate the relationship between the composition of gut microbiome and eczema in children under 3 years of age.
To study the composition of gut microbiome of young children with or without eczema analyzing the sequence of the V3-V4 hypervariable regions of the 16S rRNA gene from fecal samples.
The abundance of Bifidobacterium is significantly lower (4.94%) in the eczema group comparing to the age matched healthy group (10.74%) in 0-3 years group.
(...) we compared annotated species of Bifidobacterium genus between eczema and healthy samples (...) The six annotated species are Animalis, Pseudolongum, Breve, Bifidum, Longum and Adolescentis. Among them, Bifidum, Longum and Adolescentis (...) are much more abundant than the other species. As Bifidobacterium decreased in eczema group more than in healthy samples, five species out of the six annotated Bifidobacterium species show decreased relative abundance in eczema samples, which is consistent with the dynamic of the genus. While Breve show higher abundance in eczema samples.
Bifidobacterium is identified as a key genus by Random Forest, which provides further statistical evidence support for its role in association with childhood eczema.
Absolute quantification confirmed significantly lower abundance of Bifidobacterium in eczema group (...). However, Bacteroides did not show remarkable differences between eczema group and healthy group (...). They are consistent with the 16S rRNA gene sequencing results.
In conclusion, our study revealed significant inter-group differences in gut microbiome diversity between healthy and eczema samples in all the age groups and decreased diversity in gut microbiome was associated childhood eczema in 2-3 years age old children, while decreased abundance of Bifidobacterium was a major finding in eczema groups from 0.5 to 3 years. All the results suggested variations in early gut microbiome are associated with childhood eczema, which may provide foundation for further studies such as developing biomarkers for clinical diagnosis and/or identify possible target for treatment.