How Do Gut Microbiota Differ by Inflammatory Atopic Diseases?

Results from a small pilot study indicate that gut flora colonies differ significantly in patients with inflammatory skin conditions such as allergic dermatitis (AD) and urticaria compared with allergic rhinitis.

There’s growing evidence that the microbiota plays a major role in the development and presentation of atopic disease. In this study, the researchers, from the Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine in Taiwan, sought to compare microbiota between 3 clinical presentations of allergic diseases in patients treated at outpatient clinics.

The prospective observational study enrolled 19 patients with AD, 9 with uticaria (or chronic hives), and 11 with allergic rhinitis. The majority of the patients were female across all 3 groups, and clinical data were similar.

Fecal samples were examined using 16S ribosomal ribonucleic acid amplicon sequencing, followed by bioinformatics and statistical analyses. The use of fecal samples is key for pathogenesis research, the authors said. Microbial diversity was assessed either within a subgroup (alpha diversity) or between all 3 subgroups (beta diversity), and the Welch's t-test was used to identify specific bacteria phylotypes.

The differences seen in the microbiota analysis indicate that an axis exists between the gut and the skin and the gut and the nose, the authors said.

Bacteroidales species were more commonly found in urticaria and AD compared with rhinitis. In particular, Bacteroids plebeius DSM 17135 was significantly linked with urticaria, as was Prevotella 2.

The relative abundance of order Bacteroidales, Bacteroidia, and phylum Bacteroidetes, was significantly higher in AD than in the uticaria or hives subgroups.

In AD, genus Romboutsia and genus Sutterella were also more abundant than in the other 2 subgroups.

Rhinitis had significantly higher abundance of class Clostridia, order Clostridiales, and families Ruminococcaceae, Lachnospiraceae, genera Eubacterium coprostanoligenes, and Atropobium.

The researchers said their findings were in line with previous research and that the symptoms of AD, hives, and rhinitis can all be linked to specific microbiota, implying that the gut-skin axis and gut-nose axis do exist.

“Gut microbiota links to systemic manifestations of allergic diseases, and the combination of species of gut microbiota could predict clinical symptoms with regard to the allergic site in subjects,” the authors said.

Reference

Su YJ, Luo SD, MD, Hsu CY, Kuo HK. Differences in gut microbiota between allergic rhinitis, atopic dermatitis, and skin urticaria. Medicine (Baltimore). Published online March 5, 2021. doi: 10.1097/MD.0000000000025091