Children With Diabetes and Dry Eye Have More Diverse Ocular Microbial Composition

Children and adolescents with diabetes mellitus and dry eye (DE) have a greater diversity of, and more unique, ocular surface microbes, according to findings published in Investigative Ophthalmology & Visual Science.

Researchers conducted a study to analyze the characteristics of ocular surface microbial composition in children and adolescents with diabetes mellitus and DE by tear analysis. Participants included 65 children and adolescents aged 8 to 16 years with DE and non-DE diabetes mellitus, and 33 patients without diabetes placed into a control group. The researchers collected tears for high-throughput sequencing of the V3 and V4 region of 16S rRNA, and ocular surface microbiota (OSM) in diabetic DE (DM-DE; n=31), diabetic with nondry eye (DM-NDE; n=34), and healthy (NDM; n=33) groups were studied.

Patients in the DM-DE group had the highest amplicon sequence variants, and, across the 3 groups,differences in α-diversity and β-diversity were statistically significant (P <.05). The specific phyla and genera, respectively, in the DM-DE group were Bacteroidetes (15.6%), Tenericutes (9.3%), Firmicutes (21.8%), and Lactococcus (7.9%), Bacteroides (7.8%), Acinetobacter (3.9%), Clostridium (0.8%), Lactobacillus (0.8%) and Streptococcus (0.2%).

The researchers noted that the species composition of OSM is dissimilar in adults with diabetes, according to previous research, to that of children with diabetes. This could be the result of toxic substances secreted by pathogenic bacteria, as well as other factors, according to the study authors.

“These differences suggest that the possible mechanism underlying the high incidence of DE in children with diabetes could be flora diversity and composition change, causing abnormality of immunity and substance metabolism on the ocular surface, ocular surface barrier, and immune tolerance and, thus, promoting immune cells to secrete inflammatory factor,” the researchers explain.

Study limitations include the lack of a DE group for healthy children, and possible confounding of the difference between viable and nonviable bacteria due to the use of 16S rRNA sequencing.