Metagenomic profiling of ocular surface microbiome changes in <i>Demodex</i> blepharitis patientsOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
Researchers compared conjunctival sac and meibum microbial communities in 25 people with Demodex blepharitis (DB) and 11 healthy controls.
How was it studied?
Conjunctival swabs and meibum samples were analyzed by metagenomic next-generation sequencing (mNGS), which classifies bacteria, fungi, and viruses at species level rather than relying on 16S rRNA alone.
What did they find?
Conjunctival microbiome diversity was lower in DB patients, while meibum diversity was unchanged. Proteobacteria rose from 65 percent to 75 percent of conjunctival flora in DB (p=0.023), and Actinobacteria and Firmicutes fell (p=0.002 and p=0.025). Sphingobium sp. YG1 (1.18 percent to 11.75 percent) and Acinetobacter guillouiae (0.45 percent to 5.40 percent) were enriched in conjunctival samples from DB patients and tracked with more severe SPEED, tear break-up time, and meiboscore values.
Why it matters
The rise in Proteobacteria suggests Demodex infestation destabilizes the ocular surface microbial community. Sphingobium sp. YG1 and Acinetobacter guillouiae emerge as candidate pathogenic biomarkers, and effects were concentrated at the ocular surface rather than deeper in the meibomian gland.