Structural characteristics and regulatory mechanisms of the ocular surface microbiota and their relationship with ocular surface health
Year: 2026
Type: review
Abstract: This review delineates the spatial distribution of ocular surface microbiota (OSM) and its dynamic interplay with ocular health. Culture-independent surveys employing 16S rRNA and metagenomic sequencing reveal an ultra-low-biomass ecosystem characterized by restricted α-diversity. Firmicutes , Actinobacteria and Proteobacteria are the dominant phyla. Corynebacterium , coagulase-negative staphylococci, Propionibacterium and Streptococcus show high prevalence and temporal stability. These four genera form a conserved core. Their relative abundance is continuously reshaped by geography, lifestyle, age, sex, delivery mode, contact lens wear and systemic diseases such as dry eye and diabetes. Emerging evidence implicates host-microbe crosstalk, encompassing Toll-like receptor (TLR) and NOD-like receptor (NLR) mediated sensing of pathogen-associated molecular patterns (PAMPs), secretory immunoglobulin A (SIgA) neutralization, and a putative gut-eye immunoregulatory axis, in ocular immune maturation and the maintenance of immune homeostasis, although direct causal relationships remain to be established. Under physiological conditions, competitive exclusion and negative feedback maintain microbial equilibrium. However, surgical trauma, antibiotics or corticosteroids have been associated with destabilization of this niche, under which commensals may acquire virulence genes, form biofilms and transition into opportunistic pathogens implicated in infectious keratitis, exacerbation of meibomian gland dysfunction and increased dry eye severity. Consequently, high-resolution profiling of OSM composition and function may help clarify disease mechanisms and holds promise for furnishing microbial biomarkers for precision diagnosis and personalized therapeutic intervention.
Language: English
Subfield: Ophthalmology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7223155428