Table 1.

Dry eye related with ocular surface microbiota

Author/Date	Subjects	Groups	Comparison group	Diversity changes	Increase	Reduce	Main point
Li [32]	Human	DE: NMGD: Patients suffered from MGD MGD: Patients diagnosed with MGD NDE : Normal subjects	DE vs.NDE	α diversity: NDE> DE β diversity: DE was distinguished from NDE	Bacteroidia Bacteroidetes	Pseudomonas_ plecoglossicida Pseudomonas_ plecoglossicida Pseudomonadaceae Pseudomonas Gamma-proteobacteria Proteobacteria	1. The most predominant genera were Pseudomonas (11.49%), Acinetobacter (7.79%), Bacillus (7.10%), Chryseobacterium (2.84%), and Corynebacterium (2.73%) in DE ; 2. The predominant bacterial genera in both MGD and NMGD were Pseudomonas, Bacillus, Acinetobacter,Corynebacterium, Chryseobacterium,Pedobacter, Sphingomonas,and Photobacterium; 3. NMGD subjects had higher abundances of Bacteroidetes.
			MGD vs.NMGD	α diversity: No differences β diversity: No differences	Bacilli Bacillates Bacillus pumilus
Liang [31]	Human	DED: MGD + ATD + Mixed type Healthy: Healthy individuals	DE vs.Healthy	α diversity: DE< Healthy β diversity: DE> Healthy	Rothia mucilaginosa Malassezia globosa Neisseria sbuflava Staphylococcus aureus		1. DED was similar with healthy individuals in the phylum-level composition,Actinobacteria,Firmicutes, Proteobacteria, and Bacteroidetes were the major conjunctival microbiota; 2. The dysbiosis in DED is primarily characterized by the depletion of commensal species; 3. The sex-related differences of patients with DED are distinct from that of healthy individuals; 4. The microbial diversity in ATD was lower than mixed dry eye.
Jasmine Andersson [30]	Human	Dryeye: ADDA Control	Dryeye vs.Control	α diversity: Dryeye< Control	Staphylococcus Brevibacterium	Pseudomonas Corynebacteriu Ottowia Flavobacterium Veillonella Rothia Microbacterium Massilia Fusobacterium Thermus Haemophilus Sphingomonas	1. Cutibacterium was the only one genus identified in all patients in the DryEye group; 2. Enhydrobacter, Brevibacterium, Staphylococcus, Streptococcus, and Cutibacterium may be part of the core ocular surface microbiota; 3. Chryseobacterium and Micrococcus in the DryEye group were correlated with OSDI or Schirmer’s test.
Dong [33]	Human	MGD: Mild/Moderate/Severe Control	MGD vs.Control	α diversity: No difference β diversity: Significant difference between the severe MGD group and others	Firmicutes Proteobacteria Deinococcus-Thermus Staphylococcus Sphingomonas	Actinobacteria Corynebacterium	1. The biomarker phyla were Proteobacteria and Firmicutes in MGD, and the biomarker genera in the MGD group were Staphylococcus and Sphingomonas; 2. Meiboscores were positively correlated with the abundance of Staphylococcus; 3. There was significant difference in the abundances of Staphylococcus, Corynebacterium, and Sphingomonas between the female patients with and without MGD.
Qi [37]	Human	Dry eye Immdry eye	Dry eye vs.Immdry eye	α diversity: No differences β diversity: Immdry eyes was different from dry eye	Proteobacteria Pelomonas Herbaspirillum	Actinobacteria Firmicutes Bacteroidetes TM7 Corynebacterium Streptococcus Prevotella	1. The phyla biomaker was Proteobacteria in Dry eye and Actinobacteria, Firmicutes,and Bacteroidetes in Immdry eye; 2. The genus biomaker was Pelomonas in Dry eye and Corynebacterium in Immdry eye; 3. Herbaspirillum and Pelomonas was negatively correlated with Meibomian gland dropout score and Pseudomonas was negatively correlated with tear meniscus height in Dry eye group.
Zhang [36]	Human	DED: Pure dry eye DM + DED: DM patients with dry eye Control	DED vs.DM + DED	α diversity: Lower in DED β diversity: DM + DED was different from DED	Proteobacteria Corynebacterium	Actinobacteria Bacteroidetes Ochrobactrum Bacillus Cupriavidus Lactococcus Unclassified Clostridiale Lactobacillus	1. DM + DED has unique core members :unclassified Ruminococcaceae, Bacteroides,unclassified Peptostreptococcaceae, unclassified Barnesiellaceae; 2. Pseudomonas was the only core members in DED.
			DED vs.Control	α diversity: No differences β diversity: DED was different from control	Bacteroidetes Methylobacterium unclassified Rhizobiales Amycolatopsis unclassified Xanthomonadaceae
Chen [7]	Human	DM-DE: Diabetes children and adolescents with dry eye NDM: Healthy controls	DM-DE vs.NDM	α diversity: DM-DE> NDM β diversity: DM-DE> NDM	Firmicutes Bacteroidetes Tenericutes Acidobacteira Acinetobacter Lactococcus Bacteroides Staphylococcus	Pseudomonas Paenibacillus Rhodococcus	1. Lactococcus, Bacteroides, Acinetobacter, Clostridium, Lactobacillus, and Streptococcus are the unique flora of the DM-DE group.
Fuxin Zhao [34]	Human	MGD: Patients with MGD HC : Absence of any dry eye symptoms; Absence of any symptomology that are criteria for diagnosing MGD; Corneal fluorescein staining was negative	MGD vs.HC	Meibomian gland secretions: Chao1:MGD< HC Shannon and Simpson : No significant differences	Meibomian gland secretions: Rubrobacter Novibacillus Campylobacter Geobacillus Sphingomonas Corynebacterium Sphingobium Pedobacter Fictibacillus Enterococcus Sphingobium sp.SYK-6	Proteobacteria	1. Geobacillus,Sphingomonas,Sphingobium, Pedobacter,Fictibacillus,and Enterococcus was specific to the microbiome of the Meibomian gland secretions ; 2. The detection rate of pathogens in the secretions of MGD patients is lower than that of HC; 3. The secretions of MGD patients showed increased expression levels of genes related to carbohydrate metabolism, fatty acid elongation, biosynthesis and degradation, glyceride metabolism.
Xiaodan Jiang [35]	Human	MGD: Mild/Moderate/Severe Control	MGD vs.Control	Meibomian gland secretions: MGD(Severe)> Control	Corynebacterium macginleyi Staphylococcus		1. The detection rate of bacteria in Meibomian gland secretions of MGD patients was significantly higher than that in the conjunctival sac (CS), the bacterial composition of MG is more complex than that of CS; 2. Corynebacterium macginleyi was only detected in the severe MGD group, with a detection rate as high as 26.3%.