Fig. 4

Microbial cooccurrence in the healthy ocular surface microbiome and K-means clustering for unsupervised grouping. a Interaction network of species with an average relative abundance greater than 0.1% and appearing in more than two subjects. The colored lines represent correlations between species; red is a positive correlation, and blue is a negative correlation. The heights of the bars are positively correlated with the species’ degrees of connectivity. b K-means clustering (k = 2) performed with the relative abundances of Staphylococcus epidermidis and Streptococcus pyogenes