The modularity of microbial interaction network in healthy human saliva: Stability and specificity

The human oral cavity is an important habitat of microbes in the human body. It includes the colonization of various microorganisms such as bacteria, archaea, fungi, protozoa and viruses. Although oral diseases have been studied for decades, we have limited understanding of the boundaries of a healthy oral ecosystem and ecological shift toward dysbiosis. Here, we analyzed salivary microbiomes from 268 healthy adults after overnight fasting. The microbiome data set is firstly divided into five sample clusters based on the similarity pattern of microbial abundance. For each cluster, the correlation networks among salivary bacteria are constructed based on an ensemble of six correlations and two dissimilarity measure. The stability and specificity of modularity in the five microbial networks are investigated. The existences of conserved and changing modules were found across five microbial correlation networks.