ABSTRACT
Objective To analyze the diversity of salivary bacteria in patients with nonalcoholic fatty liv-er disease(NAFLD group)and healthy control group(HC group). Methods Saliva samples were collected from 24 patients with nonalcoholic fatty liver disease and 22 healthy control.Genomic DNA of the samples was extracted and extended to 16S rRNA V4-V5 hypervariable region after PCR with Illumina high-throughput sequencing tech-nology.All the data,including operational taxonomic units,diversity indexes and species annotation,etc.was ana-lyzed. Results 39118 optimized sequences in the saliva of each group were obtained,including nonalcoholic fatty liver group clustering OTUs about 308 ± 48 and healthy control group clustering OTUs about 305 ± 53.The diversi-ty analysis of NAFLD group and HC group showed that there was little difference in diversity of the whole salivary bacteria.The data of the species analysis of the saliva bacteria in two group indicate that the composition was simi-lar and the relative abundance was different in phylum and genus.In NAFLD group,the ratio of the abundance of firmicutes(20.42%)increased and the proportion of bacteroides(36.75%)decreased in phylum. Genus of the NAFLD group,the ratio of fusobacterium,porphyromonas and veillonella increased significantly,and the ratio of prevotella and[Prevotella]decreased.Conclusion In the NAFLD group,the abundance of firmicutes increased, and the abundance of the bacteria decreased.It was speculated that the imbalance of the salivary bacteria is associ-ated with nonalcoholic fatty liver disease.