Re-initiation of oral food intake following enteral nutrition alters oral and gut microbiota community

Gut microbiota influence systemic health. In this study, we evaluated oral and gut microbiota community profiles before and after re-initiation of oral food intake in patients recovering from enteral nutrition by 16S rRNA sequencing of saliva and feces samples. Oral food intake increased oral and gut microbiome diversity and the abundance of specific microbiota, altered microbiotal compositions. Especially, family Carnobacteriaceae and genus Granulicatella were increased in both the oral and gut microbiome. Although oral microbiota showed greater changes than those in the gut, metagenome prediction revealed that there were more differentially enriched pathways in the latter. In addition, more simple co-occurrence networks of both oral and gut microbiomes, indicating dybiosis of microbiota was improved, were observed during oral feeding as compared to tube feeding. Thus, oral food intake can affect systemic health by increasing the diversity and altering composition and co-occurrence network structure of oral and gut microbial communities.