The mouth hosts a variety of microbes: bacteria, protozoans, viruses and fungi. Bacteria dominate, and some act as gatekeepers of the mouth, protecting us from pathogens. Practices like vaping, however, can throw off the oral microbiome's delicate balance, leading to health concerns for the mouth and the rest of the body.
"It's not Vegas. What happens in the mouth doesn't stay in the mouth," said Purnima Kumar, professor of periodontology at The Ohio State University. "The mouth is the gateway to the body and because of that there is a pretty large and very vibrant, very dynamic and diverse microbial ecosystem."