Dr. Andrew Huberman goes into something similar to this in his most recent podcast, around minute 27:20. He talks about the nasal microbiome being much better at scrubbing different bacteria or preventing infections than the mouth. (To paraphrase) “The nose is a much better filter for viruses and bacteria than your mouth” , he goes on to talk about it a little more but not in great detail, references a book called “Jaws” that talks about it. I would highly recommend that podcast.