interesting and well written article. I would imagine what you eat, amount of saliva, dental hygiene, and a lot of other variables would affect your oral microbiome. what would be a better test is for people with "red complex" bacteria to take this and see the results. the fact that it didn't colonize tells me this is pretty much useless like most probiotics https://medicine.tufts.edu/news-events/news/are-probiotics-a... the author concluded that they will use it again only because of the taste, not because it works.