This is pretty much a discovery of the past two decades, and it's radically different than the prior belief that bacteria are something we only occasionally encounter, and when we do encounter them, we get sick. Rather, bacteria are something we live with every moment, and their role in the normal functioning of the body is probably enormous, though this is something we are only now coming to understand. In fact, the study of the human microbiome is just over 10 years old - the term was coined in 2001 by biologist Joshua Lederberg to describe the sum total of the bacteria that coexist with human hosts. The Human Microbiome Project, meant to mirror the Human Genome Project, was founded in 2008, making this a serious investigation for only about six years. In that time, however, thousands of symbiotic bacteria have been identified.
Of course, as this research is being done by Americans, it hasn't simply stopped at observing and cataloguing the range of bacteria present. Instead, we've begun to look at practical applications for bacteria. Some have suggested deliberately infecting children with Helicobacter pylori to prevent development of allergies in childhood, and then selectively killing off the bacteria later in life to prevent ulcers in adulthood. Others have proposed using Oxalobacter formigenes to prevent stone formation in patients who have recurrent kidney stones. Others have begun developing mouthwashes that selectively kill Streptococcus mutans to prevent dental cavities. As soon as we discover something, we immediately start fiddling with it. We're Americans, and we can't help it.
As an ND, I take the perspective that selectively killing some bacteria isn't as likely to be helpful as promoting other bacteria, with the intention that they arrive at a balance between multiple bacteria. This has long been my approach to digestive health, and it's been a pet theory of mine that something similar would prove true about oral health as well. Rather than kill the 'bad' bacteria, why not promote the 'good' bacteria? I haven't developed an oral probiotic mouthwash, but perhaps I should have, because I recently read that probiotic mouthwashes are indeed being explored as an approach to halitosis (bad breath). It turns out that some are taking my approach and looking to promote the use of 'good' bacteria to promote oral health, rather than just killing the 'bad' bacteria.
Perhaps I missed the boat on probiotic mouthwashes, but the future is teeming with possible applications for probiotic bacteria. Will nasal bacteria be used to fight chronic sinus infections? Will they be used to break down harmful substances in the digestive system? Will they perhaps even be used in wound-healing to prevent infection by pathogenic bacteria? This field is still brand new and we're learning about it very rapidly, so I wouldn't cross any of these off the list. Stay tuned.