[DIYbio] Re: Another project suggestion: oral weathermaps

Last week, I was at the dentist.  These trips haven't changed much since I was a child:  X-rays, oral inspection, cleaning with metal pick and floss, fluoride rinse, admonition about brushing, flossing, etc, and a freebie toothbrush.

My dental clinic seems like a well-run car dealership.  I'm getting regularly scheduled maintenance but little more.  The focus is prevention, managing expectations and, ultimately, mediocre care.

Teeth are complex, living structures.  And they aren't alone.  The mouth is colonized by bacteria shortly after birth.  They grow easily there, feeding on the plentiful sugars and other foods to found there.  To a bacteria, each tooth is an entire planet, with a population of billions.

Bacteria form complex ecosystems on their teeth-planets.  There are hundreds of species known considered "normal flora" in the mouth; these were identified by culturing, which means there may be 10X or 100X more, plus viruses and fungi.  It is these microorganisms that ultimately determine whether one has cavities, health gums, bad breath, etc.

Saliva helps control microbial growth.  Brushing and flossing helps knock back the population numbers to a more manageable level.  Still, the bacteria have formidable defenses, including the ability to organize into biofilms that are very resistant to chemical or mechanical attack.  They also swap genes all the time.

Most dentists recognize Streptococcus mutans, which converts sugar to acids that can attack enamel, as a prominent microbial cause of cavities.  But what about gingivitis, periodontal disease, or even foul breath?  Chances are good there are complex ecosystems that haven't been teased apart yet with modern gene-based identification technologies.

I propose a DIYbio oral weathermap, something along these lines:

1.  Brushing of teeth with a moistened brush (no toothpaste) then spitting into a commercial spit kit.

2.  The 16S ribosomal RNA genes amplified and sequenced.  The species and relative proportions thereof could be determined, produce a "weathermap" of bacteria.  (We might be able to find a sponsor for this work, given it has downstream commercial applications.)

3.  Correlate results to known oral histories.  We could get copies of our dental charts if necessary.  Mouths with health gums and no cavities would represent the gold standard "balance" of bacteria, while bacterial patterns that correlate with high cavities or more serious diseases would flag the mouth for more vigilant attention, or possible treatment.

4.  Time-course studies could be done.  How do the numbers change over a typical day in a normal mouth?  In a cavity prone mouth?

5.  Explore treatment considerations, eg alternatives for balancing the oral flora back to a healthy mix in ways that ideally do not require lengthy approval processes.  We might think about what could be done with bacterocins, natural compounds, or peptides known to selectively knock back various species, block attachment (see the related 2008 MIT iGEM project here), or interfere with biofilm formation.


Anyone trained in dentistry out in DIY world? :)

Andrew