david_l_lin
Joined 6 years ago
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cofounder at Bristle
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Comment · 2 years ago
I should clarify: there’s some more details to why S mutans actually requires low pH. The correct term wouldn’t be “tolerate low pH” but rather “requires low pH” for its stable colonization.
S mutans creates incipient lesions by making acid, incipient lesions are micro environments where the low pH that causes enamel decay is determined by the biofilm on its surface. S mutans cannot thrive in environments with neutral or high pH. the existing community (including other Streptococcus species) create local alkaline environment via multiple metabolic pathways, including the most well studied and prevalent arginine deiminase system. A “normal” healthy community antagonizes S mutans by maintaining a normal pH in saliva and the tooth surface, preventing stable colonization by S mutans.
Without acid production, S mutans cannot stably colonize. and is readily outcompeted by the existing community. Any novel strains of S mutans to “compete for the same niche” will suffer the same weakness unless they create acid. but if this “probiotic” also creates acid, then by definition it also causes cavities.
edit: adding citation https://www.futuremedicine.com/doi/10.2217/fmb-2018-0043
Comment · 2 years ago
This story has been around for far too long and evidence is unbelievably weak, and the claims border on fraudulent.
1. The claim that this strain outcompetes the same S mutans from occupying the same niche cannot be true unless this strain is also capable of creating and tolerating environments with low pH. By definition if it creates acid to the same degree it will also cause cavities.
2. Single applications are insufficient to cause any persistent colonization. Even multiple daily applications of oral probiotics don’t lead to colonization. Oral probiotics function primarily through bacteriocins, not through colonization (except in very rare cases). This is because the existing microbiome is incredibly difficult to outcompete. The community in your mouth has evolved for as long as you have lived, and in some ways was shaped for generations before as it’s technically inherited from your ancestors.
3. S mutans is not the only species that causes cavities. S sobrinus, S wiggsiae, B dentium, about a dozen other acidogenic species also cause cavities.
Source: I’m a cofounder at Bristle Health, the oral microbiome company.
Comment · 3 years ago
Indeed we do! We have an oral microbiome test you can find here:
https://www.bristlehealth.com/pages/products
and our first probiotic here: https://www.bristlehealth.com/pages/probiotic
All the species in the probiotic have been clinically studied with evidence that supports improvement in the oral microbiome and reduction of oral disease. Although, for transparency, the mechanism of action of some of the probiotics is still unclear, and we're working on figuring that out to improve oral probiotics and products in the future.
Comment · 3 years ago
Except that we can! The oral microbiome can be modulated to get exactly what you’re asking: remove pathogens that are good at creating acid and replacing them with ones that are good at remineralizing.
Shameless plug for my company (Bristle Health) that is trying to do exactly that via oral microbiome testing and personalized recommendations and products to improve.
Comment · 4 years ago
Majority were not on medication.
>Eighty-five FES patients and 35 CHR subjects were psychotropic medication naïve and all participants were free of substance abuse, suicidal ideation, and unstable medical illness.
Comment · 4 years ago
Super interesting study! Other studies also associated the oral microbiome with cognitive health, like depression and Alzheimer's, but this is an interesting finding.
>H2S-producing bacteria exhibited disease-stage-specific enrichment and could be potential diagnostic biomarkers
This would suggest that people with bad breath may have higher risk of schizophrenia? Or maybe the reverse? I also wonder if this was controlled for oral hygiene routines and oral health in general? I would assume people with uncontrolled schizophrenia have worse oral health, which may be a factor?
Comment · 4 years ago
In the last 5 years or so, research has shown tight associations between specific pathogens in the mouth and inflammation throughout the body.
Fusobacterium nucleatum and colorectal tumors, Porphyromonas gingivalis and tangles in the brain, Prevotella intermedia and rheumatoid arthritis, the list goes on.
It might be no surprise that you are what you eat, and you eat 100 billion bacteria every day via swallowing your saliva. The gut microbiome gets a lot of traction on HN for its associations with... well anything, but the oral microbiome is relatively ignored.
At Bristle, I'm hoping we can shed some light on the importance of the oral microbiome, and people will eventually stop collecting their poop, and just collect their spit.
Comment · 4 years ago
well, for the most part in healthcare we treat symptoms not causes.
cavities caused by acid producing bacteria? drill and fill
gum disease caused by oral dysbiosis? bone and gum grafts
diabetes from autoimmunity? insulin
high cholesterol from… anything? statins
Comment · 4 years ago
It's interesting that we've become so obsessed with the gut microbiome even though stool only captures a tiny fraction of the composition of the gut.
Similarly, the salivary oral microbiome has also been correlated with mental disorders, cognitive health, is modulated by diet, and plays a major role in systemic health. And saliva is objectively easier to collect. Instead of jumping straight into collecting poop, we should be collecting our spit instead!
https://www.nature.com/articles/s41398-022-01922-0 https://www.nature.com/articles/s41598-021-94498-6
Comment · 4 years ago
All you need to do is visit the dentistry reddit sub and look at threads like this: https://www.reddit.com/r/Dentistry/comments/vnv25a/how_is_he.... They all operate on "production" because billing is top priority.
Comment · 4 years ago
I think it's because incumbents in the space have played a huge role in preventing adoption of new technologies that actually prevent disease. Dentists make money not from preventing disease, but from performing procedures when disease has already progressed to the point of no return.
Cavities and gum disease are bacterial infections that are completely preventable. I feel the need to plug what we've been building at https://www.bristlehealth.com/. We've built an at-home test that leverages the microbes in the mouth to detect disease, and provide actionable and personalized recommendations that can reduce your risk of gum disease, cavities and persistent bad breath.
Comment · 4 years ago
I wonder if the same is happening to mouth microbes, which could explain the epidemic of oral disease in developed countries.
Comment · 4 years ago
Fee for service in health care is not compatible with prevention. The vast majority of oral issues are preventable because they stem from bacterial infections. Dentists take full advantage of information asymmetry: patients assume the dentist knows best. They are incentivized to maintain the status quo that has patients pay enormous costs out of pocket for procedures that could have been prevented early on.
At Bristle, we’ve created an at-home oral health test that also pairs you with ingredient recommendations to prevent the progression of oral disease. The goal is to give data around oral health without the misaligned incentives of a practitioner who benefits from your demise.
Comment · 4 years ago
Honestly, neither. Biology is complex and messy, and often not at all intuitive.
Comment · 4 years ago
Just watched John Q (2002) last night, and can't believe that despite all the attention it gets, nothing has changed at all. Can't say I'm surprised though.