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Microbes that cause cavities can form superorganisms able to ‘crawl’ (upenn.edu)
250 points by isomorph on Oct 10, 2022 | hide | past | favorite | 148 comments



The evolutionary adaptations oral bacteria have developed to coexist are fascinating. Another example is the known gum disease-causing species, P. gingivalis, can suppress our adaptive immunity [1].

This finding underscores the importance of taking preventative approaches to prevent attachment of biofilm producers (and why daily hygiene is so important), and finding more approaches to biofilm destabilization, like incorporating arginine into diets and possibly oral care products [2].

Source: founder of an oral microbiome testing company [3].

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5122233

[2] https://journals.plos.org/plosone/article?id=10.1371/journal...

[3] https://www.bristlehealth.com/


I think a very interesting field of inquiry into oral microbiota is a broad evolutionary approach. There was a study published in Nature Genetics[0] showing big changes in oral microbiota corresponding with Neolithic and Industrial dietary change. Modern oral microbiota are markedly less diverse than historic populations and the, much more developed, study of the gut microbiome shows us that very microbial diversity very often corresponds with usually-commensal microbes becoming pathogenic. It seems that cariogenic bacteria became dominant, apparently during the Industrial Revolution.[0] But we know that pre-Neolithic hominins very rarely had caries.[1] Despite affecting anywhere between 60-90% of schoolchildren in industrialized nations, less than 3% of P. robustus specimens examined had dental caries.[1]

What's MOST fascinating to me is that this dance isn't just our mouths vs the microbiomes. There's now considerable evidence that it is more likely to be the host response to the bacteria that leads to the tissue changes noted in gingivitis and periodontitis[2]

[0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3996550/

[1] https://www.sciencedirect.com/science/article/abs/pii/000399...

[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3692012/


>> There was a study published in Nature Genetics[0] showing big changes in oral microbiota corresponding with Neolithic and Industrial dietary change.

A different diet leads to a different microbiome.

I think mammals' teeth last long enough for a natural life. Of course we want a longer and better life.

For instance, all my dogs by age 13 yo have lost half their teeth to rot. We are terrible owners who don't take care of their dental hygiene, which I suppose makes it a more "natural" evolution. Old horses also lose their teeth, too.


> long enough for a natural life

What does this mean though? Ancient lifespans were actually quite close to modern American lifespans. They likely had higher childbirth mortalities so the average may have been low but the modal lifespan was around 70 years[0] which is right around in line with the modern American. Lifespans were significantly shorter in medieval Europe but that was probably the lowest it's ever gotten and that was a relatively short period in human (or at least Western) history. Yet we still find fossil evidence that early hominins and early humans generally had great dental health.[1] Even the Romans, peasant and nobility included, did.[2]

[0] https://theconversation.com/hunter-gatherers-live-nearly-as-...

[1] https://www.npr.org/sections/health-shots/2013/02/24/1726888...

[2] https://www.docseducation.com/blog/ancient-romans-had-health...


I think that we're going to discover that "scorched earth" techniques which indiscriminately decimate bacterial populations do more to perpetuate the problem than to fix it.


Dog food isn't very optimal for dogs...

Most wild dogs would eat almost exclusively fresh raw meat.

Whereas dog food tends to be dried meat with lots of corn as a filler. People wouldn't be able to afford 100% meat dogfood, because dogs eat a lot.


> Most wild dogs would eat almost exclusively fresh raw meat

Is that right? I understood most wild dogs eat a fair proportion of roots/berries and other herby stuff. A quick dig around:

"Unlike cats, dogs aren’t obligate carnivores. They can and do eat vegetable matter. Wild dogs will search for rotten fruit and will eat the semi-digested contents of their prey’s stomach. Some will dig up vegetables and eat grasses and herbs"

https://honeysrealdogfood.com/in-the-wild/


I'm not sure where that data is sourced from... Notice it's on the website of a dog food company, who I suspect has an incentive to tell owners that the veg in the dog food is 'natural'.

I suspect if dogs do eat vegetables in the wild, it's only if they can't get enough meat, since their domestication has made them less good hunters. Their wild counterparts, grey wolves, don't seem to ever eat vegetation (except when sick).


Fair enough but I've heard this (wild dog herbivory) from several sources. I can't find better, sorry.


wolves in the wild's diets are usually around 40% plants but of course that can vary widely from area to area. I'm sure wild dogs are pretty similar


Well, the coyote poop around here often has a lot of of berries in it.

And our dogs will actively eat grass sometimes, but that's probably more about upset stomachs.


> because dogs eat a lot.

Uncooked meat does not have near as many digestible calories density wise as cooked grains. Of course it would be a lot harder for them to become overweight, but the food cost would be tremendous. Remember that obligate carnivores that weigh a lot, like tigers, are incredibly expensive to feed.


> Uncooked meat does not have near as many digestible calories density wise as cooked grains

That seems very unlikely, what with fat and the lipids in cell walls - got a source?


"Our observation that mice fed cooked meat retained higher body mass despite lesser intake (fresh- or dry- weight basis) indicates that cooking increases the energy extracted per gram of meat fed. This finding contrasts with the predictions of conventional nutritional assays, which on the basis of the Atwater system, return roughly equivalent metabolizable energy densities for raw and cooked meat on a dry-weight basis (Table S1). The problem with the Atwater system is that it ignores changes in di- gestibility, costs of digestion, and costs of immune defense, all of which are likely influenced by food processing. The result is nu- tritional inaccuracy. For example, cooking is known to increase the proportion of starch digested at the terminal ileum before access by most gut bacteria (2). Starch that resists digestion in the small intestine delivers only a proportion of its metabolizable energy to the consumer, because the short-chain fatty acids produced during bacterial fermentation of starch generate less ATP than the glu- cose produced by starch hydrolysis in the small intestine. Addi- tionally, the fatty acids are consumed as fuel for gut bacteria, and there are further losses from the production of combustible gases (40–42). Cooking, thus, increases the energetic value of starch to an extent greater than is represented by the Atwater system. Such differences between the calorie values determined by the Atwater system and the physiological outcomes observed in this study are relevant for the manipulation of diets to increased or decreased caloric loading."

* Energetic consequences of thermal and nonthermal food processing Carmody, R. N., Weintraub, G. S., Wrangham, R. W., Proceedings of the National Academy of Sciences2011 / 11 Vol. 108; Iss. 48

* https://booksc.org/book/37997813/2fc522

Note that the 'Atwater' system is referring to the traditional method used to determine caloric content created in the 1890s which burns food and measures the heat obtained from it.

Here is an interesting article about this issue:

* https://www.economist.com/1843/2019/02/28/death-of-the-calor...

I apologize for the single source -- I believed that the science was far more settled on this issue than it appears to be. Regardless, I hope it proves informative for further research if you decide to pursue it.


> We are terrible owners who don't take care of their dental hygiene

Rope toys are great for cleaning their teeth continuously if you don't feel like brushing them. You will need to throw the toys away once a year though.


Do you feed your dogs kibble?

It is not a natural diet.

Horses likewise are typically eating a very unnatural diet, typically hay.

These are both perfect examples of a analogous diet to modern human diet. The difference being that they are animals and have no ability to correct for poor dietary "choices" with proper maintenance.

I agree, however, with your self assessment.


> I agree, however, with your self assessment.

Didn’t take long to go from glib self deprecation to judgy spectator sport.

Okay holier than thou pet owner, you tell me how I’m supposed to not feed my pup kibble. She has a prescription low fat diet and there are two vendors total who supply the prescription. One supplies only kibble. The other supplies kibble and canned food. She will only eat a few bites of the canned food each day. Should she starve because the kibble isn’t natural? The canned food isn’t either, should she just starve? Should I feed her chicken and rice which even with all the fat trimmed off is still too rich for her? Or should she be set free to eat whatever she can get sick on or get hit by a car trying?

I’m doubtful my pup will have rotten teeth at 13 because she’s fortunate that dental health has been among her better strokes of luck. But I’m sure as hell going to feed her the “unnatural” food she depends on to have a healthy life and not feel guilted by judgmental busybodies about it.


It was a bad assessment and a poor comparison.

It's illogical. Your statements are also illogical and emotional.

Figure it out. Dogs can eat just about anything. Kibble is a lot of dried out garbage. Vets are great at selling you stuff and you seem to be a good customer. That's the only compliment I can afford you.

The alternative to not eating kibble is starvation? This is senseless.

I'm no busy body, in fact, I think it somewhat of an admirable trait to tell animal neglectors that they should be better to their animals. But, do feel judged if you choose to air your negligence and someone tells you, rightly, that you are in the wrong.


You’re making so many wrong assumptions to arrive at your conclusion.

> Vets are great at selling you stuff and you seem to be a good customer.

They didn’t sell me anything. They don’t stock the food they prescribed, they named two brands that offer a diet consistent with the prescription and recommended ordering from Chewy. The only relationship they have with Chewy is to confirm the prescription so orders can be filled.

If anything, my vet has been exceedingly conscious of financial impact of vet care. They’ve not only detailed when certain tests or treatments are optional and a judgment call for me to make, but have recommended against certain options as unnecessary, only telling me of those options so I can make an informed decision.

> The alternative to not eating kibble is starvation? This is senseless.

The alternatives were either:

- ignore their medical advice and let her continue to be acutely ill with a high likelihood of chronic illness

- try the prescription diet, which the vet acknowledged may not be sufficient but said it was where we should start; it has been sufficient for nearly a year, the longest stretch of time without any illness in my pup’s three and half years

- try non-prescription options, including home cooked foods like chicken/rice/vegetables; in fact this was part of the diet transition and even chicken breast with all the visible fat trimmed off was too rich for her

- try to change her taste so she won’t eat the kibble, while watching her under-eat with no way of knowing whether or how long that will continue; even with the kibble she’s a very finicky eater and always has been, and I often have had to resort to hand feeding her so she’ll be comfortable enough to eat

> But, do feel judged if you choose to air your negligence and someone tells you, rightly, that you are in the wrong.

With the help of my vet’s care, have got my pup back to health, and kept her healthy. You’re sitting here calling me negligent because you believe I’ve been swindled by an unscrupulous vet and because you think you know better than they or I do what my pup should eat. You are in fact being a busy body. And quite ignorantly so.


> Okay holier than thou pet owner, you tell me how I’m supposed to not feed my pup kibble

No need to take it personally. I don't think they were judging you for feeding your pup kibble at all. Just that it's not a fair representation of a "wild animal on a natural diet"


You should re-read GP for context.


You should reread.

None of what I had stated was directed at your bizarre situation. You have internalized some kind of trauma about your dog and chose direct those statements at yourself.

Get help or something


I’ve got plenty of help thanks


The natural diet of dogs is table scraps. They’ve been eating human leftovers for thousands of years.


The natural solution for dogs which need a special restrictive diet to survive is death. I think we prefer unnatural sometimes.


I wonder how many people, upon observing people feeding dogs table scraps, argued that it was more natural for them to hunt prey, and hide from humans unless they were a present danger, and kill or maim them in those cases.

I’m glad my pup has medical professionals who take her well-being seriously and don’t think whether she gets to live a healthy life is up for abstract debate based on how her ancestors were domesticated.

Thanks for the discussion of how unnatural it is for my pup to be alive and healthy. I’m much more educated now.


I went to an exhibit of an excavation of an old (4th/5th century) settlement in the Adriatic and it detailed every single skeleton pulled out of the different cemeteries. The interesting part for me was that almost every single one of them had bad teeth -- caries and periodontitis.


Go back another 2000 years or so, and nearly every one has great teeth...

The switch of grain-based diets is suspected to be a big part of the cause.


AFAIK, Ötzi (3230 BC) had cavities.


well, Ötzi ate wheat..


Yup makes sense. From what I've read, the switch to relying on more starch in our diets played a big role and that's a population that very much relied on a select few primary crops

It's important to remember that hunter gatherers had much more diverse diets than agriculturalists (and therefore also much better food stability). I would posit that any member of a primarily agricultural society had terrible teeth. But we generally see this less in non-agricultural diets

That being said, when you have Inuit people eating mostly meat with moss being a major plant source and Ryukyuan people turning an extremely poisonous plant (cycads) into everything from flour to alcohol, it's important to note that ANY generalization about human diets (and the health outcomes heavily affected by those diets) is hard to generalize


What do you think of mouth washes that contains Cetylpyridinium Chloride (CPC)? I was reading they may help inactivate SARS-Cov-2 in saliva. I wonder though about (1) killing everything in the mouth or (2) providing oral probiotics (I take one from Life Extension).

"Cetylpyridinium chloride (CPC), a quaternary ammonium compound, which is present in mouthwash, is effective against bacteria, fungi, and enveloped viruses. ... Interestingly, we found that low concentrations of CPC suppressed the infectivity of human isolated SARS-CoV-2 strains (Wuhan, Alpha, Beta, and Gamma) even in saliva."

https://www.nature.com/articles/s41598-022-18367-6

https://pubmed.ncbi.nlm.nih.gov/34282982/


Never use toothpaste that contains triclosan as it wipes out your gut bacteria if you swallow any and nobody can prevent swallowing any.


If I don't use mouth wash I end up getting ulcers all over my mouth. It's strange, not sure why but my mouth can't handle living without it.


You're not rinsing your mouth out after brushing are you?

For most spitting but not rinsing is as good as mouth wash.


Surely rinsing out the debris dislodged during the brushing process is preferrable to letting it remain in the mouth.


No, the current day advice really is to let whatever toothpaste is in your mouth after spitting just stay there.


It's just my mouth not being able to handle even the good bacteria. My genes are weak.


A fascinating field of inquiry. Digestive systems and their inhabitants have evolved over millions of years.

I recently shifted my mindset to feed not just for me, but also for the ~2kg of microbiota [1] inhabiting my digestive system. Has been great for my health.

[1] https://www.racgp.org.au/afp/2017/april/the-gut-microbiome/


So glad to hear it! These microbial communities play a critical role in our health, so we should feed them accordingly. We're trying to help educate on the same behavior for the oral microbiome. There's a lot of focus on what not to eat (sugar, etc.), but not on what we can eat to improve our oral health. We wrote an article on it here [1].

[1] https://www.bristlehealth.com/post/improve-your-oral-microbi...


I found your article well intentioned and organised but frustrating, because it contains not enough examples for the non expert public it addresses. E.g. what are examples of "sticky and starchy foods"?


Thank you for this feedback, I appreciate it. We'll get the article updated to include more examples. If you have any other feedback on the article or site please let me know! Always trying to improve it.


Potatoes, tapioca, rice, beans...


Interesting how this article points out that foods like fish and eggs are high in sulfur contribute to gum inflammation, but that omega-3 fatty acids can help reduce this inflammation. I guess that piece of salmon may counterbalance itself.


What sort of foods do you recommend? I've heard good things about yogurt, cottage cheese, and kimchi; but don't know for certain.


It appears that probiotic foods are beneficial in isolation, but my recent reading (no singular source) indicates that it’s far more effective when combined with a varied and high fibre diet.

It seems like you can do great without the probiotics too, and only ensure you have a good quantity and diversity of high fibre foods in your diet. This seems to be the cornerstone of enriching and sustaining gut biodiversity.

A lot of people think they have the fibre part down, but the science suggests most of us are nowhere near adequate intake. Around 40 grams seems like the minimum, but if you can go higher, there doesn’t appear to be a disadvantage, but there could be more benefits.

A key factor here is that fibre from whole foods is far more beneficial to the gut flora. If it’s highly processed, it’ll move through the gut too quickly. It’ll help you move stool in the case of something like metamucil, but your gut won’t derive much benefit from it otherwise.

Off the top of my head, some excellent gut foods are:

- whole grains with the hull intact (oats are great)

- all legumes

- avocados

- berries

- many nuts and seeds, but especially chia, flax, sunflower, pistachio, walnut, coconut

I land somewhere around 65 grams per day, but I’d like to do better. In the USA, the average is around 16 grams. It’s nowhere near enough to support proper intestinal motility and robust, diverse flora.

Definitely eat probiotic foods, but include as many whole, high fibre foods as you can too.


These are pretty consistent with mine however I'm on keto so I avoid oats / carbs.

I like to add fermented foods such as pickled vegetables, sauerkraut, kimchi before meat and fat. Some insoluble fiber occasionally also such as psyllium husk. Quality of stool is a key gut health indicator so I keep a close eye on how my diet impacts that... but I don't keep a log! :-)

Avocados, walnuts, macadamias (amazing fat profile), pecans. Getting a variety of leafy greens each day.


I realize that this is a late comment, but what's your opinion of kefir (primarily homemade, not store bought) and its impact on gut health?


There is evidence that it provides some benefits, but I’m not aware of any research indicating why that is. The best guess is that certain microbes confer benefits, but I don’t believe they’re exclusive to kefir and the mechanism is unknown.

If it’s milk kefir, I’d say that there’s a wealth of research showing that dairy isn’t particularly beneficial to your health and my gut feeling is that you could replace milk kefir with other foods which are known to be health-promoting as well as flora-promoting and you’d be in a better place.

I’d also guess that sugar-free kefir would be ideal if you did decide to use it. Sugar seems like it quickly becomes harmful to gut flora and its diversity, so limiting it would be well aligned with the intent of building up better flora.

Overall it’s one of those things where you can ask: is it replacing something worse? i.e are you drinking kombucha which has very weak evidence of benefit, but some evidence of harm? Then it appears kefir is a good decision.

However, you can also ask if something better could take kefir’s place? This is a very individual thing. For some, they might be replacing Coca Cola with fruit juice, and if that’s the best they can manage than that’s fine - it’s still better.

If in your case it’s replacing milk with milk kefir, that’s also better. On the other hand, if you could replace milk with eating more greens for minerals, avocado for fat, and a blend of whole grains and legumes for protein, I suspect your baseline of health would increase and your gut flora would benefit more than from the kefir alone.

It’s all about “could I do something better?” because there are no silver bullets. Kefir, when added to a poor diet, will probably not provide a fraction of the benefit that simply improving the overall diet could.


Diluted vinegar; not a lot, not every meal, but a little bit once a day(I usually take it with canned seltzer water at dinnertime). It's the oldest recorded all-purpose tonic and it has a very clear purpose in digestive health by biasing the body's pH balance a little more acidic, which makes some foods easier to stomach, and also pushes the adaptive fitness of the gut.

While the scientific framework I'm building off of is patchy, I think of the gut biome as something you have to "train up" to give effective responses instead of dumping its issues onto other regulatory mechanisms, so exposing it to a variety of training scenarios would be an instrumental part of that, and it probably wouldn't be a factor of specific foods so much as general %s of fiber, fat, acidity, salinity, etc.


Doesn't arginine also stimulate the herpes virus? Seems that integrating it into diets could have the opposite of the intended effect for some people.


Interactions like these are why medicine always feels 30 years behind technology.


Interesting company! Are there any commercial oral care products with arginine in them? What’s your opinion on the toothpaste with lysine supplements and the oral probiotics for gum care?


Thank you! There are some commercial toothpastes (like Tom's of Maine [1]) and chews (like BasicBites [2]) that contain arginine. I expect we'll see it incorporated in more products soon.

RE: oral probiotics, there is some promising evidence of oral probiotics in improving oral health. We wrote a guide [3] based on the available research that might be helpful.

For lysine, we're still looking into the evidence, but we're excited to see more innovation and research into oral care product ingredients that work with the oral microbiome.

[1] https://www.tomsofmaine.com/our-promise/ingredients/arginine...

[2] https://www.basicbites.com/

[3] https://www.bristlehealth.com/post/a-guide-to-oral-probiotic...


Is arginine necessary to apply topically to the teeth, or can it just be ingested? If the latter, you can get l-arginine supplements easily. They are also supposed to help with certain, um, circulation issues.

Also, xylitol is a great biofilm disrupter. Chewing xylitol gum has been shown to be beneficial in preventing carries.


Its difficult to find Xylitol gum that uses traditional tree sap and not plastic resin (and also doesn't contain added sugar). Any suggestions?


Xylichew uses birch and beech resin and has a gum base free of plastic.

To ensure I get an effective amount of xylitol, I use crystals in my tea and coffee. My child eats them with a spoon. Health Garden is one of the brands that uses birch xylitol.


How much is effective? My dentist recommended it ages ago and I kind of forgot about it.

Also, any health concerns with consuming xylitol?


For dental caries, 6-10 grams per day [1]. Most adults can tolerate 40g.

Diarrhea is a concern at 45g for children and 100g for adults. If you introduce it gradually into your diet, it should not be a problem.

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4232036/


Health concerns for humans is potential digestive issues at high amounts (many tends of grams). Health concerns for canines is prolonged excruciating death due to live failure in rather small amounts. Don't let your dogs near xylitol.


Just mixing up Xylitol in water and swishing around is good too


1. I heard that oral health either predicts or is a causal effect in dementia and Alzheimer’s. What’s the mechanism?

2. Should we be having micro biome implants? And more ridiculously, but not really, should we have “celebrity micro biome” products?


Concerning 1.

The above mentioned [1] species P. gingivalis is suspected to be a link there. [2]

[1]: https://news.ycombinator.com/item?id=33158019

[2]: https://en.wikipedia.org/wiki/Dementia#Dental_health


I think a good beginning would be figuring out how to help balance the microbiome rather than destroying it routinely.


Scared of biofilms? Just take ambroxol, acetylcysteine and Loratadine.


I don’t know much about this but doesn’t arginine increase likelihood of cold sore outbreaks? This would be an unfortunate side effect of encouraging people to consume more arginine.


What do you recommend as a generic approach to improve the oral microbiota without test?


Is there an ETA on global shipping?


We're working on this right now! If you send us an email at info[at]bristlehealth.com I'll send over more information shortly.


Anecdotally, I’m having one hell of a time with my 3yo and 5yo’s teeth.

No juice. No soda. No bad snacks. Lots of dentist recommended foods and snacks. Full brushing and flossing regimen. Fluoride. Dentist applied special fluoride treatments. Trust me when I say we’re doing everything right.

And yet they’re 3 and 5 and have had so many cavities.

I asked my dad about it and he said my brothers and I had, frankly, poor dental hygiene, and not a single cavity until our teens.

I’m not saying it’s because of this organism or any specific thing. But I cannot shake the feeling that something significant has changed in the last 30 years.


It is my understanding (from reading Kiss Your Dentist Goodbye) that bacteria is seeded from primary caregivers in the first year of life, and it can be difficult to modify them after this, but it’s possible.

My sister has impeccable dental hygiene and many cavities. Her children have had anesthesia because they needed so much dental work. I’m the kind of person who would floss once a year and never had a cavity until I was 28 and drinking many acidic diet sodas. I started the book’s regimen using xylitol, eating basic foods like chocolate and cheese after acidic foods and drinks, took Florassist dental probiotic and stayed on top of cleanings and have had less problems since. My child is okay so far despite some not so great habits. I get extra cleanings that first year and make sure other caregivers do too.


Any chance they are mouth-breathing at night? It can lead to a shift in pH in the mouth which may increase risk of cavities [1]

[1] https://pubmed.ncbi.nlm.nih.gov/26666708/


Could be something has changed, or else something else is at work. I had wretched teeth throughout my youth and through my late 20s. I have 8 or 9 crowns maybe 16 teeth, a few with fillings; some were pulled for orthodontic work. Then about 10 years ago I stopped regular dental hygiene practices: I brush my teeth once a day (most days) and rarely floss. Haven't had a "watch" in years since I dropped the practice of flossing once a day and brushing twice. My breath isn't foul smelling, either, except when I have tonsil stones (which is rare these days). Maybe for me the hygiene disrupted whatever was in my mouth that was disrupting the bad bacteria.


I’ve flirted with conspiracy-like thoughts on the dental industry and how they might be “confidently wrong” about things the way the rest of the medical industry famously has been on numerous topics over the centuries.

I wondered (with absolutely no basis in fact) things like, “maybe the calcified tartar forms a barrier?”


Man I hate this line of thought because I completely fall into it too, haha. For a really, really long period of life, I had just awful dental hygiene practices. Honestly don't even want to describe it because it makes me a little disgusted with myself (ironically, in a way). But, I also never had dental issues. Ate whatever, drank whatever, didn't care.

Then a few years ago I get my shit together more and start a daily routine. A few months in, I finally visit a dentist for, I swear, the first time in a decade. I'm expecting them to find the motherload of disease in there, but nope. They tell me everything looks fine, except for a tiny bit of gingivitis. Take some x-rays and I'm on my way. 6 months later, worst head pain of my life turns out to be a deep one that needs a root canal. Now I've got a bunch of fillings, a crown, etc.

I still brush daily and my mouth feels like shit if I go without for a few days. I know in all logical ways, it's just a string of luck and coincidence. But damn does the conspiracy part of the brain start spinning up on my anecdotal experiences... lol.


I haven't had any cavity in over a decade. However, there is a Huge hole on top a molar about which I am worried. But the dentist always says it is not a problem.

Maybe a feature like that one can turn into a bad cavity when dental hygiene is abandoned for a short time?. I hope I don't find out!


I'm pretty convinced that fluoride is not needed in water or toothpaste. My family of four uses reverse osmosis to remove fluoride from tap, and have used fluoride-free toothpaste for the last 10 years. We all have impeccable dental health despite regular sugar in our diets, but we do practice strict flossing and brushing.


There's actually a lot of evidence that you're right. But only in places where flouride toothpaste use is high. It seems it mostly makes a difference in areas where use of flouride toothpaste isn't widespread. In areas where it is, the risk of dental flourosis (though a relatively small risk) seems to outweigh the potential benefits


Whatever the case is nano-hydroxyapatite is quietly becoming available on the US market and kids can safely swallow it so they don't develop fluorosis like I did which never goes away for the rest of your life


I actually had a dentist tell me this recently after a clean. That the only "good" thing about calcified tartar is that is does form a barrier.

But that we should prevent it accumulating in the first place and causing tooth damage.


This sounds similar to how not all biofilms are cariogenic and can actually play a lot of beneficial roles. We have a lot of evidence[0] that in the past we had a much more commensal microbiome but the shift to a more cariogenic one was actually rather recent. I feel like it's very likely that our oral microbiomes simply haven't had enough time to adapt to the massive shift in modern lifestyles and diet but used to play a mostly beneficial role in our health, much like our gut microbiome did. I mean just look at Google Pics of the teeth of wild monkeys and apes. Pearly whites! No dentist needed

[0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3996550/


> But I cannot shake the feeling that something significant has changed in the last 30 years.

This doesn't make sense unless everyone around you also suddenly got more cavities recently. If you ask around more, you'll find that there have always been people with good hygiene that get more cavities, and others that don't seem to get them despite poor habits. It may be related your specific oral bacterial biome, or diet.


My teeth were always complimented by the dentist as being beautiful. This is despite plenty of juice, candy, snacks, no special diet, etc, outside of regular dental cleanings and making sure to spend proper time brushing each tooth. I’m 24.

Maybe something else is at play?


Maybe you're doing too much and that's resulting in an unhealthy oral microbiota? I would imagine these microbes have a symbiotic relationship with us, similar to gut bacteria.


> I cannot shake the feeling that something significant has changed in the last 30 years.

Try the past few hundred years: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3996550/

> The composition of oral microbiota remained surprisingly constant between Neolithic and Medieval times, after which (the now ubiquitous) cariogenic bacteria became dominant, apparently during the Industrial Revolution. Modern oral microbiota are markedly less diverse than historic populations, which might be contributing to chronic oral (and other) disease in post-industrial lifestyles.


Have you moved to an area with a different water source than your childhood? Like switching from city water to well water, or vice versa?


I had the opposite experience. 9 cavities in my youth, and my brother had more. My two sons, 7 and 10, have perfect dental health. We are vegan and do eat less sweets than others, but it's not zero, and there is significant sugar in our diet. We've never used fluoride toothpaste but we have been very rigorous in teaching them how to properly floss and brush, and have almost never missed doing it.

I would have thought something changed in the opposite direction in the last 30 years.


Vitamin K? Do they eat their greens?

Natural sources of K include kale, collard greens, spinach, turnip greens, brussels sprouts, broccoli, asparagus, lettuce, sauerkraut, soybeans,edamame, pickles, pumpkin, pine nuts and blueberries.

When young I willingly ate the last two on the list if they were available. Only the command "Eat your vegetables!" at dinner made me partake otherwise.


I visit the dentist once every 5 years or so.

No cavities so far. Last time i checked I was 25 years old. I brush my teeth once a day.

I consider myself lucky, since my siblings have had a couple cavities. My mother attributes this to her being very careful when we were babies to not share any spoons to give us some bacteria from saliva.


My 6yo have had zero cavities so far. Me too had none for years, since we greatly reduced raw sugar from our diet to almost zero. No snacks, lots of fruits, sugar free yogurts etc.


Try giving your kids xylitol candies/mints (available at amazon and many health food stores), initially after every meal - you can probably reduce the frequency/amount later.

There are xylitol chewing gum, but I've read articles about kids dislike for chewing gum these days - so candies/mints may be more palatable.

search for "xylitol tooth decay" for explanation about its effects.

Excerpts from one such link: https://bellharbourdental.com/cavities/xylitol-reverse-tooth...

Mutans streptococci (MS or S. mutans) are a bacterium in plaque and saliva that are major contributors to tooth decay and oral disease.

...xylitol reduces the levels of MS in the mouth. It essentially starves the MS bacterium by not providing any energy to it when metabolized. Since xylitol is a non-nutritive sugar the MS bacteria spend energy to metabolize it and in return receive no energy gain from it. It’s a sunken cost and the S. mutans cannot keep growing. This reduces the population of S. mutans and impedes the ability of plaque and bacteria to adhere to our teeth. It also decreases the amount of lactic acid present in our mouth, making our teeth less vulnerable to decay. Curiously xylitol does all of this without affecting the other beneficial, or overall, flora of our mouths.

Another amazing find has been that when a mother of a newborn uses xylitol, that child’s teeth prove to be more resilient against cavities as they develop. Children have a dramatically lower risk of cavities when their mothers use xylitol starting 3-6 months after childbirth and continue using it until all their baby teeth are formed around the age of 2.

Xylitol comes in many forms but the most common delivery method is through chewing gum. Chewing xylitol gum for 3 weeks or more provides not only short but also long-term reductions in S. mutans levels! Even just the action of chewing the gum helps to rinse away lactic acids.

In order to be effective against bacteria the optimal intake levels are at least 6-10g of xylitol per day. Xylitol gums range from having .75g – 1g of xylitol per piece. So make sure to check the gum that you’re buying to make sure it contains closer to the ~1g/piece mark. In order to reach those levels you will need to chew more than one piece at a time a few times a day. After meals is a great routine to get into, but make sure to wait for at least 20 minutes after eating food before chewing xylitol gum.


Is it really a big deal though? Their teeth are going to be replaced anyway. If it happens in the adult teeth, then worry. Serious question -- I don't have children and it is tough to tell the difference between 'actual problem' and 'parents worry too much'.


Great question. My understanding is that it is a big deal for a few reasons:

- there's 3-5 years more time for 3yo to have these teeth. If the prognosis was long term, maybe no big deal. But cavities over _years_ can turn into far worse conditions

- these _are_ practice teeth in a way. So let's practice proper dental care now so we don't ruin the adult teeth later.

- dentist said there's an assortment of ways damaged baby teeth can harm the adult teeth


It is probably in the job definition of a parent to worry too much. Seriously, I always thought my parents were constantly overreacting, but now I get it. Because for the parent its also often tough to tell, and its also really easy to underestimate problems, especially when they are young. So better safe than sorry, I guess.

For example, really young children can dehydrate to the point of requiring immediate hospitalization within 24 hours, which happens quite fast when they are sick.

Source: an actual anxiety ridden parent.


Teeth will be replaced one by one, and their mouth microbiome and habits will not be replaced wholesale.

Yeah, adult teeth erase some of the damage but it's not a fresh start.


People have varying quality tooth enamel. My friend is meticulous with oral care yet still gets cavities. Her brother-in-law is her dentist (and mine). He said there's not much she can do to improve it.


> But I cannot shake the feeling that something significant has changed in the last 30 years.

Anecdotal, of course, but I got my first cavity at age 30 several months after dramatically improving my oral hygiene.


I could be that their enamel is not strong enough. This could change once they get their adult teeth. Have you checked with your dentist that they are receiving enough fluoride?


What are the dentist recommended foods & snacks?


Lower acidity snacks (less orange juice, less soda, less sticky sugars, more nuts, fruits, yogurts, milk-based treats)


antibiotics can do this.


Face masks during Covid. Massive contribution to cavities in young children.


There's no evidence of this, of course.


Except that every pediatric dentist you can find is pretty sure it has been a factor in large spike in cavities. However good luck having that research done properly that risks being used by anti-maskers.


Literally the Cavity Creeps from the old Crest commercials: https://theretronetwork.com/retro-commercials-crest-team-vs-...


Well done.


Sounds like advanced symbiosis. I wonder if the movement is across a gradient or whether the super organism has a control unit that makes decisions. Are we a result of similar microorganisms?


> Are we a result of similar microorganisms?

Many of the stages required to imagine how life went from solo and unicellular, to cooperative unicellular, to specialized unicellular verging on multicellular, to full-specialization unable to survive independently as a single cell, exists in some species or other today.

E.g. Dictyostelium is an amoeba. (Amoebas are not bacteria; they're eukaryotes like animals or fungi -- sexual reproduction and an encased nucleus.) Individual cells can survive independently, hunting for much smaller bacteria and nutrients. But in the presence of many other cells of its species, chemical communication occurs to trigger and guide cell differentiation. Some at the exterior of the cluster change into a protective shell, like skin, or a macro cell-wall. Others specialize into ion transfer between the interior and exterior environment. Some are even triggered to kill themselves during the reproductive phase, providing nutrients to their kin.

It's on the line between multicellular, and not. Parts can float off and re-join. I think something like that was the intermediate stage in the evolution of multicellular life like animals, but there's many other competing hypotheses and none seem to be universally accepted.


> Are we a result of similar microorganisms?

I think the answer to your question is probably "yes." I listened to an interesting show on PBS radio 30 Oct. about what happened 2Byo that jump-started evolution. I can't find the show online, which explained in depth, but this short and patronizing video[1] covers the gist of it.

[1] https://www.youtube.com/watch?v=lhF5G2k45vY


Funghi can assemble themselves into a super-organism.

Also, for fun: https://www.nature.com/articles/s41598-022-20080-3

Get "The computational beauty of nature", too. And its repo.

https://github.com/gwf/CBofN


> Are we a result of similar microorganisms?

I'm no biologist, but from what I've read: Probably not. A really important fact about multicellular life is that each cell is genetically identical to any other cell in the organism. Otherwise, different cells will start competing with one another, until the relationship falls apart. In nature, symbiosis only works because each cell has an independent means of reproduction, and that always puts a limit to how close the cooperation can be (nothing close to forming multicellular life).


If you were to pull a random cell from your body, there's a 90% chance it doesn't contain human DNA: https://www.scientificamerican.com/article/strange-but-true-...


A bit clickbait-y. Do you consider your digestive cavity a part of your body or is your body all the stuff around it?


Maybe that statement should come with an explicit topological constraint on the meaning of “inside” the body. Viewed as a donut, gut contents would be considered “outside.”


> A really important fact about multicellular life is that each cell is genetically identical to any other cell in the organism.

Not necessarily. https://en.wikipedia.org/wiki/Chimera_%28genetics%29#Humans

Our cells DNA also drift over time due to localized mutations. What matters is that they should keep obeying all the chemical signalling.

> Otherwise, different cells will start competing with one another, until the relationship falls apart.

When that happens in complex multicellular organisms, it's usually called "cancer".


> In nature, symbiosis only works because each cell has an independent means of reproduction, and that always puts a limit to how close the cooperation can be (nothing close to forming multicellular life)

Mitochondria is its own organism, has its own DNA that is separate and distinct from nuclear DNA. It has been very successful through very close cooperation.[0]

[0] https://en.wikipedia.org/wiki/Symbiogenesis


True, though largely limited to DNA necessary for its functions. I don’t have a citation on me (mobile) but there’s evidence that more “generic” mitochondrial DNA was integrated into the nuclear DNA, and that this is also the case for other endosymbionts.


I have a hypothesis for why this happens. Sexual reproduction has a very neat property: Recombination. Two individuals that each have one harmful mutation can through recombination have offspring without either of them. This allows removal of harmful mutations from the gene pool without terminating someones entire lineage - important when every generation comes with a decade of mutations, unlike microorganisms that are more on the scale of hours or days. However mitochondrial DNA cannot recombine, so it cannot benefit from this mechanism. Therefore it makes sense to move as much DNA as possible from the mitochondria to the nucleus. The same goes for the Y-chromosome, and could explain why it has been losing genes over time at a truly astounding pace.

> In the last 190 million years, the number of genes on the Y has plummeted from more than 1,000 to roughly 50, a loss of more than 95 percent.

https://www.quantamagazine.org/the-incredible-shrinking-sex-...


> > In the last 190 million years, the number of genes on the Y has plummeted from more than 1,000 to roughly 50, a loss of more than 95 percent.

How much of this has happened in the recent human history? Are we becoming less “manly”?


Not really. The y-chromosome started out as a tiny variation of the x-chromosome. So all those genes were duplicates of genes on the x-chromosome.


> and that this is also the case for other endosymbionts.

such as chloroplasts.


They are not. Trees are notorious to have variations across their branches.


I'd think it's quite likely. This also somewhat happens at animal scale FYI. See "colonial organisms" such as zooids / siphonophores, which consist of multiple separate animals that are able to join and work in together and take on specialized roles to form and behave as one larger animal.


I for one welcome our new multicellular, cross-kingdom assemblages overlords.


I for one would prefer a toothpaste with the latest phage therapy to turn these little copulators violently inside out.

Burn, baby, burn!

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4580409/

https://www.microbiologyresearch.org/content/journal/micro/1...


This blows my mind, I just this last week learned about xenobots on Lex Fridman's podcast with Michael Levin. I had no idea how fast evolution can work...


My childhood explained.

Trying to do exactly this for my kids:

"Because these assemblages are found in saliva, targeting them early on could be a therapeutic strategy to prevent childhood tooth decay, says Koo. “If you block this binding or disrupt the assemblage before it arrives on the tooth and causes damage, that could be a preventive strategy.”"


How? Do you just mean by good oral care practices from an early age? Or something more off the beaten path?


I assume they mean figuring out what mechanism they're using to bind and attacking it to prevent formation.


Sorry, my bad. When I wrote it, I realized it might imply I'm doing something special.

I'm just doing the good oral care practices and it's working. My kid is going through dentists visits with flying colors. Not to jinx it.


Xylitol can inhibit multispecies biolfilms [1]. Colonization, from what I understand, is critical in the first year of life and as teeth erupt. Some people have bad teeth and good teeth regardless of their hygiene practices because of early colonization. Artificial sweeteners other than xylitol generally supply energy to undesirable bacteria.

https://pubmed.ncbi.nlm.nih.gov/19178100/


Biofilms has been a noted phenomenon with microbiologists for at least a couple of decades, though I have to admit I haven't seen motility discussed as one of the functions before...


You might find these videos interesting.

Pattern formation by motile E. coli.

http://www.rowland.harvard.edu/labs/bacteria/movies/showmovi...

edit: here's a reference https://pubmed.ncbi.nlm.nih.gov/7596432/

Berg died about 10 months ago.


Years ago, I recall reading about a putative Cavity Vaccine which was a bateriophage which targeted the tiny fraction of species present in the mouth responsible for tooth decay. Supposedly, a one time inoculation would confer lifelong protection.

It has been decades and I have not heard anything more about this. Big Dentist keeping the research down or was there some "in mice" kind of gotcha which limited the treatment?


With the headlines like that, it's usually safe to assume the latter.

I remember reading in Popular Science on and off for years (00s) about all kinds of innovations that were right around the corner ('10-15 or so), much of which still remains firmly in "maybe one day" stage. Maybe a bunch of things didn't come to pass that I don't remember, but I clearly remember a lot of articles about air travel (delta wings everywhere!) and commercial space travel (Burt Rutan!). For a sense of how low my expectations got, I remember reading about the Boeing 7E7 and being surprised when a new generation of airliners was in fact coming out.

That experience has been born out many times since, in my adult life. I've all but completely stopped following "science journalism" as a result. I'll hear about it when it actually happens.


I tracked down the guy who invented this, if this is the version you're thinking of, and wrote him. It wasn't a vaccine so much as it was a replacement of your oral flora and fauna with a non-cavity causing bacteria.

This was maybe twelve years ago, but he said essentially that the FDA really really really didn't like the idea, and he had to sell off bits and pieces of the concept.


I couldn't find my original stuff but ...

Dr. Jeffrey Hillman, previously of Oragenics. Looks like he retired just after we corresponded, no surprise there. He had a version of strepococcus mutans that not only did not dump lactic acid (the mechanism behind dental caries), but also secreted MU1140, helping it out-compete the "bad" strepococcus mutans in your mouth. Well, it's still in the pipeline, maybe, at https://www.oragenics.com/news-media/press-releases/detail/3... ... but right now you can still get Probiora3, which is more of a probiotic for your mouth, kind of the more viable piece, since a one-time treatment replacing bacteria is a little scary to some.

Hope this helps.


This sounds amazing! Got any more info? Where can I find this guy and his patents? I wonder if I can whip something up at home...


Be sure to post a "Show HN" when you start selling unregulated oral biome replacements out of international waters, so I can partake


Count me in, I too am interested.


OMG! I came here to post a question asking if anyone remembered this, thinking surely someone in the HN crowd familiar with it would see this post and click into the comments! Where can we learn more about it?

I heard about it sometime between mid-2006 and late-2009.


I think the real question - did the inventor ever dose himself with the concoction?


Mind emailing me (email on my profile) all details that you dug up?



I am here to remind everyone that the single most important oral hygiene measure is to brush your teeth after each meal. That includes not eating anything between meals.

Then comes using toothpaste.

Then comes visiting your dentist regularly.

Them comes everything else, that includes fluorine..

If you aren't brushing your teeth when needed, the rest is almost wasted.


> I am here to remind everyone that the single most important oral hygiene measure is to brush your teeth after each meal.

Brushing your teeth right after is actually harmful for your teeth.

Your outer layer of your teeth get softer after contact with most foods. It takes a while (40+ minutes) for your spit to harden them again. So the brushing will wear this outer layer down if you're always doing it right after the meal.


Now you know what's goin' on when your gums itch. (:


Wasn’t there a vaccine for this kind of thing already developed, years ago?




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