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Gut Microbes Combine to Cause Colon Cancer, Study Suggests (nytimes.com)
228 points by montrose on Feb 2, 2018 | hide | past | web | favorite | 52 comments

Tangentially related, when implants are placed there is a so called "race to surface" where bacteria try to form a biofilm before the immune system can react properly.


After adhering to the surface, the bacterium starts to divide and encapsulate itself for protection against the host organism’s immune response. This layer of protective matrix, mostly consisting out of polysaccharides, also shields the bacteria from effective antibiotic treatment. The first stage of the biofilm formation is complete and subsequently the present bacteria start to form colonies increasing the internal pressure in the biofilm, which starts to expand.


This is very interesting. It looks like a few subtypes of colon cancers may join the list of cancers caused by bacteria (H. pylori in stomach cancer) or virus (HPV in cervical cancer, Hepatitis in liver cancer). Every bit of preventive care against cancer helps and hopefully a vaccine against these bacteria can save many lives in the future.

Interestingly, there is some push-back against treating H. pylori too aggressively. While it is linked to stomach cancer, there is also some evidence that losing H. pylori is linked with increases in other diseases like type-2 diabetes (but then again, increased rates of type-2 diabetes are linked to losing pretty much any kind of stomach/gut flora). The microbiome is a delicate thing...

Is there such a thing as a vaccine against a bacteria? I thought vaccines were for viral infections.

There very much are! For example, Diptheria, Pertussis, and Tetanus are all caused by bacteria, and we have vaccines for all three

The interesting things about diptheria and tetanus is that the vaccine is not targeted against the bacteria, but rather the toxin they produce.

If you've been vaccination against both of these diseases and are exposed, your immune system will eventually mount an attack against the bacteria, but already has antibodies floating around that inactivate the toxin, which is what is responsible for the severity of the diseases.

Probably the most popular of these are against pneumococcal bacteria (Prevnar, Pneumovax...).

It is kind of scary to see some of the "old guards" of the medical advice I grew up with getting basically tossed. In an exciting way, I should add.

Ulcers, in particular, was huge. So much of previous advice for dealing with them was just flat out wrong.

If this pans out, I'm very interested to see where it goes next.

Could you point out some of the updated advice on ulcers?

Thanks for giving that link. Highly recommend reading it for anyone. And, honestly, this makes me think I should be reading the announcements of all Nobel prizes now. Did a really good job summarizing the reasons.

Is there any cure for it apart from the restricted use of antibiotics?

I don't actually know. :(

My understanding would think diet change could work. But only if you manage to starve the bacteria. Anti biotics are much more straight forward and effective here. Obviously finish your dose.

That said, I've never had an ulcer, so have not actually read much. Other than finding it was none of the root causes I heard growing up.

Thanks :)

It's scary that Bacteroides fragilis is being seen as some kind of "autism cure" [1], and some people actively seek out probiotics with it.

[1] https://www.nature.com/news/bacterium-can-reverse-autism-lik...

Bacteroides fragilis is part of normal gut flora[1]. It can cause infections in the bloodstream(like after surgery/from disease) but trying to balance it in the gut is a different issue entirely. The 2013 study did show some reduction in autism-like symptoms in mice. And they did another mice study on probiotic Lactobacillus reuteri in 2016 with reduction of autism-like symptoms as well.

It's not a cure, but they are studying it to help symptoms. I'm fairly certain you can't buy B. Fragilis commercially anyways.


[1] https://en.wikipedia.org/wiki/Gut_flora

Do probiotics generally work against the bacteria mentioned in the article?

If the cancer risk is low enough and the treatment works it might be worth it. CT scans cause cancer too and yet people get them all the time.

Huh. The wikipedia page of bacteriodes fragilis says that it's an obligate anaerobe[1]. I thought that our bodies were filled circulating oxygen-rich fluids. How can obligate anaerobes surivive in our bodies?

[1] https://en.wikipedia.org/wiki/Bacteroides_fragilis


Gangrene can be treated in part by using a hyperbaric chamber to increase oxygen content of the body. Presumably, if our tissues were all oxygenated, gangrene would never happen.

Your colon hopefully isn't filled with oxygen-rich fluids. And I'm pretty sure that most of the oxygen in blood is bound in red blood cells, so the bacteria would be pretty unlikely to be harmed by it.

Your body is not a sack. There are different structures, with different oxygenation levels in them. Anaerobic bacteria do especially well in mucous-rich areas - the mouth, the gut, and the female genital tract.

Yes but, having B fragilis doesn't mean you'll get cancer. So it's like any medical treatment, you weigh the risks against the benefits.

Yikes. Is this a common additive to probiotics?

If anyone is interested about the topic, there is an introductory MOOC from Wageningen University about the intestinal microbiome and it's effects on health.


What I'd like to know is which types of diets either inhibit/promote the growth of these bad bacteria. The types of bacteria in your gut being linked to parents or young age, might just be a symptom of learning your diet from your parents.

Anecdotal evidence from someone who's been through some of the worst digestive issues possible (stops in involuntary peristalsis/motility, food not digesting) due to "bad" bacteria being continuously introduced from infection elsewhere: yogurt.

Specifically kefir/filmjölk. Buy a bottle, take a serving in the morning, and at night if you like/can afford.

I've turned my life around. Friends have stopped proton pump inhibitors/antacids like Prilosec/Omeprezole, etc, because of this simple lifestyle switch (one serving per day). I take many more.

Also, foods with digestive fiber feed good bacteria, and stop them from munching on YOU, aka, gut inflammation, which is also a big thing we're somehow just learning about now, with relation to how it can ruin your entire life (no exaggeration) with stuff like cancers, Alzheimer's, Parkinson's most likely, etc.

Would like to hear more about how the change in your lifestyle and food habits made a difference. If you don't mind sharing, you can email me, my email id's in my profile.

> the morning, and at night if you like/can afford.

If you have an instapot or yogurt maker, for $2.5, you can make a gallon of yogurt which lasts me about 1-2 weeks. I started my culture with a tub of Activia that my sister left in the fridge ~ a year ago.

Kimchi is also cheap to make yourself, although it does take a bit more prep.

You can also try prebiotic. It’s a blend of short chain sugars meant to preferentially feed “good” colonic bacteria.

Since this study found biofilms in colon cancer, I'd like to point out this recent discovery on the involvement of bacterial phage in biofilm formation:


I am wondering if the type of bacteria they mention is the one that can be found in probiotics. I think I suffer from intestinal candida (I have many of the symptoms) and medical exams of my intestine did not reveal anything (Helicobacter Pylori had been tested but not candida). Thus I have reduced drastically my carbs consumption and also take some probiotics to well balance the yeast/bacteria ratio in my gut.

Probiotics are typically various strains of lactobacillus. Although E. coli and B. fragilis are “commensal flora,” they can be extraordinarily pathogenic.

I don’t think any company wants to take on the liability of feeding you a bacteria with a ~20% mortality rate (the BF) and trying to ensure their cultures never get contaminated with a more toxogenic strain -and- that no one takes it the wrong way (oh, did you bite that capsule open and get the B. fragilis into your peptic ulcer...?).

I haven't seen B. fragilis in any OTC probiotic supplement, but wouldn't hurt to check the label. Typically manufacturers choose strains which are well-studied enough to be blameless, if not necessarily magically good for you (to avoid liability, the cynic in me says...)

Two types of bacteria, Bacteroides fragilis and a strain of E. coli, can pierce a mucus shield that lines the colon and normally blocks invaders from entering

The above text in the article contains a link to an abstract. The abstract does not talk about piercing the mucus lining. It talks about biofilm.

Biofilm is essentially a large colony of bacteria, so large it begins terraforming the body in order to create conditions conducive to self preservation. I have seen a number of articles over the years on how to successfully break up biofilm and thereby reverse antibiotic resistance. They generally boil down to finding some means to make the environment less acidic. There is generally a strong correlation between inflammation, acidity and infection.

This is probably not a simple relationship. The terraforming activities of biofilm suggests bacteria will foster acidity to promote inflammation etc. So the relationship is interactive. It is not as simple as "acidity causes antibiotic resistance".

I don't have these studies at my fingertips. I have no plans to try to dig them up. I am leaving the comment so that other people can look into that if they are interested.

I wasn't reading this stuff in order to support debate points in an online forum. I have a genetic disorder that predisposes me to developing antibiotic resistant infections and I was trying to suffer less.

So, you can take this comment as testimony that these studies exist and may have bearing on the topic of discussion here.

But I am not going to debate this with people who are inevitably monstrously disrespectful towards me and who act like the last 17 years of my life did not happen because I can't link you to a study. The reality is they don't get any less monstrously disrespectful when I do link to studies and supporting articles and explain my thinking etc. So I don't plan to play that game today.

TLDR: If you are interested, you might go looking up studies on how to break up biofilm. They do exist and they contain potentially useful clues to how to stop this kind of colonization of the gut by hostile invaders.

I have always been taught that antibiotic resistance came from bacterial mutation. Are you suggesting that this biofilm is contributing to this resistance as well or instead of mutation?

For your interest: https://www.ncbi.nlm.nih.gov/pubmed/12195733

Biofilms do a number of things - they can help promote between-organism signaling that can promote the upregulation of resistance, they can physically protect from antibiotic penetration (one of many resistance mechanisms), and they can potentially change the behavior of the bacteria itself, which will have impacts on the antibiotic's efficacy (for example, bacteriostatic antibiotics are less of a problem if bacteria aren't proliferating anyway).

My dad fought in WW2. He used to tell this story:

First, invaders would toss a grenade into a room, stunning all occupants, then promptly rush in and capture them at gun point.

Then people began creating a safety zone in the corner with sand bags. When the grenade hit the floor, you dive for cover. After it goes off, you stand up with your weapon, getting the upper hand on the soldiers entering the room.

Then they began tossing the grenade without pulling the pin. People dove for cover and waited for the grenade to go off. Meanwhile, you promptly enter and now you have the jump on them.

So then people would hear the grenade hit the floor and look to see if the pin had been pulled before deciding how to react.

When antibiotics were introduced, the world announced the end of disease. Now, we have antibiotic resistant super bugs.

Antibiotic resistance is an arms race. It is probably not one dimensional. If infectious process were one dimensional, then the initial prediction that antibiotics heralded the ended of disease should have been accurate.

But the only thing I am trying to suggest is that studies exist and people who are interested can look them up for themselves, read them and draw their own conclusions. I am sick to death of trying to discuss what I think about such things. It is never a positive experience.

Sorry that you haven't had a productive discussion with others regarding this.

I just remembered that I have indeed heard about biofilms and their ability to prevent antibiotic activity. However, I have only heard about them in the context of secretions by specific kinda of bacteria (e.g. pseudomonas aeruginosa) that form this wall around foreign objects preventing the efficacy of antibiotics. It is why we have to change out certain catheters after a specified amount of time.

There are a few interesting mechanisms of bacterial resistance. They don’t carry anything with them but genetics, so it’s hard to say it’s Not “always ... mutation”, but the genetic pathways have some interesting variety. You can form bio films, you can form spores, you can have Cell Wall materials that are less target-able by Cell-wall-targeting abx, you can build your own enzymes to degrade abx, you can build pumps to actively pump abx back out of the Cell, you can trap the abx between your cell membrane and your cell wall so that your defensive enzymes have a much higher effective concentration, etc. That’s not even getting into the abx that target transcription and translation, rather than just Cell wall destroyers.

I think the traditional mental model is “evolve a slightly different target molecule so abx can’t target them anymore,” which yeah, vastly understated the complexity.

Wow, what an incredibly defensive tone.

You join a discussion, refuse to provide evidence, and pre-emptively accuse those who disagree with you of being monsters.


This is a very good community with few monsters, typically dealt with expediently by both the community and excellent moderators.

I would expect someone who has been through this before to have some pretty good sources, but you share none. This indicates that they are weak and lacking or do not exist. You also share frustration at people not accepting your personal anecdote as data. This further reduces your credibility. You seek to poison the well and insult those with differing points of view, and refuse to engage in dialogue. Perhaps you'll find your monster in the mirror.

As written your comment is both manipulative and lacking value. It's offensive and insulting to this community.

I'm glad you found something that works for you. If you would give this community a chance you would find it very open minded if you approach it rationally. Hacks, like anecdotes, tend to be exceptions or new discoveries.

I have been here 8.5 years. The comment is informed by long experience, including a recent incident where multiple people chose to focus on my personal medical history, and not in a nice way, and utterly disregarded the actual point I was trying to make.

Further, your comment is filled with personal swipes in violation of community guidelines.

Edit: Here is a link to that incident so people can see for themselves: https://news.ycombinator.com/item?id=16201406

I'm curious, what do you see as a personal swipe?


Yes, I recall you being one of the people derailing the discussion in the recent incident while ignoring my actual point. And now you are justifying your right to do that because "science."

The only medical claim I am making here is that there are studies about biofilm that might interest people. I am tired of people feeling like it is open season on me because the reason I am aware of these studies is because of my health issues. That doesn't seem to be a standard applied to any other member. I am not remotely the only person here who has a serious medical condition and manages it with diet, lifestyle or alternative remedies. I am not trying to promote those remedies here. I do, in fact, have my own blog as an outlet for talking about that stuff elsewhere. That should not be reason to say I am not allowed to mention that studies exist and if I do someone is completely justified in attacking me or suggesting I am making stuff up about my medical situation.

You are free to think I am completely deluded about my medical situation and imagined the whole thing. It has zero bearing on the fact that studies of biofilm exist and people can look them up if they are interested.


No, I do not. Mentioning that I know about such things because of my diagnosis is not me making it about me. I cannot control the fact that other people focus overly much on that. I have tried various approaches. It makes no real difference how I frame things. Other people continue to rubberneck about my stuff. It isn't reasonable to act like I should not mention my diagnosis at all.

Here is the previous discussion where every single reply to me had nothing to do with my point and just chose to get into my personal stuff until I announced I was walking away:


If you do develop colon cancer and are treated with certain chemo drugs some types of bacteria may be eating the drug.


What do these microbes feed on?

They eat certain carbohydrates (such as fiber) [0] that we consume and aren't able to digest by ourselves. This is why it's recommended to eat fiber [1], which many people do not eat enough of. [2]

[0] https://en.wikipedia.org/wiki/Gut_flora#Metabolism

[1] https://www.sciencedaily.com/releases/2016/11/161117134626.h...

[2] https://www.webmd.com/diet/guide/fiber-how-much-do-you-need#...

The same stuff we do. They consume what we eat. And each other, and the byproducts of each other. We (the human) consume these latter to greater and lesser degrees as well.

Maybe the interesting question is what allows for the mucus lining of the intestines walls to deteriorate that much, that those strain of bacteria settle in.

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