Why are bacteria more likely to colonize when doing FMT compared to taking regular probiotics?

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Prodigyev

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I’m sorry I was reading the wiki and couldn’t find an answer to this. Would anyone have an answer?
 
It's because they are FROM a human gut, so they are already selected for being able to survive there! SOME of the probiotic species (such as Lactobacillus acidophilus) were originally isolated from stool, but none of them have been cultivated in the gut for many, many generations.

In addition, FMT contains MANY more species than probiotics. The most diverse of regular probiotics have 20-30 species (most contain <10, and some really rare probiotics, particularly Equilibrium, have >100, albeit none of them isolated from the gut), whereas FMT contains hundreds or even thousands. The majority of species even from a FMT don't colonize long-term, but when you have hundreds of them in total, the chance that at least a few species DO colonize is very high.
 
SFBayFMT5 said:
It's because they are FROM a human gut, so they are already selected for being able to survive there! SOME of the probiotic species (such as Lactobacillus acidophilus) were originally isolated from stool, but none of them have been cultivated in the gut for many, many generations.

In addition, FMT contains MANY more species than probiotics. The most diverse of regular probiotics have 20-30 species (most contain <10, and some really rare probiotics, particularly Equilibrium, have >100, albeit none of them isolated from the gut), whereas FMT contains hundreds or even thousands. The majority of species even from a FMT don't colonize long-term, but when you have hundreds of them in total, the chance that at least a few species DO colonize is very high.
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Thanks! This was a very helpful and well thought out reply! I appreciate it!
 
Synergy and CFU play a major role. An FMT will contain microbes that assist each other in survival and will number in the trillions, rather than billions (like most probiotic supplements). It also helps if the FMT is performed using a stool sample that had just recently exited a person (e.g. within 15 minutes). The more the stool sample is processed, the less effective it is likely to be. Not to mention that the stool itself can act as a buffer.
 
Aim for NaN said:
The more the stool sample is processed, the less effective it is likely to be.
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My own experience and the experience of people I have read about (patient testimonials as well as comparing across clinical studies), this is NOT true. In fact if anything the opposite is true, where patients had good experiences with stool banks/providers who process more extensively and struggle to reproduce that with providers who don't, or studies that used more processed stool reporting a higher percentage of successful FMTs than studies that used less processed stool.

Of the people I have encountered who advocate using minimally processed stool, I don't recall seeing ONE who has actually had the chance to try both highly processed and minimally processed FMTs and who reported a significant difference in response in favor of the minimally processed FMT (if you know of one, please do share it here). The only people I see arguing in favor of minimally processed stool are either those who have never actually done a FMT at all, or else have ONLY ever used minimally processed stool, and who are therefore speaking from assumption and/or educated guessing, not from actually having ever experienced firsthand a worse result from highly processed FMTs (or from knowing a friend or acquaintance who did).
 
SFBayFMT5 said:
My own experience and the experience of people I have read about (patient testimonials as well as comparing across clinical studies), this is NOT true. In fact if anything the opposite is true, where patients had good experiences with stool banks/providers who process more extensively and struggle to reproduce that with providers who don't, or studies that used more processed stool reporting a higher percentage of successful FMTs than studies that used less processed stool.

Of the people I have encountered who advocate using minimally processed stool, I don't recall seeing ONE who has actually had the chance to try both highly processed and minimally processed FMTs and who reported a significant difference in response in favor of the minimally processed FMT (if you know of one, please do share it here). The only people I see arguing in favor of minimally processed stool are either those who have never actually done a FMT at all, or else have ONLY ever used minimally processed stool, and who are therefore speaking from assumption and/or educated guessing, not from actually having ever experienced firsthand a worse result from highly processed FMTs (or from knowing a friend or acquaintance who did).
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There are several studies out there that show reduced diversity and viability the more the stool is processed, especially how it is processed.
Everyone knows a reduction of diversity and viability equates to a reduction of efficacy. Even the type of buffer they use has been shown to do the same. Granted, stool banks and providers more than likely use anaerobic chambers, which significantly reduce exposure to oxygen, which helps with diversity and viability, and they tend to freeze their samples at -80C. Nevertheless, some diversity and viability is lost during the straining and freezing process. Which is to say, a reduction is observed regardless.

The fact that DIY processing increases exposure to oxygen simply by the fact that anaerobic chambers are outside the reach of the average home consumer, not to mention that the average home freezer is normally set to -20C (and arguably not advertised for -80C), would prove that anecdotes show decreased efficacy, especially during cases where more than one FMT was necessary to observe long-term benefit (of which plenty of anecdotes exist). Indeed, notice how your own words use "good experience." What could "good experience" mean if it doesn't imply reduced efficacy?

Even navigating this very website lists studies and clinical trials where reduced efficacy were observed despite competence in processing. So, even in cases where incompetence of processing cannot be asserted, a "good experience" is not guaranteed. To assert that reduced efficacy from theses cases were all due to low-quality stools is arguably naive. If your entire argument hangs on a "good experience," sure, even decreased efficacy can give you a "good experience."
 
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SFBayFMT5 said:
My own experience and the experience of people I have read about (patient testimonials as well as comparing across clinical studies), this is NOT true. In fact if anything the opposite is true
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Don't you have a science degree? You constantly say the most unscientific things, demonstrating a fundamental lack of understanding of how basic evidence works.

Overwhelmingly, the evidence contradicts your claims: https://humanmicrobiome.info/where-to-get-fmt/

The sources that process their stool (Openbiome, Taymount, etc.) have had the worst results by far. And the source that doesn't process it at all (Human Microbes) has had the best results, by far, and would be even better if I did not allow people to choose lower-ranked donors.

One can also browse through the studies that got poor results and see that they processed the stool:


Your personal anecdote does not overrule all the other evidence.

Overall, processing of the stool seems largely irrelevant. Donor quality is really the only factor that seems worth worrying about.

SFBayFMT5 said:
studies that used more processed stool reporting a higher percentage of successful FMTs than studies that used less processed stool
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I think you just completely fabricated this claim to support what you want to be true. Go ahead and look through the studies I referenced above, and make a thread here listing their processing: https://forum.humanmicrobiome.info/forums/fecal-microbiota-transplant-fmt/?prefix_id=63

SFBayFMT5 said:
Of the people I have encountered who advocate using minimally processed stool, I don't recall seeing ONE who has actually had the chance to try both highly processed and minimally processed FMTs and who reported a significant difference in response in favor of the minimally processed FMT
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This is not how scientific evidence works. Anecdotes are ranked very low on the Hierarchy of evidence.
 
Michael Harrop said:
One can also browse through the studies that got poor results and see that they processed the stool:

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What about the studies with good results? It seems you don't even have a tag for that. It's pointless to just look at the failures and not the successes--the point is to find the things that are more common in the successful trials than the unsuccessful ones. Of course it wont be the case that ALL trials that are successful will use one kind of processing and ALL the ones that are UNsuccessful will use a different kind of processing. The James Adams successful autism results used processed stool (and also vancomycin pretreatment, which you claim is unimportant).
 
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