The FMT papers you listed have serious issues.
Let's start with Regular fecal microbiota transplantation to Senescence Accelerated Mouse-Prone 8 (SAMP8) mice delayed the aging of locomotor and exploration ability by rejuvenating the gut microbiota. I don't know how this passed peer review. The English is borderline unintelligible. Maybe it's because the editor was Dutch, which is basically mangled English? Chinese academia generally divides papers into two categories: busy work for meeting publication requirements and actual attempts at scientific advancement. You can generally tell if a paper is one of the former if minimal effort is made at making the English understandable, which is the case here. On the plus side, it points out a major issue with the other listed studies: they all use mice that were chronically treated with antibiotics. It claims to not do this. However, they used aging-accelerated mice. I'm guess they didn't want to spend too much time on the experiements?
They did 48 comparison for mobility. No correction for multiplicity, of course. This is sketchy. This is what you would do if you were intentionally trying to p-hack your way to a cool-sounding paper without even trying to hide it.
The other two, as mentioned, both use mice chronically administered antibiotics, explicitly to increase effect size. I'm... not enthused about this. Lab mice already live in immunologically very weird conditions. Fecal microbiota transfer between young and aged mice reverses hallmarks of the aging gut, eye, and brain [I goofed, it was actually the SAMP8 paper] even had the mice raised individually to prevent the natural exchange of gut microbiota! Mice normally engage in mutual coprophagy, so FMTs are actually something they do naturally (weirdly enough, these studies tend to show that younger mice with FMTs from older mice tend to have worse health outcomes).
I honestly don't feel comfortable extending any of these findings to humans, since the conditions are so different. Bathrooms, especially public bathrooms where almost no one flush with the toilet lid down, are filled with aerosolized fecal particles. I was unable to find any studies on the transmission of fecal bacteria via aerosols, but I suspect we're already microdosing FMTs every time we enter a bathroom.
This is one of those issues, where it's clear that Aubrey's list is missing elements of aging that do exist.
Is it possible to grow the microbes in a lab, after obtaining them? Then you would not need so many donors.
No. First of all we don't know which microbes and in which quantities we want. We have more or less no clue what constitutes a good microbiome. Bacteriophages also seem to play an important role that we know even less about. That's the beauty of FMT - we don't need to know!
Second, most microbes in the gut are anaerobic and thus cannot be grown easily. There is not a single anaerobic probiotic available at this point. That's why probiotics don't come even close to replacing something like FMT, which is done suh that bacteriophages and anaerobic microbes survive.
The problem of "growing artificial poop in the lab" for e.g. FMT pills, is similarly difficult/impossible at this point like growing ordinary "dirt".
Is there any information on durability of treatment and/or longevity in storage? Is this something you'll need to do for a month every few years, or a one-time thing in your 40s, or some other periodicity?
More importantly, this isn't particularly high-tech, what's the reason it's not common among at least some sub-groups of people who could have socially discovered this anytime since disease pathways have been common knowledge?
Re. your first question: Not really known, but you can make educated guesses after reading Human Microbes FMT wiki.
Second question: There is a pretty active FMT online community. E.g. there are several facebook groups. Ppl have been doing this privately for a while now.
Interesting; I did several Fecal Microbiota Transplants (I'd rather say transfers, as it is not really a transplant) in the past trying to address severe antibiotic damage and one of the first things I noticed was that my skin and face (in my 40s) looked much younger in a matter of days. It was like an instant lifting. These effects faded away in weeks, not sure if totally but it was something unexpected from this procedure. I also noticed some other nice "side effects" related to aging, and some other effects not so nice like skin itching and many skin rashes for days (my doc said it was an immune activation).
Forget young blood! You want young poop!
In the rest of this post, I will
For many other relevant questions about FMT, please read my other post: Being a donor for Fecal Microbiota Transplants (FMT): Do good & earn easy money (up to 180k/y).
The case for FMTs from young donors for Anti-Aging
Rather than reinventing the wheel and writing this section myself, I’ll just link to relevant sources & articles.
But first I want to freely admit that the case for FMT as an Anti-aging treatment isn't super strong. This is still early in the research. My thinking about this is something like "FMT is safe and risk free, not that much effort, and may have some anti-aging effect. At a minimum, it will improve my gut health, which alone would make it well worth it for me." The cost-risk-benefit analysis is what makes FMT interesting to me.
quotes & links from fightaging.org
Searching “FMT” on www.fightaging.org yields many positive results. Especially:
Here are some quotes from these links:
“Detrimental changes in the gut microbiome might prove to be one of the easier issues to fix in the aging human body.”
“How to go about achieving the goal of putting a youthful microbiome into an old body? The approach with the most robust evidence in animal studies is fecal microbiota transplantation.”
“[FMT] restores a youthful microbiome for a lasting period of time, reduces inflammation, improves other measures of health, and in short-lived species acts to extend life span.”
“[FMT] is already practiced in human medicine, but only as a treatment for C. difficle infection, in which a pathogenic microbial species has overtaken the gut but can be out-competed by transplanted species. It would not be a great leap to adapt this to the treatment of aging.”
“FMT can reverse the aging of the gut microbiome, at least when carried out in animal studies, and as measured by the detrimental shift in microbial populations that takes place with age. Transplanting microbes from a young gut into an old gut reverses many of the alterations in relative abundance of specific microbial species, and has been shown to improve health and extend life span in some species.”
In Gain or Loss of Specific Microbial Species May Be a Better Measure of Gut Microbiome Aging, is is argued that “it is the gain and loss of specific populations with advancing age that produces contributions to aging”.
More links
This page provides a lot of info and further links on the topic. Lots of linked papers there.
LifeXtenShow’s youtube video Are Microbes Making You Older?
Some reviews & papers on aging and gut health
A few papers on FMT for Anti-Aging
Everything else you need to know to get started with FMTs
Choosing a donor
For more info on this, read my other FMT post, especially for sources.
Donor criteria are still very much work in progress, but the following provide a good guess (most important ones first, but all are kind of important):
Screening your donor for parasites & disease
You need to test your donor thoroughly for anything that might infect you. Similar to how you would with a blood transfusion. FMT is only as safe as your donor is healthy.
Learn more on donor screening here.
Performing FMT at home
This Wiki has all the answers you need.
Here is a youtube video.
If you really do this, do some more research for yourself. But the following gives you an idea of what needs to happen:
Instructions for donor to collect the stool:
Instructions for getting FMT:
Help me!
I'm always looking for new FMT donors. In my case to treat my CFS. I also know lots of ppl looking for FMT donors. Please pm me if you think you are a good donor or if you are a (soon-to-be) parent up for this. I'm happy to pay or do whatever.