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.
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.