But does the change mean anything?
I think this is going to turn out to be an incomprehensible problem that we will never really get a handle on due to the time it would take to even begin to understand things. We just aren’t able to run those experiments and this is the general domain where science for us fails and degenerates to just-so stories and observational correlations “studies.”
To illustrate…
Last year I did 5 months of OMAD to lose weight. I’d gained a bunch in the first few months of lockdown. It wasn’t hard but it wasn’t easy especially because my wife, who is effortlessly slender and eats a ton, needs to eat a big breakfast every day.
I often wonder if a gut biome transplant from her would give me that - I’d love to see someone actually do that experiment.
But not on me.
Her and her brother can literally eat bags of iced mothers cookies per week and stay slender - her GP says she needs to gain weight. It just isn’t going to happen. It took me awhile to understand what’s going on but my observation is they get really warm and fidgety for the hours after overeating and just burn it off sitting there. Her whole family is pretty lazy, they don’t exercise recreationally. They aren’t running it off or whatever.
Whereas my chronically overweight family lives ends up with moderately high boood pressure, they also all live long lives mostly free of debilitating illness until the end. Her family, on the other hand, has all manner of terrible issues once they hit their 70s…
Obviously this could just be “genetics” but whose? Their nuclear genetics or their inhabitants? And do the long terms come out of that?
I honestly don’t think we will ever know without experiments. And given things like the above I wonder if they can be even done, even if you decided to ignore the potential long term…