"Fecal Transplants for Aging and Weight Loss"
Hippocrates said, All diseases begin in the gut.
Previously, I've talked about fecal transplants,
transferring the stool of healthy people into the colons of patients
suffering from inflammatory bowel disease, multiple sclerosis,
even psychiatric problems like depression, bipolar disorder,
and alcoholism to repopulate their gut with good bacteria
in hopes of improving their conditions.
What about fecal transplants for aging?
Might the fountain of youth be a fountain of poop?
If you give mice with accelerated aging
a fecal transplant from healthy mice, they perk up and live longer,
but what about human poop?
We don’t yet have human- to-human aging data,
but we do have mice transplanted
with fecal matter from a centenarian.
Mice fed poop from a 101-year-old versus poop from a 70-year-old.
Lipofuscin is an age pigment
that’s widely used as a biomarker for aging,
and lipofuscin accumulated significantly less
in the brain tissue of centenarian poop-fed mice raising the possibility
that we will one day be using centenarian fecal matter
for anti-aging purposes and to promote healthy aging.
Why bathe in the blood of virgins
when you can dine on the dung of the venerable?
To be continued,
once human-to-human data are published.
Poop you may want to avoid is from overweight stool donors,
given this case report about weight gain after a fecal transplant.
A 32-year-old woman “had always been of normal weight”
until...she received a fecal transplant from a healthy
but overweight donor – her daughter.
After the transplant she became obese,
gaining more than 40 pounds.
“She said she felt like there was a switch inside her body,”
her gastroenterologist reported.
“No matter how much she ate or exercised,
she couldn’t take the weight off.
She’s very frustrated.”
The same thing happens in mice.
Giving mice fecal pellets from an obese mouse
resulted in nearly a doubling in fat mass
compared to lean mouse pellets
despite eating significantly fewer calories.
This proves gut flora can play a pivotal role in obesity…in mice.
What about in people?
Researchers decided to study pairs
of human twins “discordant” for obesity,
meaning one twin was fat, the other skinny.
What would happen if you switched their microbiomes?
The siblings may have been squeamish;
so, the researchers reverted to mice again.
Mice fed stool from the obese twin rapidly swelled in size
but not those fed from the lean twin,
despite comparable calorie intakes.
Cohousing the mice together prevented the weight gain;
however, the lean-type bacteria jumped over to rescue
the mouse fed stool from the obese twin, but—
and here’s the critical point—
only in the context of a healthier diet.
The microbial cure only worked when the mice were fed
low saturated fat, high-fiber diets, which makes sense
since the lean-type bacteria appeared to be fiber feeders.
“Together,” the researchers concluded,
“these results…illustrate how a diet high in saturated fats
and low in fruits and vegetables can select against
human gut bacteria… associated with leanness.”
The results of the twin study
suggest that the role of our gut flora
in obesity is just to help take
fuller advantage of a more healthful diet.
So, if the twins had actually swapped their stool,
the obese twin might have only lost weight if they combined
the microbial makeover with healthier eating
to aid the colonization of the better bugs.
With the new bacteria on board, though,
the healthier diet could have resulted in more weight loss,
even eating the same number of calories.
But you don’t really know... until you put it to the test.
There had been previous published attempts,
randomized double-blind placebo-controlled trials
showing no weight loss benefit
to getting lean donor fecal transplants,
but they kept people on the same crappy diets
that led to obesity in the first place.
Who cares if you keep putting slimming,
fiber-feeding bacteria into your gut,
if you don’t give them any fiber to eat?
They’ll just starve and die right off.
So, maybe you have to do both,
pairing gut bacteria modulation with a dietary intervention.
But, if you do a plant-based diet along with a transplant
and they lose a bunch of weight,
how do you know if the transplant had anything to do with it?
Which brings us to this study,
What they did is put people on a healthy plant-based diet
supplemented with green tea and green smoothies
until...they lost about 20 pounds
over 6 months and grabbed a fecal sample.
Then, they were randomized to spend the rest of the year
constantly seeding their gut with the healthy microbiome
they had achieved at maximal weight loss or to placebo capsules.
The question was once they go back to their regular diets,
would those getting the constant infusion of their own skinny poop
help them keep the weight off? Yes.
They found that participants who lost weight on a healthy diet
and were then fed capsules containing fecal matter collected
during the diet period for months after the maximal weight loss,
regained less weight than participants given placebo capsules.
So, the plant-based diet appeared to produce
the optimal fecal microbiome for preventing weight regain.
But rather than eating your own plant-based poo,
why not just stick with the plant-based diet.