1,700 years ago, a Chinese
alchemist named Ge Hong
was renowned for his special soup that
could cure diarrhea-stricken patients.
The stew was deep yellow,
and had an intense aroma.
And, like many family recipes,
it had a secret ingredient.
But in this case, that ingredient
didn’t come from the kitchen—
it came from the bathroom.
It might seem unwise to consume feces,
and today, there aren’t many doctors
who would prescribe Ge Hong’s recipe.
However, exciting new research suggests
that taking poop into the body
in other ways might benefit our health.
One such treatment
is fecal microbial transplantation,
and the secret to how it works
lives in your gut.
Trillions and trillions of bacteria,
viruses, fungi, and archaea
consider your bowels their home.
Collectively, these microbes make
up what’s known as your gut microbiome,
and each of these organisms
possesses dynamic, specialized abilities
that seem to be essential for human life.
They break down our food, make vitamins,
train our immune system
and circadian rhythm,
and even protect us from infections.
In return, they receive
a nice warm place to live,
complete with an all-you-can-eat buffet.
Some research suggests our microbiomes
might start forming in the womb,
but if not, they certainly get
started when we're born.
During a vaginal birth, infants take
in some of their mother’s fecal matter
and microbe-filled fluids.
From then on, our microbiomes
are constantly diversifying
with exposure to various
foods and environments.
This is essential for maintaining
gut health.
If poor nutrition, chronic disease or
antibiotics disturb this delicate balance,
the body can become vulnerable to problems
like bacteria and fungal overgrowth
or infectious diarrhea.
But infusing a new batch
of microorganisms into the intestine
seems to help reset the gut microbiome—
this is where fecal microbial transplants
come into play.
This line of treatment is still very new,
and there are tons of unanswered
questions about how it works.
So currently, the US Food and Drug
Administration only allows doctors
to use fecal transplants experimentally
for battling one of the toughest
gut infections—
antibiotic-resistant
Clostridiodes difficile.
This infectious bacterium forms spores in
the colon that are immune to antibiotics
and very difficult to destroy.
Patients dealing with this infection can
experience months of intermittent fevers
alongside bouts of abdominal cramping
and extreme diarrhea
despite antibiotic treatment.
So when symptoms get this bad, it’s time
for a fecal microbial transplant.
To start the process,
a gastroenterologist first retrieves
some feces,
typically from a stool bank.
These frozen samples are particularly
impressive number twos—
the selected donors go
through a strict process
to ensure their samples
are infection-free.
In fact, these protective protocols
are so stringent,
one prominent stool bank’s
acceptance rate is less than 3%.
Next, the gastroenterologist gets
that sample inside the patient via a pill,
or, more commonly, a tube
into the stomach or colon.
Finally, the transplanted microbes
migrate through the tract
until they find the colon,
where they quickly multiply
and displace the infectious invader.
This process is so effective that it cures
over 80% of patients
in just one treatment.
Because each stool sample is unique,
the FDA still classifies fecal transplants
as an experimental treatment
rather than a formal medication.
But promising research in rodents
suggests new ways
we might use fecal bacteriotherapy
in the future.
For example, fecal transplants
from non-diabetic mice
improved insulin resistance in mice
with type 2 diabetes.
Similarly, some studies have shown
mice exhibiting anxiety and depression
become calmer after transplants
from their less anxious peers.
Scientists studying humans have
even started finding
different microbial patterns
associated with various intestinal,
autoimmune, oncologic,
and even psychiatric disorders.
So, it seems entirely possible
that altering a patient’s microbiome
could allow for multiple new modes
of treatment.
We still have a lot to learn about what
makes the “best” gut microbiome,
or the most beneficial fecal transplants.
But for now, at least we can say
that our feces have a bright future.