- [Narrator] The ClevelandClinic's Doctor Mark Hyman,
is one of a growing numberof physicians who believe
the path to wellness lies inour intestines, specifically
the relationship between thegood and bad bacteria there,
something called gut flora or microbiome.
- Many of the thingsfloating around in your blood
are informational moleculesproduced by bacteria
that control your biology.
So, that's how the gutmicrobiome can be linked
to everything that's goingon with us in terms of
chronic disease, from cancerto heart disease to diabetes
to dementia, to autism, toautoimmune disease, to depression
and much more.
- [Narrator] Scientistsat America's top medical
institutions are churning out mounds
of data on the microbiome.
The bottom line, as the gut goes
so goes the rest of the body.
- This is the MayoClinic's microbiome lab.
Scientists here examine human feces.
Sounds a little gross,but it tells them exactly
which bacteria are in thepatient, how much of it,
and, what bacteria might be missing.
- [Narrator] Doctor PurnaKahsyap and his team found more
than a thousand differentspecies in the intestines
of the healthiest people,very important considering 80%
of our immune system resides there.
- All of our guts havedifferent kinds of bacteria and
the more different kinds ofbacteria we have, it's more
diverse, and the lessdifferent kinds of bacteria
we have it's less diverse.
And so, as you can imagine ifyou're more different kinds
of bacteria that's generallyconsidered to be good for us
because they will be able totackle intruders much better
than if you have lessdifferent kinds of bacterias.
- [Narrator] In addition tothe variety, the healthiest
people also measure high amounts--
trillions of good bacteria and some bad,
all total 3 pounds worth,
ten times more bacteriathan regular cells.
Doctor Heidi Nelson sees this
as a complex and delicateecosystem that demands balance.
- We think of the microbiomein the gut a little bit like
a garden you have to tend to.
You have to weed it, youhave to put seeds in,
you have to water it.
There's a lot of things youdo. It's not usually one thing.
- [Narrator] Since like allliving creatures, bacteria eat
and expel certain things.
Doctor Nelson explains whyhaving too many or too few
can lead to disaster.
- If you have a build-upof certain bad nutrients,
let's take for example hydrogen sulfide.
We know that some bacteriaproduce hydrogen sulfide
and others remove it anduse it, but if you have
too much hydrogen sulfide,that could, in some people
be the cause of thebreak of DNA that starts
the chain reaction ofcolon cancer developing.
- [Narrator] Not enough goodbacteria or too many bad,
can make us sick and overweight.
According to Johns HopkinsGastroenterologist Doctor Gerard
Mullin, author of TheGut Balance Revolution,
certain bacteria increaseghrelin, the hormone
that causes hunger.
- And when the gutmicrobiome is in a state
of disruption, then weactually have a higher
appetite and we crave more food.
- [Narrator] Certain badbacteria can also cause
the body to crave particularfoods like sugar or bread.
Similarly, gut dysbiosissuppresses leptin,
the hormone that tells us to stop eating.
And it gets worse.
- The gut microbiome alsochanges the way we metabolize
fiber in foods, and can makeus absorb more of our calories
in foods in an unhealthy gut environment.
- [Narrator] A newly discoveredbacteria can possibly
determine whether someoneis either slim or obese.
In fact, research proves thinpeople carry more diverse
gut bacteria than overweight people.
Scientists found people indeveloping countries have more
of this bacteria than Americans.
- There's inflammation thatoccurs when we have an unhealthy
balance of gut bacteria. Itcould really lead to injury
in the gut, a more permeablegut, which some people
call leaky gut, and thereforewhen that inflammation
becomes more systemic, thenwe get insulin resistance
and we accumulate fat more readily.
- [Narrator] In a landmarkdevelopment, researchers
at Washington Universityin Saint Louis, studied
gut microbiomes from human twins.
While they had identical DNA,
one was obese, and the other thin.
Scientists took bacteria from each twin
and put it into germ-free mice.
The animals with the obesetwin's microbiome also
became obese, while theother mice became thinner.
Researchers noted the thinhuman and mice carried more
diverse bacteria thantheir heavier counterparts.
- There's a lot of associationswith the microbiome
and, in children, and theincreased incidence of obesity
and metabolic syndrome amongstthe pediatric population.