we can't digest fiber right? wrong. today we're going to look at how our
microbiome, the bugs in our gut, can help us lose weight and avoid
disease and ways to keep our microbiome in good shape to improve our own health
this is three mind-blowing facts about your gut microbiome
number one: we're less human than we think. we are
supraorganisms, made up of both human and microbial cells
and the microbes may actually be in the majority. our genetics
are even more skewed, one percent of the genes we carry
we inherit from our parents, that's the human genes in the human cells,
the other 99 percent are in our microbiome
and we get them from the environment like our mother's birth canal and
breast milk and all the genes in our body, human or microbial,
can impact our health. "man i feel like taking a shower!
why are all these bacteria hanging on to us?". well, they get their food from us
we have this idea that when we eat fiber it goes in one way and out the other
unchanged. nothing could be further from the truth
the soluble fiber in our food gets fermented and broken down by the
bacteria in our gut so our lunch is their lunch. "so you're
telling me these moochers are coming along for the
ride and getting a free lunch out of me while contributing nothing?". oh they
contribute plenty. fact number two: your microbiome can help
you lose weight. we think fiber is just bulk that fills
us up, and that's part of it but there's so much more. when bacteria
break down fiber they produce these incredible molecules
called short chain fatty acids. i know that's a
mouthful but just like insulin and dopamine used
to be technical terms and now they're mainstream and everybody
knows them i predict that in about five or ten years everybody will know
about short chain fatty acids because their effects are pretty
spectacular. do you sometimes overeat and end up
putting on a little bit extra weight? microbiome to the rescue. scientists
watched volunteers at a buffet lunch. when people were given short chain
fatty acids beforehand they ate less and over time they put on
less weight even though they had access to the same amount of food
they were just naturally less hungry. how does that work?
short chain fatty acids cause the cells in our gut wall
to produce hormones that reduce our appetite. also,
in animal models like rodents short chain fatty acids
cross the gut wall and go all the way to the brain directly influencing a part of
the brain known as a hypothalamus to reduce
appetite. we don't know if that happens in humans yet but whether it's through
the gut wall or directly in the brain our microbiome and short chain fatty
acids help us feel satiated with less food
still doesn't seem fair, i mean i'm feeding them, carrying them around like
i'm their uber driver, they're squatters! well you might change
your mind when we look at fact number three: our microbiome helps
us fight disease. so our microbiome feeds on fiber and
produces short chain fatty acids. we already saw
that they can help with appetite and weight loss, but that's just the tip of
the iceberg. short chain fatty acids also feed our
gut wall and prevent leaky gut, they fight
inflammation and reduce our risk of developing colon
cancer. maybe even more impressive, they can protect us against diabetes
diabetes? colon cancer i understand, it's gut stuff
but how can these bugs change my blood sugar? scientists took
people with diabetes and fed them a high fiber diet rich in whole grains
the total number of calories was kept constant
and this was a randomized controlled trial which if you watched
last week's video is a very rigorous way to conduct the experiment
and allows for a high level of confidence. now, at first glance you might
think this sounds like a bad idea. you take a
diabetic who has high blood sugar and you give them a carbohydrate-rich
food like whole grains. doesn't that make things worse? but the
fact is the opposite happened. the high fiber
whole grain rich diet was more effective at lowering blood
sugar and this effect was tied to specific gut bacteria. as the
scientists explained: "we observed more significant and faster
improvement when more diverse carbohydrates were
provided as added fibers in the diet". so how does this work?
we saw earlier that fiber and short chain fatty acids can help with weight
loss. and in fact people on the high fiber
whole grain diet shed more pounds which can improve glucose levels. the
authors suggest another possibility: remember those hormones produced by the
gut wall in response to short chain fatty acids
and that help us lose weight? well those same hormones
also regulate insulin and glucose metabolism. whether it's through weight
loss or through these incredible hormones,
it's amazing that the bugs in our gut can help us fight
diabetes and that something as simple as eating more fiber can get our microbiome
fired up to do its job and get us healthier. we already knew
from population studies that people who eat whole grains have a
lower risk of developing diabetes but that could be a coincidence. maybe
people who eat more whole grains eat less refined grains or they have other
healthy habits. these results from the randomized
controlled trial suggest that eating more fiber rich foods like whole grains
indeed has a protective effect against diabetes, that it's not just a
coincidence. it's a really powerful illustration
that testing things directly can surprise us and that we should always
try to look for the evidence, not just assume
i'm starting to like these guys. hey, microbes, you're alright.
welcome to the family! i'm not so grossed out anymore! alright,
how do we get more of these little guys? well, one extreme solution
is to just get them from somebody else. there's a medical procedure where
a stool sample from a healthy donor is transplanted to a recipient
it's called a fecal transplant. fortunately for most of us there are
much easier ways. growing a strong microbiome can be as
simple as feeding it, including a variety of fiber sources in
your diet. good sources of soluble fiber include oats, barley, apples,
strawberries, okra and eggplant but rather than
obsessing over individual foods just try to include
a variety of whole unprocessed plants in your diet. another great tool in your
arsenal are fermented foods like miso, kimchi, sauerkraut, tempeh or
kombucha. they include fiber as well as bacteria
themselves for a double whammy. you might want to be
cautious if you have high blood pressure issues
as some of those are very high in salt. you can also make them yourself if you
prefer to avoid some of the additives in the commercial versions
yogurt is also a fermented option, the problem with industrial yogurt are the
additives like sugar but you can get plain yogurt or you can make your own
and if you avoid dairy you can even make it with plant milk
for more on gut health check out this video where i break down how i helped my
own mother overcome irritable bowel or ibs and in this one
we look at more strategies for weight
loss