Recent science has established that the health of our microbiome —
especially the organisms that live in our intestines — is directly tied
to our broader well-being. To bolster our gut ecosystems, many of us
consume probiotics: living bacteria found in supplements or fermented
edibles like yogurt and sauerkraut (for more on this, see “Probiotics at Work“).
Yet downing probiotics and -fermented foods is not enough to keep our guts healthy.
“Even if I give you the very best probiotics — and large amounts of
them — those bacteria live less than an hour, then they’re gone,” says
Robynne Chutkan, MD, author of The Microbiome Solution.
We have to feed those bacteria so they can survive and thrive. That’s where prebiotics come in.
Prebiotics — including resistant starch and specific types of fiber —
are indigestible nutrients that ferment in the large intestine,
providing nourishment for the gut’s healthy bacteria. Unfortunately, the
standard American diet, high in processed ingredients, doesn’t provide
enough prebiotic foods.
“With the Western diet, the colon has become malnourished,” says
Stephen O’Keefe, MD, professor of medicine at the University of
Pittsburgh.
When intestinal bacteria don’t get enough prebiotic food, they start
to feed off the colon’s mucosal lining. Lacking appropriate nutrition,
beneficial microorganisms grow frail and become unable to ferment
prebiotics. This causes the colon to become more alkaline, which
creates an environment for acid-sensitive bacteria — like strains of E. coli and salmonella, as well as other potent pathogens — to bloom.
The proliferation of harmful bacteria can set off a microbial
imbalance, known as dysbiosis, and lead to problems such as leaky gut.
This in turn can trigger autoimmune disease and metabolic disorders.
(For more on this, see “How to Heal a Leaky Gut“.)
Sluggish prebiotic fermentation also creates a self-reinforcing
pattern that further restricts the creation of food for our friendly
microorganisms.