In the past few years intensive research has been conducted about the microbiome that inhabits all of our digestive tracts. This microbiome consists of bacteria, viruses, and fungi that live inside of us cooperatively for our mutual benefit. When the microbiome in our gut is very diverse, then our digestive systems, immune system, and nervous system – including brain function – all work better. So how do we develop a healthy diversity in our microbiome?
One answer seems to be what we have been told for years – eat your fruits, vegetables, and whole grains; limit processed foods; eat the many colors of the rainbow; exercise regularly; get adequate sleep; manage your stress, etc.
So how does eating fruits, vegetables, and whole grains actually help? Besides providing certain nutrients, eating these high fiber foods protects the natural mucus layer that lines the gut. The cells lining the gut wall produce this mucus layer in order to trap dangerous bacteria and prevent them for infecting the GI tract. This mucus layer is constantly being degraded in a normal gut so it is vital to keep replenishing it.
Eric Martens, Ph.D., the lead author of a recent study from the University of Michigan Health System says, “The lesson we’re learning from studying the interaction of fiber, gut microbes and the intestinal barrier system is that if you don’t feed them, they can eat you.”
This study in mice showed that the mucus layer stayed thick and infection didn’t take full hold in mice that received a diet that was about 15 percent fiber from minimally processed grains and plants. But when the researchers substituted a diet with no fiber in it, even for a few days, some of the microbes in their guts began to munch on the mucus.
Another recent study from the Stanford University Medical Center intensifies the importance of the above findings. The study, also conducted in mice, indicates that low-fiber diets not only deplete the microbiome, but can cause an irreversible loss of diversity in as few as three or four generations. And once lost, simply “eating right” may no longer be enough to restore these lost species in the microbiome.
The current typical Western diet that relies on processed convenience foods has decreased average fiber intake to about 15 grams per day, which is about 1/10 of the intake of our ancestors. So for the sake of yourself, your children, your grandchildren, and great grandchildren, increase your intake of fruits, vegetables, and whole grains to help benefit all.