We have a war going on inside of our guts! It is a constant battle between all kinds of bacteria, fungi, and viruses. Do you know what they are all fighting about? FOOD! So to support our health it logically follows we should find out what feeds the good guys and stick to those foods. Right?
The specific foods of choice vary for the different bacteria – good and bad (tip – the bad guys love sugar and carbs). I wrote a lot about that recently in The Skinny Gut Diet. The book is based on how the ratio of different bacteria in the gut reflects whether we are lean or overweight. One of the main nutrients necessary to support good bacteria is fiber.
An interesting recent study shows that when microbes are starved of fiber they actually feed on your gut lining!!! This certainly explains why people very commonly end up with leaky gut (intestinal permeability). The average American only gets about 12-15 grams of fiber a day in their diet. This amount is well below the amount documented as necessary for a healthy digestive system. I’ve been suggesting 35-40 grams daily for years.
Apparently, in the absence of fiber, the microbes are gobbling up the delicate mucosal lining. A thick healthy mucosal lining creates a natural barrier between our gut and our bloodstream, keeping undesirable toxins and undigested proteins where they belong – in the bowel. A thin mucosal lining begins to allow those irritating substances to pass into general circulation – the lining begins to “leak”. Various inflammatory conditions throughout our bodies are the eventual outcome – diseases like cardiovascular disease, high blood pressure, metabolic syndrome and diabetes are some examples.
The study shows that dietary fiber and the diversity of the gut microbes are the crucial elements with regard to keeping your gut lining healthy.
How does this work? A group of researchers at the University of Michigan Medical School found when they fed a group of mice a high-fiber diet the result was a healthy gut lining. When they switched the mice to a more fiber-free diet the mucosal lining layer dramatically diminished.
They then took a different group of mice and fed them a high fiber diet and a fiber-free diet on alternating days. It would be like us having a healthy day of eating with plenty of fiber in our diet and the next day eating all low fiber foods like those found at McDonald’s. I call this Yo-Yo eating. On examination, they then found that the Yo-Yo diet created a thinner mucosal lining – ½ the thickness of mice consistently fed fiber. Obviously the mucosal lining was seriously affected by dietary input.
In another study, adults with diminished gut linings were given a high fiber bar daily. Their mucosal lining thickened. As soon as the daily fiber was discontinued, their lining returned to its original compromised state.
When the gut lining thins it can manifest in severe health consequences in humans as well. A Swedish research team published a study last year that showed a link between bacteria penetrating a diminished mucus lining and the condition called ulcerative colitis, a form of severe bowel inflammation.
I hope you find these studies as interesting as I do. They show how extremely reactive the gut microbiota is to dietary input, specifically lack of fiber. Rapid diet changes likely served us in our evolutionary history in times of feast or famine, but they don’t do us any favors today.
In our culture, with so much junk food at our fingertips, we commonly shift back and forth between healthy and unhealthy food choices, often from one day to the next. We make poor food choices, and then feel guilty the next day and choose better foods = Yo-Yo dieting. Admit it, we always knew that way of eating couldn’t be healthful, and now here’s even more evidence. Science is showing us how choosing chronic low fiber diets over our lifetime, and worse yet, over generations, might very well permanently alter our guts and our health.
Studies like these make it even clearer how our gut bacteria are our key to vibrant health or debilitating disease. So keep eating that fiber! Lets feed the good guys and maintain our gut lining!