When you count all the little folds, the total surface area of our gut is about 3,000 square feet. That’s larger than a tennis court. Yet, only a single layer of cells separates our inner core from the outer chaos. The primary fuel that keeps this critical cell layer alive is a short-chain fatty acid called butyrate, which our good bacteria make from the fiber we eat. We feed the good bacteria in our gut, and they feed us right back. As shown in my video, Prebiotics: Tending Our Inner Garden, our good gut bacteria take the prebiotics we eat, like fiber, and, in return, provide the vital fuel source that feeds the cells that line our colon—a prototypical example of the symbiosis between us and our gut flora.

, there has to be a way for our good bacteria to signal to our immune system that they’re the good guys. There is. And that signal is butyrate. Researchers found that butyrate suppresses the inflammatory reaction and tells our immune system to stand down, so butyrate “may behave as a microbial signal to inform [our] immune system that the relative levels of [good] bacteria are within the desired range.” Butyrate calms the immune system down, saying in effect, “All’s well. You’ve got the good guys on board.” This ultimately renders the intestinal immune system hyporesponsive, (i.e., accommodating) to the beneficial bacteria. But, in the absence of the calming effect of butyrate, our immune system is back in full force, attacking the bacteria within our gut under the assumption that those are obviously not the good ones since butyrate levels are so low.

at evolved over millions of years getting massive fiber intake. Even during the Paleolithic period, humans ingested 100 grams of fiber a day. So, on fiber-deficient Western diets (Spam on Wonder Bread, anyone?), when our body detects low butyrate levels in the gut, it doesn’t think low fiber. As far as our body is concerned, there’s no such thing as low fiber. So, instead, it thinks bad bacteria. For millions of years, low butyrate has meant bad bacteria, so that’s the signal for our body to go on the inflammatory offensive. That’s one reason why fiber can be so anti-inflammatory and one of the reasons it’s said that “[f]iber intake is critical for optimal health.”

It’s important to feements here, but whole plant foods. Fiber supplementation with something like Metamucil may “not replicate the results seen with a diet naturally high in fiber.”

Written By Michael Greger M, agraph –>