I have always  been a big fan of fiber. One of the greatest disservices to the field of nutrition has been to label fiber as “non-nutritive”. While it is true that fiber is not directly absorbed into our system, the name non-nutritive” implies that fiber has no importance for us. Nothing could be further from the truth. Our dietary fiber is not digested by us, but by our colonic bacteria. In so doing, do mahy wonder things for us.

 Fiber is the food of the intestinal bacteria which inhabit our colon. We carefully nurture (that is before antibiotics came along) our bacteria as they do many good things for us: make a number of our needed vitamins, and butyrate, a fuel for our colonocytes.  In addition, they occupy ecological niches, thus keeping pathogenic bacteria at  bay, and, in general, keep our colons functioning smoothly. If all these were not enough, there is an even more important  role for these bacteria in keeping our immune system from over-working. This last activity has been the last to  be studied, and is still not fully appreciated by doctors and practitioners. All of these functions of fiber are the result of fiber being the food of our intestinal bacteria. They digest the fiber, and, in so doing, do all these wonderful things for us.