Dietary fiber and gut microbiota - why this changes things?

Bruce R. Hamaker, Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, Indiana 47907

The link between the gut microbiota and localized gut and whole body health is now well established. At a basic level, a healthy microbiota is one that ferments fibers well to produce substantial levels of short chain fatty acids (acetate, propionate, butyrate) and low endotoxin for reduction of gut inflammation and maintenance of good barrier function. High inflammation and poor gut barrier function are directly related to non-communicable chronic diseases such as those associated with obesity and metabolic syndrome diseases. Dietary fibers that ferment in the gut and make favorable changes to the microbiota are encompassed in the concept of prebiotics. Although early work focused more on certain oligosaccharides and their promotion of bifidobacteria and lactobacilli, prebiotics now cover a broader range of fermentable fibers that promote beneficial gut bacteria. The challenge confronting scientists is to understand how to use prebiotic fibers (oligo- and polysaccharides) to generate predictable changes in the gut microbiota for improved health. In this presentation, new opportunities for dietary fiber, gut microbiota and health will be discussed; as well as a primer on the complexity of fiber chemical and physical structures and they are utilized by the gut bacteria.