You really need the three Ps: Prebiotics, probiotics, and polyphenols. Consider the prebiotics to be the fertilizer (fructose polymers are the best, and glucose polymers less effective) for the gut microbes, probiotics to the new plants for the glue and polyphenols as the gardeners. If you have a bad combination of microbes, the prebiotics will help both grow, meaning you really haven’t solved any real underlying problem. Our knowledge of probiotics is minimal because most of the microbes in the colon can’t be grown in tissue culture. Therefore, you have no idea of the best ones to ingest, realizing that 99.9% will never make it to the colon. It’s the polyphenols that are the real key to better gut health as they promote the growth of the friendly bacteria and inhibit the growth of the pathogenic bacteria. That’s why you pay gardeners more money.