[Ballast matter from a microecological viewpoint]

In a traditional sense, ballast matter means food constituents not attacked by digestion enzymes of macro-organism. Thus, they get to the hind-gut chemically unchanged. There they can be metabolised by microbes. Intestinal bacteria also utilize substances that are usually digestible and have escaped digestion within the small intestine, for various reasons. Such substances reveal the same effects as undigestible "classic" ballast matter. Therefore, from microecological-physiological aspects it is suggested to expand the term ballast matter by so-called "optional" or "potential" ballast matter (in the small intestine usually digestible but incompletely degraded nutriments) in addition to "obligatory" ballast matter (nutriments not digestible by indigene enzymes). In experiments with rats, microecological effects caused by the "optimal" ballast matter lactose are evidenced.