Prophylactic and therapeutic aspects of fermented milk.

Many claims have been made concerning prophylactic and therapeutic effects of fermented bovine milk consumption. Of these, the amelioration of lactose intolerance symptoms in humans and rats due to the reduced lactose level caused by fermentation is convincingly documented and corroborated. In addition, some kinds of fermentation microbes can contribute to lactose digestion in vivo thus augmenting the preingestive fermentative decrease of lactose. Relief of the growth inhibition and the gastrointestinal infection susceptibility due to high dietary lactose levels can also be achieved by fermentation of milk lactose. The hypocholesterolemic activity of fermented milk is apparently related to a similar uncharacterized activity of ordinary milk. Antitumorigenic effects in rats have been reported. Microfloral alterations due to dietary dairy microbes have been reported to retard the development of colon cancer. Purported human longevity effects have not been supported by appropriate data.