Fermented milks and milk products as functional foods--a review.
The response of yogurt-fed rats and the corresponding unfermented milk-fed rats to an infectious gastrointestinal challenge has been compared. After 1 (2 trials), 7 (4 trials), 14 and 21 (1 trial each) days on freeze-dried milk or yogurt diets, the rats were inoculated intra-gastrically by intubation per os with 4.5 X 10(10) +/- 0.7 colony forming units (mean +/- SEM) of Salmonella enteritidis. Challenged and control rats were monitored during the 3 weeks post-inoculation for viability, weight gain, feed consumption, and feed efficiency. In general, challenged yogurt-fed rats exhibited significantly superior weight gain and feed efficiency (but not feed consumption) values in week 1 post-infection, but the differences were not significant in week 2 post-infection. Sick milk- and yogurt-fed rats convalesced in week 3. Pooled mortality data indicated that yogurt-fed rats survived better than milk-fed rats. Yogurt did not prevent salmonellosis per se but significantly reduced the mortality and weight gain deceleration.