Probiotics taken within 30 minutes of a meal survived in much higher numbers than probiotics taken more than 30 minutes after a meal as found by a 2011 study. (1)
The study found that more bacteria survived when taken with food, than when they were taken with water or apple juice. (1)
Moreover, the study stated it was the fat content of the meal that was important for survival of the probiotics, so ideally the meal probiotics are taken with should contain a little fat. (1)
In summary, probiotic bacterial survival was best when provided within 30 minutes before or simultaneously with a meal or beverage that contained some fat content. (2).
Further Reading And References
(2) Michael Greger M.D. FACLM: How Should I Take Probiotics?, NutritionFacts.org, January 2nd, 2014
IBS Researcher 