Initial Posting: 11/30/2013    Last Update: 6/27/2019
Answer: As discussed in more detail in the Probiotic Supplements Review, probiotics can be taken starting the first day of oral antibiotic treatment and continued for 1 to 2 weeks after the completion of antibiotic therapy (be aware that taking probiotics for longer periods of time may delay the restoration of normal bacteria in the gut). It may be advisable to take probiotics and antibiotics at least 2 hours apart to reduce the possibility of the antibiotic killing the probiotic organisms.
For more details about the types and amounts of organisms which have been shown helpful in reducing the risk of antibiotic-related diarrhea see the Dosage section of the Probiotic Supplements Review.
Note: If diarrhea occurs when taking an antibiotic and persists for several days, see a physician. Severe cases of C. difficile-associated diarrhea, for example, can be life-threatening.