Research suggests that taking probiotics after you have taken antibiotics can be very helpful for restoring health and preventing further infections. This is especially true in the case of urinary tract infections, because a disruption in the bacteria that live in the vaginal and rectal areas can lead to more frequent infections.
Probiotics: Consumer Information
This article, provided by the International Scientific Association for Probiotics and Prebiotics, has excellent guidelines for choosing a probiotic formula.
Probiotics Information Page
This fact sheet, published by the American Gastroenterological Association, also provides great information on probiotics and our current understanding of them.