BEVERLY HILLS, CALIF. — The jury may still be out on whether probiotics are beneficial, but at least they do no harm and can be safely recommended to patients, right? Not so, said Dr. David R. Mack at the International Probiotics Association World Congress. Several recent studies have uncovered some risks associated with probiotic use, in both children and adults. “We [physicians] are always looking for new things, but we're a conservative, skeptical lot, and safety is a primary concern.”