Are probiotics safe?

Generally, the answer is yes. Many probiotics have been added to foods such as yogurt. Eating probiotic rich foods like yogurt, pickles, sauerkraut, miso and kefir are safe for everyday consumption.

However, probiotics can be unsafe for certain groups of people. Anyone with immune deficiencies, auto-immune conditions, or cancer could be at risk.  These individuals have weakened immune systems that cannot protect against a probiotic if it gets into the bloodstream. One study using a probiotic to treat Crohn's disease in children had to be stopped because patients on the probiotic got sicker than those who weren't taking it. 

Another question is how long should you take probiotics. We don't know exactly. Most doctors usually recommend a 2-4 week course of probiotics during and after an infection.

The bottom line, the right probiotic can be helpful in certain conditions, for a period of time. We still have a lot to learn about how probiotics work and when they are best used to boost a healthy intestinal immune system.