Probiotics are live bacteria or other microorganisms that are similar to those also found naturally in the human body. They are potentially beneficial to our health. Think about the human body as a “host” for bacteria and other microbes. This will help you better understand probiotics. The body, especially the lower gastrointestinal tract (the gut), contains a complex and diverse community of bacteria. We usually tend to think about bacteria in terms of harmful “germs,” but many bacteria actually help the body function properly.

Probiotics can be purchased in different forms. Oral products such as dietary supplements and yogurts are very popular. Other probiotic products such as suppositories and creams are also widely available. It is important to know that the U.S. Food and Drug Administration (FDA) has not approved any health claims for probiotics.

Here are some other things you should be aware of:

1. There is some evidence that probiotics may be helpful for acute diarrhea, antibiotic-associated diarrhea, and atopic eczema (a skin condition most commonly seen in infants).
2. Although some probiotic formulations have shown promise in research, strong scientific evidence to support other uses of probiotics for most conditions is lacking.
3. Studies suggest that probiotics usually have few side effects. However, the data on safety, particularly long-term safety, are limited, and the risk of serious side effects may be greater in people who have underlying health conditions.
4. Probiotic products may contain different types of probiotic bacteria and have different effects in the human body. The effects also may vary from person to person.
5. If you are considering a probiotic dietary supplement, talk to your health care provider first. Do not replace scientifically proven treatments with unproven products or practices.