Is it possible to take too many probiotics?

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Is it possible to take too many probiotics?

Since our bodies normally host upwards of 100 trillion bacteria, it's very hard to overdose on probiotics, or "good" bacteria. If anything, research suggests that eating lots of these bugs via fermented foods, like yogurt or sauerkraut, or supplements can help you maintain a healthy balance of intestinal microbes that aid digestion and keep your immune system strong.

Healthy adults can consume anywhere up to 20 billion CFUs of probiotics from food or supplements daily; there's a wide range because everyone's microbiome is different. To keep your gut in shape, work more fermented foods into your diet. If you want to add a supplement, ask your doctor for brands she recommends. For some people, a probiotic boost leads to bloating or diarrhea, so cut back if your stomach gets upset.

The one exception to all this: People with depressed immune systems—such as those with HIV, cancer or other illness—should talk to their physician before starting them. In rare instances, if your immune system is very weak, probiotics may cause a serious infection.

Health's medical editor, ROSHINI RAJAPAKSA, MD, is assistant professor of medicine at the NYU School of Medicine and co-founder of Tula Skincare.