Yogurt fortified with healthy bacteria may help you ward off certain illnesses.

In a recent study, researchers gave workers a daily dose of either Lactobacillus reuteri, a type of beneficial bacteria, or a placebo for 80 days. Only about 10 percent of workers who took L. reuteri came down with a respiratory or gastrointestinal infection that caused them to miss work; more than 26 percent of the workers who took the placebo fell ill.

Beneficial bacteria inhabit your intestines, preventing infection by harmful bacteria and aiding in digestion. Antibiotic use or bouts of diarrhea or vomiting can disrupt the balance of intestinal bacteria, leaving you more vulnerable to illnesses. Lactobacillus reuteri, a type of beneficial bacteria, may help prevent harmful bacteria from colonizing in the gastrointestinal tract and enhance the function of immune cells that combat viral infections. Not all kinds of yogurt contain L. reuteri. Read yogurt labels carefully.