According to researchers, probiotics may improve a person’s health by affecting their immune function.  In fact, some probiotic supplements have been shown to prevent respiratory infections.  Results have limitations and there was no adequate data concerning older adults.  Probiotics are microbes that include bacteria and yeast that have been promulgated to improve human health.  They are widely available in various foods and supplements.  Probiotics and have been proported to improve functioning of the intestine, particularly of those individuals who have digestive symptoms.  In a panel of experts at Yale University, probiotics were mentioned in prevention of a variety of digestive conditions.  In a study published in 2010, probiotics were associated with a decrease in colds, ear infections, and diarhea in children.  As always if you are taking any medication, check with your health care provider before taking any supplements.  There is no substitute for a healthy, nutrtionally adequate diet and of course exercise.