Probiotics are live microorganisms that are similar in nature to the beneficial or “good” microorganisms found in the human gut. The true definition of probiotics as developed from the World Health Organization is "live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host." Many provide their benefits by adjusting the microflora, the natural balance of organisms in the intestines, or by acting directly on body functions, such as digestion or immune function. Probiotics are generally bacteria. Most often, the bacteria come from two groups, Lactobacillus or Bifidobacterium. Within each group, there are different species (for example, Lactobacillus acidophilus and Bifidobacterium bifidus), and within each species, different strains (or varieties). In the body, bacteria are critical to proper development of the immune system, in protection against microorganisms that could cause disease, and to the digestion and absorption of food and nutrients.  Probiotics have been found to help reduce the risk of certain diarrheal illnesses, enhance immune function and to aid those with lactose intolerance. Most recently studies have shown probiotics to be effective for treating irritable bowel syndrome and Crohn’s disease, and reducing the recurrence of bladder cancer, and even reducing food and seasonal allergies in some cases. In addition, probiotics can help improve the function of the immune system and improve digestive function in general. So to answer the question, yes, you do benefit from probiotics. But what kind? For years, probiotics were available with active cultures in yogurt. However, the active cultures amounts are generally not noted on the yogurt packages. It is well known that some yogurts do contain billions of active cultures before the manufacturing process but many do not survive. Most yogurts contains live probiotics, though not as many strains or as high a potency as a probiotic supplement and some yogurts may not contain any live cultures. Now, probiotics are available in powders and pill form so that dosing is easier and the exact amount of active cultures contained is known. Research appears to show that many daily portions of yogurt are necessary to equal the probiotics in a supplement capsule or powder, which shows a caloric disadvantage to using yogurt alone.  Sixteen to twenty ounces of yogurt daily may be necessary to achieve the same activity as a probiotic capsule or powder resulting in a caloric intake of over 500-1000 calories/day of yogurt. Probiotic supplements have zero calories.  In choosing a probiotic supplement, look for one with 5 billion or more live cultures per serving and a variety of strains. Yours in good health, Linda Hlivka Clinical Nutritionist