Probiotics are defined by The Joint FAO/WHO Working Group as "live microorganisms that when administered in adequate amounts confer a health benefit on the host". Because we associate bacteria with disease it is probably difficult for some people to get behind the idea that consuming a couple of billion of them a day is good for your health. But the scientific evidence is mounting that you can treat or prevent some diseases with foods or supplements that contain certain types of bacteria. In Northern Europe people consume a lot of these beneficial bacteria, called probiotics, because their diets traditionally contain foods that are fermented with live bacteria such as yogurt. Beverages containing probiotics are also very common in Japan. While demand for probiotics foods and supplements has not been as enthusiastic in the United States it is on the rise. Some medical professionals that specialize in digestive diseases have found that they are effective in treating conditions that frustrate conventional medicine such as irritable bowel disease. Over the last 20 years clinical studies have shown that probiotics are effective in treating some gastrointestinal diseases, delaying the onset of allergies in children and treating urinary and vaginal infections in women. Additional studies have shown that probiotics therapy can also: * Improve the bio-availability of important nutrients * Provide powerful abilities to normalize bowel function in those suffering from irritable bowel syndrome. * Clinical trials at the Mayo Clinic showed improvements in patients suffering from bloating. * Lowered the rate of diarrhea and diaper rash in infants. * Reduce lactose intolerance. * Reduce constipation in the elderly. * Some forms can aid in the growth of healthy bacteria in the colon. This lowers the conversion of bile in the colon into carcinogens. * Enhance the immune system. In a healthy person there is an estimated 1 trillion bacteria of about 500 different types living in the bowel. These microorganisms do not make you sick; in fact most of them are beneficial to our health. The function of these microorganisms is to keep harmful bacteria at a minimum, aid in the digestion and absorption of nutrients in food and help our immune systems. Knowing this self-dosing with live bacteria does not seem a strange thing to do. The best case for probiotics can be made for treatment of diarrhea. Studies have shown that they can reduce the duration of infectious diarrhea in children and infants, but not in adults. Two important studies have shown that probiotics can reduce this duration by as much as 60% when compared to a placebo. People that suffer from Crohn's Disease and irritable bowel disease have had some success with probiotics therapy. Both of these conditions have been frustrating for conventional medicine to come up with a cure. Probiotics have been used successfully in maintaining urogenital health in women. Like the intestinal tract the vagina is a finely tuned ecosystem. The bacteria that normally inhabit the vagina cause it to be to acidic for harmful microorganisms to survive. Several factors such as spermicides, birth control pills and antibiotics can throw this system out of balance. Treatment with probiotics can restore the balance of microorganisms and is helpful in treating common urogenital problems in women such as bacterial vaginosis, yeast infections and urinary tract infections. Vaginosis must be treated as it can create a risk of pregnancy related complications and pelvic inflammatory disease. Probiotics are generally considered to be safe. This is because they are already present in a normal digestive system. People with impaired immune systems could be at a theoretical risk. As with any supplementation program one should always consult with their primary care provider.