Probiotics are the opposite of antibiotics, which are intended to kill microorganisms causing infection in the body. The World Health Organization defines probiotics as "live microorganisms which, when administered in adequate amounts, confer a health benefit on the host," including better digestion and regularity of bodily functions. Probiotics are most often found as added active live cultures and can be found in certain yogurts, soy foods or dietary supplement vitamins. The most commonly utilized probiotics are lactic acid bacteria and bifidobacteria. The goal of using probiotics is to introduce a healthy quantity of beneficial bacteria into the digestive tract, preventing the growth and survival of harmful microorganisms.
There are several studies which lead researchers to believe there are significant advantages to introducing probiotics to your digestive system. The ingestion of certain active strains of lactic acid bacteria may allow lactose intolerant individuals to enjoy more dairy products, and some animal studies have indicated probiotics may reduce the buildup of bad cholesterol in the body. Another major benefit is improved immune function and the infection prevention capabilities. Probiotics assist in preventing infections, especially intestinal disorders, by inhibiting the growth of bad bacteria in the digestive system. This protection may also help in patients with digestive disorders such as constipation, diarrhea and irritable bowel syndrome.
One disadvantage of probiotics, which was observed by researchers in a University of Western Australia study, was a higher incidence of allergies in children who were given probiotics for the first six months of their lives. Probiotics sometimes have the adverse effects in patients who are already ill or have a severely compromised immune system. Some of these patients required treatment for lactobacillus septicemia, or lactose toxicity, after ingesting probiotics. There is also indication that probiotics will replace healthy bacteria in patients who no longer have any healthy bacteria in their intestines. They are only intended to supplement healthy bacteria that already exist.