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What are probiotics?
Probiotics are edible products containing the helpful or "friendly" bacteria (usually Lactobacillus or Bifidobacterium) that normally inhabit the human digestive tract. In the intestinal tract, these beneficial microbes help complete the digestive process, and some assist in the production of vitamins.

Why are they necessary?
Probiotics are used to increase the number of beneficial bacteria in your digestive tract. They can help to keep the digestive system in balance and functioning optimally, restore normal flora, and may support immune system function, especially when a person is taking antibiotics, which can wipe out intestinal bacteria indiscriminately, including those that help keep the intestinal tract healthy. Probiotics are an effective treatment for diarrhea, lactose intolerance, irritable bowel syndrome, vaginal yeast infections, oral thrush, Crohn's disease, and ulcerative colitis. When there's a family history of allergy or eczema, babies receiving probiotics in their first six months of life (and whose mothers took probiotics during the last trimester of pregnancy) are less prone to eczema. Children with autism can also benefit from probiotics, possibly because they decrease leakage of large molecules from the gut that can trigger immune reactions with effects on brain function.

What are the signs of a deficiency?
There's evidence that without adequate normal flora, the immune system can't work properly, lessening resistance to infection.

How much, and what kind, does an adult need?
As soon as you start taking antibiotics, start taking probiotics in liquid or capsule form twice a day with meals and continue for a few days after you finish your prescribed therapy. Look for brands containing Bacillus coagulans (BC-30) or Lactobacillus GG. The dose is one tablespoon of the liquid culture or one to two capsules with meals unless the label directs otherwise. Always check the expiration date to make sure that the bacteria these products contain are alive and in good condition and look for probiotics with "colony forming units" (CFUs) in the billions. After you buy, be sure to protect your supply from heat, moisture, and air.

How much does a child need?
Many experts suggest one-quarter teaspoon or one-quarter capsule of commercially available probiotics. Consult with your pediatrician for more information.

How do you get enough from foods?
Most probiotic organisms occur naturally in cultured milk products, such as yogurt with active cultures, acidophilus milk and kefir, as well as natural pickles and sauerkraut. Many traditional cultures around the world value these fermented food products highly, and incorporate them in meals daily for both health and flavor.

Are there any risks associated with too much?

Are there any other special considerations?
You should not take probiotics if you have had an allergic reaction to lactobacillus, acidophilus, bifidobacterium, or streptococcus thermophilus.

Are probiotics right for you?
Everyone's dietary needs are different based on a number of factors including lifestyle, diet, medications and more. To find out if probiotics are right for you, take Dr. Weil's Vitamin Advisor. This 4-step questionnaire requires just minutes to complete, and generates a free, no-obligation vitamin and nutritional supplement recommendation that is personalized to meet your unique nutritional needs.