During birth, we obtained a special "friendly" kind of bacteria from our mothers. This bacteria is called "lactobacillus acidophilus," and "bifidobacterium" among others. Without this bacteria our immune systems cannot function properly. It takes 6 months of breastfeeding to establish the optimal amount of good bacteria in our bodies. Unfortunately, most (if not all) of us have taken antibiotics at some point in our lives, which kills good bacteria along with the bad. If you were not breast-fed as a baby, did not breast-feed your child, or have ever taken anti-biotics, I strongly urge you to take friendly bacteria supplements, and give them to your children. Friendly bacteria help keep our intestinal walls clean, extract nutrients from food, keep harmful bacteria under check, and keep yeast under check. Some benefits you may notice after taking them regularly include: less illness, improved overall health, shorter duration of illnesses (such as colds, flu), increased energy, among others. There are many reliable brands on the market--my favorite is Primadophilus Bifidus from Nature's Way, which can be found in most health-food stores.