Probiotics are live microorganisms, bacteria and yeasts that provide health benefits for the digestive system. They help with food digestion, produce some vitamins, kill bad cells, keep the natural PH balance in the body, and influence the immune system. They are especially helpful when used alongside strong antibiotics that could interfere with the good bacteria levels in the body. Digestive medical specialists recommend them for irritable bowel syndrome and several other gastrointestinal illnesses as well as for vaginal and urinary infections. They are best taken on an empty stomach, at least 30 minutes before eating.