Adding fermented foods to your diet could help with any digestive issues including bloating, gas, constipation, diarrhea. I have also seen it help people with acne and people with low immune systems. The key is to eat a small portion of fermented foods on a very regular basis. Once or twice daily with meals is best. Fermented foods include sauerkraut, natto (fermented soybeans, be careful, it's an acquired taste!), fish sauce, miso, kimchi, shrimp paste, soy sauce, tabasco sauce, tempeh, kefir, yogurt (Fage brand muscle tests the best), kombucha, and pickled vegetables. Do not eat fermented foods if you have or suspect candida.
Here are four explanations of how eating fermented foods help the body:
Explanation #1: Traditional fermented foods help balance the production of stomach acid. Fermented foods have the unique ability to ease digestive discomfort related to having either too much or too little stomach acid. When the production of hydrochloric acid by the stomach is low, fermented foods help increase the acidity of gastric juices. On the other hand, when the stomach produces too much acid, fermented foods help protect the stomach and intestinal lining.
Explanation #2: Traditional fermented foods help the body produce acetylcholine. Acetylcholine is a neurotransmitter. In simple terms, it facilitates the transmission of nerve impulses. In practical terms, it helps increase the movement of the bowel, and can alleviate constipation problems. It also helps improve the release of digestive juices and enzymes from the stomach, the pancreas, and the gallbladder. So by helping your body produce acetylcholine, fermented foods act as potent digestive aids.
Explanation #3: Traditional fermented foods are beneficial for people with blood sugar problems, including diabetes. In addition to improving pancreatic function, which is of great benefit to diabetics, the carbohydrates in lactic acid–fermented foods have been broken down or "pre-digested." As a result, they do not place an extra burden on the pancreas, unlike ordinary carbohydrates.
Explanation #4: Traditional fermented foods produce numerous compounds that destroy and inhibit the growth of pathogenic bacteria. Many pathogenic forms of bacteria are sensitive to acidic environments and will not grow.