Most of them have a good dose of live bacteria that in this day and age and well hell any time can be good keeping that level in the intestines HIGH they digest food and fight illness etc. Then some like bromalean (sp) found in Pineapple etc help with faster easier digestion of protein, there are several that help different areas of digestion.
Us being bombarded with chemicals and preservatives on a daily basis even those of us who eat very clean compared to the rest of the world. it cant hurt to take a nice cheap digestive aid and get the bacteria from sources like yoghurt. Keep the intestine health and colon Happy.
Hope that helps a little,