Dairy products are a good source of friendly lactobacillus, especially yogurt and kefir. However, the milk that most people drink today is pasteurized, or heated to about 165 degrees F. So, for the most part, we have lost this source of lactobacillus and are not receiving the quantities of these bacteria in our diets as we used to. It is a good idea to routinely eat some live culture containing foods such as yogurt, kefir, etc. Be sure the products are guaranteed to contain live cultures. It is actually best to make your own yogurt to be assured of bacteria content.
Bad breath is usually a good indication that normal bacteria levels are low.
When lactobacillus levels are low in the colon, partially digested food decays, produce foul gas and toxemia. They cannot digest lactose, or milk sugar, and this can lead to allergies, headaches, cramps, mucous formation and many other health problems. The various kinds of lactobacillus bacteria can digest it. This is why many people can eat yogurt, cultured milks and kefir even though they cannot handle dairy products like milk, cheese, ice cream, etc. Constipation and diarrhea can develop from decreased levels of friendly bacteria.