bacteria

some bacterias are helpful,the other are harmful.wo need to regonize them,here is a helpful bacteria.http://www.mansfieldct.org/schools/mms/staff/hand/Immunebacteriavsviruses.htm

This type of bacteria live in the intestines of human beings. They help in digestion and in destroying the harmful organisms. Intestinal bacteria also produce some vitamins required by the human body.Certain bacteria help break down lactose in the digestive tract.It is observed that Infants who were administered the bacteria Lactobacillus reuteri or Bifidobacterium had fewer and shorter episodes of diarrhea.

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Harmful bacteria may cause small infections like strep throat and some serious diseases like pneumonia. Certain streptococci may be fatal.Bacteria that usually live harmlessly in the body may cause infections when a person's resistance to disease is reduced in conditions such as AIDS (Acquired Immune Deficiency Syndrome).Not all stomach bacteria are beneficial, some of the stomach bacteria enter the body through the mouth, and they can survive in the acidic conditions in the stomach and can cause serious diseases and can be fatal.