There are 100,000,000,000,000 (100 trillion) microbes within the gastrointestinal system and scientists have learned that by transplanting microbes from one animal to another, weight gain and weight loss can be turned on and off at will. Scientists now understand that the greater diversity a person has in terms of the types of microbial life which live within their body, the less likely they are to gain weight or maintain a higher than ideal body weight, with the exact opposite effect occurring in those who have lower than average values in reference to the number of microbes living within the body. Diets rich in fiber are typically associated with higher values of microbes, so increasing fiber intake, can significantly reduce overall body weight and promote the existence and health of many different kinds of microbes. Increasing fiber content for only a few days, has a measurable and marked effect upon microbrial gastrointestinal health