English: The gastrointestinal tract, also call...

English: The gastrointestinal tract, also called the digestive tract, alimentary canal, or gut, is the system of organs within multicellular animals that takes in food, digests it to extract energy and nutrients, and expels the remaining waste. (Photo credit: Wikipedia)

Microorganisms in our gastrointestinal tract can alter how nutrients are absorbed and effect weight.So it’s not just the food we put into our guts but the bacteria that comes with the foods and that lives in our guts that can cause weight problems. What we eat affects us in many ways!