Have you ever started eating healthier, reducing processed foods, increasing fiber, exercising more, or making other positive lifestyle changes—only to feel bloated, tired, achy, congested, irritable, or just "off"? You may not be getting sick. Your body may be adapting. Your gut is home to trillions of microorganisms, collectively known as the gut microbiome. These microbes play a major role in digestion, metabolism, immune function, inflammation, and even mood. When you mak