If you’ve been hearing more and more about the gut microbiome lately, you’re not alone—and for good reason. Your gut is home to a bustling community of trillions of bacteria, fungi, viruses, and even tiny parasites, all of which play an essential role in your overall well-being. This ecosystem is called the gut microbiome , and it starts forming at birth, evolving throughout your life based on your genetics, lifestyle, diet, and environment.