Which type of microorganisms are commonly found in the human gut?

The human gut is a complex ecosystem that harbors trillions of microorganisms, collectively known as the gut microbiota. Among them, bacteria are the most abundant and diverse, with more than 1000 different species. These bacteria play important roles in digestion, metabolism, and immune function, and have been linked to various health conditions such as obesity, diabetes, and inflammatory bowel disease. Fungi, viruses, and protozoans are also present in the gut, but they are much less abundant and less well-studied than bacteria.