While there are also some fungi, viruses, and archaea in the gut, bacteria make up the vast majority (estimated to be trillions of bacteria). These bacteria belong to thousands of different species, with the most common phyla being:
* Bacteroidetes: These bacteria play a role in breaking down complex carbohydrates and producing short-chain fatty acids.
* Firmicutes: These bacteria are involved in the production of vitamins and the breakdown of dietary fibers.
* Actinobacteria: These bacteria contribute to the immune system development and help with nutrient absorption.
* Proteobacteria: While some Proteobacteria are beneficial, others can be pathogenic and contribute to gut inflammation.
The specific composition of the intestinal flora varies from person to person, influenced by factors such as genetics, diet, lifestyle, and medications.
