Our bodies are covered in rich ecosystems invisible to the naked eye and inhabited by trillions of microscopic organisms that collectively make up the human microbiome (see video overview). Studies increasingly show that one of the most consequential microbiomes lies inside the digestive tract. Scientists hypothesize that the gut microbiome comes from bacterial colonization that slowly covers the body, inside and out, after birth.
> Visualize the different parts of the digestive tract. (More)
> See how the gut and the brain communicate through a bundle of nerves running from the brain to the digestive tract. (More, w/video)
This 30-foot-long tube—which includes the large and small intestines—may have as many as 100 trillion microbes that help break down food and perform other essential tasks, including producing hormones and neurotransmitters and training immune system cells.
> Trillions of bacteria, viruses, fungi, protists, and archaea live in our guts, producing a wide range of molecules, hormones, and more. (More)
> Farts are tiny status reports from our gut microbiome, with American adults typically passing gas more than 30 times daily. (More)
> Researchers generally group gut bacteria into six different categories. (More, w/visualization)
Finding ways to alter that composition and target specific microbes with future therapies is a key focus area as scientists learn about the microbiome's role in a wide range of mental and physical conditions, ranging from allergies to depression to autoimmune disorders.
> Rodents given gut microbes from depressed people may show depression-like symptoms. (More, w/video)
> Specific gut microbiome "fingerprints" are associated with cancer recurrence, with up to 94% accuracy. (More)
Discover more:
> Fecal transplants use processed donor stool to introduce healthy gut bacteria into a patient's intestines. (More)
> Some animals, including certain tropical ants, have little or no microbial populations in their gut. (More)
> Artificial sweeteners may disrupt gut health, throwing off the balance of beneficial bacteria and shifting the composition of the microbiome. (More)