Summary
The community of microorganisms living in and on a host, such as the human gut.
In depth
Gut communities include Bacteroidetes and Firmicutes. They ferment fibre into short-chain fatty acids, make vitamins and prevent colonisation by pathogens. Diversity is reduced by antibiotics and a low-fibre diet. Dysbiosis is linked to obesity, IBD and others.
Microbiota composition is shaped by diet, birth mode, age and antibiotics. Beneficial functions include vitamin synthesis and immune training.
Key idea: we are ecosystems hosting trillions of microbes.
The human microbiome comprises trillions of microbes with about 100 times more genes than the human genome. Composition differs by body site (gut, skin, mouth, vagina) and is set largely in early life, influenced by birth mode, breastfeeding, diet and antibiotics. A healthy gut has high diversity; loss (dysbiosis) is linked with inflammatory bowel disease, obesity, allergies and C. difficile infection.
Microbes train the immune system, make short-chain fatty acids that feed colon cells, synthesise vitamins K and B12, and metabolise drugs. Germ-free mice have underdeveloped immune systems. Faecal transplants cure recurrent C. difficile in over 80 percent of cases. Causation in many conditions is still being studied.
Key idea: we are a holobiont, a host plus its microbes.
Frequently asked questions
What is Microbiome?
The community of microorganisms living in and on a host, such as the human gut.
Which area of biology covers Microbiome, and how advanced is it?
Microbiome is one of the 54 topics in Microbiology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Microorganisms, Gut-Brain Axis, Metagenomics.
Can you give an example of Microbiome?
Faecal microbiota transplants can cure recurrent C. difficile infection.
What should I learn before Microbiome?
Work through the Beginner topics in Microbiology first, such as Microorganisms, Bacteria, Archaea, then return to Microbiome. Intermediate topics assume the Beginner vocabulary.
What topics are related to Microbiome?
The closest topics to Microbiome are Microorganisms, Gut-Brain Axis, Metagenomics, Probiotics. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Microbiome?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Microbiome. To practise the whole of Microbiology, use the Microbiology quiz.
How is Microbiome different from Microorganisms?
Microbiome: The community of microorganisms living in and on a host, such as the human gut. Microorganisms: Living things too small to see without a microscope, including bacteria, archaea, protists, fungi and microscopic algae. Read both side by side and note what each one explains.
How should I study Microbiome step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Microorganisms and explain the difference aloud. Finally, take the Microbiology quiz and come back to this page for any question you miss.