Human microbiome

The human microbiome is the aggregate of all <a href="/facts/Microbiota/V4ymrawz">microbiota</a> that reside on or within <a href="/facts/Human_tissue/H7CpML7A">human tissues</a> and <a href="/facts/Biofluid/RkAXIBVN">biofluids</a> along with the corresponding <a href="/facts/List_of_human_anatomical_features/jtnE70I2">anatomical sites</a> in which they reside, including the <a href="/facts/Human_gastrointestinal_tract/nK2zwqBS">gastrointestinal tract</a>, <a href="/facts/Human_skin/cfRXQwSs">skin</a>, <a href="/facts/Mammary_gland/6fVBnNSA">mammary glands</a>, <a href="/facts/Seminal_fluid/02mVLGfb">seminal fluid</a>, <a href="/facts/Uterus/LIrApMXs">uterus</a>, <a href="/facts/Ovarian_follicle/7eKGUwb6">ovarian follicles</a>, <a href="/facts/Lung/gTWXI6Fj">lung</a>, <a href="/facts/Saliva/gK4nvayc">saliva</a>, <a href="/facts/Oral_mucosa/uJyDj6c0">oral mucosa</a>, <a href="/facts/Conjunctiva/3UTlea10">conjunctiva</a>, and the <a href="/facts/Biliary_tract/NJPQ5oy4">biliary tract</a>. Types of <a href="/facts/List_of_human_microbiota/KerK9YGP">human microbiota</a> include <a href="/facts/Bacterium/wC8xSCsU">bacteria</a>, <a href="/facts/Archaea/Adxh0aHw">archaea</a>, <a href="/facts/Fungus/BHo5DP59">fungi</a>, <a href="/facts/Protist/NYVfaGVz">protists</a>, and <a href="/facts/Viruses/mf88Bcbl">viruses</a>. Though <a href="/facts/Micro-animal/C6whJqKQ">micro-animals</a> can also live on the human body, they are typically excluded from this definition. In the context of <a href="/facts/Genomics/pVU3BGpL">genomics</a>, the term human microbiome is sometimes used to refer to the collective <a href="/facts/Genome/31Sm08JT">genomes</a> of resident microorganisms; however, the term <a href="/facts/Metagenome/GWFeMd7z">human metagenome</a> has the same meaning.
The human body hosts many microorganisms, with approximately the same <a href="/facts/Order_of_magnitude/cWzRP2dM">order of magnitude</a> of non-human cells as human cells. Some microorganisms that humans host are <a href="/facts/Commensalism/KnJkboX0">commensal</a>, meaning they co-exist without harming humans; others have a <a href="/facts/Mutualism_(biology)/29hCDDS2">mutualistic</a> relationship with their human hosts.: 700  Conversely, some non-<a href="/facts/Pathogenic/axMXtV1M">pathogenic</a> microorganisms can harm human hosts via the <a href="/facts/Metabolites/nAyywVtA">metabolites</a> they produce, like <a href="/facts/Trimethylamine/cj1dWmJq">trimethylamine</a>, which the human body converts to <a href="/facts/Trimethylamine_N-oxide/DnRxSjgJ">trimethylamine N-oxide</a> via <a href="/facts/FMO3/SIPG8pAd">FMO3</a>-mediated oxidation. Certain microorganisms perform tasks that are known to be useful to the human host, but the role of most of them is not well understood. Those that are expected to be present, and that under normal circumstances do not cause disease, are sometimes deemed normal flora or normal microbiota.
During early life, the establishment of a diverse and balanced human microbiota plays a critical role in shaping an individual's long-term health. Studies have shown that the composition of the gut microbiota during infancy is influenced by various factors, including mode of delivery, breastfeeding, and exposure to environmental factors. There are several beneficial species of bacteria and potential probiotics present in <a href="/facts/Breast_milk/wVfKCjyw">breast milk</a>. Research has highlighted the beneficial effects of a healthy microbiota in early life, such as the promotion of immune system development, regulation of metabolism, and protection against pathogenic microorganisms. Understanding the complex interplay between the human microbiota and early life health is crucial for developing interventions and strategies to support optimal microbiota development and improve overall health outcomes in individuals.
The <a href="/facts/Human_Microbiome_Project/yqBkY8PL">Human Microbiome Project</a> (HMP) took on the project of sequencing the genome of the human microbiota, focusing particularly on the microbiota that normally inhabit the skin, mouth, nose, digestive tract, and vagina. It reached a milestone in 2012 when it published its initial results.

Human microbiome open-in-new

Human microbiome