Human Microbiome in Health and Disease
Human biology can no longer concern itself only with human cells: Microbiomes at different body sites and functional metagenomics must be considered part of systems biology. The emergence of metagenomics has resulted in the generation of vast data sets of microbial genes and pathways present in different body habitats.
The microbiome is the collection of all microbes, such as bacteria, fungi, viruses, and their genes, that naturally live on our bodies and inside us. Interest in the role of the microbiome in human health has burgeoned over the past decade with the advent of new technologies for interrogating complex microbial communities. The large-scale dynamics of the microbiome can be described by many of the tools and observations used in the study of population ecology.
Metagenomics examines the structure and functional potential of microbial communities in their native habitats through the direct isolation and analysis of community DNA. In inflammatory bowel disease, gut microbiome studies have shown an association with perturbations in community composition and, especially, function.
How can the microbiome affect health?
Microbiota stimulate the immune system, break down potentially toxic food compounds, and synthesize certain vitamins and amino acids, including the B vitamins and vitamin K. For example, the key enzymes needed to form vitamin B12 are only found in bacteria, not in plants and animals.
A person’s core microbiome is formed in the first years of life but can change over time in response to different factors including diet, medications, and environmental exposures. Differences in the microbiome may lead to different health effects from environmental exposures and may also help determine individual susceptibility to certain illnesses.
Dietary prebiotics have been defined as “a selectively fermented ingredient that results in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon host health”
The microbiota of a healthy person will also provide protection from pathogenic organisms that enter the body such as through drinking or eating contaminated water or food.
Human Microbiome data:
The tremendous expansion of information collected on the human microbiome in recent years is highlighted by data generated through several large-scale endeavors to characterize the human microbiome, namely the European Metagenomics of the Human Intestinal Tract (MetaHIT) and the NIH-funded Human Microbiome Project (HMP).
The Common Fund’s Human Microbiome Project (HMP) developed research resources to enable the study of the microbial communities that live in and on our bodies and the roles they play in human health and disease.
Reference:
Pflughoeft KJ, Versalovic J. Human microbiome in health and disease. Annu Rev Pathol. 2012;7:99-122. doi: 10.1146/annurev-pathol-011811-132421. Epub 2011 Sep 9. PMID: 21910623.
Shreiner AB, Kao JY, Young VB. The gut microbiome in health and in disease. Curr Opin Gastroenterol. 2015 Jan;31(1):69-75. doi: 10.1097/MOG.0000000000000139. PMID: 25394236; PMCID: PMC4290017.