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What are the consequences of the disappearing human microbiota?

Nature Reviews Microbiology volume 7, pages 887894 (2009) | Download Citation

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Abstract

Humans and our ancestors have evolved since the most ancient times with a commensal microbiota. The conservation of indicator species in a niche-specific manner across all of the studied human population groups suggests that the microbiota confer conserved benefits on humans. Nevertheless, certain of these organisms have pathogenic properties and, through medical practices and lifestyle changes, their prevalence in human populations is changing, often to an extreme degree. In this Essay, we propose that the disappearance of these ancestral indigenous organisms, which are intimately involved in human physiology, is not entirely beneficial and has consequences that might include post-modern conditions such as obesity and asthma.

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Acknowledgements

M. Blaser gratefully acknowledges funding from the US National Institutes of Health (NIH; grants RO1GM62370 and UH2AR057506) and from the Diane Belfer Program for Human Microbial Ecology. S. Falkow gratefully acknowledges funding from NIH (grants R01AI026195 and R01AI038459).

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  1. Martin J. Blaser is at the Department of Medicine and the Department of Microbiology, New York University Langone Medical Center, New York, New York 10017, USA.

    • Martin J. Blaser
  2. Stanley Falkow is at the Department of Microbiology and Immunology and the Department of Medicine, Stanford University School of Medicine, Stanford, California 94307, USA.

    • Stanley Falkow

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Correspondence to Martin J. Blaser.

Glossary

Commensal relationship

An intimate, although generally benign, relationship between a resident microorganism and its host. Probably the product of a long evolutionary interplay between the microorganism and the host. The relationship need not be symbiotic.

Gene transfer

The transfer of individual genes or their components, islands of genes, entire organisms, or communities of organisms from parent to offspring (vertical transfer) or between individuals not in a direct lineage (horizontal transfer).

Microbiome

The collective genomes of the microorganisms that reside in an environmental niche.

Nash equilibrium

In game theory, a solution concept in which players in a game are aware of the strategies of the other players but do not deviate from their own, because they do not have anything to gain; it will be disadvantageous to deviate (to 'cheat').

Pan-genome

The set of all of the genes that are found in members of a single species.

Parasite

An organism that diminishes the reproductive fitness of another organism or benefits from another organism without reciprocity.

Pathogen

In medicine, any organism that causes disease. In biological terms, a pathogen is a microorganism that has the inherent capacity to cross anatomical barriers and resist host defences that ordinarily restrict most other microorganisms.

Symbiont

An organism that has a biological relationship with one or more organisms that leads to mutual benefit.

Syntrophic interactions

Interactions in which organisms do more together than alone.

Virulence

A quantitative estimate of the ability of one organism to harm another.

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https://doi.org/10.1038/nrmicro2245

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