Archaeal Lineages within the Human Microbiome: Absent, Rare or Elusive?

Archaea are well-recognized components of the human microbiome. However, they appear to be drastically underrepresented compared to the high diversity of bacterial taxa which can be found on various human anatomic sites, such as the gastrointestinal environment, the oral cavity and the skin. As our...

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Main Author: Hans-Peter Horz
Format: Article
Language:English
Published: MDPI AG 2015-05-01
Series:Life
Subjects:
Online Access:http://www.mdpi.com/2075-1729/5/2/1333
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author Hans-Peter Horz
author_facet Hans-Peter Horz
author_sort Hans-Peter Horz
collection DOAJ
description Archaea are well-recognized components of the human microbiome. However, they appear to be drastically underrepresented compared to the high diversity of bacterial taxa which can be found on various human anatomic sites, such as the gastrointestinal environment, the oral cavity and the skin. As our “microbial” view of the human body, including the methodological concepts used to describe them, has been traditionally biased on bacteria, the question arises whether our current knowledge reflects the actual ratio of archaea versus bacteria or whether we have failed so far to unravel the full diversity of human-associated archaea. This review article hypothesizes that distinct archaeal lineages within humans exist, which still await our detection. First, previously unrecognized taxa might be quite common but they have eluded conventional detection methods. Two recent prime examples are described that demonstrate that this might be the case for specific archaeal lineages. Second, some archaeal taxa might be overlooked because they are rare and/or in low abundance. Evidence for this exists for a broad range of phylogenetic lineages, however we currently do not know whether these sporadically appearing organisms are mere transients or important members of the so called “rare biosphere” with probably basic ecosystem functions. Lastly, evidence exists that different human populations harbor different archaeal taxa and/or the abundance and activity of shared archaeal taxa may differ and thus their impact on the overall microbiome. This research line is rather unexplored and warrants further investigation. While not recapitulating exhaustively all studies on archaeal diversity in humans, this review highlights pertinent recent findings that show that the choice of appropriate methodological approaches and the consideration of different human populations may lead to the detection of archaeal lineages previously not associated with humans. This in turn will help understand variations found in the overall microbiomes from different individuals and ultimately may lead to the emergence of novel concepts/mechanisms impacting human health.
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spelling doaj.art-c59c6b7bb24f4534b4544c74f77de84a2022-12-22T02:11:59ZengMDPI AGLife2075-17292015-05-01521333134510.3390/life5021333life5021333Archaeal Lineages within the Human Microbiome: Absent, Rare or Elusive?Hans-Peter Horz0Division of Virology, Institute of Medical Microbiology, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52057 Aachen, GermanyArchaea are well-recognized components of the human microbiome. However, they appear to be drastically underrepresented compared to the high diversity of bacterial taxa which can be found on various human anatomic sites, such as the gastrointestinal environment, the oral cavity and the skin. As our “microbial” view of the human body, including the methodological concepts used to describe them, has been traditionally biased on bacteria, the question arises whether our current knowledge reflects the actual ratio of archaea versus bacteria or whether we have failed so far to unravel the full diversity of human-associated archaea. This review article hypothesizes that distinct archaeal lineages within humans exist, which still await our detection. First, previously unrecognized taxa might be quite common but they have eluded conventional detection methods. Two recent prime examples are described that demonstrate that this might be the case for specific archaeal lineages. Second, some archaeal taxa might be overlooked because they are rare and/or in low abundance. Evidence for this exists for a broad range of phylogenetic lineages, however we currently do not know whether these sporadically appearing organisms are mere transients or important members of the so called “rare biosphere” with probably basic ecosystem functions. Lastly, evidence exists that different human populations harbor different archaeal taxa and/or the abundance and activity of shared archaeal taxa may differ and thus their impact on the overall microbiome. This research line is rather unexplored and warrants further investigation. While not recapitulating exhaustively all studies on archaeal diversity in humans, this review highlights pertinent recent findings that show that the choice of appropriate methodological approaches and the consideration of different human populations may lead to the detection of archaeal lineages previously not associated with humans. This in turn will help understand variations found in the overall microbiomes from different individuals and ultimately may lead to the emergence of novel concepts/mechanisms impacting human health.http://www.mdpi.com/2075-1729/5/2/1333human-associated archaeahuman microbiomeperiodontal diseaseintestinal disordersrare biosphereanthropology of microbes
spellingShingle Hans-Peter Horz
Archaeal Lineages within the Human Microbiome: Absent, Rare or Elusive?
Life
human-associated archaea
human microbiome
periodontal disease
intestinal disorders
rare biosphere
anthropology of microbes
title Archaeal Lineages within the Human Microbiome: Absent, Rare or Elusive?
title_full Archaeal Lineages within the Human Microbiome: Absent, Rare or Elusive?
title_fullStr Archaeal Lineages within the Human Microbiome: Absent, Rare or Elusive?
title_full_unstemmed Archaeal Lineages within the Human Microbiome: Absent, Rare or Elusive?
title_short Archaeal Lineages within the Human Microbiome: Absent, Rare or Elusive?
title_sort archaeal lineages within the human microbiome absent rare or elusive
topic human-associated archaea
human microbiome
periodontal disease
intestinal disorders
rare biosphere
anthropology of microbes
url http://www.mdpi.com/2075-1729/5/2/1333
work_keys_str_mv AT hanspeterhorz archaeallineageswithinthehumanmicrobiomeabsentrareorelusive