What are the consequences of the disappearing microbiota?

Department of Medicine and the Department of Microbiology, New York University Langone Medical Center, New York, New York 10017, USA.
Nature Reviews Microbiology (Impact Factor: 23.57). 11/2009; 7(12):887-94. DOI: 10.1038/nrmicro2245
Source: PubMed


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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    • "Similar improvement in host fitness has been reported for insects, in which endosymbiotic species of Burkholderia are acquired horizontally every generation (Kikuchi et al., 2007). Even in humans it has been shown that the disappearance of ancestral indigenous commensal microbiota, which is intimately involved in human physiology, is not beneficial and may have many health consequences (Sears, 2005; Blaser and Falkow, 2009). Protective mutualism conferred by horizontally transmitted microbes has been poorly studied in plants (except for mycorrhizal or rhizobial associations), especially in their native environments (Evans et al., 2003; Berlec, 2012). "
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    ABSTRACT: It has been shown that the disappearance of, or drastic changes in, ancestral and indigenous (or native) endosymbiotic microbiota can lead to many adverse health consequences. However, the effects of changes in beneficial endosymbionts in plants are poorly known (except for mycorrhizal and rhizobial associations). We sampled and compared endophytes from hundreds of trees belonging to the economically important genus Hevea, the source of natural rubber, in their native range in the Amazon basin and in plantations. We also conducted antagonism tests to determine the potential effects that some of these endophytes may have on selected plant pathogenic fungi. The natural and indigenous endosymbiotic mycota of the rubber tree (Hevea) contains a high diversity of beneficial fungi that may protect against pathogens (protective mutualism). In contrast, plantation trees have a reduced and different diversity of these beneficial fungi. We propose that abundance, and not just presence, of competitive fungal strains and species (i.e., Trichoderma and Tolypocladium) create a protective effect against pathogens in wild trees. This study provides support for the importance of mutualistic endosymbionts in plant health and ecosystem resilience, and calls for awareness of their potential loss by human-related activities.
    Fungal Ecology 10/2015; 17. DOI:10.1016/j.funeco.2015.04.001 · 2.93 Impact Factor
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    • "Co-habitation in humans leads to sharing of microbiota, which is enhanced when dogs also co-habit in the same house (Song et al., 2013). Ironically, hygiene measures aimed at reducing pathogen transmission may have had broad negative impacts on the transmission of commensals and may underlie the loss of diversity observed in the West (Blaser and Falkow, 2009). Who Are They? "
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    ABSTRACT: Plants and animals each have evolved specialized organs dedicated to nutrient acquisition, and these harbor specific bacterial communities that extend the host's metabolic repertoire. Similar forces driving microbial community establishment in the gut and plant roots include diet/soil-type, host genotype, and immune system as well as microbe-microbe interactions. Here we show that there is no overlap of abundant bacterial taxa between the microbiotas of the mammalian gut and plant roots, whereas taxa overlap does exist between fish gut and plant root communities. A comparison of root and gut microbiota composition in multiple host species belonging to the same evolutionary lineage reveals host phylogenetic signals in both eukaryotic kingdoms. The reasons underlying striking differences in microbiota composition in independently evolved, yet functionally related, organs in plants and animals remain unclear but might include differences in start inoculum and niche-specific factors such as oxygen levels, temperature, pH, and organic carbon availability. Copyright © 2015 Elsevier Inc. All rights reserved.
    Cell host & microbe 05/2015; 17(5):603-616. DOI:10.1016/j.chom.2015.04.009 · 12.33 Impact Factor
    • "A Helicobacter-macacae-like OTU was also exclusively detected in PNG samples as a core member. Deliberate eradication of Helicobacter pylori has led to a significant reduction of this species in westernized countries (Blaser and Falkow, 2009), and other species of this genus might also have been affected. However, PNGspecific core OTUs were not detected in data sets from other non-westernized samples and we therefore cannot conclude that they represent members of an ancestral microbiome. "
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    ABSTRACT: Although recent research revealed an impact of westernization on diversity and composition of the human gut microbiota, the exact consequences on metacommunity characteristics are insufficiently understood, and the underlying ecological mechanisms have not been elucidated. Here, we have compared the fecal microbiota of adults from two non-industrialized regions in Papua New Guinea (PNG) with that of United States (US) residents. Papua New Guineans harbor communities with greater bacterial diversity, lower inter-individual variation, vastly different abundance profiles, and bacterial lineages undetectable in US residents. A quantification of the ecological processes that govern community assembly identified bacterial dispersal as the dominant process that shapes the microbiome in PNG but not in the US. These findings suggest that the microbiome alterations detected in industrialized societies might arise from modern lifestyle factors limiting bacterial dispersal, which has implications for human health and the development of strategies aimed to redress the impact of westernization. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.
    Cell Reports 04/2015; 11(4). DOI:10.1016/j.celrep.2015.03.049 · 8.36 Impact Factor
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