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GUT MICROBIOTA IN 2020

Demonstration of causality: back to cultures

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From Nature Reviews Gastroenterology & Hepatology

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In 2020, studies have used pure cultures of members of the gut microbiota to establish a molecular chain of causation for the role of these key bacteria in aggravating or alleviating cancer and metabolic diseases. These studies highlight the need for microbiome studies to move from associations back to cultures to demonstrate causality.

Key advances

  • When chronically exposed to human intestinal organoids, a genotoxin-producing Escherichia coli strain isolated from human colorectal cancer (CRC) tissue can induce mutational signatures similar to those found in patients with CRC4.

  • A butyrate-producing strain of Faecalibaculum rodentium in mice and an isolate identified from its human homologue species Holdemanella biformis demonstrated anti-tumorigenic effects in CRC animal model ApcMin/+ mice7.

  • The most upstream event of Enterobacter cloacae B29 (a human obesogenic strain)-induced obesity was identified through genetic manipulation of the interaction between lipopolysaccharide and Toll-like receptor 4 in germ-free mice9.

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Fig. 1: Establishing causality in microbiome studies.

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Authors and Affiliations

  1. Center for Nutrition, Microbiome and Health, New Jersey Institute for Food, Nutrition and Health, Rutgers University, New Brunswick, NJ, USA

    Liping Zhao & Naisi Zhao

  2. Rutgers-Jiaotong Joint Laboratory for Microbiome and Human Health, Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, USA

    Liping Zhao

  3. Rutgers-Jiaotong Joint Laboratory for Microbiome and Human Health, State Key Laboratory of Microbial Metabolism, Ministry of Education Laboratory of Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China

    Liping Zhao

  4. Department of Public Health and Community Medicine, School of Medicine, Tufts University, Boston, MA, USA

    Naisi Zhao

Authors
  1. Liping Zhao
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  2. Naisi Zhao
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Corresponding author

Correspondence to Liping Zhao.

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Competing interests

L.Z. is co-founder of Notitia Biotechnologies. N.Z. declares no competing interests.

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Zhao, L., Zhao, N. Demonstration of causality: back to cultures. Nat Rev Gastroenterol Hepatol 18, 97–98 (2021). https://doi.org/10.1038/s41575-020-00400-6

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  • DOI: https://doi.org/10.1038/s41575-020-00400-6

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