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Nitrate, bacteria and human health

Nature Reviews Microbiologyvolume 2pages593602 (2004) | Download Citation



Nitrate is generally considered a water pollutant and an undesirable fertilizer residue in the food chain. Research in the 1970s indicated that, by reducing nitrate to nitrite, commensal bacteria might be involved in the pathogenesis of gastric cancers and other malignancies, as nitrite can enhance the generation of carcinogenic N-nitrosamines. More recent studies indicate that the bacterial metabolism of nitrate to nitrite and the subsequent formation of biologically active nitrogen oxides could be beneficial. Here, we will consider the evidence that nitrate-reducing commensals have a true symbiotic role in mammals and facilitate a previously unrecognized but potentially important aspect of the nitrogen cycle.

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The authors wish to thank the Ekhaga Foundation, the Swedish Research Council, the EU 6th Framework Programme and the Swedish Heart and Lung Foundation for generous support.

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  1. Department of Physiology & Pharmacology, Karolinska Institute, Stockholm, 171 77, Sweden

    • Jon O. Lundberg
  2. Department of Anaesthesiology and Intensive Care, Karolinska Hospital, Stockholm, 171 76, Sweden

    • Eddie Weitzberg
  3. School of Biochemistry, University of Birmingham, PO Box 363, Edgbaston, Birmingham, B15 2TT, UK

    • Jeff A. Cole
  4. Peninsula Medical School, St. Luke's Campus, Heavitree Road, Exeter, EX1 2LU, UK

    • Nigel Benjamin


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Competing interests

Jon O. Lundberg and Eddie Weitzberg own shares in Aerocrine AB, a company that manufactures equipment to measure nitric oxide in exhaled air.

Nigel Benjamin is the named inventor on several patents concerning the use of nitrate and nitrite as a therapeutic agent.

Jeff A. Cole declares he has no competing interests.

Corresponding author

Correspondence to Jon O. Lundberg.

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