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OPINION

Urbanization and the gut microbiota in health and inflammatory bowel disease

Abstract

In the 21st century, urbanization represents a major demographic shift in developed and developing countries. Rapid urbanization in the developing world has been associated with an increasing incidence of several autoimmune diseases, including IBD. Patients with IBD exhibit a decrease in the diversity and richness of the gut microbiota, while urbanization attenuates the gut microbial diversity and might have a role in the pathogenesis of IBD. Environmental exposures during urbanization, including Westernization of diet, increased antibiotic use, pollution, improved hygiene status and early-life microbial exposure, have been shown to affect the gut microbiota. The disparate patterns of the gut microbiota composition in rural and urban areas offer an opportunity to understand the contribution of a ‘rural microbiome’ in potentially protecting against the development of IBD. This Perspective discusses the effect of urbanization and its surrogates on the gut microbiome (bacteriome, virome, mycobiome and helminths) in both human health and IBD and how such changes might be associated with the development of IBD.

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Fig. 1: Differential gut microbial community assembly scenarios in rural and urban settings.
Fig. 2: Diet changes during urbanization and effects on the gut microbiota.
Fig. 3: The changing landscape of the gut microbiome during urbanization and its relation to IBD.

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Acknowledgements

S.C.N. and M.A.K. are supported by The Helmsley Charitable Trust through the ENIGMA study. S.C.N. and T.Z. are supported by a seed fund for Gut Microbiome Research provided by the Faculty of Medicine, The Chinese University of Hong Kong. The authors also thank F. K. L. Chan, The Chinese University of Hong Kong, China, for his intellectual input into this article.

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T.Z. and S.C.N. devised the concept, acquired data and wrote the manuscript. M.A.K. and J.F.C. provided critical revision of the manuscript and important intellectual content.

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Correspondence to Siew C. Ng.

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Zuo, T., Kamm, M.A., Colombel, JF. et al. Urbanization and the gut microbiota in health and inflammatory bowel disease. Nat Rev Gastroenterol Hepatol 15, 440–452 (2018). https://doi.org/10.1038/s41575-018-0003-z

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