Impact of ethnicity, geography, and disease on the microbiota in health and inflammatory bowel disease.
BACKGROUND
The gut microbiota is central to health and disorders such as inflammatory bowel disease. Differences in microbiota related to geography and ethnicity may hold the key to recent changes in the incidence of microbiota-related disorders.


METHODS
Gut mucosal microbiota was analyzed in 190 samples from 87 Caucasian and Chinese subjects, from Australia and Hong Kong, comprising 22 patients with Crohn's disease, 30 patients with ulcerative colitis, 29 healthy controls, and 6 healthy relatives of patients with Crohn's disease. Bacterial 16S rRNA microarray and 454 pyrosequencing were performed.


RESULTS
The microbiota was diverse in health, regardless of ethnicity or geography (operational taxonomic unit number and Shannon diversity index). Ethnicity and geography, however, did affect microbial composition. Crohn's disease resulted in reduced bacterial diversity, regardless of ethnicity or geography, and was the strongest determinant of composition. In ulcerative colitis, diversity was reduced in Chinese subjects only, suggesting that ethnicity is a determinant of bacterial diversity, whereas composition was determined by disease and ethnicity. Specific phylotypes were different between health and disease. Chinese patients with inflammatory bowel disease more often than healthy Chinese tended to have had a Western diet in childhood, in the East and West.


CONCLUSIONS
The healthy microbiota is diverse but compositionally affected by geographical and ethnic factors. The microbiota is substantially altered in inflammatory bowel disease, but ethnicity may also play an important role. This may be key to the changing epidemiology in developing countries, and emigrants to the West.
1Department of Gastroenterology, St Vincent's Hospital Melbourne, Australia; 2Department of Medicine, The University of Melbourne, Parkville, Australia; 3Preventative Health National Research Flagship Program, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia; 4Enteric Virus Group, Murdoch Childrens Research Institute, Parkville, Australia; 5Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu, China; 6Department of Gastroenterology, Zhongnan Hospital, Wuhan University School of Medicine, Wuhan, China; 7Department of Gastroenterology, Box Hill Hospital, Melbourne, Australia; 8Department of Medicine and Therapeutics, Li Ka Shing Institute of Health Sciences, the Chinese University of Hong Kong, Hong Kong, China; 9The Ohio State University, Columbus, Ohio; 10Department of Microbiology, La Trobe University, Bundoora, Australia; and 11Department of Immunology, Imperial College, London, United Kingdom.
Lani
L
Prideaux
Seungha
S
Kang
Josef
J
Wagner
Michael
M
Buckley
Jackie E
JE
Mahar
Peter
P
De Cruz
Zhonghui
Z
Wen
Liping
L
Chen
Bing
B
Xia
Daniel R
DR
van Langenberg
Trevor
T
Lockett
Siew C
SC
Ng
Joseph J Y
JJ
Sung
Paul
P
Desmond
Chris
C
McSweeney
Mark
M
Morrison
Carl D
CD
Kirkwood
Michael A
MA
Kamm
D000328:Adult; D000368:Aged; D001315:Australia; D016022:Case-Control Studies; D004269:DNA, Bacterial / Q000032:analysis; D005006:Ethnicity / Q000235:genetics / Q000706:statistics & numerical data*; D005243:Feces / Q000382:microbiology; D005260:Female; D005500:Follow-Up Studies; D041981:Gastrointestinal Tract / Q000382:microbiology*; D005843:Geography; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000208:ethnology* / Q000382:microbiology* / Q000473:pathology; D008297:Male; D064307:Microbiota; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011379:Prognosis; D012336:RNA, Ribosomal, 16S / Q000235:genetics
D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S