Imperial College London
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Dr Joram M. Posma PhD MSc B AS MRSC

Faculty of Medicine, Department of Metabolism, Digestion and Reproduction

Senior Lecturer in Biomedical Informatics
 
 
 
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Contact

 

j.posma11 Website

 
 
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Location

 

E305Burlington DanesHammersmith Campus

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Summary

 

Publications

Citation

BibTex format

@article{Ocvirk:2019:ajcn/nqz301,
author = {Ocvirk, S and Wilson, AS and Posma, JM and Li, JV and Koller, KR and Day, GM and Flanagan, CA and Otto, JE and Sacco, PE and Sacco, FD and Sapp, FR and Wilson, AS and Newton, K and Brouard, F and DeLany, JP and Behnning, M and Appolonia, CN and Soni, D and Bhatti, F and Methé, B and Fitch, A and Morris, A and Gaskins, HR and Kinross, J and Nicholson, JK and Thomas, TK and O'Keefe, SJD},
doi = {ajcn/nqz301},
journal = {American Journal of Clinical Nutrition},
pages = {406--419},
title = {A prospective cohort analysis of gut microbial co-metabolism in Alaska Native and rural African people at high and low risk of colorectal cancer},
url = {http://dx.doi.org/10.1093/ajcn/nqz301},
volume = {111},
year = {2019}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - BACKGROUND: Alaska Native (AN) people have the world's highest recorded incidence of sporadic colorectal cancer (CRC) (∼91:100,000), whereas rural African (RA) people have the lowest risk (<5:100,000). Previous data supported the hypothesis that diet affected CRC risk through its effects on the colonic microbiota that produce tumor-suppressive or -promoting metabolites. OBJECTIVES: We investigated whether differences in these metabolites may contribute to the high risk of CRC in AN people. METHODS: A cross-sectional observational study assessed dietary intake from 32 AN and 21 RA healthy middle-aged volunteers before screening colonoscopy. Analysis of fecal microbiota composition by 16S ribosomal RNA gene sequencing and fecal/urinary metabolites by 1H-NMR spectroscopy was complemented with targeted quantification of fecal SCFAs, bile acids, and functional microbial genes. RESULTS: Adenomatous polyps were detected in 16 of 32 AN participants, but not found in RA participants. The AN diet contained higher proportions of fat and animal protein and less fiber. AN fecal microbiota showed a compositional predominance of Blautia and Lachnoclostridium, higher microbial capacity for bile acid conversion, and low abundance of some species involved in saccharolytic fermentation (e.g., Prevotellaceae, Ruminococcaceae), but no significant lack of butyrogenic bacteria. Significantly lower concentrations of tumor-suppressive butyrate (22.5 ± 3.1 compared with 47.2 ± 7.3 SEM µmol/g) coincided with significantly higher concentrations of tumor-promoting deoxycholic acid (26.7 ± 4.2 compared with 11 ± 1.9 µmol/g) in AN fecal samples. AN participants had lower quantities of fecal/urinary metabolites than RA participants and metabolite profiles correlated with the abundance of distinct microbial genera in feces. The main microbial and metabolic CRC-associated markers were not significantly altered in
AU  - Ocvirk,S
AU  - Wilson,AS
AU  - Posma,JM
AU  - Li,JV
AU  - Koller,KR
AU  - Day,GM
AU  - Flanagan,CA
AU  - Otto,JE
AU  - Sacco,PE
AU  - Sacco,FD
AU  - Sapp,FR
AU  - Wilson,AS
AU  - Newton,K
AU  - Brouard,F
AU  - DeLany,JP
AU  - Behnning,M
AU  - Appolonia,CN
AU  - Soni,D
AU  - Bhatti,F
AU  - Methé,B
AU  - Fitch,A
AU  - Morris,A
AU  - Gaskins,HR
AU  - Kinross,J
AU  - Nicholson,JK
AU  - Thomas,TK
AU  - O'Keefe,SJD
DO  - ajcn/nqz301
EP  - 419
PY  - 2019///
SN  - 0002-9165
SP  - 406
TI  - A prospective cohort analysis of gut microbial co-metabolism in Alaska Native and rural African people at high and low risk of colorectal cancer
T2  - American Journal of Clinical Nutrition
UR  - http://dx.doi.org/10.1093/ajcn/nqz301
UR  - https://www.ncbi.nlm.nih.gov/pubmed/31851298
UR  - https://academic.oup.com/ajcn/article/111/2/406/5680465
UR  - http://hdl.handle.net/10044/1/76375
VL  - 111
ER  -
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