Numerical ecology validates a biogeographical distribution and gender-based effect on mucosa-associated bacteria along the human colon.
We applied constrained ordination numerical ecology methods to data produced with a human intestinal tract-specific phylogenetic microarray (the Aus-HIT Chip) to examine the microbial diversity associated with matched biopsy tissue samples taken from the caecum, transverse colon, sigmoid colon and rectum of 10 healthy patients. Consistent with previous studies, the profiles revealed a marked intersubject variability; however, the numerical ecology methods of analysis allowed the subtraction of the subject effect from the data and revealed, for the first time, evidence of a longitudinal gradient for specific microbes along the colorectum. In particular, probes targeting Streptococcus and Enterococcus spp. produced strongest signals with caecal and transverse colon samples, with a gradual decline through to the rectum. Conversely, the analyses suggest that several members of the Enterobacteriaceae increase in relative abundance towards the rectum. These collective differences were substantiated by the multivariate analysis of quantitative PCR data. We were also able to identify differences in the microarray profiles, especially for the streptococci and Faecalibacterium prausnitzii, on the basis of gender. The results derived by these multivariate analyses are biologically intuitive and suggest that the biogeography of the colonic mucosa can be monitored for changes through cross-sectional and/or inception cohort studies.
CSIRO Preventative Health National Research Flagship and Livestock Industries, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia, Queensland 4068, Australia.
Daniel
D
Aguirre de Cárcer
Páraic O
PO
Cuív
Tingting
T
Wang
Seungha
S
Kang
Daniel
D
Worthley
Vicki
V
Whitehall
Iain
I
Gordon
Chris
C
McSweeney
Barbara
B
Leggett
Mark
M
Morrison
D000368:Aged; D001419:Bacteria / Q000145:classification* / Q000235:genetics; D044822:Biodiversity; D016000:Cluster Analysis; D003106:Colon / Q000382:microbiology*; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D058974:Phylogeography; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012007:Rectum / Q000382:microbiology; D012737:Sex Factors