Mucosa-associated Faecalibacterium prausnitzii and Escherichia coli co-abundance can distinguish Irritable Bowel Syndrome and Inflammatory Bowel Disease phenotypes.
BACKGROUND
Crohn's disease (CD) and ulcerative colitis (UC) diagnosis requires comprehensive examination of the patient. Faecalibacterium prausnitzii and Escherichia coli have been reported as representatives of Inflammatory Bowel Disease (IBD) dysbiosis. The aim was to determine whether or not quantification of these species can be used as a complementary tool either for diagnostic or prognostic purposes.


METHODS
Mucosa-associated F. prausnitzii and E. coli abundance was determined in 28 controls (H), 45 CD, 28 UC patients and 10 irritable bowel syndrome (IBS) subjects by quantitative polymerase chain reaction (qPCR) and the F. prausnitzii-E. coli index (F-E index) was calculated. Species abundances were normalized to total bacteria and human cells. Data was analyzed taking into account patients' phenotype and most relevant clinical characteristics.


RESULTS
IBD patients had lower F. prausnitzii abundance than H and IBS (P<0.001). CD patients showed higher E. coli counts than H and UC patients (P<0.001). The F-E index discriminated between H, CD and UC patients, and even between disease phenotypes that are usually difficult to distinguish as ileal-CD (I-CD) from ileocolonic-CD and colonic-CD from extensive colitis. E. coli increased in active CD patients, and remission in I-CD patients was compromised by high abundance of this species. Treatment with anti-tumor necrosis factor (TNF) α diminished E. coli abundance in I-CD whereas none of the treatments counterbalanced F. prausnitzii depletion.


CONCLUSIONS
F. prausnitzii and E. coli are useful indicators to assist in IBD phenotype classification. The abundance of these species could also be used as a supporting prognostic tool in I-CD patients. Our data indicates that current medication does not restore the levels of these two species to those found in a healthy gut.
Laboratory of Molecular Microbiology, Biology Department, Universitat de Girona, Girona, Spain.
Mireia
M
Lopez-Siles
Laboratory of Molecular Microbiology, Biology Department, Universitat de Girona, Girona, Spain.
Margarita
M
Martinez-Medina
Departament de Gastroenterologia, Hospital Dr. Josep Trueta, Girona, Spain.
David
D
Busquets
Departament de Gastroenterologia, Hospital Santa Caterina, Salt, Girona, Spain.
Miriam
M
Sabat-Mir
Microbiology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom.
Sylvia H
SH
Duncan
Microbiology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom.
Harry J
HJ
Flint
Departament de Gastroenterologia, Hospital Dr. Josep Trueta, Girona, Spain.
Xavier
X
Aldeguer
Laboratory of Molecular Microbiology, Biology Department, Universitat de Girona, Girona, Spain. Electronic address: jesus.garcia@udg.edu.
L Jesús
LJ
Garcia-Gil
D000293:Adolescent; D000328:Adult; D058491:Bacterial Load; D015331:Cohort Studies; D004926:Escherichia coli / Q000302:isolation & purification*; D005260:Female; D006094:Gram-Positive Bacteria / Q000302:isolation & purification*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis / Q000382:microbiology*; D007413:Intestinal Mucosa / Q000382:microbiology*; D043183:Irritable Bowel Syndrome / Q000175:diagnosis / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D060888:Real-Time Polymerase Chain Reaction; D055815:Young Adult
Diagnostics; Escherichia coli; Faecalibacterium prausnitzii; Inflammatory Bowel Disease; Irritable Bowel Syndrome; Prognostics