585P - Changes in the intestinal environments of patients with colorectal cancer or adenoma

Date 01 October 2012
Event ESMO Congress 2012
Session Poster presentation III
Topics Colon Cancer
Rectal Cancer
Presenter Seiji Ohigashi
Authors S. Ohigashi1, K. Sudo1, H. Onodera1, D. Kobayashi2, O. Takahashi3, T. Takahashi4, T. Asahara4, K. Nomoto4
  • 1Gastroenterological Surgery, St. Luke's International Hospital, 104-8560 - Tokyo/JP
  • 2General Internal Medicine, St. Luke's International Hospital, 104-8560 - Tokyo/JP
  • 3Center For Clinical Epidemiology, St. Luke's Life Science Institute, Tokyo/JP
  • 4Microbiological Research, Yakult Central Institute, Tokyo/JP

Abstract

Background

An increasing amount of evidence suggests a role for microbiota in colorectal cancer (CRC). However, it remains unclear whether microbial dysbiosis is the cause or the result of CRC onset. We analyzed the intestinal environments to determine whether the changes differed with the stage of CRC.

Patients and methods

We analyzed 13 groups of microbiota, 8 types of organic acids, and pH in fecal matter obtained from the following groups: individuals with CRC, individuals with adenoma, and individuals with normal intestinal tracts. Ninety-three patients with CRC and 49 healthy individuals (22 with adenoma and 27 without adenoma) were enrolled. The fecal microbiota was identified using reverse transcription-quantitative PCR.

Results

The counts of total bacteria (10.3 ± 0.7 vs. 10.8 ± 0.3 log10 cells/g of feces; P < 0.001), 5 groups of obligate anaerobe (Clostridium coccoides group, C. leptum subgroup, Bacteroides fragilis group, Bifidobacterium, and Atopobium cluster), and 2 groups of facultative anaerobes (Enterobacteriaceae and Staphylococcus) were significantly lower in the cancer group than in the healthy individuals. While the concentrations of short chain fatty acids (SCFA) such as acetic acid, propionic acid, and butyric acid were significantly decreased in the CRC group, the pH was increased in the CRC group (7.4 ± 0.8 vs. 6.9 ± 0.6; P < 0.001). Comparison among the CRC, adenoma, and non-adenoma groups revealed that fecal SCFAs concentrations and pH in the adenoma group were intermediate to the CRC group and the non-adenoma group. Within the CRC group, no differences in either microbiota or organic acids were observed among T-stages or Dukes stages.

Conclusions

CRC patients showed significant changes in the fecal microbiota, SCFA concentrations, and pH. These changes are not a result of CRC progression but are involved in CRC onset.

Disclosure

All authors have declared no conflicts of interest.