title: Clinical value of radionuclide small intestine transit time measurement combined with lactulose hydrogen breath test for the diagnosis of bacterial overgrowth in irritable bowel syndrome.
abstract: OBJECTIVE
  Small intestine bacterial overgrowth (SIBO) may be a pathogenetic factor for irritable bowel syndrome (IBS). This syndrome cannot be explained by structural abnormalities and has no specific diagnostic laboratory tests or biomarkers. We studied quantitatively and semi-quantitatively, using lactulose hydrogen breath test (LHBT), small intestinal transit time (SITT) (99m)technetium-diethylene triamine pentaacetic acid ((99m)Tc-DTPA) in order to examine the mobility of small intestine as an indication of bacterial overgrowth in patients.
  
  
  METHODS
  Eighty nine consecutive patients who met Rome criteria for IBS were retrospectively studied. According to the diagnostic criteria, all patients were divided into two groups: the SIBO group and the non-SIBO group. The tracer was a mixture of 10g lactulose, 37MBq (99m)Tc-DTPA and 100mL water. The patient drank the whole mixture during 1min and the SITT study started immediately. The SITT and the LHBT followed every 15min for up to 3h after emptying the urine bladder. Spearman's rank correlation was applied to assess the correlation of oro-cecum transit time (OCTT) between imaging and LHBT. The semi-quantitative index between the SIBO group and the non-SIBO group was analyzed with Wilcoxon's rank sum test. If there was significant group difference, the receiver operating characteristic (ROC) curve was used. P<0.05 was considered significant.
  
  
  RESULTS
  The median and inter-quartile range for OCTT for the LHBT (OCTT-L) for all patients was 90min and 60min, respectively, and 75min and 45min for OCTT for the SITT study (OCTT-i). There was positive correlation between OCTT-L and OCTT-i at the 0.05 level (R=0.290, P=0.000). There were no differences in OCTT-i and in the rate of radioactivity (counts of regions of interest ROI) over the abdomen between the SIBO group and the non-SIBO group (P=0.116 and 0.290). There were significant differences in the temporal association of the hydrogen (H2) value with OCTT-i (H2-i) and OCTT-L between the two groups (P=0.000 and 0.000). The areas under the curve (AUC) of H2-i and OCTT-L were 0.749 and 0.138 respectively.
  
  
  CONCLUSIONS
  Small intestinal transit time study using a lactose hydrogen breath test and (99m)Tc-DTPA is a real-time test for small intestine bacteria overgrowth in IBS patients and can be used as an indicator of the disease.
authors.affiliation: Department of Nuclear Medicine, Sir Run Run Shaw Hospital, Affiliated to School of Medicine, Zhejiang University, 3 Qingchun East Road, Hangzhou 310016, Zhejiang, P.R.China. loucen126@126.com.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Ning
authors.forename: Cen
authors.initials: C
authors.lastname: Lou
authors.forename: Zhongke
authors.initials: Z
authors.lastname: Huang
authors.forename: Dongfang
authors.initials: D
authors.lastname: Chen
authors.forename: Huacheng
authors.initials: H
authors.lastname: Huang
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.forename: Bucheng
authors.initials: B
authors.lastname: Zhang
authors.forename: Ning
authors.initials: N
authors.lastname: Dai
authors.forename: Jianmin
authors.initials: J
authors.lastname: Zhao
authors.forename: Xia
authors.initials: X
authors.lastname: Zhen
mesh_terms: D000328:Adult; D001944:Breath Tests; D005189:False Positive Reactions; D005260:Female; D005772:Gastrointestinal Transit; D006801:Humans; D006859:Hydrogen / Q000378:metabolism*; D007421:Intestine, Small / Q000382:microbiology / Q000503:physiopathology*; D043183:Irritable Bowel Syndrome / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000382:microbiology* / Q000503:physiopathology; D007792:Lactulose; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D016284:Technetium Tc 99m Pentetate
chemical_list: D007792:Lactulose; D006859:Hydrogen; D016284:Technetium Tc 99m Pentetate