Volatile organic compound (VOC) testing in breath has potential in gastric cancer (GC) detection. Our objective was to assess the reproducibility of VOCs in GC, and the effects of conditions modifying gut microbiome on the test results. Ten patients with GC were sampled for VOC over three consecutive days; 17 patients were sampled before and after H. pylori eradication therapy combined with a yeast probiotic; 61 patients were sampled before and after bowel cleansing (interventions affecting the microbiome). The samples were analyzed by: (1) gas chromatography linked to mass spectrometry (GC-MS), applying the non-parametric Wilcoxon test (level of significance p < 0.05); (2) by cross-reactive nanoarrays combined with pattern recognition. Discriminant function analysis (DFA) was used to build the classification models; and leave-one-out cross-validation analysis was used to classify the findings. Exhaled VOCs profiles were stable for GC patients over a three day period. Alpha pinene (p  =  0.028) and ethyl acetate (p  =  0.030) increased after the antibiotic containing eradication regimen; acetone (p  =  0.0001) increased following bowel cleansing prior to colonoscopy. We further hypothesize that S. boulardii given with the standard eradication regimen to re-establish the gut microbiome was the source for long-term ethyl acetate production. Differences between the initial and the follow-up sample were also revealed in the DFA analysis of the sensor data. VOC measurement results are well-reproducible in GC patients indicating a useful basis for potential disease diagnostics. However, interventions with a potential effect on the gut microbiome may have an effect upon the VOC results, and therefore should be considered for diagnostic accuracy.

Our study revealed the importance of NADPH oxidase in the pathogenesis of both acute and chronic inflammation of the colon.

BackgroundThe aim of this study is to evaluate the role of NADPH oxidase in primary intestinal epithelial cells during the active phase of UC.MethodsThe primary human colonic epithelial cells were isolated from 19 patients with mild to moderate inflammatory activity of UC and 14 controls using chelation method. The cells were cultivated under the effect of mediators. Viability of cells was assessed by fluorescent microscopy. Production of reactive oxygen species (ROS) by the cells was measured fluorimetrically using Amplex Red. Production of TNF-α cytokine by the colonic epithelial cells was analysed by ELISA.ResultsThe results of our study showed that unstimulated cells of UC patients had a decreased viability, increased ROS production, but similar TNF-α level when compared to the controls. Stimulation with LPS increased hydrogen peroxide and TNF-α level in the UC group. Treatment of colonic epithelial cells with NADPH oxidase inhibitor increased cell viability decreased the levels of ROS and TNF-α in the LPS-treated cells isolated from UC patients.ConclusionsOur study showed that bacterial endotoxins induced NADPH oxidase activation in the colonic epithelial cells. Moreover, we revealed that treatment with NADPH oxidase inhibitors had a protective effect against pro-inflammatory action of LPS in human colonic epithelium cells during inflammation.

Background The efficacy of histological analysis of colon sections used for evaluation of inflammation severity can be improved by means of digital imaging giving quantitative estimates of main diagnostic features. The aim of this study was to reveal most valuable diagnostic features reflecting inflammation severity in colon and elaborate the evaluation method for computer-aided diagnostics. Methods Tissue specimens from 24 BALB/c mice and 15 patients were included in the study. Chronic and acute colon inflammation in mice was induced by oral administration of dextran sulphate sodium (DSS) solution, while mice in the control group did not get DSS. Human samples of inflamed colon tissue were obtained from patients with ulcerative colitis ( n = 6). Non-inflamed colon tissue of control subjects ( n = 9) was obtained from patients with irritable bowel syndrome or functional obstipation. Analysis of morphological changes in mice and human colon mucosa was performed using 4-μm haematoxylin-eosin (HE) sections. The features reflecting morphological changes in the images of colon mucosa were calculated by convolution of Gabor filter bank and array of pixel values. All features were generalized by calculating mean, histogram skewness and entropy of every image response. Principal component analysis was used to construct optimal representation of morphological changes. Results First principal component (PC1) was representing the major part of features variation (97 % in mice and 71 % in human specimens) and was selected as a measure of inflammation severity. Validation of new measure was performed by means of custom-made software realizing double blind comparison of differences in PC1 with expert’s opinion about inflammation severity presented in two compared pictures. Overall accuracy of 80 % for mice and 67 % for human was reached. Conclusion Principal component analysis of spatial frequency features of histological images may provide continuous scale estimation of inflammation severity of colon tissue.

Background Klebsiella quasipneumoniae is an opportunistic pathogen causing antibiotic-resistant infections of the gastrointestinal tract in many clinical cases. Orally delivered bioactive Klebsiella-specific antimicrobial proteins, klebicins, could be a promising method to eradicate Klebsiella species infecting the gut. Methods Mouse infection model was established based on infection of antibiotic-treated BALB/C mice with K. quasipneumoniae strain DSM28212. Four study groups were used (3 animals/group) to test the antimicrobial efficacy of orally delivered klebicin KvarIa: vehicle-only group (control, phosphate-buffered saline), and other three groups with bacteria, antibiotic therapy and 100 µg of uncoated Kvarla, 100 µg coated KvarIa, 1000 µg coated-KvarIa. Because of the general sensitivity of bacteriocins to gastroduodenal proteases, Kvarla doses were coated with Eudragit®, a GMP-certified formulation agent that releases the protein at certain pH. The coating treatment was selected based on measurements of mouse GI tract pH. The quantity of Klebsiella haemolysin gene (khe) in faecal samples of the study animals was used to quantify the presence of Klebsiella. Results GI colonization of K. quasipneumoniae was achieved only in the antibiotic-treated mice groups. Significant changes in khe marker quantification were found after the use of Eudragit® S100 formulated klebicin KvarIa, at both doses, with a significant reduction of K. quasipneumoniae colonization compared to the vehicle-only control group. Conclusions Mouse GI tract colonization with K. quasipneumoniae can be achieved if natural gut microbiota is suppressed by prior antibiotic treatment. The study demonstrates that GI infection caused by K. quasipneumoniae can be significantly reduced using Eudragit®-protected klebicin KvarIa.