Colonic Biopsies Research Articles

The Relationship of Enterotoxigenic Bacteroides fragilis and Fusobacterium nucleatum Intestinal Colonization with Colorectal Cancer: A Case-Control Study Performed with Colon Biopsies

In recent years, it has been shown that some bacteria may be associated with colorectal cancer (CRC). In this study, it was aimed to investigate the role of Fusobacterium nucleatum and enterotoxigenic Bacteroides fragilis (ETBF) in the etiology of CRC by comparing the amounts of these bacteria in colon biopsy tissues of patients with CRC and healthy individuals. The amounts of F.nucleatum and ETBF were determined by quantitative polymerase chain reaction (qPCR) in colon biopsy samples taken from 35 CRC and 35 healthy individuals, and the results were compared in the patient and control groups. The detection rate and amounts of F.nucleatum were found to be statistically significantly higher in tissues of female patients with CRC compared to male patients (p= 0.003, p= 0.013, respectively). There was no statistically significant difference between the tissues of female and male patients with CRC in terms of detection rate and amount of ETBF (p= 0.521, p= 0.515, respectively). It was found that in the 50-74 age group, the amount of ETBF was statistically significantly higher in women and men with CRC compared to the controls (p= 0.005, p= 0.047, respectively), while the amount of F.nucleatum was statistically significantly higher in female patients compared to controls. However, no difference was found between male patients and controls (p= 0.009, p= 0.083). It was determined that the detection rate and amount of F.nucleatum in the tissues of patients with CRC, regardless of age and gender, were not statistically different from the controls (p= 0.473, p= 0.995, respectively), however, the detection rate of ETBF and the amount of ETBF were found to be statistically significantly higher (p= 0.002, p= 0.004, respectively). It has been determined that ETBF can play a role in the etiology of CRC in both men and women, and F.nucleatum only in women, in the age range of 50-74 years, when routine screenings for CRC are performed.

Mucosal α4β7+ Lymphocytes and MAdCAM+ Venules Predict Response to Vedolizumab in Ulcerative Colitis.

Therapeutic strategies for patients with ulcerative colitis (UC) are based on patient- and disease-related factors in combination with drug characteristics but fail to predict success in individual patients. A considerable proportion of UC patients do not respond to the biological vedolizumab. Therefore, pretreatment biomarkers for therapeutic efficacy are urgently needed. Mucosal markers related to the integrin-dependent T lymphocyte homing could be potent predictors. We prospectively included 21 biological- and steroid-naive UC patients with moderate-to-severe disease activity planned to escalate therapy to vedolizumab. At week 0, before initiating treatment, colonic biopsy specimens were obtained for immunophenotyping and immunohistochemistry. Clinical and endoscopic disease activity were determined at week 16 after 4 infusions of vedolizumab. In addition, we retrospectively included 5 UC patients who were first treated with anti-tumor necrosis factor α before receiving vedolizumab to compare with biological-naive patients. Abundance of α4β7 on more than 8% of all CD3+ T lymphocytes in colonic biopsies at baseline was predictive for responsiveness to vedolizumab (sensitivity 100%, specificity 100%). The threshold for the proportion of MAdCAM-1+ and PNAd+ of all venules in the biopsies predictive for responsiveness to vedolizumab was ≥2.59% (sensitivity 89%, specificity 100%) and ≥2.41% (sensitivity 61%, specificity 50%), respectively. At week 16, a significant decrease of α4β7+CD3+T lymphocytes was demonstrated in responders (18% [12%-24%] to 8% [3%-9%]; P = .002), while no difference was seen in nonresponders (4% [3%-6%] to 3%; P = .59). UC responders to vedolizumab have a higher percentage of α4β7+CD3+ T lymphocytes and a higher proportion of MAdCAM-1+ venules in colonic biopsies than nonresponders before initiating therapy. Both analyses could be promising predictive biomarkers for therapeutic response and may lead to more patient tailored treatment in the future.

Clinical Implications of Microscopic Colitis Isolated to Polyps.

Microscopic colitis is generally identified on random colon biopsies performed for chronic diarrhea, but rarely incidental polyps have histologic features of microscopic colitis. We compared patients with polypoid microscopic colitis to control patients with conventional polyps to determine the implications of polypoid microscopic colitis. Medical records were searched for patients without prior or concurrent microscopic colitis who were found to have polypoid microscopic colitis. For each patient with polypoid microscopic colitis, one patient with conventional polyps was selected as a control. We reviewed the histologic features of each polypoid microscopic colitis specimen, and evaluated endoscopic and clinical findings for polypoid microscopic colitis patients and controls. Twenty-six patients with polypoid microscopic colitis were identified with histologic features of collagenous colitis in 8 patients (31%) and lymphocytic colitis in 18 patients (69%). Polypoid microscopic colitis was unifocal in 14 patients (54%) and multifocal in 12 patients (46%). Patients with polypoid microscopic colitis were older than control patients (median age = 60 years vs 66 years, P = .04). On follow-up 7 patients with polypoid microscopic colitis (33%) developed chronic diarrhea compared to 3 (12%) controls ( P = .16). Of patients with follow-up biopsies, 1 patient with polypoid microscopic colitis (13%) and no control patients developed microscopic colitis ( P = 1). Polypoid microscopic colitis may be identified in asymptomatic patients and most patients do not develop chronic diarrhea, but some patients with polypoid microscopic colitis develop diarrhea (33% vs 12% in controls) or conventional microscopic colitis on follow-up. Thus pathologists should distinguish polypoid microscopic colitis from conventional microscopic colitis but may inform clinicians of the uncertain association with chronic diarrhea to guide decisions regarding follow-up.

Exploring the Relationship between the Gut Mucosal Virome and Colorectal Cancer: Characteristics and Correlations.

The fecal virome has been reported to be associated with CRC. However, little is known about the mucosal virome signature in CRC. This study aimed to determine the viral community within CRC tissues and their contributions to colorectal carcinogenesis. Colonic mucosal biopsies were harvested from patients with CRC (biopsies of both neoplasia and adjacent normal tissue (CRC-A)) and healthy controls (HC). The shot-gun metagenomic sequencing of virus-like particles (VLPs) was performed on the biopsies. Viral community, functional pathways, and their correlations to clinical data were analyzed. Fluorescence in situ hybridizations (FISH) for the localization of viruses in the intestine was performed, as well as quantitative PCR for the detection of Torque teno virus load in human mucosal VLP DNA. A greater number and proportion of core species were found in CRC tissues than in CRC-A and HC tissues. The diversity of the mucosal virome in CRC tissues was significantly increased compared to that in HC and CRC-A tissues. The mucosal virome signature of CRC tissues were significantly different from those of HC and CRC-A tissues at the species level. The abundances of eukaryotic viruses from the Anelloviridae family and its sub-species Torque teno virus (TTV) were significantly higher in CRC patients than in HC. Furthermore, increased levels of TTV in the intestinal lamina propria were found in the CRC group. Multiple viral functions of TTV associated with carcinogenesis were enriched in CRC tissues. We revealed for the first time that the mucosal virobiota signature of CRC is characterized by a higher diversity and more eukaryotic viruses. The enrichment of TTV species in CRC tissues suggests that they may play an oncogenic role in CRC. Targeting eukaryotic viruses in the gut may provide novel strategies for the prevention and treatment of CRC.

Expression of HMGCS2 in intestinal epithelial cells is downregulated in inflammatory bowel disease associated with endoplasmic reticulum stress.

The Unfolded Protein Response, a mechanism triggered by the cell in response to Endoplasmic reticulum stress, is linked to inflammatory responses. Our aim was to identify novel Unfolded Protein Response-mechanisms that might be involved in triggering or perpetuating the inflammatory response carried out by the Intestinal Epithelial Cells in the context of Inflammatory Bowel Disease. We analyzed the transcriptional profile of human Intestinal Epithelial Cell lines treated with an Endoplasmic Reticulum stress inducer (thapsigargin) and/or proinflammatory stimuli. Several genes were further analyzed in colonic biopsies from Ulcerative Colitis patients and healthy controls. Lastly, we generated Caco-2 cells lacking HMGCS2 by CRISPR Cas-9 and analyzed the functional implications of its absence in Intestinal Epithelial Cells. Exposure to a TLR ligand after thapsigargin treatment resulted in a powerful synergistic modulation of gene expression, which led us to identify new genes and pathways that could be involved in inflammatory responses linked to the Unfolded Protein Response. Key differentially expressed genes in the array also exhibited transcriptional alterations in colonic biopsies from active Ulcerative Colitis patients, including NKG2D ligands and the enzyme HMGCS2. Moreover, functional studies showed altered metabolic responses and epithelial barrier integrity in HMGCS2 deficient cell lines. We have identified new genes and pathways that are regulated by the Unfolded Protein Response in the context of Inflammatory Bowel Disease including HMGCS2, a gene involved in the metabolism of Short Chain Fatty Acids that may have an important role in intestinal inflammation linked to Endoplasmic Reticulum stress and the resolution of the epithelial damage.

Study the Bacterial Activity Isolated from Colon and Rectal Cancer Biopsy in Cell Lines Culture

Colorectal cancer (CRC) is the most common disease and cause of death globally. The aim of the study is investigation and detection of some bacterial interfering with CRC occurrence and progression. The study conducted between September 2022 till February 2023, a total of 50 specimens were collected from confirmed CRC patients. In addition, 50 stool specimens were collected from Healthy volunteers, considers as control group. Isolation and identification of bacteria in all collected specimens were done by using cultural and differential media (blood agar, macconkey agar and Pfizer agar), as well as the VITEK- 2 compact system. The bacterial species, in the specimens of control were ( Escherichia coli 50 (86.20%), Klebsiella Pneumonia 3(5.17%), Salmonella typhi 2(3.44%), Staphylococcus aureus 1(1.72%), Proteus mirabilis 1(1.72%) and Pseudomonas aeruginosa 1(1.72%), while in the specimens of CRC and polyp were (Escherichia coli 30(38.69%), Streptococcus uberis 6(7.79%), Enterobacter cloacae 4(5.19%), Proteus mirabilis 11(14.28), Streptococcus constellatus pharyneis 1(1.29%), Micrococcus luteus 1(1.29%), Staphlococcus pseudintermedius 1(1.29%), Streptococcus thoraltensis 1(1.29%), Citrobacter freundii 1(1.29%), Streptoccus mutans 1(1.29%), Enterococcus faecium 5(6.49%), Enterococcus faecalis 4(5.19%), Granulicatella elegans 1(1.29%), Enterococcus gallinarum 2(2.59%), Serratia marcescens 1(1.29%), Streptococcus sangunis 1(1.29%), Staphylococcus lentus 1(1.29%), Comamons testosteroni 1(1.29%), Morganella morganii 1(1.29%), Pseudomonas aeruginosa 1(1.29%), Klebsiella pneumonia 2(2.59%). The bacteria which has been shown to be associated and more abundance in the specimens of CRC tissues are Escherichia.coli 30(38.96%), Streptococcus uberis 6(7.79%), Enterobacter cloacae 4(5.19%), Enterococcus faecium 5(6.49%), Enterococcus faecalis 4(5.19%). Cell-line culture techniques for the five species showed a cellular viability, sequentially Streptocccus uberis (16.12%), Enterococcus faecium (16.39%), Entreococcus faecalis (9.48%), Enterobacter cloacae (15.11%) and Escherichia coli (17.61%). The results statistically studied by using SPSS, which showed excellent or (highly) significant (p-value is in the range of 0.001).

Study the Bacterial Activity Isolated from Colon and Rectal Cancer Biopsy in Cell Lines Culture

Colorectal cancer (CRC) is the most common disease and cause of death globally. The aim of the study is investigation and detection of some bacterial interfering with CRC occurrence and progression. The study conducted between September 2022 till February 2023, a total of 50 specimens were collected from confirmed CRC patients. In addition, 50 stool specimens were collected from Healthy volunteers, considers as control group. Isolation and identification of bacteria in all collected specimens were done by using cultural and differential media (blood agar, macconkey agar and Pfizer agar), as well as the VITEK- 2 compact system. The bacterial species, in the specimens of control were ( Escherichia coli 50 (86.20%), Klebsiella Pneumonia 3(5.17%), Salmonella typhi 2(3.44%), Staphylococcus aureus 1(1.72%), Proteus mirabilis 1(1.72%) and Pseudomonas aeruginosa 1(1.72%), while in the specimens of CRC and polyp were (Escherichia coli 30(38.69%), Streptococcus uberis 6(7.79%), Enterobacter cloacae 4(5.19%), Proteus mirabilis 11(14.28), Streptococcus constellatus pharyneis 1(1.29%), Micrococcus luteus 1(1.29%), Staphlococcus pseudintermedius 1(1.29%), Streptococcus thoraltensis 1(1.29%), Citrobacter freundii 1(1.29%), Streptoccus mutans 1(1.29%), Enterococcus faecium 5(6.49%), Enterococcus faecalis 4(5.19%), Granulicatella elegans 1(1.29%), Enterococcus gallinarum 2(2.59%), Serratia marcescens 1(1.29%), Streptococcus sangunis 1(1.29%), Staphylococcus lentus 1(1.29%), Comamons testosteroni 1(1.29%), Morganella morganii 1(1.29%), Pseudomonas aeruginosa 1(1.29%), Klebsiella pneumonia 2(2.59%). The bacteria which has been shown to be associated and more abundance in the specimens of CRC tissues are Escherichia.coli 30(38.96%), Streptococcus uberis 6(7.79%), Enterobacter cloacae 4(5.19%), Enterococcus faecium 5(6.49%), Enterococcus faecalis 4(5.19%). Cell-line culture techniques for the five species showed a cellular viability, sequentially Streptocccus uberis (16.12%), Enterococcus faecium (16.39%), Entreococcus faecalis (9.48%), Enterobacter cloacae (15.11%) and Escherichia coli (17.61%). The results statistically studied by using SPSS, which showed excellent or (highly) significant (p-value is in the range of 0.001).

Composition of the colon microbiota in the individuals with inflammatory bowel disease and colon cancer.

The human intestine is a habitat for microorganisms and, recently, the composition of the intestinal microbiota has been correlated with the etiology of diseases such as inflammations, sores, and tumors. Although many studies have been conducted to understand the composition of that microbiota, expanding these studies to more samples and different backgrounds will improve our knowledge. In this work, we showed the colon microbiota composition and diversity of healthy subjects, patients with inflammatory bowel disease (IBD), and colon cancer by metagenomic sequencing. Our results indicated that the relative abundance of prokaryotic and eukaryotic microbes differs between the healthy vs. tumor biopsies, tumor vs. IBD biopsies, and fresh vs. paraffin-embedded tumor biopsies. Fusobacterium, Escherichia-Shigella, and Streptococcus genera were relatively abundant in fresh tumor biopsies, while Pseudomonas was significantly elevated in IBD biopsies. Additionally, another opportunist pathogen Malasseziales was revealed as the most abundant fungal clade in IBD biopsies, especially in ulcerative colitis. We also found that, while the Basidiomycota:Ascomycota ratio was slightly lower in tumor biopsies compared to biopsies from healthy subjects, there was a significant increase in IBD biopsies. Our work will contribute to the known diversity of prokaryotic and eukaryotic microbes in the colon biopsies in patients with IBD and colon cancer.

Сonnection of immunological markers with morphological manifestations in ulcerative colitis

Background. Inflammatory bowel diseases, including ulcerative colitis and Crohn’s disease, are an urgent problem of modern gastroenterology. Therefore, the discovery of new laboratory approaches makes it possible to assess the degree of the disease. Purpose: to reveal the relationship between morphological manifestations and immunological indicators in patients with ulcerative colitis. Materials and methods. The studies were conducted on biological material (blood and colonic biopsy samples) of 90 patients with ulcerative colitis. The thickness of the mucosa, density of the inflammatory infiltrate and its composition, crypt sizes, their architectonics, the presence of crypt abscesses, atrophic and fibrotic changes were calculated in biopsies by morphological and morphometric methods. Immunological studies included the evaluation of mononuclear cells, the levels of B-lymphocytes, interleukin-10, tumor necrosis factor α, immunoglobulins (Ig) A, M, G. Results. The histological activity of the disease was determined by an increased level of inflammatory infiltrate (14,431.4 ± 483.3 per 1 mm2 of stroma) and the presence of many neutrophilic granulocytes (212.2 ± 20.9 per 1 mm2 of stroma) and lymphocytes (2,922.8 ± 76.6 per 1 mm2 of stroma) in it. Also, some patients had crypt abscesses (36.7 % of the total number of patients) and breaches in the epithelial integrity (54.4 % of the total number of patients). A correlation was found between the level of CD22+ lymphocytes and some morphometric parameters: the width of the crypts (r = 0.27; P < 0.01) and the height of the surface epithelium (r = 0.30; P < 0.01); between IgM concentrations and cellular density of mucosal infiltrate (r = 0.29; P < 0.01), neutrophils (r = 0.28; P < 0.01) and basophils (r = 0.24; P < 0.05); level of IgA and macrophages (r = 0.21; P < 0.05), lymphocytes (r = 0.24; P < 0.05), basophils (r = 0.25; P < 0.05). Conclusions. It is shown that some morphological and morphometric indicators are related to immunological parameters. It was found that the elevated level of cytokines correlates with the activity of inflammation in patients with ulcerative colitis. The level of CD22+ lymphocytes and changes in some morphometric indicators (crypt width and surface epithelium height) are directly related to an increase in inflammatory processes in the intestinal mucosa.

Apoptosis, Crypt Dropout, and Equivocal Immunohistochemical Staining May Indicate Cytomegalovirus Infection in Inflammatory Bowel Disease Patients.

Cytomegalovirus (CMV) colitis superimposed on inflammatory bowel disease (IBD) can be challenging to diagnose. This study aimed to determine what histologic clues and immunohistochemistry (IHC) utilization practices, if any, can help diagnose CMV superinfection in IBD. Colon biopsies were reviewed from all patients with CMV colitis with and without IBD between 2010 and 2021 at one institution, along with a separate cohort of IBD patients with negative CMV IHC. Biopsies were assessed for histologic features of activity and chronicity, phlebitis, fibrin thrombi, basal crypt apoptosis, CMV viral cytopathic effect (VCE), and CMV IHC positivity. Features between groups were compared, with statistical significance set at P -value <0.05. The study included 251 biopsies from 143 cases (21 CMV-only, 44 CMV+IBD, 78 IBD-only). Compared with the IBD-only group, the CMV+IBD group was more likely to show apoptotic bodies (83% vs. 64%, P =0.035) and crypt dropout (75% vs. 55%, P =0.045). CMV was detected by IHC in 18 CMV+IBD cases without VCE on hematoxylin and eosin (41%). In the 23 CMV+IBD cases where IHC was performed on all concurrent biopsies, IHC was positive in at least 1 biopsy in 22 cases. Six individual CMV+IBD biopsies with no VCE on hematoxylin and eosin demonstrated equivocal IHC staining. Of these, 5 had evidence of CMV infection. IBD patients with superimposed CMV infection are more likely to demonstrate apoptotic bodies and crypt dropout compared with their noninfected counterparts. Equivocal IHC staining for CMV may indicate true infection in IBD patients, and staining multiple biopsies from the same accession can improve CMV detection.

A randomised, double-blind, placebo-controlled study of the LAG-3-depleting monoclonal antibody GSK2831781 in patients with active ulcerative colitis.

Selective depletion of T cells expressing LAG-3, an immune checkpoint receptor that is upregulated on activated T cells, has been investigated in pre-clinical models as a potential therapeutic approach in inflammatory and autoimmune diseases where activated T cells are implicated. GSK2831781, a depleting monoclonal antibody that specifically binds LAG-3 proteins, may deplete activated LAG-3+ cells in ulcerative colitis (UC). Patients with moderate to severe UC were randomised to GSK2831781 or placebo. Safety, tolerability, efficacy, pharmacokinetics and pharmacodynamics of GSK2831781 were evaluated. One hundred four participants across all dose levels were randomised prior to an interim analysis indicating efficacy futility criteria had been met. Efficacy results focus on the double-blind induction phase of the study (GSK2831781 450 mg intravenously [IV], N = 48; placebo, N = 27). Median change from baseline (95% credible interval [CrI]) in complete Mayo score was similar between groups (GSK2831781 450 mg IV: -1.4 [-2.2, -0.7]; placebo: -1.4 [-2.4, -0.5]). Response rates for endoscopic improvement favoured placebo. Clinical remission rates were similar between groups. In the 450-mg IV group, 14 (29%) participants had an adverse event of UC versus 1 (4%) with placebo. LAG-3+ cells were depleted to 51% of baseline in blood; however, there was no reduction in LAG-3+ cells in the colonic mucosa. Transcriptomic analysis of colon biopsies showed no difference between groups. Despite evidence of target cell depletion in blood, GSK2831781 failed to reduce inflammation in the colonic mucosa suggesting no pharmacological effect. The study was terminated early (NCT03893565).

Quantitative Phase Imaging Using Digital Holographic Microscopy to Assess the Degree of Intestinal Inflammation in Patients with Ulcerative Colitis.

Ulcerative colitis (UC) is characterized by chronic inflammation of the colorectum. Histological remission has emerged as a potential future treatment goal; however, the histopathological assessment of intestinal inflammation in UC remains challenging with a multitude of available scoring systems and the need for a pathologist with expertise in inflammatory bowel disease (IBD). In previous studies, quantitative phase imaging (QPI) including digital holographic microscopy (DHM) was successfully applied as an objective method for stain-free quantification of the degree of inflammation in tissue sections. Here, we evaluated the application of DHM for the quantitative assessment of histopathological inflammation in patients with UC. In our study, endoscopically obtained colonic and rectal mucosal biopsy samples from 21 patients with UC were analyzed by capturing DHM-based QPI images that were subsequently evaluated using the subepithelial refractive index (RI). The retrieved RI data were correlated with established histological scoring systems including the Nancy index (NI) as well as with endoscopic and clinical findings. As a primary endpoint, we found a significant correlation between the DHM-based retrieved RI and the NI (R2 = 0.251, p < 0.001). Furthermore, RI values correlated with the Mayo endoscopic subscore (MES; R2 = 0.176, p < 0.001). An area under the receiver operating characteristics (ROC) curve of 0.820 confirms the subepithelial RI as a reliable parameter to distinguish biopsies with histologically active UC from biopsies without evidence of active disease as determined by conventional histopathological examination. An RI higher than 1.3488 was found to be the most sensitive and specific cut-off value to identify histologically active UC (sensitivity of 84% and specificity of 72%). In conclusion, our data demonstrate DHM to be a reliable tool for the quantitative assessment of mucosal inflammation in patients with UC.

The orphan MRGPRF receptor is expressed in entero-endocrine cells of the human gut mucosa.

In the past years, it has become clear that the family of Mas-related G protein-coupled receptors plays a central role in neuro-immune communication at mucosal barrier surfaces, in particular in the skin. Remarkably, MRGPR expression at other mucosal surfaces remains poorly characterized. To fill this gap in our understanding, the present study was undertaken to screen and verify the expression of the human MRGPR family members in the mucosal biopsies of the human gastrointestinal (GI) tract. Our findings revealed that, of all human MRGPRs family members, only MRGPRF mRNA is expressed at detectable levels in human mucosal biopsies of both terminal ileum and sigmoid colon. Furthermore, immunohistochemical stainings revealed that MRGPRF is specifically expressed by mucosal entero-endocrine cells (EECs). Overall, this study showed for the first time that the human ileum and colonic mucosa represent a novel expression site for the orphan MRGPRF, more specifically in EECs.

Flat nodular lymphoid hyperplasia resembling "apple tree branches" in the colon.

A 19-year-old woman with a history of adjustment disorder presented with abdominal pain, bloating, and chronic diarrhea. Colonoscopy revealed multiple flat whitish areas, less than 3 mm in diameter, diffusely distributed throughout the entire colon and rectum. These findings were prominent under narrow-band imaging (NBI) ([Fig. 1 a]) and more difficult to distinguish with white-light imaging ([Fig. 1 b]). The flat areas and the surrounding superficial vessels were described in the report as resembling “apple tree branches” ([Video 1]). Inspection of the terminal ileum was unremarkable, and esophagogastroduodenoscopy was unrevealing. Histologic examination of the colonic biopsy specimens showed nodules of benign lymphoid tissue with enlarged germinal centers and an intact mantle zone, consistent with a diagnosis of nodular lymphoid hyperplasia (NLH) ([Fig. 2]). Laboratory investigations and fecal calprotectin were within normal limits. Stool pathogen testing was negative. The patient was diagnosed with irritable bowel syndrome (IBS) and diffuse flat NLH.

Colonic mucosal biopsy location can not affect the results of mucosal metabolomics and mucosal microbiota analysis in IBS.

To compare and analyze the mucosal metabolites and mucosal microbiota of different parts of colon in patients with IBS. A total of 10 patients with IBS-D and six healthy controls (HC) were enrolled. All enrolled participants underwent two biopsies of the ileocecal and sigmoid colon during colonoscopy. Metabolomic profiling of one piece of tissue was conducted using desorption electrospray ionization-mass spectrometry (DESI-MS), and the gut flora of the other piece was examined using 16S rRNA sequencing. The metabolic profiles and flora of the ileocecal and sigmoid colonic mucosa in each group were further analyzed in this study. (1) Principal components analysis (PCA) indicated that mucosal metabolites did not differ in different parts of the colon in either the IBS-D or HC groups. (2) In the mucosal microbiome analyses, no differences between the microbiota of the two parts of the colon were found by using Principal Co-ordinates Analysis (PCoA). In IBS group, comparing with sigmoid mucosa, the chao1 richness indice was higher and the Shannon index was lower in the ileocecal mucosa (p = 0.40, p = 0.22). However, in the HC group, microbiome analysis of the ileocecal mucosa showed lower values for Chao 1 and Shannon indices than those of the sigmoid colon mucosa (p = 0.06, p = 0.86). (3) Compared with the HC group, 1,113 metabolic signal peaks were upregulated, whereas 594 metabolites were downregulated in the IBS-D samples. Moreover, the PCA of the metabolites showed significant separation between the IBS-D and HC groups. (4) Chao1 expression was significantly higher in the mucosal microbiota with IBS-D than in the HC (p = 0.03). The Shannon index was lower in IBS-D, but the difference was not statistically significant (p = 0.53). PCoA revealed a significant difference in the microflora structure between the IBS-D and HC groups. The mucosal metabolic profile and mucosal flora structure of the colon were similar, despite different locations in IBS and healthy subjects. IBS had abnormal colonic mucosal metabolism and flora disturbances.

Omentin-1 ameliorates experimental inflammatory bowel disease via Nrf2 activation and redox regulation

AimsOmentin-1 production is decreased in patients with IBD. However, the specific role of Omentin-1 in IBD has not been fully elucidated. This study aimed to investigate the expression and role of Omentin-1 in IBD and the potential mechanisms. Main methodsWe collected human serum and colon biopsy samples at the Wuhan Union Hospital. Omentin-1 recombinant protein was injected intraperitoneally in a DSS-induced experimental IBD mouse model. Omentin-1 levels were measured in IBD patients, colitis mice, and LPS-induced HT-29 cells. Omentin-1 and/or a Nrf2 specific inhibitor (ML385) were administered to DSS mice and LPS-induced HT-29 cells. The effects of Omentin-1 on inflammation, intestinal barrier function, Nrf2 pathway, oxidative stress, and NF-κB signaling were detected in vivo and in vitro. Key findingsSerum Omentin-1 levels were significantly reduced in UC and CD patients compared with controls (173.7 (IQR, 120.1–221.2) ng/ml, 80.8 (43.8–151.8) ng/ml, and 270.7 (220.7–306.5) ng/ml, respectively). The levels of Omentin-1 were also significantly lower in colitis mice and LPS-induced HT-29 cells. Omentin-1 treatment effectively ameliorated inflammation and impaired intestinal barrier, decreased ROS and MDA levels, and increased GSH and SOD production in the DSS-induced colitis mice and LPS-induced HT-29 cells. Mechanically, Omentin-1 repaired the intestinal barrier by activating Nrf2, then improving oxidative stress and inhibiting NF-κB signaling. Furthermore, the interaction between Omentin-1 and Nrf2 was identified. SignificanceOmentin-1 activates the Nrf2 pathway to regulate redox balance, ultimately protecting intestinal barrier function and reducing intestinal inflammation. In general, Omentin-1 can be used as a promising therapeutic target for IBD.

Free heme exacerbates colonic injury induced by anti-cancer therapy.

Gastrointestinal inflammation and bleeding are commonly induced by cancer radiotherapy and chemotherapy but mechanisms are unclear. We demonstrated an increased number of infiltrating heme oxygenase-1 positive (HO-1+) macrophages (Mø, CD68+) and the levels of hemopexin (Hx) in human colonic biopsies from patients treated with radiation or chemoradiation versus non-irradiated controls or in the ischemic intestine compared to matched normal tissues. The presence of rectal bleeding in these patients was also correlated with higher HO-1+ cell infiltration. To functionally assess the role of free heme released in the gut, we employed myeloid-specific HO-1 knockout (LysM-Cre : Hmox1flfl), hemopexin knockout (Hx-/-) and control mice. Using LysM-Cre : Hmox1flfl conditional knockout (KO) mice, we showed that a deficiency of HO-1 in myeloid cells led to high levels of DNA damage and proliferation in colonic epithelial cells in response to phenylhydrazine (PHZ)-induced hemolysis. We found higher levels of free heme in plasma, epithelial DNA damage, inflammation, and low epithelial cell proliferation in Hx-/- mice after PHZ treatment compared to wild-type mice. Colonic damage was partially attenuated by recombinant Hx administration. Deficiency in Hx or Hmox1 did not alter the response to doxorubicin. Interestingly, the lack of Hx augmented abdominal radiation-mediated hemolysis and DNA damage in the colon. Mechanistically, we found an altered growth of human colonic epithelial cells (HCoEpiC) treated with heme, corresponding to an increase in Hmox1 mRNA levels and heme:G-quadruplex complexes-regulated genes such as c-MYC, CCNF, and HDAC6. Heme-treated HCoEpiC cells exhibited growth advantage in the absence or presence of doxorubicin, in contrast to poor survival of heme-stimulated RAW247.6 Mø. In summary, our data indicate that accumulation of heme in the colon following hemolysis and/or exposure to genotoxic stress amplifies DNA damage, abnormal proliferation of epithelial cells, and inflammation as a potential etiology for gastrointestinal syndrome (GIS).

Comparison of gut microbiome composition in colonic biopsies, endoscopically-collected and at-home-collected stool samples.

The goal of this study is to compare microbiome composition in three different sample types in women, namely stool brought from home vs. solid stool samples obtained at the time of an unprepped sigmoidoscopy vs. biopsies of the colonic mucosa at the time of an unprepped sigmoidoscopy, using alpha- and beta-diversity metrics following bacterial 16S rRNA sequencing. The findings may have relevance to health and disease states in which bacterial metabolism has a significant impact on molecules/metabolites that are recirculated between the gut lumen and mucosa and systemic circulation, such as estrogens (as in breast cancer) or bile acids. Concomitant at-home-collected stool, endoscopically-collected stool, and colonic biopsy samples were collected from 48 subjects (24 breast cancer, 24 control.) After 16S rRNA sequencing, an amplicon sequence variant (ASV) based approach was used to analyze the data. Alpha diversity metrics (Chao1, Pielou's Evenness, Faith PD, Shannon, and Simpson) and beta diversity metrics (Bray-Curtis, Weighted and Unweighted Unifrac) were calculated. LEfSe was used to analyze differences in the abundance of various taxa between sample types. Alpha and beta diversity metrics were significantly different between the three sample types. Biopsy samples were different than stool samples in all metrics. The highest variation in microbiome diversity was noted in the colonic biopsy samples. At-home and endoscopically-collected stool showed more similarities in count-based and weighted beta diversity metrics. There were significant differences in rare taxa and phylogenetically-diverse taxa between the two types of stool samples. Generally, there were higher levels of Proteobacteria in biopsy samples, with significantly more Actinobacteria and Firmicutes in stool (all p < 0.001, q-value < 0.05). Overall, there was a significantly higher relative abundance of Lachnospiraceae and Ruminococcaceae in stool samples (at-home collected and endoscopically-collected) and higher abundances of Tisserellaceae in biopsy samples (all p < 0.001, q-value < 0.05). Our data shows that different sampling methods can impact results when looking at the composition of the gut microbiome using ASV-based approaches.

A case of Familial Mediterranean Fever presented with recurrent infection.

The periodic fever syndrome Familial Mediterranean Fever (FMF) is caused by mutations in MEFV, which promote inflammation and present with uncontrolled systemic and organ-specific inflammation that can resemble infectious conditions. It is diagnosed based on clinical criteria, including frequent symptoms such as abdominal and thoracic pain, family history, and response to treatment with colchicine, which is confirmed by genetic assessment. Herein, we present a case of FMF with a relatively uncommon presentation. A 22-month-old female was referred to the allergy and clinical immunology clinic with eczematoid skin rashes. She was admitted to the hospital several times since the 2nd day of life with different complaints like fever, seizure, and restlessness, and treated with the diagnosis of septicemia. Endoscopy and colonoscopy were done at the age of 6 months due to poor weight gain and bloody diarrhea, which revealed active crypt-destructive colitis with foci of erosion in favor of infectious or allergic colitis. The colon biopsy was negative for Cytomegalovirus (CMV). Regarding family history, she was the second child of the first cousins parents and had a healthy 12-year-old sister. There was a history of death for unknown reasons of her cousin, whose parents were related. The immunologic evaluation was done, which showed a relatively normal immunoglobulin level, antibody response, flow cytometry, and lymphocyte transformation test. Nonetheless, a genetic study was done, which showed a homozygote mutation in exon 10 of the MEFV gene in the patient and a heterozygote mutation in both her parents. The periodic fever syndrome Familial Mediterranean Fever (FMF) is caused by mutations in MEFV, which promote inflammation and present with uncontrolled systemic and organ-specific inflammation that can resemble infectious conditions. The patient was diagnosed with FMF, and treatment was started using colchicine, which successfully controlled the patient's symptoms and prevented the recurrence of fever and other inflammatory manifestations.

Bacterial Oncotraits Rather than Spatial Organization Are Associated with Dysplasia in Ulcerative Colitis.

Colonic bacterial biofilms are frequently present in ulcerative colitis [UC] and may increase dysplasia risk through pathogens expressing oncotraits. This prospective cohort study aimed to determine [1] the association of oncotraits and longitudinal biofilm presence with dysplasia risk in UC, and [2] the relation of bacterial composition with biofilms and dysplasia risk. Faeces and left- and right-sided colonic biopsies were collected from 80 UC patients and 35 controls. Oncotraits [FadA of Fusobacterium, BFT of Bacteroides fragilis, colibactin [ClbB] and Intimin [Eae] of Escherichia coli] were assessed in faecal DNA with multiplex quantitative polymerase chain reaction [qPCR]. Biopsies were screened for biofilms [n = 873] with 16S rRNA fluorescent in situ hybridiation. Shotgun metagenomic sequencing [n = 265], and ki67-immunohistochemistry were performed. Associations were determined with a mixed-effects regression model. Biofilms were highly prevalent in UC patients [90.8%] with a median persistence of 3 years (interquartile range [IQR] 2-5 years). Biofilm-positive biopsies showed increased epithelial hypertrophy [p = 0.025] and a reduced Shannon diversity independent of disease status [p = 0.015], but were not significantly associated with dysplasia in UC: adjusted odds ratio [aOR] 1.45, 95% confidence interval [CI] 0.63-3.40. In contrast, ClbB independently associated with dysplasia [aOR 7.16, 95% CI 1.75-29.28], and FadA and Fusobacteriales were associated with a decreased dysplasia risk in UC [aOR 0.23, 95% CI 0.06-0.83, p <0.01]. Biofilms are a hallmark of UC; however, because of their high prevalence are a poor biomarker for dysplasia. In contrast, colibactin presence and FadA absence independently associate with dysplasia in UC and might therefore be valuable biomarkers for future risk stratification and intervention strategies.