Gut microbiota is considered a separate organ with endocrine capabilities, actively contributing to tissue homeostasis. It consists of at least two separate microbial populations, the lumen-associated (LAM) and the mucosa-associated microbiota (MAM). In the present study, we compared LAM and MAM, by collecting stools and sigmoid brush samples of forty adults without large-bowel symptoms, and through a 16S rRNA gene next-generation sequencing (NGS) approach. MAM sample analysis revealed enrichment in aerotolerant Proteobacteria, probably selected by a gradient of oxygen that decreases from tissue to lumen, and in Streptococcus and Clostridium spp., highly fermenting bacteria. On the other hand, LAM microbiota showed an increased abundance in Bacteroides, Prevotella, and Oscillospira, genera able to digest and to degrade biopolymers in the large intestine. Predicted metagenomic analysis showed LAM to be enriched in genes encoding enzymes mostly involved in energy extraction from carbohydrates and lipids, whereas MAM in amino acid and vitamin metabolism. Moreover, LAM and MAM communities seemed to be influenced by different host factors, such as diet and sex. LAM is affected by body mass index (BMI) status. Indeed, BMI negatively correlates with Faecalibacterium prausnitzii and Flavonifractor plautii abundance, putative biomarkers of healthy status. In contrast, MAM microbial population showed a significant grouping according to sex. Female MAM was enriched in Actinobacteria (with an increased trend of the genus Bifidobacterium), and a significant depletion in Veillonellaceae. Interestingly, we found the species Gemmiger formicilis to be associated with male and Bifidobacterium adolescentis, with female MAM samples. In conclusion, our results suggest that gut harbors microbial niches that differ in both composition and host factor susceptibility, and their richness and diversity may be overlooked evaluating only fecal samples.

In our experience EMR is a simple and safe procedure for removing large and giant sessile and flat colorectal polyps, and is associated with a very low risk of complication and local recurrence.

Background and Study Aims: The study examines the outcomes of the ‘inject and cut’ endoscopic mucosal resection (EMR), for large sessile and flat colorectal polyps. Patients and Methods: Between January 2006 and December 2008 all patients referred to our institution for EMR of large polyps were prospectively evaluated. The accuracy of lifting sign and the rate of en bloc and piecemeal resection, complications and recurrence were analyzed. Results: A total of 157 patients with 182 lesions (median size 24.7 ± 10.2 mm) were included in the study. The most frequent location was the sigmoid colon in 30.2%. Because of non-lifting sign, 5/182 lesions were referred to surgical resection and 177 (43 flat and 134 sessile) were resected, 79 (44.6%) en bloc and 98 (55.4%) piecemeal. There were 20 procedural (11.3%) and 2 late (1.1%) bleeding, 4 post-polypectomy syndrome (2.2%) and 2 perforations (1.1%). Bleeding was related to malignancy (p = 0.01). Intramucosal cancer was observed in 5 cases (2.8%) while invasive cancer was seen in 8 (4.5%). Malignancy was related to polyp size ≧30 mm (p = 0.002). Follow-up colonoscopy was performed in 147 patients with 172 EMR for a mean of 19.8 months. Recurrence was observed in 12/172 (6.9%) polyps. Conclusion: Inject and cut EMR is practical and effective with a low risk of complication and local recurrence.

AIM:To examine the efficacy and complications of colonoscopic resection of colorectal polypoid lesions. M E T H O D S :We r e t r o s p e c t i v e l y r e v i e w e d 1 3 5 4 polypectomies performed on 1038 patients over a tenyear period. One hundred and sixty of these were performed for large polyps, those measuring ≥ 20 mm. Size, shape, location, histology, the technique of polypectomy used, complications, drugs assumption and associated intestinal or extra intestinal diseases were analyzed. For statistical analysis, the Pearson χ 2 test, NPC test and a Binary Logistic Regression were used. RESULTS:The mean patient age was 65.9 ± 12.4 years, with 671 men and 367 women. The mean size of polyps removed was 9.45 ± 9.56 mm while the size of large polyps was 31.5 ± 10.8 mm. There were 388 pedunculated and 966 sessile polyps and the most common location was the sigmoid colon (41.3%). The most frequent histology was tubular adenoma (55.9%) while for the large polyps was villous (92/160 -57.5%). Coexistent malignancy was observed in 28 polyps (2.1%) and of these, 20 were large polyps. There were 17 procedural bleeding (1.3%) and one perforation. The statistical analysis showed that cancer is correlated to polyp size (P < 0.0001); sessile shape (P < 0.0001) and bleeding are correlated to cardiac disease (P = 0.034), tubular adenoma (P = 0.016) and polyp size. CONCLUSION:The endoscopic resection is a simple and safe procedure for removing colon rectal neoplastic lesions and should be considered the treatment of choice for large colorectal polyps. The polyp size is an important risk factor for malignancy and for bleeding.

Stents are tubular devices made of plastic or metal. Endoscopic stenting is the most common treatment for obstruction of the common bile duct or of the main pancreatic duct, but also employed for the treatment of bilio-pancreatic leakages, for preventing post- endoscopic retrograde cholangiopancreatography pancreatitis and to drain the gallbladder and pancreatic fluid collections. Recent progresses in techniques of stent insertion and metal stent design are represented by new, fully-covered lumen apposing metal stents. These stents are specifically designed for transmural drainage, with a saddle-shape design and bilateral flanges, to provide lumen-to-lumen anchoring, reducing the risk of migration and leakage. This review is an update of the technique of stent insertion and metal stent deployment, of the most recent data available on stent types and characteristics and the new applications for biliopancreatic stents.