BackgroundColorectal cancer (CRC) is a common malignant gastrointestinal tumor. In China, CRC is the 5th most commonly diagnosed cancer. The vast majority of CRC cases are sporadic and evolve with the adenoma-carcinoma sequence. There is mounting evidence indicating that gut microbiota and inflammation play important roles in the development of CRC although study results are not entirely consistent. In the current study, we investigated the changes in the CRC-associated bacteria and plasma inflammatory factors and their relationships based on data from a case-control study of Han Chinese. We included 130 initially diagnosed CRC patients, 88 advanced colorectal adenoma patients (A-CRA), 62 patients with benign intestinal polyps and 130 controls.ResultsFecal microbiota composition was obtained using 16S ribosomal DNA (16S rDNA) sequencing. PCOA analysis showed structural differences in microbiota among the four study groups (P = 0.001, Unweighted Unifrac). Twenty-four CRC-associated bacteria were selected by a two-step statistical method and significant correlations were observed within these microbes. CRC-associated bacteria were found to change with the degree of malignancy. Plasma C-reactive protein (CRP) and soluble tumor necrosis factor II (sTNFR-II) displayed significant differences among the four study groups and increased with adenoma-carcinoma sequence. The correlations of CRP and sTNFR-II with several CRC-associated microbes were also explored.ConclusionsCRC-associated species and plasma inflammatory factors tended to change along the adenoma-carcinoma sequence. Several CRC-associated bacteria were correlated with CRP and sTNFR-II. It is likely that gut microbiome and inflammation gradually form a microenvironment that is associated with CRC development.Electronic supplementary materialThe online version of this article (10.1186/s12866-018-1232-6) contains supplementary material, which is available to authorized users.

Background: Endoscopic submucosal dissection (ESD) is widely used in the treatment of early esophageal cancer. However, the incidence of postoperative esophageal stricture is relatively high, especially after full circumferential ESD. Previous studies have shown that thymosin β4 (Tβ4) has anti-fibrotic activity and prevents scar formation. In this study, we investigated the safety and therapeutic effect of Tβ4 injection in preventing esophageal stricture after circumferential ESD in a porcine model. Methods: A total of 8 Bama pigs underwent esophageal circumferential ESD under anesthesia (n = 4 for experimental and control group). Local injection of Tβ4 gel was administered in the experimental group. Follow-up endoscopy was conducted, and balloon dilation (EBD) was performed to prevent the occurrence of esophageal stricture. Results: Esophageal stricture developed after circumferential ESD in all pigs. Local Tβ4 gel injection has shortened resolution of the stricture (p = 0.012) and was associated with a lesser number of EBD sessions (p = 0.002). The severity of esophageal stricture was milder in the experimental group (p = 0.046 vs. control group). No adverse events occurred in the study. Conclusions: Local Tβ4 gel injection appeared to be safe and effective for the prevention of esophageal stricture after circumferential ESD in a porcine model.