Media from macrophages co-incubated with Enterococcus faecalis induces epithelial cell monolayer reassembly and altered cell morphology

The implication of gut microbiota in recovery from gastrointestinal surgery

Recovery from gastrointestinal (GI) surgery is often interrupted by the unpredictable occurrence of postoperative complications, including infections, anastomotic leak, GI dysmotility, malabsorption, cancer development, and cancer recurrence, in which the implication of gut microbiota is beginning to emerge. Gut microbiota can be imbalanced before surgery due to the underlying disease and its treatment. The immediate preparations for GI surgery, including fasting, mechanical bowel cleaning, and antibiotic intervention, disrupt gut microbiota. Surgical removal of GI segments also perturbs gut microbiota due to GI tract reconstruction and epithelial barrier destruction. In return, the altered gut microbiota contributes to the occurrence of postoperative complications. Therefore, understanding how to balance the gut microbiota during the perioperative period is important for surgeons. We aim to overview the current knowledge to investigate the role of gut microbiota in recovery from GI surgery, focusing on the crosstalk between gut microbiota and host in the pathogenesis of postoperative complications. A comprehensive understanding of the postoperative response of the GI tract to the altered gut microbiota provides valuable cues for surgeons to preserve the beneficial functions and suppress the adverse effects of gut microbiota, which will help to enhance recovery from GI surgery.

[Research Progress on the Interaction Between Microorganisms and Macrophages and Their Role in the Mediation of the Onset and Development of Oral Cancer]

Oral squamous cell carcinoma is the sixth most common malignant tumor in the world, and the clinical treatment effect is not satisfactory. Because of the special nature of its location, oral cancer is inextricably linked with a wide variety of microorganisms, and its pathogenesis and development are also extremely susceptible to microbial regulation. In addition, the mediating role of the immune system is also indispensable to the course of tumor pathogenesis and development, especially tumor-associated macrophages, which amplify the regulatory role of microorganisms, and in turn regulate the microbial population components--two complementary effects that jointly exacerbate oral cancer. Herein, we summarized the existing research on the relationship between microorganisms and macrophages, as well as the regulatory role of microorganisms and macrophages in the pathogenesis and development of oral cancer. We also discussed the current status of and gaps in research on the relationship between microorganisms and macrophages and oral cancer. Both microorganisms and macrophages are considered promising indicators for prognosis, showing potentials to be used as new therapeutic targets. Despite some research interest in the role of microorganisms and macrophages in oral cancer, very few studies have linked them to oral precancerous lesions, and the mutual regulatory relationship between microorganisms and macrophages remains unclear. Therefore, in-depth exploration of the relationship network of microorganisms, macrophages and oral cancer is expected to provide more possibilities for the early diagnosis and treatment of tumors.

The Potential Role of the Intestinal Micromilieu and Individual Microbes in the Immunobiology of Chimeric Antigen Receptor T-Cell Therapy

Cellular immunotherapy with chimeric antigen receptor (CAR)-T cells (CARTs) represents a breakthrough in the treatment of hematologic malignancies. CARTs are genetically engineered hybrid receptors that combine antigen-specificity of monoclonal antibodies with T cell function to direct patient-derived T cells to kill malignant cells expressing the target (tumor) antigen. CARTs have been introduced into clinical medicine as CD19-targeted CARTs for refractory and relapsed B cell malignancies. Despite high initial response rates, current CART therapies are limited by a long-term loss of antitumor efficacy, the occurrence of toxicities, and the lack of biomarkers for predicting therapy and toxicity outcomes. In the past decade, the gut microbiome of mammals has been extensively studied and evidence is accumulating that human health, apart from our own genome, largely depends on microbes that are living in and on the human body. The microbiome encompasses more than 1000 bacterial species who collectively encode a metagenome that guides multifaceted, bidirectional host-microbiome interactions, primarily through the action of microbial metabolites. Increasing knowledge has been accumulated on the role of the gut microbiome in T cell-driven anticancer immunotherapy. It has been shown that antibiotics, dietary components and gut microbes reciprocally affect the efficacy and toxicity of allogeneic hematopoietic cell transplantation (allo HCT) as the prototype of T cell-based immunotherapy for hematologic malignancies, and that microbiome diversity metrics can predict clinical outcomes of allo HCTs. In this review, we will provide a comprehensive overview of the principles of CD19-CART immunotherapy and major aspects of the gut microbiome and its modulators that impact antitumor T cell transfer therapies. We will outline i) the extrinsic and intrinsic variables that can contribute to the complex interaction of the gut microbiome and host in CART immunotherapy, including ii) antibiotic administration affecting loss of colonization resistance, expansion of pathobionts and disturbed mucosal and immunological homeostasis, and ii) the role of specific gut commensals and their microbial virulence factors in host immunity and inflammation. Although the role of the gut microbiome in CART immunotherapy has only been marginally explored so far, this review may open a new chapter and views on putative connections and mechanisms.

Patient Acceptance of Routine Serial Postoperative Endoscopy Following Low Anterior Resection (LAR) and Its Ability to Detect Biomarkers in Anastomotic Lavage Fluid

BACKGROUND

Various reports have now established that postoperative endoscopy to examine and intervene in the process of anastomotic healing is both feasible and safe. Here we present our preliminary experience with serial postoperative endoscopy to determine its feasibility, patient acceptance and the ability to obtain and the utility of perianastomotic material for molecular analysis.

METHODS

Patients undergoing LAR with ileostomy for rectal cancer were recruited for study to undergo routine serial endoscopic surveillance (SES) at three time points during the course of LAR: intraoperatively, before discharge (postoperative day 3-7) and at follow-up (postoperative day 10-28). At each endoscopy, images were captured, anastomotic tissues were lavaged and lavage fluid was retrieved. Fluid samples were analyzed using proteomics, zymography, ELISA and bacteria via 16S rRNA gene amplicon sequencing and culture of collagenolytic strains.

RESULTS

SES is feasible and acceptable to this limited set of patients following LAR. Biologic analysis of perianastomotic fluids was able to detect the presence of proteins, microbiota and inflammatory mediators previously identified at anastomotic sites in animals with pathologic healing.

CONCLUSION

SES can be implemented in patients undergoing LAR with a high degree of patient compliance and capture of biologic information and imaging. Application of this approach has the potential to uncover, for the first time, the natural history of normal versus pathologic anastomotic healing in patients undergoing anastomotic surgery.

Intestinal Microbiota in Colorectal Cancer Surgery

Simple Summary

The microbial communities of the intestine exist in a delicate balance with the human. Colorectal cancer is one of the most common gastrointestinal malignancies, and the microbiota seems to be related to it. The intestinal microbiota of patients after colorectal surgery is changed due to surgical stress and other perioperative factors. The occurrence of complications after colorectal cancer (CRC) surgery may depend on these bacterial shifts, which could also be associated with prognosis and survival in postoperative CRC patients.

Abstract

The intestinal microbiota consists of numerous microbial species that collectively interact with the host, playing a crucial role in health and disease. Colorectal cancer is well-known to be related to dysbiotic alterations in intestinal microbiota. It is evident that the microbiota is significantly affected by colorectal surgery in combination with the various perioperative interventions, mainly mechanical bowel preparation and antibiotic prophylaxis. The altered postoperative composition of intestinal microbiota could lead to an enhanced virulence, proliferation of pathogens, and diminishment of beneficial microorganisms resulting in severe complications including anastomotic leakage and surgical site infections. Moreover, the intestinal microbiota could be utilized as a possible biomarker in predicting long-term outcomes after surgical CRC treatment. Understanding the underlying mechanisms of these interactions will further support the establishment of genomic mapping of intestinal microbiota in the management of patients undergoing CRC surgery.

The Role of the Intestinal Microbiome on Colorectal Cancer Pathogenesis and its Recurrence Following Surgery

Colorectal cancer is the result of multiple genetic mutations that drive normal cells to adenoma and then carcinoma. Recent technology has evolved to allow for an in-depth examination of the microbiota and it has become clear that many components of the intestinal microbiome play a role in promoting carcinogenesis. This review aims to describe the potential mechanisms that lead to the dysbiosis that initiates tumor formation and that influence the development of cancer recurrence following surgical resection. We further discuss how manipulation of the microbiome may be a future novel strategy to prevent both primary and secondary colorectal cancer. While we discuss how bacterial communities and individual strains can promote cancer, the microbiome is individualized, dynamic, and complex, and our understanding of its role in carcinogenesis is still in its infancy.

Gut microbiome influences on anastomotic leak and recurrence rates following colorectal cancer surgery

BACKGROUND

The pathogenesis of colorectal cancer recurrence after a curative resection remains poorly understood. A yet-to-be accounted for variable is the composition and function of the microbiome adjacent to the tumour and its influence on the margins of resection following surgery.

METHODS

PubMed was searched for historical as well as current manuscripts dated between 1970 and 2017 using the following keywords: 'colorectal cancer recurrence', 'microbiome', 'anastomotic leak', 'anastomotic failure' and 'mechanical bowel preparation'.

RESULTS

There is a substantial and growing body of literature to demonstrate the various mechanisms by which environmental factors act on the microbiome to alter its composition and function with the net result of adversely affecting oncological outcomes following surgery. Some of these environmental factors include diet, antibiotic use, the methods used to prepare the colon for surgery and the physiological stress of the operation itself.

CONCLUSION

Interrogating the intestinal microbiome using next-generation sequencing technology has the potential to influence cancer outcomes following colonic resection.