The Gut Microbiota in Causation, Detection, and Treatment of Cancer.

The gut microbiota has emerged as an important consideration in clinical oncology. The role of the microbiome in cancer extends beyond causation and cancer risk. It is now known that the microbiome not only acts at a local epithelial level in the gut but also modifies immune responses within intestinal and extraintestinal tumors. Microbial signaling influences the clinical course of cancer including the efficacy, bioavailability, and toxicity of chemotherapeutic and immunotherapy agents. This has focused research on microbiota profiling in different cancer states with an aim of developing prognostic biomarkers of risk. The potential value of microbiome manipulation with live biotherapeutics or microbial transplantation has also become a realistic consideration. Maintenance of microbial diversity in patients with cancer is a variable challenge given the modifying influences of the tumor itself, chemotherapy, nutritional status, and sporadic antimicrobial therapy. Here, we address current evidence for the role of the microbiome in cancer therapy.

Colorectal microbiota after removal of colorectal cancer.

The colonic microbiome has been implicated in the pathogenesis of colorectal cancer (CRC) and intestinal microbiome alterations are not confined to the tumour. Since data on whether the microbiome normalises or remains altered after resection of CRC are conflicting, we studied the colonic microbiota of patients after resection of CRC. We profiled the microbiota using 16S rRNA gene amplicon sequencing in colonic biopsies from patients after resection of CRC (n = 63) in comparison with controls (n = 52), subjects with newly diagnosed CRC (n = 93) and polyps (i = 28). The colonic microbiota after surgical resection remained significantly different from that of controls in 65% of patients. Genus-level profiling and beta-diversity confirmed two distinct groups of patients after resection of CRC: one with an abnormal microbiota similar to that of patients with newly diagnosed CRC and another similar to non-CRC controls. Consumption levels of several dietary ingredients and cardiovascular drugs co-varied with differences in microbiota composition suggesting lifestyle factors may modulate differential microbiome trajectories after surgical resection. This study supports investigation of the colonic microbiota as a marker of risk for development of CRC.

Defining gastrointestinal transit time using video capsule endoscopy: a study of healthy subjects.

Background and study aims Determining the etiology and location of gastrointestinal motility disorders can be challenging. A range of investigations targeting specific areas of gastrointestinal transit are available, but many provide clinical data for a given gastrointestinal region alone or for non-specific whole gut transit, and are otherwise of limited use. Video capsule endoscopy allows endoscopic visualisation of the entire gastrointestinal tract, and may also provide more specific data for regional transit time abnormalities. Patients and methods Data from video capsules ingested by 71 ambulatory healthy subjects were recorded and analyzed to determine gastric and small bowel transit times in the fasting state. Results Median, and interquartile range (IQR), gastric transit time was 22 (10-48) minutes, and median (IQR) small bowel transit time was 198.5 (157-240.5) minutes. Conclusion These data, for the first time to our knowledge, provide references for gastrointestinal transit times among healthy ambulatory subjects using video capsule endoscopy. This potentially strengthens clinical use of video capsule endoscopy in the investigation of patients with suspected gastrointestinal motility disorders.