Altered Gut Microbiota Associated with Hemorrhage in Chronic Radiation Proctitis
Abstract Background: Pelvic cancer radiotherapy may cause chronic radiation proctitis (CRP) that adversely affects patient’s quality of life, especially in patients with prolonged hematochezia. However, previous studies of radiation enteropathy mainly focused on acute irradiation hazards, and the detail pathogenesis process and mechanism of prolonged hematochezia associated with radiation-induce toxicity remain unclear. Methods: The 16S DNA of gut microbiota of 32 CRP patients with or without hematochezia were sequenced. The diversities and densities of gut microbiota were analyzed. Findings: Differential patterns of dysbiosis were observed. The abundance of Peptostreptococcaceae, Eubacterium and Allisonella were significantly higher in CRP patients with hematochezia, while the compositions of the Lachnospiraceae, Megasphera, Megamonas and Ruminococcaceae were lower in the microbiota of non-hematochezia patients. Functional prediction suggested significant difference in the expression of mineral absorption and the Arachidonic Acid metabolism proteins between hematochezia and non-hematochezia patients, possibly interdependent on radiation-induced inflammation. Interpretation: This study provides new insight to the function of gut microbiota in hemorrhage symptom of CRP patients. Further study is required to select probiotics and prebiotics to improve intestinal homoeostasis and relief prolonged hematochezia in CRP patients.