Impact of Pelvic Radiotherapy on Gut Microbiota of Gynecological Cancer Patients Revealed by Massive Pyrosequencing

Although pelvic irradiation is effective for the treatment of various cancer types, many patients who receive radiotherapy experience serious complications. Gut microbial dysbiosis was hypothesized to be related to the occurrence of radiation-induced complications in cancer patients. Given the lack of clinical or experimental data on the impact of radiation on gut microbiota, a prospective observational study of gut microbiota was performed in gynecological cancer patients receiving pelvic radiotherapy. In the current study, the overall composition and alteration of gut microbiota in cancer patients receiving radiation were investigated by 454 pyrosequencing. Gut microbial composition showed significant differences (P < 0.001) between cancer patients and healthy individuals. The numbers of species-level taxa were severely reduced after radiotherapy (P < 0.045), and the abundance of each community largely changed. In particular, the phyla Firmicutes and Fusobacterium were significantly decreased by 10% and increased by 3% after radiation therapy, respectively. In addition, overall gut microbial composition was gradually remolded after the full treatment course of pelvic radiotherapy. In this set of cancer patients, dysbiosis of the gut microbiota was linked to health status, and the gut microbiota was influenced by pelvic radiotherapy. Although further studies are needed to elucidate the relationship between dysbiosis and complications induced by pelvic radiotherapy, the current study may offer insights into the treatment of cancer patients suffering from complications after radiation therapy.

尽管盆腔放射治疗对多种癌症的治疗效果显著，但诸多接受放射疗法的患者会出现严重并发症。有假说提出，肠道菌群失调（gut microbial dysbiosis）与癌症患者放射诱导并发症的发生存在关联。鉴于目前关于放射对肠道菌群影响的临床或实验数据较为匮乏，本研究针对接受盆腔放射治疗的妇科癌症患者开展了一项肠道菌群的前瞻性观察研究。在本研究中，研究人员通过454焦磷酸测序（454 pyrosequencing）对接受放射治疗的癌症患者的肠道菌群整体组成及变化进行了分析。结果显示，癌症患者与健康个体的肠道菌群组成存在显著差异（P < 0.001）。放射治疗后，物种水平分类群的数量大幅减少（P < 0.045），且各菌群群落的丰度也发生了显著改变。具体而言，厚壁菌门（Firmicutes）的丰度降低了10%，而梭杆菌属（Fusobacterium）的丰度则升高了3%，二者的变化均具有统计学意义。此外，在完成全程盆腔放射治疗疗程后，患者的整体肠道菌群组成逐渐发生重塑。在本研究的癌症患者队列中，肠道菌群失调与健康状态密切相关，而盆腔放射治疗也对肠道菌群产生了显著影响。尽管还需开展进一步研究以阐明肠道菌群失调与盆腔放射治疗诱导并发症之间的关联，但本研究可为罹患放射治疗后并发症的癌症患者的临床干预提供新的见解。