Microbiome Structures and Function Changes in RE of Cervical Cancer Based on 16S-rDNA Sequencing
PH-0233
Abstract
Microbiome Structures and Function Changes in RE of Cervical Cancer Based on 16S-rDNA Sequencing
Authors: MA|, Chenying(1)*[mcy612@qq.com];Xiaoting|, Xu(1);Songbing|, Qin(1);Xiaolan|, He(1);Juying|, Zhou(1);
(1)The First Affiliated Hospital of Soochow University, Dept. of Radiotherapy & Oncology, Suzhou, China;
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Purpose or Objective
To investigate the changes in contents and function of intestinal microbial colonies of the radiation enteritis model, which included time variable.
Material and Methods
A total of 50 cervical cancer patients who received radiotherapy (RT) in our hospital from September 2017 to June 2018 and 15 healthy female controls were enrolled. Fecal samples were collected from patients at five time points during radiotherapy, i.e. baseline, 2 weeks post-RT starting, 4 weeks post-RT starting, ending of RT and 3 months post-RT ending, and the control group on the baseline, respectively. The fecal supernatent samples were detected by 16S-rDNA amplicon sequencing to investigate the changes in colonial contents and diversities using bioinformatic analysis. The samples were analyzed by liquid chromatography-mass spectrometry (LC-MS) to investigate the changes in colonical functions.
Results
The top three enrichments were as follows: on phylum level, Firmicutes, Bacteroidetes, Proteobacteria; on genus level, Bacteroidaceae, brauteria, E. coli-shigella. As to the microbial alpha-diversity, the samples of the control group were homogeneous while radiotherapy groups were more diversed. The diversities of radiotherapy groups were much lower than that of the control group, and negatively related to the time-dose relationship. However, there were not significant differences in the recheck time, compared with the control group. Further analyses of correlation between microbial diversity and clinical characteristics showed that specific microorganism changes were strongly positively or negatively related to normal tissue constraints, such as rectum V40, colon V40, left-semicolon V40, right-semicolon V40, small intestine V20. In terms of microbial community structure, the internal diversities of radiotherapy groups were more than that of the contol group. Compared with the control group, the abundance of Barnesiella was much lower, while abundances of Ruminococcus gnavus and Erysipelatoclostridiu were higher during radiotherapy, according to the Metastats analysis. At the time point of the highest radiation enteritis occurency, i.e. four weeks after RT starting, E. coli-shigella and Tyzzerella abundances increased. PICRUSt functional predictive analysis revealed the vital participation of intestinal microorganisms in animino acid and carbohydrate transportation and metabolism in the radiation enteritis model, and the consenquences of these microbial function changes using LC-MS.
Conclusion
The changes in structures and diversities of intestinal microorganisms in radiation enteritis were dependent on time-dose relationship, and they activated the change of metabolic function as well as the symbiotic environment of intestine-microorganism. However, the fluctuation of intestinal microorganisms was normalized as the radiation interference terminated. It indicates that the microbial ecology can be improved by controlling the dose constraints of the normal tissues in radiotherapy.