Relationship Between Intestinal Microecology And Esophageal Squamous Cell Carcinoma In Older People

Background and objective : Esophageal cancer(EC)is a common upper gastrointestinal cancer,which causes a certain cancer burden worldwide,especially in developing countries.Esophageal cancer(EC)is the ninth most common cancer and the sixth leading cause of cancer-related deaths in the world.In 2018 there were nearly572,034 new cases and 508,585 deaths[1].However,even if patients with esophageal cancer undergo several combined treatments including surgery,chemotherapy and radiotherapy,their prognosis is still very poor with 5-year survival rate less than 20%.With the official launch of the Human Microbiome Project(HMP)in 2007,more and more attentions were paid to the indispensable role of human microbiome.Numerous studies have pointed out that the abnormal structure of the intestinal flora is likely to be an important factor in metabolic diseases such as hypertension,diabetes,obesity,coronary heart disease and stroke.Recently,researches on the relationship between human microbiome and tumors have been carried out.The arising evidences suggest that the intestinal microbiota is related to a variety of cancers,which might provide possibility for the development of cancer treatments targeting intestinal microbiota.Therefore,in this study,high-throughput sequencing technology was used to study the diversity of the intestinal flora of patients with esophageal squamous cell carcinoma(ESCC),to further explore the relationship between ESCC and the intestinal flora,and screen for specific flora expressed in patients with ESCC,which might provide a simple and non-invasive method for early screening and treatment of ESCC.Methods:This study recruited 20 patients with ESCC and 20 gender-and age-matched healthy controls from January 2020 to January 2021 in Subei People’s Hospital of Jiangsu province,using 16 S r RNA gene sequencing of fresh stool samples to analyze the intestinal flora.According to the significant characteristics of the amplified 16 S region,a small fragment library was constructed,and then paired-end sequencing was performed on the small fragment library based on the high-throughput sequencing platform called Illumina Nova Seq.Through Reads splicing and filtering and OTUs(Operational Taxonomic Units)clustering,species annotations and abundance analyses were carried out.Finally,alpha and beta diversity analyses(Beta Diversity)were performed on the processed data,which revealed the composition and differences of bacteria community structure between the two groups.Results:In this study,the difference in the diversity of the intestinal flora between the cancer group and the healthy control group was small(P>0.05),and the uniformity was significantly different(P<0.05).Diversity analysis at the phylum level suggested that the average abundance of Desulfobacterota in the healthy control group was 0.1% and that of the cancer group was 0.5%.Through t-test we found that this species was significantly different between the two groups(P value is 0.0061).Species analyses showed that compared with the healthy control group,the cancer group had a higher proportion of Phascolarctobacterium,Sutterella and Streptococcus,while Lachnospira,Lachnospira and Parasutterella were significantly reduced(P<0.05).Through LEf Se analysis of the two groups,we found that there were four biomarkers with LDA score>4,namely Bacteroides stercoris,Prevotella copri,Prevotella,and Prevotellaceae.Conclusions : Patients with esophageal squamous cell carcinoma compared with healthy people had significant differences in the microbial composition at the phylum and genus level.Bacteroides stercoris,Prevotella copri,Prevotella,and Prevotellaceae might be potential biomarkers of ESCC,which provides a reference for further research on the diagnosis and treatment of esophageal cancer based on the intestinal microbiome.