In China, esophageal cancer is one of the most common cancers, and its incidence and mortality are more than twice the global average. However, most esophageal cancers in China are not detected until they are at moderate and advanced stages with poor prognosis, so early diagnosis and treatment are urgently needed. At present, the role of gut flora in the diagnosis and treatment of esophageal cancer has attracted much attention.

To explore the basic characteristics of gut flora in patients with esophageal squamous cell carcinoma.

From the Fourth Hospital of Hebei Medical University from April to August 2022, 35 patients with esophageal squamous cell carcinoma with no previous anti-cancer treatments were included as esophageal cancer group (EC group), and 35 healthy volunteers as control group. Stool samples of the two groups were collected to detect the gut flora using 16S rDNA sequence. Then an analysis was performed on the Alpha diversity, Beta diversity〔using the principal coordinate analysis (PCoA) 〕 and differential species of gut flora 〔using the linear discriminant analysis Effect Size (LEfSe) 〕 of two groups according to the species annotation of the test results.

The Alpha diversity indices, such as Shannon index, Simpson index, Chao1 index, ACE index and Goods_coverage index demonstrated no significant differences between the two groups (P>0.05), while PCoA graph showed that the Beta diversity differed significantly between the two groups on the whole, and the community structures were different (t=10.837, P<0.001). T-test results showed that there were significant intergroup differences in the abundance of 16 genera at the genus level. Among the top eight genera with relatively high abundance, the abundance of Faecalibacterium, Roseburia and Citrobacter notably decreased, while that of Lactobacillus, Romboutsia, Ruminococcus_torques_group, Intestinibacter and Turicibacter notably increased in EC group (P<0.05). LEfSe analysis showed that two groups had differences in the abundance of 14 different species of gut flora. The abundance of Faecalibacterium and Faecalbacterium-prausnitzii declined significantly, and that of Romboutsia and Romboutsia-ilealis increased significantly in EC group at the genus and species levels (P<0.05) .

Esophageal squamous cell carcinoma patients have significantly differential gut flora, among which Faecalibacterium, Faecalibacterium -prausnitzii, Romboutsia and Romboutsia-ilealis may be specific altered species of esophageal cancer, which are closely related to the occurrence of esophageal cancer.

食管癌是我国的高发肿瘤之一，其发病与死亡人数均为世界平均水平的2倍以上。在我国大多数食管癌发现时已是中晚期，预后较差，所以迫切需要早期诊断及干预治疗，目前肠道菌群在食管癌诊断及治疗中的作用备受关注。

探索食管鳞状细胞癌患者肠道菌群基本特征。

纳入2022年4—8月就诊于河北医科大学第四医院未经任何抗肿瘤治疗的食管鳞状细胞癌患者35例作为食管癌组，健康志愿者35例作为对照组。收集两组人群粪便标本，应用16S rDNA技术检测肠道菌群，根据检测结果物种注释情况分析两组人群肠道菌群的Alpha多样性、Beta多样性〔主坐标分析（PCoA）〕及菌群物种差异性〔线性判别分析及影响因子（LEfSe）分析〕。

两组人群肠道菌群Alpha多样性香农（Shannon）、辛普森（Simpson）、Chao1、ACE及Goods_coverage指数比较均无明显差异（P>0.05）；而PCoA图显示两组样本整体上相距较远，群落结构存在差异（t=10.837，P<0.001）。两组人群肠道菌群T-test检验结果在属水平共有16类菌属的丰度存在明显差异，相对丰度较高的前8位菌属中，食管癌组栖粪杆菌属（Faecalibacterium）、罗斯氏菌属（Roseburia）、柠檬酸杆菌属（Citrobacter）丰度低于对照组，乳杆菌属（Lactobacillus）、罗姆布茨菌属（Romboutsia）、瘤胃球菌属组（Ruminococcus_torques_group）、肠杆菌属（Intestinibacter）、土杆菌属（Turicibacter）丰度高于对照组（P<0.05）。LEfSe分析结果显示14种肠菌丰度存在差异，在属及种水平上与对照组相比，食管癌组Faeculibacterium及普拉梭菌（Faecalibacterium-prausnitzii）丰度降低，Romboutsia及Rombutsia-ilealis丰度升高（P<0.05）。

食管鳞状细胞癌患者具有显著性差异肠菌，其中Faecalibacterium、Faecalibacterium-prausnitzii、Romboutsia及Rombutsia-ilealis可能是食管癌特异性改变物种，与食管癌发生密切相关。