Alterations in the gut microbiome in patients with esophageal carcinoma in response to esophagectomy and neoadjuvant treatment

Purpose: Analyzing the gut microbiome is essential for planning treatment strategies to manage esophageal squamous cell carcinoma. This study aimed to characterize the gut microbiome of patients with esophageal squamous cell carcinoma and to identify alterations in its composition during treatment. Methods: We observed alterations in the gut microbiome in 21 consecutive patients with esophageal squamous cell carcinoma at five different time points, from neoadjuvant treatment to postoperative surgery. Ten healthy individuals were used as a non-cancer control group. Fecal samples were collected and analyzed using 16S ribosomal ribonucleic acid sequencing. Results: Before treatment, participants with esophageal squamous cell carcinoma had different alpha and beta diversity in comparison to healthy controls. The number of Streptococcus, a facultative anaerobic bacterium, was significantly higher, whereas that of Faecalibacterium, an obligate anaerobic bacterium, was significantly lower. Both alpha and beta diversity remained unchanged during neoadjuvant treatment, but the alterations were pronounced after surgery. The increase in the relative abundance of Streptococcus and the decrease in that of Faecalibacterium also tended to be more pronounced after surgery. Conclusions: The gut microbiome in patients with esophageal squamous cell carcinoma is altered with surgical intervention.