Objective To systematically evaluate the diversity of oral flora in patients with pancreatic cancer.

Methods A cross-sectional study was conducted, focusing on the oral flora diversity profiles of patients with pancreatic cancer. The studies were retrieved from PubMed, Web of science, EMbase, The Cochrane Library, CBM, CNKI, Wanfang, and VIP databases, and the search period was from the establishment of the database to July 15, 2023. According to the inclusion and exclusion criteria, two researchers screened intensive review literature, extracted data and information, and carried out Meta-analysis using qualitative systematic review and Review Manager 5.4.

Results Seven cross-sectional studies were reviewed, including 187 patients with pancreatic cancer and 440 healthy controls. The results of meta-analysis showed that the oral microbiota diversity Simpson index of patients with pancreatic cancer was reduced compared with that of healthy controls. Qualitative analysis showed that the relative abundance of Firmicute, Prevotella, Roseburia, and Streptococcus in patients with pancreatic cancer was higher than that in healthy people. The relative abundance of Proteobacteria, Neisseria, Haemophilus, porphyromonas, and Haemophilus parainfluenza in patients with pancreatic cancer was lower than that in healthy people.

Conclusion Patients with pancreatic cancer have distinct oral flora, which has high relative abundance of Firmicutes, Prevotella etc. and low relative abundance of Proteobacteria, Neisseria, etc.