Analysis Of Intestinal Flora And Metabolites In Patients With Primary Gastrointestinal Diffuse Large B-cell Lymphoma

Objective:To explore the differences in intestinal flora structure between patients with primary gastrointestinal diffuse large B-cell lymphoma and healthy population and the relationship between intestinal flora dysbiosis and lymphoma development.To explore the taxonomic flora and metabolites associated with gastrointestinal lymphomagenesis.Methods:Nine patients with diffuse large B-cell lymphoma of the gastrointestinal tract initially diagnosed at the First Affiliated Hospital of Gannan Medical College from May 2021 to September 2022 and 7 healthy controls were included in this study.In the first part,a total of 9 samples were collected from DLBCL patients before chemotherapy and 7 controls,and in the second part,a total of 8 samples were collected from patients included who returned to hospital for chemotherapy and were hospitalized again.Combined Macrogenomic and untargeted metabolomics were performed on the collected samples for testing and analysis.Results:1.In the first part,there was no significant difference in α-diversity and significant difference in β-diversity between untreated patients and healthy controls,with the presence of dominant groups in the untreated group in a hierarchical evolution at six levels,including p＿Proteobacteria,c＿Gammaproteobacteria,o＿Enterobacterales,f＿Escherichia,g＿Escherichia,s＿Escherichia＿coli.;another series of groups existed with decreasing abundance,including p＿Firmicutes,c＿Clostridia,o＿Clostridiales,f＿Clostridiaceae,f＿Ruminococcaceae,f＿Lachnospiraceae,f＿Eubacteriaceae,g＿Clostridium,g＿Eubacterium,g＿Ruminococcus.2.In the KEGG functional annotation of the intestinal flora of untreated DLBCL patients,amino acid metabolism,UDP-glucose/GDP-mannose dehydrogenase family protein was relatively enriched in abundance,and sensor histidine kinase,cytidylate kinase,two component transcriptional regulator winged helix family and β-galactosidase/β-glucuronidase were relatively downregulated.3.Screening of fecal differential metabolites from untreated and healthy controls revealed that the abundance of Deoxycholic acid,Ursodeoxycholic acid,Cholic acid and 2-Hydroxyglutarate in untreated DLBCL patients were downregulated and the functional module of bile acid biosynthesis was reduced.4.Metabolomics of P＿PRE were mainly downregulated at secondary bile acids and bile acid biosynthesis was decreased.In the second part,β-diversity was significantly different between the P＿POST and P＿PRE,significantly between the P＿POST and Normal.the P＿POST showing a significant increase in the abundance of Bacteroides and predominant upregulation of primary bile acids.Conclusion:1.Primary gastrointestinal diffuse large B-cell lymphoma was significantly associated with intestinal flora,and the most significant intestinal flora alteration was the loss of homeostasis in commensal microbiota,as evidenced by a higher proportion of the Proteobacteria/Firmicutes,with E.coli forming the absolute dominant bacterium and significantly decreased of butyrate-producing bacteria such as Clostridium,Eubacterium,Ruminococcus and Roseburia.2.Feedback and negative feedback regulation between dysbiosis of the intestinal flora and secondary bile acids in patients with primary gastrointestinal DLBCL,ultimately leading to a reduction in the composition of the bile acid pool,which may play a pathogenic role in patients with primary gastrointestinal DLBCL.3.After the chemotherapeutic intervention,the abundance of the genus Synechococcus started to increase and the abundance of E.coli tended to decrease,which may be a result of the alteration of the intestinal flora caused by tumor extinction,and the composition of the bile acid pool started to recover after the chemotherapeutic intervention.