Effect Of Appendectomy On The Ecological Structure Of Intestinal Fungi

Objective: The appendix has abundant lymphatic tissue and can play the function of lymphatic organs.Studies have shown that the presence of the appendix may be more conducive to the growth of beneficial bacteria in the gut and plays an important role in maintaining the balance of intestinal microecology.However,there are only few studies concentrating on the effects of the appendix on intestinal microecology,suggesting that the significant changes of intestinal bacteria after appendectomy may be related to the occurrence of some diseases.However,the effect of the appendix on intestinal fungi has rarely been reported.Therefore,the changes of intestinal fungi after appendectomy were studied by means of ITS2 sequencing in this work,further improving the study on the relationship between appendix and intestinal microecology.Design: According to the inclusion criteria,healthy people with history of appendectomy(Hw A group,n=30)were enrolled as the experimental group and healthy people without history of appendectomy as the control group(Hwo A group,n=30).Fresh fecal specimens were collected from the two groups.At the same time,the subgroup analysis of Hw A group was further performed based on the time after appendectomy(2 years and 5 years).High-throughput sequencing technology was used to amplify the ITS2 region of 18 Sr DNA of fecal fungi,and the sequencing results were analyzed by the biodiversity and microbial-related network.The differences of intestinal fungi between the two groups were identified,and then the conjoint analysis of previous bacteria-related research was also carried out.Results: 30 subjects were included in Hw A group and Hwo A group,respectively.There was no statistical difference in age(33.1±6.7 vs 35.1±7.7),sex ratio(15/15 vs17/13)and BMI(20.8±3.0 vs 22.3±2.5).The α-diversity analysis indicated that the fungal diversity of Hw A was higher than that of Hwo A group(P<0.05),and this difference still existed 5 years later after appendectomy.At the phylum level,Ascomycota and Basidiomycetes were dominant in both groups,while Saccharomycetaceae,Aspergillaceae,unclassified Ascomycota and unclassified Basidiomycetes were dominant in the family level.Further genus level analysis indicated that the relative abundance of Aspergillus,Hanseniaspora,Alternaria,Chaetomium,Fusarium,Candida,Penicillium etc.in the Hw A group was higher than that of the Hwo A group(P<0.05).The β-diversity analysis showed that the fungal community structure of Hw A group was different from that of Hwo A group(P<0.001),and the fungal community structure of Hw A subgroups were different from that of Hwo A group(P<0.001).The correlation network analysis suggested that the interaction between different intestinal fungi and between fungi and bacteria after appendectomy was more intense and complex,and changed dynamically with the time after appendectomy.Conclusion: Appendectomy can affect the composition and interaction of intestinal fungi,and then bring out significant impact on the structure of intestinal ecosystem.