Evaluation of the microbiome in children’s appendicitis

Abstract

Background/aimThe role of the microbiome has been widely discussed in the etiology of appendicitis. The primary aim was to evaluate the microbiome in the normal appendix and in appendicitis specifically divided into the three clinically and histopathologically defined grades of inflammation. Secondary aims were to examine whether there were any microbiome differences between proximal and distal appendices, and relate the microbiome with histopathological findings.MethodsA prospective pilot study was conducted of children undergoing appendectomy for appendicitis. The diagnosis was based on histopathological analysis. Children with incidental appendectomy were used as controls. The proximal and distal mucosa from the appendices were analyzed with 16S rRNA gene sequencing.ResultsA total of 22 children, 3 controls and 19 appendicitis patients; 11 phlegmonous, 4 gangrenous, and 4 perforated appendices, were prospectively included. The amount of Fusobacterium increased and Bacteroides decreased in phlegmonous and perforated appendicitis compared to controls, but statistical significance was not reached, and this pattern was not seen in gangrenous appendicitis. No relation could be seen between different bacteria and the grade of inflammation, and there was a wide variation of abundances at phylum, genus, and species level within every specific group of patients. Further, no significant differences could be detected when comparing the microbiome in proximal and distal mucosa, which may be because the study was underpowered. A trend with more abundance of Fusobacteria in the distal mucosa was seen in appendicitis patients with obstruction (25 and 13 %, respectively, p = 0.06).ConclusionThe pattern of microbiome differed not only between groups, but also within groups. However, no statistically significant differences could be found in the microbiome between groups or clinical conditions. No correlation between a specific bacteria and grade of inflammation was found. In the vast majority of cases of appendicitis, changes in microbiome do not seem to be the primary event. Since there seem to be differences in microbiome patterns depending on the sample site, the exact localization of biopsy sampling must be described in future studies.

Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines

“…A number of prospective studies of children were conducted to find urinary biomarkers for AA, such as leucine-rich α-2-glycoprotein (LRG), not to be used alone but combined with PAS and routine blood tests. LRG in conjunction with PAS showed 95% sensitivity, 90% specificity, 91% positive predictive value, and 95% negative predictive value for AA in children [62].…”

Whole metagenomic sequencing reveals different compositions of pathogenic bacteria in patients with appendicitis:Bacterial culture is not suitable as the only therapeutic guidance

“…Martin Salö et al conducted a study of 3 control samples, 11 phlegmonous samples, 4 gangrenous samples and 4 perforated samples. They also utilized 16S rRNA gene sequencing but did not observe a signi cant difference among the different groups (8). Our results demonstrated that there was not signi cant difference in the microbiota between the non-perforated and perforated appendicitis groups, suggesting that antibiotic selection does not need to be altered based on bacterial culture results.…”

“…Alexander Swidsinski's group applied rRNA-based uorescence in situ hybridization to investigate sections of 70 appendixes, and their results supported the hypothesis that the local microbiota was responsible for the occurrence and development of appendicitis (7). However, some scholars believe that there is no correlation between local microbiota and the grade of in ammation (8). Moreover, it is di cult to explain why although the results of bacterial cultures were different, patients recovered similarly after treatment with appendectomy.…”

Review. Gastrointestinal Surgery in Neonates: Practice, Facts, and Trends

“…Discussion surrounding the removal of the appendix in cases of rotation anomalies of the intestine has proven to be controversial. On the basis of infectious-immunological reasons, we prefer not to remove the appendix, as it is a space for the normal intestinal flora to reside during enteritis [32] [33]. Nevertheless, parents and, depending on the case, an intelligent child should be made aware of the possibility of left-sided appendicitis [34].…”