Gut microbiome patterns correlate with higher postoperative complication rates after pancreatic surgery.
Schmitt FCF, Brenner T, Uhle F, Loesch S, Hackert T, Ulrich A, Hofer S, Dalpke AH, Weigand MA, Boutin S
BMC Microbiol. Feb 2019. doi: 10.1186/s12866-019-1399-5
COMMENT: Postoperative complications are an important problem in clinical practice. This works investigates the influence of the gut microbiome in the postoperative clinical course of pancreatic surgery and its potential complications, by 16S rRNA gene (V4 region) sequencing approach. In total, 32 patients undergoing pancreatic surgery were included, of whom 17 patients suffered postoperative complications and 15 had a non-complicated clinical course.
This prospective, observational, clinical study aimed to examine changes in the gut microbiome, as well as the consequences on the postoperative course, after pancreatic surgery.
Based on the microbiome structure it was possible to discriminate three separate microbial communities of the gut microbiome (A, B and C), each with different composition. Community B was associated with higher C-reactive protein (CRP) levels, an increased leukocyte count, more frequent incidence of postoperative complications as well as prolonged hospitalisation.
Although alpha-diversity and richness were not significantly different among the distinct microbial communities, the specific composition at the OTU level was found to be different. The composition of community A was characterized by a high abundance of Prevotella, while community C showed an increase in Bacteroides.
Community A resembles the previous described enterotype 2 and community C resembles enterotype 1 (Arumugam et al., 2011), However, the composition of community B differs from these previous reported results, the composition of community B was characterized, among others, by an increase in Akkermansia
Using Tax4Fun software the authors attempted to predict the potential functions of the gut microbiome in the different communities, the results of this predictive analysis and the changes in the gut microbiome may indicate a shift toward a more competitive and virulent microbial community. However, these results need to be validated by metagenomic or metatranscriptomic analyses.
In the complicated group, gut microbiome patterns showed only slight changes toward dysbiosis. Both groups revealed a typical gut microbiome composition despite various external factors….there were large individual differences in the composition of the gut microbiome among patients at baseline (prior to surgery), as well as over the longitudinal course….These results suggest that individual patients not only have a unique microbiome, but also react in a unique way to exposure to surgical stress and antibiotics.
Differences in the gut microbiome are associated with the development of postoperative complications. Sequencing of the gut microbiome or methods that take into account differences in the NGS-defined microbial communities might represent a useful diagnostic tool in future clinical practice.
Whether the observed changes in the gut microbiome are a physiological defence mechanism or represent the cause remains unclear, and this needs to be evaluated in further investigations.