Objective:

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults and remains associated with a poor prognosis despite aggressive therapeutic interventions. This study investigates potential differences in the gut microbiome and mycobiome compositions between primary GBM patients and healthy control subjects.

Methods:

We enrolled 23 GBM patients treated at the University Hospital in Wuerzburg and 23 control participants in a prospective case-control study. Rectal swabs from GBM patients were collected before surgery. DNA was extracted from rectal swabs for 16S and ITS sequencing. We also performed FISH analysis using universal eukaryotic and fungal probes on GBM sections.

Results:

Preliminary results indicated differences in the composition of the microbiome and mycobiome between GBM patients and controls. Bacteroidaceae and Lachnospiraceae were lower abundant in GBM patients compared to healthy controls. In contrast, Candida and Cryptococcus were found in higher abundance in GBM patients. FISH analysis did not detect any bacteria or fungi in GBM sections.

Conclusions:

Our preliminary findings provide insights into the microbiome in GBM patients. These results will contribute to our understanding of the gut microbiome in GBM patients and potentially might lead to therapeutic avenues in the pursuit of improved outcomes.