Clinical impact of altered gut microbiota and metabolite profiles on mortality in patients with candidemia: a prospective observational pilot cohort study.

Abstract

Background: The gut microbiota plays an important role in defending against infectious diseases. However, data on the clinical implications of the microbiome profiles in patients with candidemia remain limited. In this study, we investigated the association between the intestinal microbiome and mortality in patients with candidemia.

Methods: This prospective, observational, pilot cohort study enrolled adult patients with culture-confirmed candidemia. Fecal samples were collected within 5 days of diagnosis and analyzed using 16 S ribosomal RNA gene sequencing for microbiota profiling and gas chromatography-mass spectrometry for metabolomic analysis. Multivariate logistic regression was used to identify predictors of in-hospital mortality, defined as death during hospitalization.

Results: Fifty-nine patients with candidemia were analyzed, and the in-hospital mortality rate was 40.7%. The median Shannon diversity index of the gut microbiota was significantly lower in non-survivors than that in survivors (P = 0.009). Linear discriminant analysis revealed 11 bacterial species that differed significantly between the two groups. Among the 111 fecal metabolites, only 3-isopropoxy-hexamethyl-tetrasiloxane differed significantly between the survivors and non-survivors (P = 0.007). Septic shock (adjusted odds ratio: 10.59; 95% confidence interval, 1.70-65.97), underlying malignancy (7.79 [1.41-43.10]), and Shannon diversity index (0.40 [0.19-0.84]) were significant predictors of in-hospital mortality.

Conclusions: Low gut bacterial diversity is independently associated with mortality in patients with candidemia. These preliminary findings warrant confirmation through larger, well-powered studies.