Gut microbiome features are associated with sepsis onset and outcomes

Background:

Sepsis is a life-threating condition, where an extreme immune response to infection occurs, causing widespread inflammation and damage to the body. Sepsis is therefore associated with high mortality. Prior exposure to antibiotics which alter the gut microbiome is linked to subsequent sepsis infection. Therefore, the aim of this study is to examine a contributory role of gut microbiome disruption in increased risk of sepsis infection.

Key findings:

Patients which had gut microbiota samples from previous intensive care or haematology departments visits were screened for sepsis infection. Those which were categorised as sepsis patients were chosen for comparison to matched controls (patients without sepsis) to examine the role of the gut microbiome in sepsis infection. To do so, the abundance of different bacterial species, as well as the total amount of bacteria were analysed.

The authors first highlight the important finding that significant differences in the gut microbiome were found in those with sepsis infection in comparison to controls. Three microbiota changes were associated with increased likelihood of sepsis infection; a high relative abundance of Enterococcus species, a high total bacterial amount, or a decreased relative abundance of butyrate-producing bacteria. Furthermore, a reduced abundance of butyrate-producing bacteria was associated with a worse sepsis mortality outcome.

The authors conclude that an altered gut microbiome is associated with the initiation of sepsis infection, and raise an interesting possibility that butyrate-producing bacteria may have immunomodulatory effects which warrants further investigation in a sepsis scenario.

Why I chose this Preprint:

This study furthers our understanding of biological mechanisms which lead to sepsis infection, specifically, how gut microbiota changes (which follow exposure to antibiotics) may ultimately affect subsequent sepsis infection. In addition, this study identifies targets for potential prophylactic interventions to prevent sepsis following antibiotic treatments. Early detection of increased risk of sepsis may be hugely beneficial in the treatment/prevention of sepsis, where using changes in gut microbiota as a diagnostic test for the risk of sepsis infection may allow faster treatments resulting in improved patient outcomes.

Questions to the authors:

1. Since use of antibiotics can alter the gut microbiota, is it possible that the methodology used in this study could be used to identify certain antibiotic treatments which are least harmful in respect to human gut bacterial changes?
2. You demonstrate that loss of butyrate-producing bacteria increases sepsis risk and mortality. Do you suggest that increasing the amount of these bacteria present, for example with probiotics, would reduce sepsis infection risk?
3. Do you think that the methodology used to analyse gut microbiota may be useful in for analysing other diseases associated with microbiota changes, such as inflammatory bowel disease?

 

Tags: microbiota, sepsis

Posted on: 15 January 2021 , updated on: 25 March 2021

doi: https://doi.org/10.1242/prelights.26999

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