Head injury and intestinal dysbiosis in rats
A startling new discovery was recently made in animals: head injuries (HI) could lead to gut dysbiosis, which in turn could increase the risk of infectious complications (often observed in HI patients).
To confirm this surprising hypothesis, French researchers tried to understand why the risk of infection increases following a head injury. Although HI often induces a hypercatabolic state as well as dysimmunity and septic complications, gut dysbiosis could also be involved in this phenomenon and had never been considered before. The researchers studied the causal relation in an animal model.
They analyzed the intestinal microbiota of rats assigned to two groups: a control group (n=7) and a HI group (n=12). To ensure that the intestinal transit was not compromised, the rats received enteral nutrition, just like intensive care patients with HI. The authors observed that a head injury significantly decreased the proportion of anaerobic bacteria (such as Bacteroides, Prevotella, Clostridium and Bifidobacterium), which usually characterize the microbiota of healthy individuals, thus generating a dysbiosis. To a lesser extent, they also observed a decrease in the proportion of Lactobacillus and Leuconostoc, which are known to provide beneficial effects to healthy hosts, especially a barrier function against pathogens. These findings confirm observations made in patients requiring intensive care following a head injury, who often present dysbiosis and weakening of the intestinal barrier which may lead to post-traumatic sepsis. These studies could open a new field of research in the management of infectious complications in HI patients by restoring gut microbiota homeostasis.
Waligora-Dupriet AJ et al. Head injury profoundly affects gut microbiota homeostasis: Results of a pilot study. Nutrition. 2018 Jan;45:104-107. https://www.ncbi.nlm.nih.gov/pubmed/29129229