Consuming a Western diet, low in fibre and high in fat and sugar, can put you at increased risk of developing severe sepsis, researchers say.

The study, published in the journal Proceedings of the National Academy of Sciences, found mice that were fed the Western diet showed an increase in chronic inflammation, sepsis severity and higher mortality rates than mice that were fed a normal diet.

Sepsis is a potentially life-threatening condition caused by the body's response to an infection. It can lead to shock and organ failure. It is one of the most common cause of death worldwide. According to the researchers, including Brooke Napier from the Portland State University, the mice had more severe sepsis and were dying faster because of something in their diet, not because of the weight gain or microbiome, the body's community of bacteria.

"The mice's immune system on the Western diet looked and functioned differently. It looks like the diet is manipulating immune cell function so that you are more susceptible to sepsis, and then when you get sepsis, you die quicker," Napier said.

The researcher said the findings can help hospitals better monitor the diets of patients in the intensive care unit (ICU) since they are already the ones most likely to develop sepsis. "If you know that a diet high in fat and sugar correlates with increased susceptibility to sepsis and increased mortality when those patients are in the ICU, you can make sure they're eating the right fats and the right ratio of fats," she said. 

"If you could introduce a dietary intervention while they are in the ICU to decrease their chances of manipulating their immune system in that way, you can somehow influence the outcome," she added. The team also identified molecular markers in Western diet-fed mice that could be used as predictors or biomarkers for patients that are at high risk for severe sepsis or patients that may need more aggressive treatment.