According to a recent study, the so-called Western diet could help explain why sepsis affects some people more severely than others. Sepsis, although not a household name, is one of the leading causes of death in the US. This life-threatening condition is a complication that arises from an infection.

Sepsis, which people colloquially refer to as blood poisoning, occurs when the body's immune response begins to damage organs and tissues. Without treatment, blood pressure can become fatally low, which doctors describe as septic shock.

According to the Centers for Disease Control and Prevention (CDC), 1.7 million adults in the US develop sepsis each year, and approximately 270,000 of them die. In fact, 1 in 3 people who die in the hospital has sepsis. There are still many unanswered questions about sepsis. For instance, experts do not know why sepsis occurs in some people and not others. It is also difficult to predict who will develop the most severe cases.

There is some evidence that sepsis is becoming more common too. This may be partly due to the aging population as people aged 65 years and over are more susceptible to sepsis and more likely to die as a result. As sepsis can be fatal and is so difficult to predict, there is a push to understand what drives the condition and how to prevent it.

Sepsis and diet

According to a recent study, diet could help predict which cases of sepsis might be most severe. The researchers, from Portland State University in Oregon, published their findings recently in the journal Proceedings of the National Academy of Sciences. To investigate, they fed mice the equivalent of a Western diet, which is high in fat and sugar and low in fiber, while the mice in a control group received standard food.

They found that the mice that consumed the Western-type diet had higher levels of inflammation, even before sepsis began. This finding backs up earlier studies demonstrating that a Western-type diet can increase levels of inflammation in a number of systems in the body, including the cardiovascular system, the brain, and the intestines. Importantly, the mice that ate a Western diet experienced more severe cases of sepsis and had a higher mortality risk.

"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're more susceptible to sepsis, and then when you get sepsis, you die quicker."

—Senior author and assistant biology professor Brooke Napier

From data to the clinic

As sepsis is a huge concern in hospitals, these findings could be very useful. As Napier explains, "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 intensive care unit, you can make sure they're eating the right fats and the right ratio of fats."

In their paper, the investigators also describe some markers that might help predict which people are more at risk of these extreme immune responses. By checking for these biomarkers in the blood, it might be possible to identify the patients who have a higher risk of sepsis and potentially treat their infections more aggressively.

To follow this study up, the researchers plan to drill down into the content of a Western diet. They hope to identify whether certain types of fat are interacting with the immune cells to alter their functionality.

Napier says, "If it's the fats in the diet that are doing the reprogramming, then it'll be applicable to any diet that's high-fat, like the ketogenic diet or any sort of Atkins-related diet." As these diets are becoming increasingly popular, this would be a significant finding.

Scientists already know that the Western diet can increase the risk of diabetes and cardiovascular disease, among other serious conditions. It seems that we might now need to add sepsis to this list.