Does the Western Diet Promote Endotoxemia and Inflammation?

A high-fat diet can cause endotoxemia, which promotes the systemic inflammation and metabolic disorders associated with obesity, according to a human study published in the May issue of Gastroenterology.

Chronic endotoxemia (the presence of endotoxins such as lipopolysaccharide in blood) occurs with obesity, yet little is known about the source or mechanisms of endoxins in obese patients. Some studies have shown that increased calorie or fat intake can cause endotoxemia, but no one has compared Western and healthy diets.

Swaroop Pendyala and colleagues investigated whether differences in diet affect the development of endotoxemia in people. They fed 8 healthy subjects a Western-style diet for 1 month (while they were hospitalized in a metabolic ward and all activity was carefully monitored), and measured blood levels of endotoxin and other markers of inflammation. After a 1-month washout period, the subjects were fed a prudent-style diet for 1 month, while the same factors were measured.

Compared with baseline measurements, the Western-style diet caused a 71% increase in plasma levels of endotoxin activity, whereas the prudent-style diet caused a 38% decrease (see figure).

Plasma levels of endoxin activity before and after the Western diet (A), the prudent diet (B), at baseline before the Western and prudent diets (C), and compared after the Western and prudent diets (D).

On the prudent-style diet, subjects also had significant decreases in serum levels of tumor necrosis factor-α and a trend for reduced levels of monocyte chemotactic protein 1 and interleukin-8 (markers of inflammation); levels of these factors were unchanged on the Western-style diet.

Pendyala et al. propose that the Western-style diet contributes to endotoxemia by causing changes in gastrointestinal barrier function or the composition of the microbiota. Prebiotics or probiotics might be used to reduced endotoxemia and its concomitant complications in obese individuals.

Read the article online.
Pendyala S, Walker JM, Holt PR. A high-fat diet is associated with endotoxemia that originates from the gut. Gastroenterology 2012;142:1100–1101.e2.