Energy intake is associated with endotoxemia in apparently healthy men

The bridge between food intake and weight is not fully understood. Recently, the role of gut microbiota and bacterial lipopolysacharides (LPS) in weight has been noted.

The objective was to evaluate the relation between plasma LPS concentration and food intake.

A dietary survey was conducted in 1015 subjects randomly recruited in France. The participants were given oral and written instructions on how to keep a consecutive 3-d food record. Plasma LPS was measured in a subsample of 201 men. To assess, under controlled conditions, the differential impact of various high-energy diets, plasma LPS concentrations were measured in mice fed a high-fat or a high-carbohydrate diet over a 4-wk period.

In humans, no significant relation was observed between cardiovascular disease risk factors, carbohydrate and protein intakes, and plasma LPS concentration. Conversely, positive correlations were observed with fat and energy intakes. In a multivariate analysis, endotoxemia was independently associated with energy intake. Compared with the control mice, mice fed a high-energy diet showed an increase in plasma LPS. However, in mice fed a high-carbohydrate diet, the increase in plasma LPS was blunted compared with mice fed a high-fat diet.

In this large sample of healthy men from a population-based sample, we found a link between food intake and plasma LPS. Experimental data suggest that fat was more efficient in transporting bacterial LPS from the gut lumen into the bloodstream. The results of this study add to the knowledge of mechanisms responsible for relations between food intake and metabolic diseases.