Background: Lipopolysaccharide (LPS), derived from gram-negative bacteria, is associated with inflammation, and serum levels increase after high-fat meals, with saturated fatty acids (SFA) potentially producing a greater response than other fatty acids. This study examined whether SFA, compared with monounsaturated fatty acids (MUFA), differentially affects postprandial endotoxemia and inflammatory responses in older adults with overweight or obesity. Methods: In a randomized crossover study, older adults consumed a high-fat (46%/550 kcal) meal enriched with either MUFA or SFA, both matched for energy and macronutrients. Meals included foods enriched in MUFA (peanuts) or SFA (butter) to achieve these differences and were given in random order on two separate study days. Blood samples were collected before and 0.5, 2, 3, 4, 5, and 6 hours after the meal to assess LPS, triglycerides, glucose, and inflammatory markers. Results: Participants (n=16, 75% female) were 62.7±4.8 years with a body mass index of 33.4±6.3 kg/m2. The postprandial rise for serum endotoxin at 4 hours was twice as high after the SFA meal as after the MUFA meal (p<0.05), and lipopolysaccharide binding protein (LBP) was also higher (p<0.05). No other inflammatory markers differed between meals, although the rise to postprandial peak LPS and peak tumor necrosis factor-α correlated after the SFA (p<0.05) but not the MUFA meal. Conclusion: Consumption of the SFA-enriched compared to the MUFA-enriched meal led to a greater rise in postprandial serum endotoxin and LBP concentration. These findings suggest that although dietary SFA increased circulating LPS and the mediator protein, this did not translate to an upregulation of downstream inflammatory markers.
Jui Ling Chang (Thu,) studied this question.