Antiinflammatory and ros suppressive effects of the addition of fiber to a high-fat high-calorie meal husam ghanim, manav batra, sanaa abuaysheh, kelly green, antoine makdissi

Background: Fiber intake is associated with a reduction in the occurrence of cardiovascular events and diabetes. Objective: To investigate whether the addition of fiber to a high-fat, high-calorie (HFHC) meal prevents proinflammatory changes induced by the HFHC meal. Design: Ten normal fasting subjects consumed an HFHC meal with or without an additional 30 g of insoluble dietary fiber on 2 separate visits. Blood samples were collected over 5 hours, and mononuclear cells (MNCs) were isolated. Results: Fiber addition to the HFHC meal significantly lowered glucose excursion in the first 90 minutes and increased insulin and C-peptide secretion throughout the 5-hour follow-up period compared with the meal alone. The HFHC meal induced increases in lipopolysaccharide (LPS) concentrations, MNC reactive oxygen species generation, and the expression of interleukin (IL)-1b, tumor necrosis factor a (TNF-a), Toll-like receptor (TLR)-4, and CD14. The addition of fiber prevented an increase in LPS and significantly reduced the increases in ROS generation and the expression of IL-1b, TNF-a, TLR-4, and CD14. In addition, the meal increased Suppressor of cytokine signaling (SOCS)-3 and protein tyrosine phosphatase 1B (PTP-1B)messengerRNAand protein levels, whichwere inhibitedwhen fiber was added. Conclusions: The addition of fiber to a proinflammatory HFHC meal had beneficial antiinflammatory and metabolic effects. Thus, the fiber content of the American Heart Association meal may contribute to its noninflammatory nature. If these actions of dietary fiber are sustained following long-term intake, they may contribute to fiber's known benefits in the prevention of insulin resistance, type 2 diabetes, and atherosclerosis.