Dietary thylakoids reduce visceral fat mass and increase expression of genes involved in intestinal fatty acid oxidation in high-fat fed rats

Abstract

Thylakoids reduce body weight gain and body fat accumulation in rodents. This study investigated whether an enhanced oxidation of dietary fat-derived fatty acids in the intestine contributes to the thylakoid effects. Male Sprague-Dawley rats were fed a high-fat diet with (n = 8) or without thylakoids (n = 8) for 2 wk. Body weight, food intake, and body fat were measured, and intestinal mucosa was collected and analyzed. Quantitative real-time PCR was used to measure gene expression levels of key enzymes involved in fatty acid transport, fatty acid oxidation, and ketogenesis. Another set of thylakoid-treated (n = 10) and control rats (n = 10) went through indirect calorimetry. In the first experiment, thylakoid-treated rats (n = 8) accumulated 25% less visceral fat than controls. Furthermore, fatty acid translocase (Fat/Cd36), carnitine palmitoyltransferase 1a (Cpt1a), and mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase 2 (Hmgcs2) genes were upregulated in the jejunum of the thylakoid-treated group. In the second experiment, thylakoid-treated rats (n = 10) gained 17.5% less weight compared with controls and their respiratory quotient was lower, 0.86 compared with 0.91. Thylakoid-intake resulted in decreased food intake and did not cause steatorrhea. These results suggest that thylakoids stimulated intestinal fatty acid oxidation and ketogenesis, resulting in an increased ability of the intestine to handle dietary fat. The increased fatty acid oxidation and the resulting reduction in food intake may contribute to the reduced fat accumulation in thylakoid-treated animals.

Thylakoids reduce body fat and fat cell size by binding to dietary fat making it less available for absorption in high-fat fed mice

“…We however found no sign of steatorrhea in spite of a body weight loss, neither in rodent studies [7] nor in human studies [8, 9]. We also observed an increased expression of fat oxidative enzymes in the gut and an increased fat oxidation in rat fed high-fat diet with thylakoid supplementation [10], suggesting other mechanisms to explain the fat mass reduction. This could be fecal fat excretion and/or a recruitment of new adipocytes that have a more active metabolism.…”

“…The thylakoid enriched high-fat diet used in mice was the same as previously used for rat, suggesting a species difference. In rat, the absence of fat in faeces could be due to a slower passage of food through the intestine [9], giving the possibility for an increased intestinal fatty acid oxidation [10] and/or a more complete fat absorption.…”

Food Components in Health Promotion and Disease Prevention

“…. Thylakoids appear to specifically and efficiently inhibit eating in humans and animals. − This effect appears to be related to a stimulation of the secretion of satiating gut peptides, such as CCK and glucagon-like peptide 1 (GLP-1) , and, possibly, to a stimulation of the oxidation of dietary-derived fatty acids in the small intestine . Interestingly, in humans, thylakoids appear to have a particularly strong inhibitory effect on hedonic eating, i.e., on the overeating when exposed to good-tasting, attractive food .…”

Dietary green-plant thylakoids decrease gastric emptying and gut transit, promote changes in the gut microbial flora, but does not cause steatorrhea

“…The gut microbiota also promotes the production of SCFA, which have been proposed to have effects on lipid, glucose and cholesterol metabolism in the host [ 33 , 34 ]. Indeed, a recent study in rats fed a high-fat diet with or without thylakoids demonstrated that thylakoid supplementation resulted in a reduced respiratory quotient (RQ), indicative of increased fatty acid oxidation [ 35 ]. This may have been caused by altered gut microbiota.…”