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

Abstract

Green-plant thylakoids increase satiety by affecting appetite hormones such as ghrelin, cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1). The objective of this study was to investigate if thylakoids also affect gastrointestinal (GI) passage and microbial composition. To analyse the effects on GI passage, 16 rats were gavage-fed a control or thylakoid-supplemented high-fat diet (HFD) 30 min before receiving Evans blue. Another 16 rats were fed a control HFD or thylakoid HFD for two weeks prior to the intragastric challenge with Evans blue. The amount of Evans blue in the stomach and the distance of migration in the intestines after 30 min were used as a measurement of gastric emptying and intestinal transit. These were reduced by thylakoid supplementation in the acute study, and however not significantly also after the two-week diet study.The second aim of the study was to investigate if thylakoid-supplementation affects the gut microbiota and amount of faecal fat in healthy human volunteers (n = 34) receiving thylakoid or placebo treatments for three months. Microbiota was analysed using 16S rRNA gene sequencing and qPCR, and faecal fat was extracted by dichloromethane. The total bacteria, and specifically the Bacteriodes fragilis group, were increased by thylakoid treatment versus placebo, while thylakoids did not cause steatorrhea. Dietary supplementation with thylakoids thus affects satiety both via appetite hormones and GI fullness, and affects the microbial composition without causing GI adverse effects such as steatorrhea. This suggests thylakoids as a novel agent in prevention and treatment of obesity.

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

“…An increased release of satiety hormones suggests a delayed absorption of nutrients from the intestine during digestion through thylakoid membranes. In previous publications, we have found no evidence of increased faecal fat excretion by the addition of thylakoids despite body weight and fat mass loss, neither in man [9], nor in rat [7]. The thylakoid enriched high-fat diet used in mice was the same as previously used for rat, suggesting a species difference.…”

“…There might also be a reduced fat absorption or an increased fatty acid oxidation. 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.…”

“…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.…”

The Effects of Thylakoid-Rich Spinach Extract Combined with the Calorie-Restricted Diet on Cardiometabolic Risk Factors in Obese Women with Polycystic Ovary Syndrome: A Randomized Controlled Clinical Trial

“…Due to the lack of studies regarding the effects of spinach-derived thylakoids on lipid metabolism, the mechanism by which thylakoid-rich spinach extract might affect lipid pro le are still unknown. The existing evidence shows that the prebiotic effect of spinach thylakoids, and hence, modulation of gut microbiota may be involved in the lipid-lowering properties of the thylakoid-rich spinach extract [38,57]. In this regard, it is demonstrated that spinach thylakoid consumption induces fatty acid oxidation and inhibits de novo synthesis of lipids through increasing the generation of shortchain fatty acids (SCFAs).…”

Effects of Thylakoid-Rich Spinach Extract on the Pharmacokinetics of Drugs in Rats

“…39) Moreover, Stenblom et al have reported that a delay in gastric emptying mediated by food intake. 40) Therefore, this phenomenon may be ascribed to the fact that gastric emptying was delayed by thylakoid-rich spinach extract. 41) Conversely, we observed that the T max of GF and IM was not affected by thylakoid-rich spinach extract; this is likely because dissolution is a rate-limiting step for gastrointestinal absorption of GF and IM, which are poorly water-soluble.…”