Feeding spinach thylakoids to rats modulates the gut microbiota, decreases food intake and affects the insulin response

Abstract

Thylakoid membranes derived from green leaf chloroplasts affect appetite-regulating hormones, suppress food intake, reduce blood lipids and lead to a decreased body weight in animals and human subjects. Thylakoids also decrease the intestinal in vitro uptake of methyl-glucose in the rat. The aim of this study was to investigate the effect of dietary thylakoids on the gut microbiota composition, mainly the taxa of lactobacilli and bifidobacteria, in rats fed either a thylakoid-enriched diet or a control diet for 10 d. At the same time, a glucose-tolerance test in the same rats was also performed. Food intake was significantly decreased in the thylakoid-fed rats compared with the control-fed rats over the 10-d study. An oral glucose tolerance test after 10 d of thylakoid- or control-food intake resulted in significantly reduced plasma insulin levels in the thylakoid-fed rats compared with the control-fed rats, while no difference was observed for blood glucose levels. Analysis of gut bacteria showed a significant increase of lactobacilli on the ileal mucosa, specifically Lactobacillus reuteri, in the rats fed the thylakoid diet compared with rats fed the control diet, while faecal lactobacilli decreased. No difference in bifidobacteria between the thylakoid and control groups was found. Analyses with terminal restriction fragment length polymorphism and principal component analysis of faeces demonstrated different microbial populations in the thylakoid- and control-fed animals. These findings indicate that thylakoids modulate the gut microbial composition, which might be important for the regulation of body weight and energy metabolism.

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

“…The diets were based on the D12451 high fat diet from Research Diets (Research Diets®, New Brunswick, NJ, USA). The thylHFD contained 33% w/w thylakoid extract (Appethyl®, Greenleaf Medical AB, Stockholm, Sweden), which is comparable to previous studies in rat that demonstrated effects on body weight and food intake [5–7]. …”

“…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 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

“…Considering the weight loss and central obesity reduction, as well as insulin sensitivity improvement and insulin resistance attenuation following thylakoid supplementation without changes in glucose concentration in our study, which has also been demonstrated in some studies [17,32], thus, it presents good implications of spinach thylakoid for obesity treatment. On the contrary, regarding glucose levels, multiple animal studies reported the hypoglycemic action of spinach-derived thylakoids [23,[37][38][39]. Park et al found that spinach extract inhibited intestinal α-glucosidase in vitro, and the digestion of disaccharides (− 19.6%), hence, by lowering the uptake of dietary glucose, glycemia might be improved [40].…”

Consumption of thylakoid-rich spinach extract reduces hunger, increases satiety and reduces cravings for palatable food in overweight women

“…We found that these effects are connected to an altered secretion of appetite regulating hormones, including ghrelin, cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1), in rodents, pigs and humans (Köhnke, Lindbo et al, 2009;Montelius, Osman et al, 2013;Montelius, Szwiec et al, 2013;Montelius et al, 2014). Based on these findings of suppressed hedonic hunger and increased levels of GLP-1, we were interested to deepen our knowledge of these effects on overweight middle-aged women in a similar group of participants but in a non-laboratory setting.…”