Objective To investigate whether milk polar lipids (PL) impact human intestinal lipid absorption, metabolism, microbiota and associated markers of cardiometabolic health. Design A double-blind, randomised controlled 4-week study involving 58 postmenopausal women was used to assess the chronic effects of milk PL consumption (0, 3 or 5 g-PL/day) on lipid metabolism and gut microbiota. The acute effects of milk PL on intestinal absorption and metabolism of cholesterol were assessed in a randomised controlled crossover study using tracers in ileostomy patients. Results Over 4 weeks, milk PL significantly reduced fasting and postprandial plasma concentrations of cholesterol and surrogate lipid markers of cardiovascular disease risk, including total/high-density lipoprotein-cholesterol and apolipoprotein (Apo)B/ApoA1 ratios. The highest PL dose preferentially induced a decreased number of intestine-derived chylomicron particles. Also, milk PL increased faecal loss of coprostanol, a gut-derived metabolite of cholesterol, but major bacterial populations and faecal short-chain fatty acids were not affected by milk PL, regardless of the dose. Acute ingestion of milk PL by ileostomy patients shows that milk PL decreased cholesterol absorption and increased cholesterol-ileal efflux, which can be explained by the observed co-excretion with milk sphingomyelin in the gut. Conclusion The present data demonstrate for the first time in humans that milk PL can improve the cardiometabolic health by decreasing several lipid cardiovascular markers, notably through a reduced intestinal cholesterol absorption involving specific interactions in the gut, without disturbing the major bacterial phyla of gut microbiota. Trial registration number NCT02099032 and NCT02146339; Results.
Formulating healthy food rich in omega 3 fatty acids requires prior knowledge of the parameters influencing their bioavailability and their metabolic fate. In this context, we studied the effects of various emulsifiers widely used in the food industry, on the gastrointestinal lipolysis of flaxseed oil emulsions in an in vitro model and on the intestinal absorption and lymphatic secretion of alpha-linolenic acid (ALA) in rats. In vitro data showed that the emulsification of flaxseed oil with soya lecithin improved the gastric lipolysis of the oil (+30%), while the presence of Tween 80 or of sodium caseinate decreased it (−80% and −40%, respectively). The in vivo data demonstrated that the intestinal absorption and the lymphatic secretion of ALA were improved with soya lecithin (Cmax = 24 mg mL−1) and reduced in the presence of sodium caseinate (Cmax = 7 mg mL−1) compared to unemulsified flaxseed oil (Cmax = 16 mg mL−1); Tween 80 had no effect. In addition, the synthesized chylomicrons were notably larger and more numerous with soya lecithin whereas they were smaller in the presence of sodium caseinate (p < 0.05). This study shows that the intestinal bioavailability of ALA was increased by the emulsification of flaxseed oil with soya lecithin via an improved lipolysis, favouring the intestinal absorption of ALA and the secretion of many large chylomicrons in lymph.
23 November 2015 in Molecular Nutrition & Food Research
Berry (poly)phenol consumption has been associated with cardioprotective benefits, however little is known on the role the gut microbiome may play on such health benefits. Our objective was to investigate the effects of aronia berry (poly)phenol consumption on cardiometabolic health and gut microbiome richness and composition in prehypertensive middle-aged men and women. A total of 102 prehypertensive participants were included in a parallel 12-week randomized double-blind placebo-controlled trial. Volunteers were randomly allocated to daily consume an encapsulated (poly)phenol-rich aronia berry extract (Aronia, n = 51) or a matched maltodextrin placebo (Control, n = 51). Blood pressure (BP) and arterial function (office and 24 h), endothelial function (measured as flow-mediated dilation), serum biochemistry (including blood lipids), plasma and urine (poly)phenol metabolites as well as gut microbiome composition through shotgun metagenomic sequencing were monitored over the study period. Relationships between vascular outcomes, (poly)phenol metabolites and gut microbiome were investigated using an integrated multi-levels approach. A significant improvement in arterial indices measured as augmentation index (AIx) and pulse wave velocity (PWV) was found in the Aronia compared to Control group (awake Δ PWV = -0.24 m/s; 95% CI: -0.79, -0.01 m/s, P < 0.05; 24 h peripheral Δ AIx = -6.8; -11.2, -2.3, %, P = 0.003; 24 h central Δ AIx = -3.3; -5.5, -1.0, %, P = 0.006). No changes in BP, endothelial function or blood lipids were found following the intervention. Consumption of aronia (poly)phenols led to a significant increase in gut microbiome gene richness and in the abundance of butyrate-producing species such as Lawsonibacter asaccharolyticus and Intestinimonas butyriciproducens species, compared to Control group. Results from an approach including metabolomic, metagenomic and clinical outcomes highlighted associations between aronia-derived phenolic metabolites, arterial stiffness, and gut microbiome. Aronia berry (poly)phenol consumption improved arterial function in prehypertensive middle-aged individuals, possibly via modulation of gut microbiome richness and composition based on the associations observed between these parameters. The National Institutes of Health (NIH)-randomized trial records held on the NIH ClinicalTrials.gov website (NCT03434574). Aronia Berry Consumption on Blood Pressure.
Estrogen deficiency increases the risk of osteoporosis and fracture. The aim of this study was to investigate whether a hop extract standardized in 8-prenylnaringenin (8-PN), a potent phytoestrogen, could improve bone status of osteopenic women and to explore the gut microbiome roles in this effect. In this double-blind, placebo-controlled, randomized trial, 100 postmenopausal, osteopenic women were supplemented with calcium and vitamin D3 (CaD) tablets and either a hop extract (HE) standardized in 8-PN (n = 50) or a placebo (n = 50) for 48 weeks. Bone mineral density (BMD) and bone metabolism were assessed by DXA measurements and plasma bone biomarkers, respectively. Participant’s quality of life (SF-36), gut microbiome composition, and short-chain fatty acid (SCFA) levels were also investigated. In addition to the CaD supplements, 48 weeks of HE supplementation increased total body BMD (1.8 ± 0.4% vs. baseline, p < 0.0001; 1.0 ± 0.6% vs. placebo, p = 0.08), with a higher proportion of women experiencing an increase ≥1% compared to placebo (odds ratio: 2.41 ± 1.07, p < 0.05). An increase in the SF-36 physical functioning score was observed with HE versus placebo (p = 0.05). Gut microbiome α-diversity and SCFA levels did not differ between groups. However, a higher abundance of genera Turicibacter and Shigella was observed in the HE group; both genera have been previously identified as associated with total body BMD. These results suggest that an 8-PN standardized hop extract could beneficially impact bone health of postmenopausal women with osteopenia.