Although elevated blood levels of trimethylamine N-oxide (TMAO) have been associated with atherosclerosis development in humans, the role of its gut microbiota-derived precursor, TMA, in this process has not been yet deciphered. Taking this into account, and the fact that increased intestinal fatty acid absorption contributes to atherosclerosis onset and progression, this study aimed to evaluate the effect of TMA on fatty acid absorption in a cell line that mimics human enterocytes. Caco-2 cells were treated with TMA 250 μM for 24 h. Fatty acid absorption was assessed by measuring the apical-to-basolateral transport and the intracellular levels of BODIPY-C12, a fluorescently labelled fatty acid analogue. Gene expression of the main intestinal fatty acid transporters was evaluated by real-time quantitative reverse transcription PCR. Compared to control conditions, TMA increased, in a time-dependent manner and by 20–50 %, the apical-to-basolateral transport and intracellular levels of BODIPY-C12 fatty acid in Caco-2 cells. Fatty acid transport protein 4 (FATP4) and fatty acid translocase (FAT)/CD36 gene expression were not stimulated by TMA, suggesting that TMA-induced increase in fatty acid transport may be mediated by an increase in FAT/CD36 and/or FATP4 activity and/or fatty acid passive transport. This study demonstrated that TMA increases the intestinal absorption of fatty acids. Future studies are necessary to confirm if this may constitute a novel mechanism that partially explains the existing positive association between the consumption of a diet rich in TMA sources (e.g. red meat) and the increased risk of atherosclerotic diseases.

We sought to examine the effects of daily consumption of macadamia nuts on body weight and composition, plasma lipids and glycaemic parameters in a free-living environment in overweight and obese adults at elevated cardiometabolic risk. Utilising a randomised cross-over design, thirty-five adults with abdominal obesity consumed their usual diet plus macadamia nuts (~15 % of daily calories) for 8 weeks (intervention) and their usual diet without nuts for 8 weeks (control), with a 2-week washout. Body composition was determined by bioelectrical impedance; dietary intake was assessed with 24-h dietary recalls. Consumption of macadamia nuts led to increased total fat and MUFA intake while SFA intake was unaltered. With mixed model regression analysis, no significant changes in mean weight, BMI, waist circumference, percent body fat or glycaemic parameters, and non-significant reductions in plasma total cholesterol of 2⋅1 % (−4⋅3 mg/dl; 95 % CI −14⋅8, 6⋅1) and low-density lipoprotein (LDL-C) of 4 % (−4⋅7 mg/dl; 95 % CI −14⋅3, 4⋅8) were observed. Cholesterol-lowering effects were modified by adiposity: greater lipid lowering occurred in those with overweight v. obesity, and in those with less than the median percent body fat. Daily consumption of macadamia nuts does not lead to gains in weight or body fat under free-living conditions in overweight or obese adults; non-significant cholesterol lowering occurred without altering saturated fat intake of similar magnitude to cholesterol lowering seen with other nuts.

Clinical Trial Registry Number and Website: NCT03801837 https://clinicaltrials.gov/ct2/show/NCT03801837?term = macadamia + nut&draw = 2&rank = 1

Postprandial hyperglycaemia is recognised as an important target in type 2 diabetes management. Dietary pattern, meal composition, and amount of food intake are major factors for maintaining postprandial blood glucose levels. The aim of this study was to investigate the effect of consuming a whey protein-based multi-ingredient nutritional drink (WD) on postprandial glycaemic, insulinaemic, and active glucagon-like peptide-1 (GLP-1) responses in comparison to a typical breakfast, which is boiled white rice with chicken (BC) in patients with type 2 diabetes mellitus (T2DM). Fifteen subjects with T2DM participated in a randomised, controlled, cross-over study. Two isocaloric diets with similar nutrient composition were randomly tested with at least 7 d in between. Glucose, insulin, and active GLP-1 were measured by standard methods with blood samples collected with a venous catheter for 240 min during a kinetic test. The incremental area under the curve (iAUC0–240 min) for plasma glucose was significantly lower after the consumption of WD (WD: 3551 ± 546; BC: 9610 ± 848 mg min/dl; P < 0⋅01), while insulinaemic response tended to be lesser (iAUC0–240 min) than those of BC. In addition, higher iAUC0–240 min for active GLP-1 was obtained with WD diet (WD: 2230 ± 441; BC: 925 ± 183 pM min/ml; P < 0⋅01). This study showed that WD can be used to replace a regular breakfast for improving postprandial glucose response and active GLP-1 levels in people with T2DM. Further studies are required to elucidate the clinical efficacy of WD on long-term glycaemic control in people with T2DM.