Effects of wholegrain cereal foods on plasma short chain fatty acid concentrations in individuals with the metabolic syndrome

Short chain fatty acids (SCFAs) derived from dietary fiber fermentation by gut microbiota have been identified as one of the mechanisms behind the association between habitual whole-grain intake and a lower risk of cardiometabolic diseases. The aims of the present work are: (1) to evaluate whether a whole-grain wheat-based diet may increase SCFAs concentration, and (2) to identify possible associations between SCFAs and metabolic changes observed after the nutritional intervention

Effect of a probiotic administration on inflammatory profile and clinical features in patients with Alzheimer's disease

AbstractBackgroundIncreasing evidence shows that the gut microbiota (GMB) may affect the inflammatory status and influence the pathogenesis of several brain disorders, including Alzheimer's Disease. Moreover, it has been suggested that probiotics may have potential beneficial effects on the immune system via microbiome composition, influencing in turn also cognitive performances.MethodSixty‐two old subjects with normal cognitive performance and 37 AD patients were recruited and stool and blood samples were collected. Moreover, the group of AD patients received a probiotic administration for three months and stool and blood samples were collected again at the end of the treatment. Plasma levels of a panel of pro‐inflammatory cytokines were measured by using the High Sensitivity 9‐Plex Human ProcartaPlex™ Panel (IFN‐ϒ, IL‐1b, IL‐2, IL‐4, IL‐6, IL‐10, IL‐12p70, IL‐17A and TNFα, Thermo Fisher Scientific) on Luminex Bio‐Plex® 200™ system. Moreover, we also measured the plasma levels of C‐Reactive Protein (CRP) using the CRP Human Instant ELISA Kit (Thermo Fisher Scientific). Bacterial composition of fecal samples was inferred using 16s sequencing; the levels of the short chain fatty acids acetate, propionate, valerate and butyrate were measured by mass spectrometry and adhesion molecules by FACS.ResultWe found higher levels of the pro‐inflammatory cytokines IL‐6, IFN gamma, TNF‐alpha, IL‐1beta, and il12p70 and of IL‐2 and lower levels of the anti‐inflammatory cytokine IL‐10 in AD patients as compared to control subjects (all p<0.05). Moreover, we found a positive correlation between MMSE score and the levels of pro‐inflammatory cytokine IL‐6 (p=0.03, r=0.56). Interestingly, the three months treatment with the probiotic composition was able to significantly reduce the level of IL‐6 (p=0.03) and increase the levels of IL‐10 (p=0.023). Bioinformatic analyses on the 16s sequencing data as well as on the SCFAs and endothelial markers are ongoing.ConclusionInflammatory status is higher in AD patients as compared to control subjects and it correlates with cognitive performances. Interestingly probiotic composition is able to push down the inflammatory status in patients, possibly via changes in microbiome composition. Probiotics may be beneficial in delaying neurodegeneration and cognitive deficits in subjects at risk of developing Alzheimer Disease

Nutritional factors influencing plasma adiponectin levels: results from a randomised controlled study with whole-grain cereals

Data from intervention studies about the effects of a high intake of whole-grain cereals on adiponectin expression are still inconclusive. We evaluated the effects of whole-grain or refined cereals on fasting and postprandial serum adiponectin in people at high cardiovascular risk. According to a randomised controlled parallel group design, participants with metabolic syndrome were assigned to an isoenergetic diet based on either whole-grain cereal (WGC) or refined cereal (RC) products for 12-weeks. Anthropometric and biochemical measures were taken. Compared to baseline, fasting and postprandial serum adiponectin levels increased after both RC and WGC. In the WGC and RC groups combined, adiponectin concentrations significantly increased after 12-week intervention, and are directly associated with plasma SCFAs and acetate. Only increasing whole-grain cereals may not influence adiponectin levels, which could be modified by a fibre rich, low-fat, low-glycemic index diet, possibly through changes in gut microbiota, as suggested by the relation with SCFAs. Clinical Trials number: NCT00945854

Reduction in liver fat by dietary MUFA in type 2 diabetes is helped by enhanced hepatic fat oxidation

The aim of this work was to investigate hepatic lipid metabolic processes possibly involved in the reduction of liver fat content (LF) observed in patients with type 2 diabetes after an isoenergetic diet enriched in monounsaturated fatty acids (MUFAs)

Bioavailability and pharmacokinetic profile of grape pomace phenolic compounds in humans

Grape pomace, the major byproduct of the wine and juice industry, is a relevant source of bioactive phenolic compounds. However, polyphenol bioavailability in humans is not well understood, and the inter-individual variability in the production of phenolic metabolites has not been comprehensively assessed to date. The pharmacokinetic and excretive profiles of phenolic metabolites after the acute administration of a drink made from red grape pomace was here investigated in ten volunteers. A total of 35 and 28 phenolic metabolites were quantified in urine and plasma, respectively. The main circulating metabolites included phenyl-γ-valerolactones, hydroxybenzoic acids, simple phenols, hydroxyphenylpropionic acids, hydroxycinnamates, and (epi)catechin phase II conjugates. A high inter-individual variability was shown both in urine and plasma samples, and different patterns of circulating metabolites were unravelled by applying unsupervised multivariate analysis. Besides the huge variability in the production of microbial metabolites of colonic origin, an important variability was observed due to phase II conjugates. These results are of interest to further understand the potential health benefits of phenolic metabolites on individual basi

Reduction of De Novo Lipogenesis Mediates Beneficial Effects of Isoenergetic Diets on Fatty Liver: Mechanistic Insights from the MEDEA Randomized Clinical Trial

Background: Non‐alcoholic liver steatosis (NAS) results from an imbalance between hepatic lipid storage, disposal, and partitioning. A multifactorial diet high in fiber, monounsaturated fatty acids (MUFAs), n‐6 and n‐3 polyunsaturated fatty acids (PUFAs), polyphenols, and vitamins D, E, and C reduces NAS in people with type 2 diabetes (T2D) by 40% compared to a MUFA‐rich diet. We evaluated whether dietary effects on NAS are mediated by changes in hepatic de novo lipogenesis (DNL), stearoyl‐CoA desaturase (SCD1) activity, and/or β‐ oxidation.; Methods: According to a randomized parallel group study design, 37 individuals with T2D completed an 8‐week isocaloric intervention with a MUFA diet (n = 20) or multifactorial diet (n = 17). Before and after the intervention, liver fat content was evaluated by proton magnetic resonance spectroscopy, serum triglyceride fatty acid concentrations measured by gas chromatography, plasma β‐hydroxybutyrate by enzymatic method, and DNL and SCD‐1 activity assessed by calculating the palmitic acid/linoleic acid (C16:0/C18:2 n6) and palmitoleic acid/palmitic acid (C16:1/C16:0) ratios, respectively; Results: Compared to baseline, mean ± SD DNL significantly decreased after the multifactorial diet (2.2 ± 0.8 vs.1.5 ± 0.5, p = 0.0001) but did not change after the MUFA diet (1.9 ± 1.1 vs. 1.9 ± 0.9, p = 0.949), with a significant difference between the two interventions (p = 0.004). The mean SCD‐1 activity also decreased after the multifactorial diet (0.13 ± 0.05 vs. 0.10 ± 0.03; p = 0.001), but with no significant difference between interventions (p = 0.205). Fasting plasma β‐hydroxybutyrate concentrations did not change significantly after the MUFA or multifactorial diet. Changes in the DNL index significantly and positively correlated with changes in liver fat (r = 0.426; p = 0.009). Conclusions: A diet rich in multiple beneficial dietary components (fiber, polyphenols, MUFAs, PUFAs, and other antioxidants) compared to a diet rich only in MUFAs further reduces liver fat accumulation through the inhibition of DNL. Registered under ClinicalTrials.gov no. NCT03380416

Mathematical optimization of the green extraction of polyphenols from grape peels through a cyclic pressurization process

In the current era of high consumption and increasing waste, many products that are believed to be unusable can find a new purpose in the market. For example, the grape peel waste resulting from the production of wine contains numerous bioactive compounds. In reality, grape peels are by-products of winemaking that can be conveniently reused in many different ways, including agronomic use and cosmetic industry applications. Moreover, the by-products can also be used in the energy field as biomass for the production of biogas or in food plants for the production of energy. In this article, to extract polyphenols, grape peels were processed via a cyclically pressurized extraction method known as rapid solid-liquid dynamic extraction (RSLDE), which does not require the use of any organic solvent or include heating or cooling processes that can cause the loss of substances of interest. To better understand the cyclically pressurized extraction process, a numerical simulation was performed to evaluate the exchange between the grape piece solid matrix and water during the extraction process. Furthermore, a finite element model was used to numerically determine the time-dependent concentration distribution at specific times