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Purpose: To investigate the relationships between the habitual diet, the protein to fiber ratio (P/F), and the gut microbiome in one Italian and one Dutch cohort of healthy subjects consuming an omnivore diet. Methods: The Italian cohort included 19 males (M_IT, BMI 25.2 ± 0.72 kg/m2, age 25.4 ± 0.96 years) and 20 females (F_IT, BMI 23.9 ± 0.81 kg/m2, age 23.8 ± 0.54 years); the Dutch cohort included 30 females (F_NL, BMI: 23.9 ± 0.81 kg/m2, age: 23.8 ± 0.54 years). Individual diets were recorded through Food Frequency Questionnaires and analyzed to assess the nutrient composition. Gut microbiome was assessed in fecal samples. Results: M_IT consumed higher levels of proteins than F_NL and F_IT, whereas dietary fiber intake did not differ among groups. Data showed that consumption of plant protein to animal protein (PP/AP) and PP to total proteins ratio can determine a differentiation of F_NL more than the absolute amount of dietary fiber. Conversely, the protein to fiber (P/F) and AP to total proteins better characterized M_IT. M_IT harbored the highest abundance of proteolytic microorganisms and the lowest microbial gene richness. Conversely, F_NL had more fiber-degrading microorganisms like Bacteroides thetaiotaomicron, Bacteroides xylanisolvens, Roseburia sp., Coprococcus eutactus and Parabacteroides along with the highest number of genes encoding carbohydrate-active enzymes and gene richness. It was predicted that by each unit decrease in the P/F a 3% increase in gene richness occurred. Conclusion: Study findings suggested that dietary P/F, rather than the absolute amount of dietary fiber, could contribute to the shaping of the microbiome towards a more proteolytic or fiber-degrading gut ecosystem. ClinicalTrials.gov Identifier NCT04205045—01-10-2018, retrospectively registered. Dutch Trial Register NTR7531—05-10-2018.

gut metagenome of 19 non-habitual milk consumers with gastro-intestinal discomfort upon cow's milk consumption (NHMC) and 20 habitual milk consumers without GID (HMC), participating in a gut permeability and a milk load

The aryl hydrocarbon receptor (AhR) plays an important role in intestinal homeostasis, and some microbial metabolites of tryptophan are known AhR agonists. In this study, we assessed the impact of tryptophan supplementation on the formation of tryptophan metabolites, AhR activation, and microbiota composition in the simulator of the human intestinal microbial ecosystem (SHIME). AhR activation, microbial composition, and tryptophan metabolites were compared during high tryptophan supplementation (4 g/L tryptophan), control, and wash-out periods. During tryptophan supplementation, the concentration of several tryptophan metabolites was increased compared to the control and wash-out period, but AhR activation by fermenter supernatant was significantly decreased. This was due to the higher levels of tryptophan, which was found to be an antagonist of AhR signaling. Tryptophan supplementation induced most microbial changes in the transverse colon including increased relative abundance of lactobacillus. We conclude that tryptophan supplementation leads to increased formation of AhR agonists in the colon.

Proteolytic side activity of the lactase preparations (LPs) intended for ultra-high temperature hydrolyzed-lactose milk (UHLM) production induces changes in the product quality during shelf-life. The problem is particularly relevant when the enzyme is added aseptically in the packaging (“in pack” process), while the negative quality effects can be mitigated following the “in batch” process adding the LP before thermal sterilization. In this study, we monitored the quality over time of UHLM produced “in batch” and stored at 4, 20, 30 and 40 °C focusing on proteolysis, volatiles organic compounds (VOCs) formation and color changes. The goal was to identify the key reactions and compounds relevant for the product quality. An increase in storage temperature determined significant changes in the free amino acids profile increasing Strecker aldehydes and methyl ketones formation. At 30 and 40 °C, Maillard reaction and lipid oxidation ended up in a modification of the milk color, whereas at 4 and 20 °C no significant alteration was observed. Altogether, the results suggested a coordinate involvement of Maillard reaction, protein and lipid oxidation to milk browning and off-flavors formation in UHLM.

Objectives: This study aimed to explore the effects of an isocaloric Mediterranean diet (MD) intervention on metabolic health, gut microbiome and systemic metabolome in subjects with lifestyle risk factors for metabolic disease.Design: Eighty-two healthy overweight and obese subjects with a habitually low intake of fruit and vegetables and a sedentary lifestyle participated in a parallel 8-week randomised controlled trial. Forty-three participants consumed an MD tailored to their habitual energy intakes (MedD), and 39 maintained their regular diets (ConD). Dietary adherence, metabolic parameters, gut microbiome and systemic metabolome were monitored over the study period.Results: Increased MD adherence in the MedD group successfully reprogrammed subjects' intake of fibre and animal proteins. Compliance was confirmed by lowered levels of carnitine in plasma and urine. Significant reductions in plasma cholesterol (primary outcome) and faecal bile acids occurred in the MedD compared with the ConD group. Shotgun metagenomics showed gut microbiome changes that reflected individual MD adherence and increase in gene richness in participants who reduced systemic inflammation over the intervention. The MD intervention led to increased levels of the fibre-degrading Faecalibacterium prausnitzii and of genes for microbial carbohydrate degradation linked to butyrate metabolism. The dietary changes in the MedD group led to increased urinary urolithins, faecal bile acid degradation and insulin sensitivity that co-varied with specific microbial taxa.Conclusion: Switching subjects to an MD while maintaining their energy intake reduced their blood cholesterol and caused multiple changes in their microbiome and metabolome that are relevant in future strategies for the improvement of metabolic health.

The oil-water interface can be used as an efficient reaction controller in foods by carrying specific reactants and products in either the hydrophobic or hydrophilic phase. The formation of the taste-active compounds N-(1-carboxyethyl)-6-hydroxymethyl-pyridinium-3-ol inner salt (alapyridaine) and 1-(1-carboxyethyl)-3-hydroxy-pyridinium inner salt is influenced by the presence of a dispersed saturated triglyceride oil phase and by the pH of the aqueous phase. At pH 6.5, the formation of both betaines was 1.24 and 6 times higher in emulsions than in aqueous solution after 4 min at 140 °C. In alkaline emulsions (pH = 9.5, 4 min), the concentrations of alapyridaine and 1-(1-carboxyethyl)-3-hydroxy-pyridinium ion were 6.2 and 3.8 times higher, respectively, than in unbuffered emulsions as a result of the interaction between the polar head group of the surfactant and pyridinium rings. Here, we reported for the first time the effects of multiphase systems on the formation of nonvolatile, taste-active end products.

Manufacturing shelf-stable Ultra-high temperature hydrolyzed-lactose milk (UHLM) is a challenge for dairy producers, as the product undergoes chemical changes during storage due to both reducing sugars reactivity and proteolysis arising from the impurity of the lactase preparations. In the present study, the “in batch” production system, which includes the addition of the lactase before the thermal treatment, was demonstrated a valuable alternative to the more popular “in pack” system, where lactase is added directly into each milk package after thermal sterilization. The features of the technology were investigated by monitoring the changes in free amino acids, volatile organic compounds, color and sensory properties of UHLMs produced with three different lactase preparations (LPs), up to 120 days at 20 °C. Upon UHT processing, the proteolytic side activity of lactases was minimized, so minimum breakdown of milk protein was achieved. The release of free amino acids was dependent on the lactase purity only in the early production phases, whereas it did not change over time. The Strecker aldehydes benzaldehyde and 2-methylbutanal resulted as effective markers to correlate with the initial lactase purity during storage. Color and sensory slightly changed during storage but were poorly correlated with the different lactases, resembling to phenomena typical of milk aging. This latter result suggested that production costs might be lowered by opting for less-purified lactases when considering the “in batch” technology, supporting the application of this production system for the design of UHLM with high-quality standards and low risk of alterations during shelf-life.

This review summarises 25 years of investigations on antioxidants research in foods and biological fluids and critically analyses the merits and limitations of using the total antioxidant capacity (TAC) measurement in the metabolomic era. An enormous bulk of knowledge was produced regarding the antioxidant capacity of foods and large TAC databases were developed. A direct link between a food TAC value and any health benefit is erroneous and has led to several cases of consumer deception. However, the striking epidemiological evidence associating a high dietary TAC with some disease prevention and the availability of well-constructed TAC databases deserve attention and must be taken into account to establish the usefulness of measuring TAC in both foods and biological samples. The in vivo TAC measurement, usually performed in plasma, is influenced by many external factors, such as dietary habits, as well as environmental and behavioural factors, which are integrated towards homeostatic control by fine physiological mechanisms with high inter-individual variability. Therefore, plasma TAC cannot be considered as a unique biomarker of individual antioxidant status. However, the combined evaluation of plasma TAC with known markers of disease, individual metabolism, inflammation and genetics, as well as with markers of gut microbiota composition and activity, may lead to the identification of populations that are more responsive to food/diet TAC. In this framework, the appropriate use of TAC measurement both in food and in vivo can still provide support for the interpretation of complex phenomena and be a tool for sample screening when making a quick decision toward in-depth research investigations.

In foods, the Maillard reaction (MR) and lipid oxidation lead to the formation of several molecules through interrelated chemical pathways. MR and lipid oxidation products were investigated in model oil-in-water emulsions consisting of canola oil, water, and Tween 20, a nonionic surfactant, with glucose and phenylalanine. The presence of 1% Tween 20, either in emulsion or as a control surfactant solution, sped up the formation of N-(1-deoxy-d-fructos-1-yl)-phenylalanine and of phenylacetaldehyde. Overall, the formation of MR products was up to sixteen times higher in emulsions than in an aqueous system without a surfactant. The formation of conjugated dienes, total aldehydes, hexanal, and (Z)-2-octenal was reduced down to six times when MR products were present in the emulsion. These results confirm that the formation of MR intermediates is influenced by the reactants' location, and the presence of a discrete nonpolar environment (oil droplets or surfactant micelles) promotes MR volatile formation through Strecker degradation.

This study describes differences in considerations and value conflicts between mothers living in the North and the South of Italy during snack provision to their 2–7 years old children. Semi-structured interviews with 20 mothers living in the North and 20 mothers living in the South of Italy were conducted. Participants matched on educational level and weight status. Mothers’ considerations in snack provision were grouped into four key themes: health-related, child-related, time-related, and product-related. North Italian mothers showed more health-related considerations while providing a snack compared to mothers living in the South. In case mothers from the South mentioned healthiness as a consideration, it was often related to giving energy. The child-related key theme revealed that a snack needs to be liked by the child, otherwise Italian mothers do not provide it. For the time-related key theme, differences were small between North and South Italian mothers. The product-related key theme showed the brand to be more important for South Italian mothers. Mothers from the North of Italy experienced more value conflicts, all related to health. The current studied showed that even within the same country, geographical differences in mothers’ considerations and value conflicts for providing snacks exist. This implies that snack choice, considerations and values seem to be influenced by tradition and family culture.

This study investigates which values play a role in the decision of mothers about snacks to offer to their young children with a focus on the value conflicts that might occur. The study explores whether national culture is reflected in mothers' values in snack choice for their young children and the related value conflicts. Semi-structured interviews with 67 mothers of 2–7 years old children divided over 4 national cultures (Dutch, Polish, Indonesian and Italian) were conducted. Questions were asked about their values and value conflicts when providing a snack to their young children. Four key themes could be distinguished to cluster the mentioned values. The health-related key theme includes all values that are associated with the healthiness of the product, the child-related key theme all values that connects to the child, the time-related key theme includes the value convenience and the product-related key theme includes all values that are associated with the product itself. Dutch and Polish mothers mostly valued health of the snack, whereas Indonesian and Italian mothers mostly valued the preference of their child. Data also shows specific prevalence between values and nationalities: convenience was very important for Dutch mothers, valuing organic food was typical for Polish mothers, religion played a role for Indonesian mothers, while Italian mothers placed more value on brand compared to the mothers of other cultures. In all cultures, the value conflicts mentioned were mainly related to health.

Objectives: Unhealthy dietary patterns have been associated with colorectal cancer (CRC) onset while Mediterranean Diet (MD) has been proposed for CRC prevention. This study evaluated the effect of a Mediterranean Diet Mix (MD-MIX) on colonic tumors development in A/J mice fed a low-fat (LFD) or a high-fat western diet (HFWD), and injected with the procarcinogen azoxymethane (AOM). Materials and Methods: Forty A/J male mice were randomly assigned into four feeding arms (10 mice/arm; LFD, LFD-MD-MIX, HFWD, HFWD-MD-MIX) to be treated with AOM. Ten mice were exposed to the diets alone (Healthy LFD and Healthy HFWD) to be used as control. Tumor incidence and multiplicity were evaluated at sacrifice. Mucosal fatty acid content and urinary phenolic compounds were assayed by mass spectrometry. Apoptosis was evaluated by TUNEL assay and gene expression markers. Cell proliferation was evaluated by Ki67 immunohistochemistry. Microbiota composition was assessed at different time points by 16S RNA sequencing. Results: A tumor incidence of 100% was obtained in AOM-treated mice. The MD-MIX supplementation was able to reduce the number of colonic lesions in both LFD and HFWD-fed mice and to induce apoptosis, in particular in the LFD-MD-MIX arm. Moreover, a preventive effect on low-grade dysplasia and macroscopical lesions (>1 mm) development was found in HFWD-fed mice together with a regulation of the AOM-driven intestinal dysbiosis. Conclusions: MD-MIX was able to counteract CRC development in mice under different dietary backgrounds through the regulation of apoptosis and gut microbiota.