Impact of dietary carbohydrate, fat, or protein restriction on the human gut microbiome: a systematic review.

Restriction of dietary carbohydrates, fat, and/or protein is often used to reduce body weight and/or treat (metabolic) diseases. Since diet is a key modulator of the human gut microbiome, which plays an important role in health and disease, this review aims to provide an overview of current knowledge of the effects of macronutrient-restricted diets on gut microbial composition and metabolites. A structured search strategy was performed in several databases. After screening for in-and exclusion criteria, 36 articles could be included. Data are included in the results only when supported by at least three independent studies to enhance the reliability of our conclusions. Low-carbohydrate (<30 energy%) diets tended to induce a decrease in the relative abundance of several health-promoting bacteria, such as Bifidobacterium, as well as a reduction in short-chain fatty acid (SCFA) levels in faeces. In contrast, low-fat diets (<30 energy%) increased alpha diversity, faecal SCFA levels, and abundance of some beneficial bacteria, including F. prausnitzii. There was insufficient data to draw conclusions concerning the effects of low-protein (<10 energy%) diets on gut microbiota. Although the data of included studies unveils possible benefits of low-fat and potential drawbacks of low-carbohydrate diets for human gut microbiota, the diversity in study designs made it difficult to draw firm conclusions. Using a more uniform methodology in design, sample processing and sharing raw sequence data could foster our understanding of the effects of macronutrient restriction on gut microbiota composition and metabolic dynamics relevant to health. This systematic review was registered at https://www.crd.york.ac.uk/prospero as CRD42020156929.

Exploring the short-term impact of swapping consumption from standard protein snacks to higher protein snacks on energy intake in social drinkers: Is protein worth a nudge?

Drinking alcoholic beverages stimulates food intake and contributes to the passive overconsumption of dietary energy. As protein is the most satiating of all the macronutrients, increased levels in snacks taken with alcohol have the potential to minimize excess energy consumption. We hypothesized that swapping consumption from retail-available standard protein (SP) snacks to higher protein (HP) snack foods would increase satiety and reduce acute food energy intake in social drinkers. A randomized single-blind crossover trial with 19 healthy participants aged 19-31 years was conducted. Participants attended two separate testing sessions, where they ingested white wine (30 g alcohol) and were offered ad libitum access to either HP snacks with a protein-fortified dip or SP snacks with a dip. There were no significant differences in mean food mass, food energy intake, or subjective appetite ratings between the high and SP snacks (all p > .05). Mean protein intake was significantly increased with HP snacks compared with standard snacks (p < .001). Plasma glucose median incremental area under the curve and mean peak were significantly higher with the SP snacks (all p < .05) but remained within the reference range. This study demonstrated that consumption of a higher amount of protein after a moderate alcohol dose does not result in a change in food mass and energy intake or promote satiety in healthy young adults. The potential for a simple swap to different snack types is unlikely to bring substantial benefits to social drinkers and reduce passive energy consumption.

Efficacy of intradialytic neuromuscular electrical stimulation and oral nutritional supplementation in hemodialysis patients: a multicenter, randomized controlled trial.

Background: Sarcopenia is common in hemodialysis patients. This study aimed to evaluate the effect of simultaneous nutritional support and intradialytic neuromuscular electrical stimulation (NMES) in hemodialysis patients. Methods: We performed a 12-week, multicenter, randomized controlled trial. The participants were randomly assigned to the control group, the protein group (25 g of protein at every dialysis session), the NMES group (intradialytic NMES to quadriceps femoris muscles), and the NMES + P group (NMES with protein supplementation). The primary outcome was the difference in hand grip strength (HGS) and leg muscle strength (LMS) among groups. Secondary outcomes included body composition, physical performance (the 10-m walk test and the timed up and go test [TUG]), and questionnaires about quality of life (QoL), physical activity, and depression. In addition, subgroup analysis was performed by dividing NMES and NMES + P groups into high- and low-intensity NMES groups. Results: Fifty-nine patients completed all the study outcomes. There was no difference in muscle strength (HGS and LMS) and muscle mass among groups. Gait speed improved in NMES and NMES + P groups. Subscale scores for QoL (kidney disease effect, role limitations due to physical or emotional problems, and overall health ratings) improved in the NMES + P group. In subgroup analysis, LMS and TUG improved only in the high-intensity NMES group. Conclusion: In this study, NMES and-/or- protein supplementation did not make a significant difference in HGS and LMS. However, NMES or NMES + P improved functional capacity and QoL. Furthermore, higher NMES was superior in improving LMS and functional capacity.

Effects of a high-protein, increased-fibre, dry diet supplemented with omega-3 fatty acids on quality of life in dogs undergoing chemotherapy.

Quality of life (QOL) in dogs with cancer is a key consideration in the assessment of cancer treatment options. Despite interest in dietary strategies to improve management of oncology patients, there have been very few clinical studies showing the impact of diet on adverse effects of chemotherapy in dogs. This study was a randomised, controlled, double-blinded, multicenter clinical trial to investigate a high-protein, increased-fibre diet supplemented with omega-3 fatty acids, for dogs with cancer undergoing standard-of-care chemotherapy. Client-owned dogs with newly diagnosed grade 2 or higher mast cell tumours (or non-resectable/incompletely resected tumours) or multicentric lymphoma were randomised to receive the test diet (n = 24) or control diet (n = 21) for 8 weeks. Primary outcomes were QOL assessments, faecal scores, and blood concentrations of C-reactive protein and monocyte chemoattractant protein-1. Of 12 QOL parameters, 10 significantly improved from baseline to Week 8 in the test group compared with one in the control group. However, differences between the two groups were only statistically significant for 'frequency of signs of illness' (P = .009). There were no significant differences in the incidence of any adverse events, including gastrointestinal adverse events or clinically significant differences in laboratory parameters or faecal scores between the two groups. The absence of an observed negative impact of the test diet, combined with the magnitude of QOL improvements associated with the diet, suggest that a larger trial is warranted.

The effect of a ketogenic diet on weight loss in CKD: a randomized controlled trial in obese stage G1-3a CKD patients.

This study describes a multicentre randomized controlled trial comparing the effects of a ketogenic diet with a low-energy standard diet containing 0.8 g/kg/day on weight loss and metabolic alterations in adult patients with mild-to-moderate non-diabetic chronic kidney disease (CKD) and mild-to-severe obesity. The study is being conducted to understand the impact of the ketogenic diet on weight loss in these patients, as the existing evidence on the ketogenic diet's effect in CKD patients is limited and inconclusive. The study will enrol mild-to moderate adult CKD patients (Stages G1-3a) with albumin to creatinine ratio ≥200 mg/g, without diabetes, with obesity (body mass index ≥30 kg/m2), and stable body weight and estimated glomerular filtration rate from at least 3 months. The primary outcome will be weight loss at 6 months, and secondary outcomes will include adherence to prescribed dietary regimens, body composition changes, changes in standardized blood pressure measurements, metabolic parameters, lipid profile, liver profile, mineral bone disease biomarkers, and changes in renal function and albuminuria. The findings of this study will contribute to a better understanding of the potential benefits and risks of the ketogenic diet in CKD patients with obesity. The results will help guide future research on the ketogenic diet and renal health.

The effect of source of protein fed during pregnancy and lactation on the development of characteristics of metabolic syndrome in male offspring of obese Wistar rats.

Gestational obesity has major negative impacts on both mothers and their offspring. More than two-thirds of women of reproductive age in the United States are overweight and/or obese. We previously reported that the source of protein in the maternal diet influences the phenotype of offspring born to normal-weight dams. However, whether it has the same effect in obese mothers was unclear. The casein- and soya protein-based diets were fed to obese pregnant Wistar rats and compared for their effects on characteristics of the metabolic syndrome in male offspring. Dams randomized to either a casein (CD) or soya protein (SD) diet (n 12). Pups were weaned to either a CD or SD for 16 weeks. Offspring of SD dams had higher birthweight (P < 0⋅01). Glucose metabolism was not altered at birth but fasting blood glucose (FBG) (P < 0⋅02), insulin (P < 0⋅0002), insulin/glucose ratio (P < 0⋅03), and HOMA-IR index (P < 0⋅0002) were higher in offspring of SD dams at week 17. The pulse rate was higher in dams (P < 0⋅03). Food intake and body weight of offspring were affected by interactive effects of time and dams' diet (P < 0⋅05). Food intake was not influenced by maternal diet, but it was higher in pups weaned to SD dams (P < 0⋅03) The results of this study indicate that although the source of protein in the maternal diet is still an influencing factor in the outcome of the pregnancy in obese mothers, gestational obesity may mask this effect possibly by imposing general detrimental effects on measured parameters regardless of the source of protein in maternal diet.

Nutritional and health benefits and risks of plant-based substitute foods.

Plant-based substitutes (PBS) are seen as a convenient way to transition to a more plant-based diet, but their potential health benefits and nutritional concerns remain debated. Based on a review of the literature, it is concluded here that the primary risk of insufficient nutrient intake with PBS concerns iron and calcium, which are critical to the nutritional value of PBS. Other risks were identified but these would depend on the characteristics of the overall diet, as is the case for iodine in a diet containing no seafood or dairy, and vitamin B12 in a vegetarian/vegan diet. Conversely, the use of PBS is also expected to confer some benefits for long-term health because it would result in higher fibre intakes (in the case of meat PBS) and lower SFA intakes (but higher PUFA/MUFA intakes), but attention should be paid to a potential increase in sodium intake with PBS of meat products. In fact, a recurring finding in this review was that PBS is a very heterogeneous food category involving considerable variations in ingredient and nutrient composition, and whose design could be improved in order to foster nutritional and health benefits. The latter also depend on the animal food that is being replaced and are only deemed likely when PBS replace red meat. The fortification of PBS with key nutrients such as iron and calcium may constitute an actionable public health solution to further shift the balance in favour of PBS in the context of the current dietary transition in western countries.

Association between plant protein intake and grip strength in Koreans aged 50 years or older: Korea National Health and Nutrition Examination Survey 2016-2018.

BACKGROUND/OBJECTIVES: We investigated the association of plant and animal protein intake with grip strength in Koreans aged ≥ 50 yrs. SUBJECTS/METHODS: The data was collected from 3,610 men and 4,691 women (≥ 50 yrs) from the 2016-2018 Korea National Health and Nutrition Examination Survey. We calculated the total energy intake, and the intake of animal and plant protein and collected dietary data using 1-day 24-h dietary recalls. Low grip strength (LGS) was defined as the lowest quintile (men: up to 26.8 kg, women: up to 15.7 kg). The association of protein intake with grip strength was examined using Pearson's correlation and multiple linear regression analysis. RESULTS: The results proved that participants with LGS had lower daily energy, protein and fat intake, and percent energy from protein than those with normal or high grip strength (P < 0.0001). Total energy intake, animal protein, and plant protein were positively associated with grip strength. A higher intake of total plant protein (P for trend = 0.004 for men, 0.05 for women) and legumes, nuts, and seeds (LNS) protein (P for trend = 0.01 for men, 0.02 for women) was significantly associated with a lower prevalence of LGS. However, non-LNS plant protein intake was not associated with LGS (P for trend = 0.10 for men, 0.15 for women). In women, a higher total animal protein intake was significantly associated with decreased LGS (P for trend = 0.03). CONCLUSIONS: Higher total plant protein and LNS protein intake are negatively associated with LGS.

Associations between protein to non-protein ratio and intakes of other dietary components in a cohort aged 65-75 years: the Nutrition for Healthy Living Study.

OBJECTIVE: Diets with a low proportion of energy from protein have shown to cause overconsumption of non-protein energy, known as Protein Leverage. Older adults are susceptible to nutritional inadequacy. The aim was to investigate associations between protein to non-protein ratio (P:NP) and intakes of dietary components and assess the nutritional adequacy of individuals aged 65-75 years from the Nutrition for Healthy Living (NHL) Study. DESIGN: Cross-sectional. Nutritional intakes from seven-day weighed food records were compared with the Nutrient Reference Values for Australia and New Zealand, Australian Guide to Healthy Eating, Australian Dietary Guidelines and World Health Organisation Free Sugar Guidelines. Associations between P:NP and intakes of dietary components were assessed through linear regression analyses. SETTING: NHL Study. PARTICIPANTS: 113 participants. RESULTS: Eighty-eight (59 female and 29 male) with plausible dietary data had a median (interquartile range) age of 69 years (67-71), high education level (86 %) and sources of income apart from the age pension (81 %). Substantial proportions had intakes below recommendations for dairy and alternatives (89 %), wholegrain (89 %) and simultaneously exceeded recommendations for discretionary foods (100 %) and saturated fat (92 %). In adjusted analyses, P:NP (per 1 % increment) was associated with lower intakes of energy, saturated fat, free sugar and discretionary foods and higher intakes of vitamin B12, Zn, meat and alternatives, red meat, poultry and wholegrain % (all P < 0·05). CONCLUSIONS: Higher P:NP was associated with lower intakes of energy, saturated fat, free sugar and discretionary. Our study revealed substantial nutritional inadequacy in this group of higher socio-economic individuals aged 65-75 years.

Nutrient content and cost of canned and dried legumes and plant-based meat analogues available in New Zealand supermarkets.

AIMS: Plant-based eating patterns are recommended for human and planetary health. Plant-based protein sources in supermarkets include traditional options and plant-based meat analogues. This cross-sectional survey examined the nutritional content, healthiness, cost and labelling of these products. METHODS: Nutrient content and claims on canned legumes (plain [N = 64] and flavoured [N = 25]), canned baked beans (N = 23), dried legumes (N = 21), tofu (plain [N = 8] and flavoured [N = 5]), falafels (N = 14), meat analogues (meat-free burgers [N = 11], meat-free sausages [N = 10] and 'other' meat-free products [N = 20]) were obtained from a database of packaged foods in New Zealand. Mean (SD) energy, protein, total fat, saturated fat, sodium and dietary fibre content (per 100 g) was calculated for each category. Healthiness was assessed using an estimated Health Star Rating (Rating ≥3.5 considered 'healthy'). Product data were linked with household purchasing data from the 2019 Nielsen IQ® consumer panel to calculate mean purchase price/100 g/category. The number and type of nutrition claims were compared across categories. RESULTS: The highest mean protein content was 'other' meat-free products (14.8 ± 6.9 g/100 g). Meat-free sausages had the highest sodium and saturated fat content (643 ± 148 mg/100 g, 3.7 ± 4.5 g/100 g). Overall, few meat analogues (N = 5, 12%) scored an estimated Health Star Rating ≥3.5. Dried legumes were the cheapest plant protein (mean ± SD) purchase price = NZ $0.30 ± 0.16/100 g), compared with 'other' meat-free products (purchase price = NZ $2.57 ± 0.88/100 g). The most common nutrition claims on meat analogues were about protein content. Dietary fibre claims were the most common on canned and dried legumes. CONCLUSION: Meat analogues offer convenience, however, may be less healthy and more expensive than traditional plant-based proteins. This study assists dietitians in providing accurate consumer messaging about healthy plant-based proteins.

Patients with Diverticular Disease Have Different Dietary Habits Compared to Control Subjects: Results from an Observational Italian Study.

The role of dietary habits as risk factor for the development of diverticular complications has strongly emerged in the last years. We aimed to evaluate possible differences in dietary habits between patients with diverticular disease (DD) and matched controls without diverticula. Dietary habits were obtained from standardized food frequency questionnaires collected at entry to the Diverticular Disease Registry (REMAD). We compared controls (C) (n = 119) with asymptomatic diverticulosis (D) (n = 344), symptomatic uncomplicated diverticular disease (SUDD) (n = 154) and previous diverticulitis (PD) (n = 83) patients, in terms of daily calories, macro and micronutrients and dietary vitamins. Daily kcal intake and lipids, both saturated and unsaturated, were significantly lower in patients with DD than C. Total protein consumption was lower in PD than D, with differing consumption of unprocessed red meat, white meat and eggs between groups. Consumption of fibre, both soluble and insoluble, was lower in patients with PD compared to patients with SUDD, D and C, whereas dietary vitamins A, C, D and E and Oxygen Radical Adsorbance Capacity index were lower in all DD groups compared to C. This observational study showed that DD patients have different dietary habits, mainly in terms of caloric, fat, fibre and vitamin intake, compared to control subjects.

Temperature- and Diet-Induced Plasticity of Growth and Digestive Enzymes Activity in Spongy Moth Larvae.

Temperature and food quality are the most important environmental factors determining the performance of herbivorous insects. The objective of our study was to evaluate the responses of the spongy moth (formerly known as the gypsy moth) [Lymantria dispar L. (Lepidoptera: Erebidae)] to simultaneous variation in these two factors. From hatching to the fourth instar, larvae were exposed to three temperatures (19 °C, 23 °C, and 28 °C) and fed four artificial diets that differed in protein (P) and carbohydrate (C) content. Within each temperature regime, the effects of the nutrient content (P+C) and ratio (P:C) on development duration, larval mass, growth rate, and activities of digestive proteases, carbohydrases, and lipase were examined. It was found that temperature and food quality had a significant effect on the fitness-related traits and digestive physiology of the larvae. The greatest mass and highest growth rate were obtained at 28 °C on a high-protein low-carbohydrate diet. A homeostatic increase in activity was observed for total protease, trypsin, and amylase in response to low substrate levels in the diet. A significant modulation of overall enzyme activities in response to 28 °C was detected only with a low diet quality. A decrease in the nutrient content and P:C ratio only affected the coordination of enzyme activities at 28 °C, as indicated by the significantly altered correlation matrices. Multiple linear regression analysis showed that variation in fitness traits in response to different rearing conditions could be explained by variation in digestion. Our results contribute to the understanding of the role of digestive enzymes in post-ingestive nutrient balancing.

Effect of unsaturated fat and protein intake on liver fat in people at risk of unhealthy aging: 1-year results of a randomized controlled trial.

BACKGROUND: Short-term trials indicate improvement of intrahepatic lipids (IHLs) and metabolism by dietary protein or unsaturated fatty acids (UFAs) beyond weight loss. OBJECTIVES: We aimed to assess the effect of a dietary intervention high in protein and UFAs on IHLs and metabolic outcome after 12 mo, as long-term effects of such a combined intervention are unknown. METHODS: Within a 36-mo randomized controlled trial, eligible subjects (aged 50 to 80 y, ≥1 risk factor for unhealthy aging) were randomly assigned to either intervention group (IG) with high intake of mono-/poly-UFAs [15-20 percent of total energy (%E)/10%-15%E, respectively], plant protein (15%-25%E), and fiber (≥30 g/d), or control group [CG, usual care, dietary recommendations of the German Nutrition Society (fat 30%E/carbohydrates 55%E/protein 15%E)]. Stratification criteria were sex, known cardiovascular disease, heart failure, arterial hypertension, type 2 diabetes, and cognitive or physical impairment. Nutritional counseling and supplementation of foods mirroring the intended dietary pattern were performed in the IG. Diet-induced effects on IHLs, analyzed by magnetic resonance spectroscopy, as well as on lipid and glucose metabolism were predefined secondary endpoints. RESULTS: IHL content was analyzed in 346 subjects without significant alcohol consumption at baseline and in 258 subjects after 12 mo. Adjusted for weight loss, sex, and age, we observed a comparable decline of IHLs in IG and CG (-33.3%; 95% CI: -49.3, -12.3%; n = 128 compared with -21.8%; 95% CI: -39.7, 1.5%; n = 130; P = 0.179), an effect that became significant by comparing adherent IG subjects to adherent CG subjects (-42.1%; 95% CI: -58.1, -20.1%; n = 88 compared with -22.2%; 95% CI: -40.7, 2.0%; n = 121; P = 0.013). Compared with the CG, decline of LDL cholesterol (LDL-C) and total cholesterol (TC) was stronger in the IG (for LDL-C P = 0.019, for TC P = 0.010). Both groups decreased in triglycerides and insulin resistance (P for difference between groups P = 0.799 and P = 0.124, respectively). CONCLUSIONS: Diets enriched with protein and UFAs have beneficial long-term effects on liver fat and lipid metabolism in adherent older subjects. This study was registered at the German Clinical Trials Register, https://www.drks.de/drks_web/setLocale_EN.do, DRKS00010049. Am J Clin Nutr 20XX;xx:xx-xx.

A randomised crossover trial: Exploring the dose-response effect of carbohydrate restriction on glycaemia in people with well-controlled type 2 diabetes.

BACKGROUND: Trials investigating the role of carbohydrate restriction in the management of glycaemia in type 2 diabetes (T2D) have been confounded by multiple factors, including degree of calorie restriction and dietary protein content, as well as by no clear definition of a low-carbohydrate diet. The present study aimed to provide insight into the relationship between carbohydrate restriction and glycaemia by testing the effect of varying doses of carbohydrate on continuous glucose concentrations within a range of intakes defined as low-carbohydrate at the same time as controlling for confounding factors. METHODS: This was a randomised crossover trial in participants with T2D (HbA1c: 6.6 ± 0.6%, 49 ± 0.9 mmol mol-1 ) testing five different 6-day eucaloric dietary treatments with varying carbohydrate content (10%, 15%, 20%, 25%, and 30% kcal). Diets exchanged %kcal from carbohydrate with fat, keeping protein constant at 15% kcal. Daily self-weighing was employed to ensure weight stability throughout each treatment arm. Between dietary treatments, participants underwent a washout period of at least 7 days and were advised to maintain their habitual diet. Glycaemic control was assessed using a continuous glucose monitoring device. RESULTS: Twelve participants completed the study. There were no differences in 24-h and post-prandial sensor glucose concentrations between the 30 and 10%kcal doses (7.4 ± 1.1 mmol L-1 vs. 7.6 ± 1.3 mmol L-1 [p = 0.28] and 8.1 ± 1.5 mmol L-1 vs. 8.5 ± 1.4 mmol L-1 [p = 0.28], respectively). In our exploratory analyses, we did not find any dose-response relationship between carbohydrate intake and glycaemia. A small amount of weight loss occurred in each treatment arm (range: 0.4-1.1 kg over the 6 days) but adjusting for these differences did not influence the primary or secondary outcomes. CONCLUSIONS: Modest changes in dietary carbohydrate content in the absence of weight loss at the same time as keeping dietary protein intake constant do not appear to influence glucose concentrations in people with well-controlled T2D. SUMMARY: This study randomised people with T2D to receive five different doses of carbohydrate from 10% to 30% of calories in random order to see what effect it had on their blood glucose.

Association of dietary proteins with serum creatinine and estimated glomerular filtration rate in a general population sample: the CHRIS study.

BACKGROUND: Diet is known to affect kidney function. However, population-based studies provide contrasting evidence, resulting in a poor understanding of the effect of proteins from specific foods on kidney health. METHODS: We analyzed the effect of total daily protein intake (TDPI) and source-specific daily protein intake (DPI) on fasting serum creatinine (SCr) and estimated glomerular filtration rate (eGFR) in the Cooperative Health Research In South Tyrol (CHRIS) cross-sectional study (n = 5889), using the GA2LEN food frequency questionnaire for TDPI and DPI estimation. We fitted multivariable adjusted mixed models of SCr and eGFR on TDPI and DPI quartiles (Q1-Q4) in the overall sample, and after removing individuals with known hypertension, diabetes or chronic kidney disease (CKD). RESULTS: Higher TDPI as well as DPI from overall animal sources, fish, and poultry, were associated with higher SCr (trend test p, ptrend < 0.01), with larger effect after excluding individuals with known hypertension, diabetes or CKD. The eGFR was lower at higher TDPI (Q4 vs Q1: - 1.6 ml/min/1.73 m2; 95% CI - 2.5, - 0.7; ptrend = 3e-4) and DPI from fish (Q4 vs Q1: - 2.1 ml/min/1.73 m2; 95% CI - 2.9, - 1.20; ptrend = 4.3e-6), overall animal source (Q4 vs Q1: - 1.6 ml/min/1.73 m2; 95% CI -2.5, - 0.8), processed meat (Q4 vs Q1: - 1.4 ml/min/1.73 m2; ptrend = 0.027), red meat, offal and processed meat (Q4 vs Q1: - 1.4 ml/min/1.73 m2; ptrend = 0.015) and poultry (Q4 vs Q1: - 0.9 ml/min/1.73 m2; ptrend = 0.015). CONCLUSIONS: TDPI and DPI from specific animal sources were positively associated with SCr and negatively associated with eGFR. Lacking an alternative marker of kidney function, confounding involving muscle mass metabolism cannot be fully excluded.

Potential implications of oxidative modification on dietary protein nutritional value: A review.

During food processing and storage, proteins are sensitive to oxidative modification, changing the structural characteristics and functional properties. Recently, the impact of dietary protein oxidation on body health has drawn increasing attention. However, few reviews summarized and highlighted the impact of oxidative modification on the nutritional value of dietary proteins and related mechanisms. Therefore, this review seeks to give an updated discussion of the effects of oxidative modification on the structural characteristics and nutritional value of dietary proteins, and elucidate the interaction with gut microbiota, intestinal tissues, and organs. Additionally, the specific mechanisms related to pathological conditions are also characterized. Dietary protein oxidation during food processing and storage change protein structure, which further influences the in vitro digestion properties of proteins. In vivo research demonstrates that oxidized dietary proteins threaten body health via complicated pathways and affect the intestinal microenvironment via gut microbiota, metabolites, and intestinal morphology. This review highlights the influence of oxidative modification on the nutritional value of dietary proteins based on organs and the intestinal tract, and illustrates the necessity of appropriate experimental design for comprehensively exploring the health consequences of oxidized dietary proteins.

Remission of Acute Food Protein-Induced Enterocolitis Syndrome Confirmed by Oral Food Challenges in Japan.

The oral food challenge test (OFC) is the gold standard for evaluating the remission of food protein-induced enterocolitis syndrome (FPIES). Few acute FPIES remissions confirmed by OFC were reported. This study aimed to examine the OFC for Japanese children with acute FPIES to evaluate its remission. A retrospective cohort study was performed on children with acute FPIES with remission evaluation by OFC based on one food challenge dose (1/50, 1/10, 1/2, and full dose per day). Acute FPIES remission was observed in 65.2% of patients (15/23 patients). Vomiting episodes occurred with 1/50 full doses on the first day among 75% of positive patients. The median duration between the onset and OFC was 14 months (IQR, 8-24 months). Soy was the most common causative food, followed by egg yolk, milk, and wheat. All patients could receive OFC safely without intensive care unit care, based on the FPIES OFC protocol. The remission rate of acute FPIES was high. However, vomiting episodes commonly occurred with 1/50 full doses on the first day. This study suggested that our OFC protocol for acute FPIES was safe and feasible, but it might be safer for some patients to start at a minimal loading dose.

The Effect of Fava Bean (Vicia faba L.) Protein Ingestion on Myofibrillar Protein Synthesis at Rest and after Resistance Exercise in Healthy, Young Men and Women: A Randomised Control Trial.

The aim of the present study was to evaluate the effect of feeding fava bean (Vicia faba L.) protein (FBP) on resting and post-exercise myofibrillar fractional synthetic rate (myoFSR). In a parallel, double-blind, randomised control trial, sixteen young, healthy recreationally active adults (age = 25 (5) years, body mass = 70 (15) kg, stature = 1.72 (0.11) m, mean (SD)) ingested 0.33 g·kg-1 FBP (n = 8) or a negative control (CON, i.e., EAA-free mixture) (n = 8), immediately after a bout of unilateral knee-extensor resistance exercise. Plasma, saliva, and m. vastus lateralis muscle samples were obtained pre-ingestion and 3 h post-ingestion. MyoFSR was calculated via deuterium labelling of myofibrillar-bound alanine, measured by gas chromatography-pyrolysis-isotope ratio mass spectrometry (GC-Pyr-IRMS). Resistance exercise increased myoFSR (p = 0.012). However, ingestion of FBP did not evoke an increase in resting (FBP 29 [-5, 63] vs. CON 12 [-25, 49]%, p = 0.409, mean % change [95% CI]) or post-exercise (FBP 78 [33, 123]% vs. CON 58 [9, 107]%, p = 0.732) myoFSR. Ingestion of 0.33 g·kg-1 of FBP does not appear to enhance resting or post-exercise myoFSR in young, healthy, recreationally active adults.

Osteo-modulatory dietary proteins and peptides: A concise review.

The integrity of the bone is dependent on the strict balance between osteoclastogenesis and osteoblastogenesis, and any imbalance results in bone diseases. Dietary proteins (DP) have been shown to promote osteogenesis while inhibiting bone resorption in cultured osteoblasts, and in animal models of bone diseases such as ovariectomy, 1α,25-dihydroxy-vitamin D3 (VD3), and prostaglandin E2 (PGE2)-induced bone resorption. Hydrolysis of some of these DPs with osteo-modulatory properties has been shown to generate hydrolysates with bioactive peptides that exhibit higher osteo-modulatory properties in comparison to intact (parent) proteins. The higher bioactivity of the isolated peptides and protein hydrolysates compared to intact proteins indicates that the osteo-modulatory properties are dependent on the degree of exposure of the functional groups of amino acid residues involved in target interaction. This review provides an overview of the preparation of DP and select peptides with osteo-modulatory properties, and summarizes the potential underlying mechanisms of action through which the bioactive peptides help maintain bone health. PRACTICAL APPLICATIONS: Bone diseases such as osteoporosis (OP), osteoarthritis (OA), bone cancer (BC), and others have negative impacts on the quality of life, especially in older women after menopause. Current drugs used in treating many bone diseases such as bisphosphonates, anabolic steroids, and selective estrogen receptor modulators have been limited by worrisome adverse effects such as organ toxicity, increased risk of cancer, and cardiovascular abnormalities, and gastrointestinal discomfort. There is growing scientific evidence that certain multifunctional dietary proteins and bioactive peptides may positively modulate bone health by modifying risk factors for bone diseases including inflammation, oxidative stress, hyperlipidemia, and hyperglycemia.

In Vivo and In Vitro Comparison of the DPP-IV Inhibitory Potential of Food Proteins from Different Origins after Gastrointestinal Digestion.

Dipeptidyl-peptidase IV (DPP-IV) plays an essential role in glucose metabolism by inactivating incretins. In this context, food-protein-derived DPP-IV inhibitors are promising glycemic regulators which may act by preventing the onset of type 2 diabetes in personalized nutrition. In this study, the DPP-IV-inhibitory potential of seven proteins from diverse origins was compared for the first time in vitro and in vivo in rat plasma after the intestinal barrier (IB) passage of the indigested proteins. The DPP-IV-inhibitory potentials of bovine hemoglobin, caseins, chicken ovalbumin, fish gelatin, and pea proteins were determined in rat plasma thirty minutes after oral administration. In parallel, these proteins, together with bovine whey and gluten proteins, were digested using the harmonized INFOGEST protocol adapted for proteins. The DPP-IV half-maximal inhibitory concentration (IC50) was determined in situ using Caco-2 cells. The DPP-IV-inhibitory activity was also measured after IB passage using a Caco2/HT29-MTX mixed-cell model. The peptide profiles were analyzed using reversed-phase high-performance liquid chromatography tandem mass spectrometry (RP-HPLC-MS/MS) with MS data bioinformatics management, and the IC50 of the identified peptides was predicted in silico. The in vitro and in vivo DPP-IV-inhibitory activity of the proteins differed according to their origin. Vegetable proteins and hemoglobin yielded the highest DPP-IV-inhibitory activity in vivo. However, no correlation was found between the in vivo and in vitro results. This may be partially explained by the differences between the peptidome analysis and the in silico predictions, as well as the study complexity.