In vivo imaging of intragastric gelation and its effect on satiety in humans

The therapeutic effect and possible mechanisms of alginate oligosaccharide on metabolic syndrome by regulating gut microbiota

Metabolic syndrome (MetS) is a disease condition incorporating the abnormal accumulation of various metabolic components, including overweight or abdominal obesity, insulin resistance and abnormal glucose tolerance, hypertension, atherosclerosis, or dyslipidemia. It has been proved that the gut microbiota and microbial-derived products play an important role in regulating lipid metabolism and thus the onset and development of MetS. Previous studies have demonstrated that oligosaccharides with prebiotic effects, such as chitosan oligosaccharides, can regulate the structure of the microbial community and its derived products to control weight and reduce MetS associated with obesity. Alginate oligosaccharides (AOS), natural products extracted from degraded alginate salts with high solubility and extensive biological activity, have also been found to modulate gut microbiota. This review aims to summarize experimental evidence on the positive effects of AOS on different types of MetS while providing insights into mechanisms through which AOS regulates gut microbiota for preventing and treating MetS.

Edible hydrogel with dual network structure for weight management

Obesity, a global health crisis, is fueled by shifts in behavior and environmental factors, notably increased consumption of energy-dense processed foods and inadequate dietary fiber. Traditional weight loss methods pose safety challenges. Sodium carboxymethylcellulose (CMC), a promising dietary fiber supplement, aids weight management. However, CMC-based hydrogels have mechanical weaknesses and poor gastrointestinal retention. A new dual-network structured hydrogel here was introduced to address these issues, maintaining volume and elasticity in the digestive system without adding calories, reducing caloric density, and enhancing food elasticity for prolonged satiety. The study assessed four distinct hydrogels, analyzing their mechanical characteristics under simulated gastrointestinal conditions and biomimetic digestion to identify promising options for clinical development. This dual-network hydrogel exhibits a mechanical strength up to 100 times that of the original gel, while its swelling rate throughout the digestion process is approximately twice that of the original gel. This offers a potential solution for obesity management, providing sustained satiety and addressing the mechanical deficiencies of current hydrogels within the digestive system.

Regulation of glycose and lipid metabolism and application based on the colloidal nutrition science properties of konjac glucomannan: A comprehensive review

The physicochemical properties of dietary fiber in the gastrointestinal tract, such as hydration properties, adsorption properties, rheological properties, have an important influence on the physiological process of host digestion and absorption, leading to the differences in satiety and glucose and lipid metabolisms. Based on the diversified physicochemical properties of konjac glucomannan (KGM), it is meaningful to review the relationship of structural characteristics, physicochemical properties and glycose and lipid metabolism. Firstly, this paper bypassed the category of intestinal microbes, and explained the potential of dietary fiber in regulating glucose and lipid metabolism during nutrient digestion and absorption from the perspective of colloidal nutrition. Secondly, the modification methods of KGM to regulate its physicochemical properties were discussed and the relationship between KGM's molecular structure types and glycose and lipid metabolism were summarized. Finally, based on the characteristics of KGM, the application of KGM in the main material and ingredients of fat reduction food was reviewed. We hope this work could provide theoretical basis for the study of dietary fiber colloid nutrition science.

Preparation of a novel expandable konjac fiber at different freezing temperatures and exploration of its digestion regulation functions

A new form of konjac fiber was successfully prepared, and it could instantaneously expand when in contact with the digestive fluid. The expanded konjac fiber could inhibit the digestion of the ingested food by competing with the substrate for digestive enzymes and space. The konjac fiber with desirable physical properties was obtained at 4 different freezing temperatures (-20 °C, -40 °C, -80 °C, and -196 °C), and the digestion regulation mechanisms of these fibers were systematically explored. The results showed that the konjac fiber prepared at -20 °C displayed an outstanding performance in delaying gastric emptying and preventing intestinal starch hydrolysis, while the fiber prepared under liquid nitrogen conditions (-196 °C) showed the weakest digestion regulation ability. However, the digestion regulation ability of this novel fiber was highly related to the food rheological property, and it exhibited a stronger interference effect on high-viscosity food. Our novel konjac fibers exhibited a great digestion regulation potential. Our findings provide valuable references for the development of dietary fiber-based satiety-enhancing functional foods.

A comparative, randomised MRI study of the physiological and appetitive responses to gelling (alginate) and non-gelling nasogastric tube feeds in healthy men

Inclusion in nasogastric tube feeds (NGTF) of acid-sensitive, seaweed-derived alginate, expected to form a reversible gel in the stomach, may create a more normal intragastric state and modified gastrointestinal responses. This may ameliorate NGTF-associated risk of diarrhoea, upper gastrointestinal symptoms and appetite suppression. In a randomised, crossover, comparison study, undertaken in twelve healthy males, an alginate-containing feed (F + ALG) or one that was alginate-free (F-ALG) (300 ml) was given over 1 h with a 7-14-d washout period between treatments. Baseline and for 4-h post-feed initiation, MRI measurements were made to establish small bowel water content (SBWC), gastric contents volume (GCV) and appearance, and superior mesenteric artery blood flux. Blood glucose and gut peptides were measured. Subjective appetite and upper gastrointestinal symptoms scores were obtained. Ad libitum pasta consumption 3-h post-feeding was measured. F + ALG exhibited a gastric appearance consistent with gelling surrounded by a freely mobile water halo. Significant main effects of feed were seen for SBWC (P = 0·03) and peptide YY (PYY) (P = 0·004) which were attributed to generally higher values for SBWC with F + ALG (max difference between adjusted means 72 ml at 210 min) and generally lower values for PYY with F + ALG. GCV showed a faster reduction with F + ALG, less between-participant variation and a feed-by-time interaction (P = 0·04). Feed-by-time interactions were also seen with glucagon-like-peptide 1 (GLP-1) (P = 0·02) and glucose-dependent insulinotropic polypeptide (GIP) (P = 0·002), both showing a blunted response with F + ALG. Apparent intragastric gelling with F + ALG and subsequent differences in gastrointestinal and endocrine responses have been demonstrated between an alginate-containing and alginate-free feed.

Supplement of Caulerpa lentillifera polysaccharide by pre-prandial gavage and free feeding demonstrates differences to prevent obesity and gut microbiota disturbance in mice

BACKGROUND

Caulerpa lentillifera has received extensive attention regarding expansion of its farming and increasing consumption. In our previous study, the structure of C. lentillifera polysaccharide (CLP) was elucidated. However, little information is available about its health effects. In this study, the anti-obesity effect of CLP was investigated by using a high-fat diet-induced obese mice model with two different supplementation methods.

RESULTS

In vitro simulated digestion results showed that CLP significantly decreased the lipid digestibility and induced the lipid droplets aggregation in the intestinal stage to inhibit the absorption of lipids. As revealed by 16S ribosomal RNA sequencing and non-targeted metabolomics, supplement of CLP by both pre-prandial gavage and free feeding patterns effectively prevented mice obesity via ameliorating intestinal flora disturbance and regulating bile acids circulation metabolism. Of note was that CLP administration had no effect on short-chain fatty acids production, suggesting the anti-obesity effect was uncorrelated with their production. Moreover, pre-prandial administration of CLP had a better anti-obesity effect in lowering body weight and serum lipid levels, but the free feeding resulted in a higher α-diversity of gut microbiota.

CONCLUSION

The findings of this study indicate that CLP could be a potential anti-obesity nutraceutical and that pre-prandial supplement of CLP may be a better intake method to exhibit its hypolipidemic effect. © 2022 Society of Chemical Industry.

Incorporating dietary fiber from fruit and vegetable waste in meat products: a systematic approach for sustainable meat processing and improving the functional, nutritional and health attributes

Background

Every year, the food business produces a sizeable amount of waste, including the portions of fruits and vegetables that are inedible, and those that have reached a stage where they are no longer suitable for human consumption. These by-products comprise of components such as natural antioxidants (polyphenols, carotenoid etc.), dietary fiber, and other trace elements, which can provide functionality to food. Due to changing lifestyles, there is an increased demand for ready-to-eat products like sausages, salami, and meat patties. In this line, meat products like buffalo meat sausages and patties are also gaining the interest of consumers because of their rich taste. Meat, however, has a high percentage of fat and is totally deprived of dietary fiber, which poses severe health problems like cardiovascular (CV) and gastrointestinal diseases. The health-conscious consumer is becoming increasingly aware of the importance of balancing flavor and nutrition. Therefore, to overcome this problem, several fruit and vegetable wastes from their respective industries can be successfully incorporated into meat products that provide dietary fiber and play the role of natural antioxidants; this will slow down lipid oxidation and increase the shelf-life of meat products.

Methodology

Extensive literature searches have been performed using various scientific search engines. We collected relevant and informative data from subject-specific and recent literature on sustainable food processing of wasted food products. We also looked into the various applications of waste fruit and vegetable products, including cereals, when they are incorporated into meat and meat products. All relevant searches meeting the criteria were included in this review, and exclusion criteria were also set.

Results

The pomace and peels of fruits like grapes, pomegranates, cauliflower, sweet lime, and other citrus are some of the most commonly used fruit and vegetable by-products. These vegetable by-products help inhibit oxidation (of both lipids and proteins) and the growth of pathogenic and spoilage bacteria, all without altering the consumer's acceptability of the product on a sensory level. When included in meat products, these by-products have the potential to improve the overall product quality and lengthen its shelf-life under certain circumstances.

Conclusion

Cost-effective and easily accessible by-products from the fruit and vegetable processing industries can be used in meat products to enhance their quality features (physicochemical, microbial, sensory, and textural aspects) and health benefits. Additionally, this will provides environmental food sustainability by lowering waste disposal and improving the food's functional efficacy.

The role of dietary fibers in regulating appetite, an overview of mechanisms and weight consequences

Dietary fibers prevent obesity through reduction of hunger and prolongation of satiety. A number of mechanical and endocrine signals from gastrointestinal tract are stimulated by fibers and their fermentation products, reach regions of brain involved in the regulation of appetite, and ultimately reduce food intake. Gastric distention, delayed gastric emptying, prevention of hypoglycemic, increased amounts of unabsorbed nutrients reaching to the ileum, and stimulation of enteroendocrine cells for secretion of cholecystokinin, glucagon-like peptide-1 (GLP-1), and peptide YY are among mechanisms of fibers in decreasing hunger and prolongation of satiety. Fermentation of fibers produces short-chain fatty acids that also stimulates enteroendocrine cells to secrete GLP-1 and PYY. Randomized controlled trials have shown reductions in energy intake and body weight along with increased satiation and reduced hunger following consumption of fibers. Prospective cohort studies have confirmed these results but the extent of weight loss in some studies has been small. Controversies exist between studies particularly for the effect of fibers on the gastrointestinal hormones, subsequent food intake, and the resultant weight loss. More studies are needed before a clear conclusion can be drawn especially for the effect of fibers on appetite-related hormones and weight loss.

Insights into the constellating drivers of satiety impacting dietary patterns and lifestyle

Food intake and body weight regulation are of special interest for meeting today's lifestyle essential requirements. Since balanced energy intake and expenditure are crucial for healthy living, high levels of energy intake are associated with obesity. Hence, regulation of energy intake occurs through short- and long-term signals as complex central and peripheral physiological signals control food intake. This work aims to explore and compile the main factors influencing satiating efficiency of foods by updating recent knowledge to point out new perspectives on the potential drivers of satiety interfering with food intake regulation. Human internal factors such as genetics, gender, age, nutritional status, gastrointestinal satiety signals, gut enzymes, gastric emptying rate, gut microbiota, individual behavioral response to foods, sleep and circadian rhythms are likely to be important in determining satiety. Besides, the external factors (environmental and behavioral) impacting satiety efficiency are highlighted. Based on mechanisms related to food consumption and dietary patterns several physical, physiological, and psychological factors affect satiety or satiation. A complex network of endocrine and neuroendocrine mechanisms controls the satiety pathways. In response to food intake and other behavioral cues, gut signals enable endocrine systems to target the brain. Intestinal and gastric signals interact with neural pathways in the central nervous system to halt eating or induce satiety. Moreover, complex food composition and structures result in considerable variation in satiety responses for different food groups. A better understanding of foods and factors impacting the efficiency of satiety could be helpful in making smart food choices and dietary recommendations for a healthy lifestyle based on updated scientific evidence.

The Effect of Sodium Alginate and Pectin Added to a Carbohydrate Beverage on Endurance Performance, Substrate Oxidation and Blood Glucose Concentration: A Systematic Review and Meta-analysis

INTRODUCTION

Scientific and public interest in the potential ergogenic effects of sodium alginate added to a carbohydrate (CHO) beverage has increased in the last ~ 5 years. Despite an extensive use of this technology by elite athletes and recent research into the potential effects, there has been no meta-analysis to objectively elucidate the effects of adding sodium alginate to a CHO beverage on parameters relevant to exercise performance and to highlight gaps in the literature.

METHODS

Three literature databases were systematically searched for studies investigating the effects of sodium alginate added to CHO beverage during prolonged, endurance exercise in healthy athletes. For the systematic review, the PROSPERO guidelines were followed, and risk assessment was made using the Cochrane collaboration's tool for assessing the risk of bias. Additionally, a random-effects meta-analysis model was used to determine the standardised mean difference between a CHO beverage containing sodium alginate and an isocaloric control for performance, whole-body CHO oxidation and blood glucose concentration.

RESULTS

Ten studies were reviewed systematically, of which seven were included within the meta-analysis. For each variable, there was homogeneity between studies for performance (n = 5 studies; I² = 0%), CHO oxidation (n = 7 studies; I² = 0%) and blood glucose concentration (n = 7 studies; I² = 0%). When compared with an isocaloric control, the meta-analysis demonstrated that there is no difference in performance (Z = 0.54, p = 0.59), CHO oxidation (Z = 0.34, p = 0.71) and blood glucose concentration (Z = 0.44, p = 0.66) when ingesting a CHO beverage containing sodium alginate. The systematic review revealed that several of the included studies did not use sufficient exercise intensity to elicit significant gastrointestinal disturbances or demonstrate any ergogenic benefit of CHO ingestion. Risk of bias was generally low across the included studies.

CONCLUSIONS

This systematic review and meta-analysis demonstrate that the current literature indicates no benefit of adding sodium alginate to a CHO beverage during exercise. Further research is required, however, before firm conclusions are drawn considering the range of exercise intensities, feeding rates and the apparent lack of benefit of CHO reported in the current literature investigating sodium alginate.

Overview of the Composition of Whole Grains’ Phenolic Acids and Dietary Fibre and Their Effect on Chronic Non-Communicable Diseases

Chronic non-communicable diseases are the major cause of death globally. Whole grains are recommended in dietary guidelines worldwide due to increasing evidence that their consumption can improve health beyond just providing energy and nutrients. Epidemiological studies have suggested that the incorporation of whole grains, as part of a healthy diet, plays a key role in reducing one’s risk for cardiovascular diseases (CVDs), obesity, type 2 diabetes (T2D) and cancer. Phenolic acids and dietary fibre are important components found in whole grains that are largely responsible for these health advantages. Both phenolic acids and dietary fibre, which are predominantly present in the bran layer, are abundant in whole-grain cereals and pseudo-cereals. Several studies indicate that whole grain dietary fibre and phenolic acids are linked to health regulation. The main focus of this study is two-fold. First, we provide an overview of phenolic acids and dietary fibres found in whole grains (wheat, barley, oats, rice and buckwheat). Second, we review existing literature on the linkages between the consumption of whole grains and the development of the following chronic non-communicable diseases: CVDs, obesity, T2D and cancer. Altogether, scientific evidence that the intake of whole grains reduces the risk of certain chronic non-communicable disease is encouraging but not convincing. Based on previous studies, the current review encourages further research to cover the gap between the emerging science of whole grains and human health.

Sugar-sweetened beverages, effects on appetite and public health strategies to reduce the consumption among children: a review

Sugar-sweetened beverages (SSBs) consumption have been of public health concern and a target of interventions due to their high consumption and burden in health-related consequences, particularly in children and adolescents. SSBs provide high energy intake with low nutritional value and are a major contributor for added and free sugars intake of Portuguese in all age-groups, especially adolescents. Despite its recognized effect on weight gain, it might also disrupt appetite regulation. Research on the effect of SSBs on appetitive traits is still scarce and unclear, and the current knowledge of these potential effects will be discussed in this review. This review also aims to describe public health strategies implemented to decrease SSBs consumption among children, particularly in Portugal, such as: (i) implemented taxation measures and its impact in sales and in preventable cases of disease and death, (ii) marketing regulations applied to children and adolescents, and ultimately (iii) the intention of application of a single Front-of-Package labeling system in all countries, aiming to increase consumers’ food literacy.

Seaweeds as Ingredients to Lower Glycemic Potency of Cereal Foods Synergistically-A Perspective

Seaweeds are traditional food ingredients mainly in seaside regions. Modern food science and nutrition researchers have identified seaweed as a source of functional nutrients, such as dietary soluble and insoluble fibers, proteins, omega-3 fatty acids, prebiotic polysaccharides, polyphenols, and carotenoids. Owing to the rich nutrients, seaweeds and seaweed extract can be used as functional ingredients by modifying the nutrients composition to reduce the proportion of available carbohydrates, delaying the gastric emptying time and the absorption rate of glucose by increasing the digesta viscosity, and attenuating the digesting rate by blocking the activity of digestive enzymes. This review presents the concept of using seaweed as unconventional ingredients that can function synergistically to reduce the glycemic potency of cereal products.

An evolving view on food viscosity regulating gastric emptying

Viscosity is a property of most foods. The consumption of the high-viscosity food is associated with a variety of physiological responses, one of which is their ability to regulate gastric emptying and modulate postprandial glycemic response. Gastric emptying has been proven to be a key step affecting the digestion and absorption of food, whereas, the relationship between viscosity and gastric emptying is still far away from being understood. Here, we reviewed the factors that influence food viscosity and food viscosity changes during digestion. Besides, the effect of food viscosity on gastric emptying and food-viscosity-physiological response were highlighted. Finally, "quantitative relationship" of viscosity and gastric emptying was discussed. This review can contribute to the understanding that how food viscosity affects gastric emptying, and help for developing foods that could control satiety and manage body weight for the specific populations.

Toxicological studies and some functional properties of carboxymethylated cellulose nanofibrils as potential food ingredient

Carboxymethylated cellulose nanofibrils (CNF) with different carboxyl contents (0, 0.36, 0.72 and 1.24 mmol/g) were prepared and characterized via morphology, diameter distribution, zeta potential, structural features, rheological properties, suspension stability, and thermal properties. The results of toxicological studies of ingested CNF via in vitro and in vivo models were present. In vitro studies used an epithelial-like cell line (Caco-2) to assess the effects of a 24 h incubation with CNF, in which no significant cytotoxicity was observed. In vivo studies were evaluated in mice gavage once per day for 8 weeks with 1% or 3.5% w/w suspension of CNF in water. Blood and serum were collected for analysis. No significant differences in hematology, and serum markers were observed between controls and mice given CNF suspensions. Weight, food intake and feces were recorded for growing development and nutrient retention in feces was measured for investigation of functional properties of CNFs. Mice given CNF suspensions gained a significant increment in fecal fat but a reduction in food intake and weight compared to controls. These findings suggested that CNFs are non-toxic and have potentials in behaving as food additives or supplements to reduce caloric intake.

Size and Number of Food Boluses in the Stomach after Eating Different Meals: Magnetic Resonance Imaging Insights in Healthy Humans

Oral processing of food results in the formation of food boluses, which are then swallowed and reach the stomach for further digestion. The number, size and surface properties of the boluses will affect their processing and emptying from the stomach. Knowledge of these parameters, however, is incomplete due to limitations of the techniques used. In this work, non-invasive magnetic resonance imaging (MRI) was used for the first time to measure boluses in the stomach a few minutes after swallowing. Three groups of nine healthy participants were fed three different meals: chicken and roasted vegetables (Meal 1), bread and jam (Meal 2) and cheese and yogurt (Meal 3), and then, their stomach content was imaged. The median number of boluses within the stomach was 282, 106 and 9 for Meal 1, Meal 2 and Meal 3 (p < 0.0001) with an average volume of 0.47 mL, 2.4 mL and 13.6 mL, respectively (p < 0.0001). The cohesiveness as well as the meal composition seem to play a key role in the resulting boluses. These new in vivo data from undisturbed organ imaging can improve knowledge of the digestion process, which will, in turn, inform in vitro and in silico modelling of digestion, thus improving their in vitro/in vivo relevance.

The effect of sugar-sweetened beverages at 4 years of age on appetitive behaviours of 7-year-olds from the Generation XXI birth cohort

The consumption of energy-dense sugar-sweetened beverages (SSB) and its low satiating effects may influence the development of child eating behaviours. We aimed to investigate the association of SSB consumption at 4 years on appetitive behaviours at age 7 years. Children from the Generation XXI birth cohort were included (n 3880). SSB consumption was evaluated through a FFQ and appetitive behaviours were evaluated through the Children's Eating Behaviour Questionnaire, which includes eight subscales. Two composite factors, derived by principal component analysis (Appetite Restraint - related to Food Fussiness, Enjoyment of Food, Slowness in Eating and Satiety Responsiveness - and Appetite Disinhibition - related to Food Responsiveness, Emotional Under- and Overeating and Desire to Drink), were also investigated. The dose-response relationship between SSB consumption and appetitive behaviours was examined using multivariable linear regression (continuous eating behaviour scores) and multinomial logistic regression (tertile categories of eating behaviour scores). Child SSB consumption at 4 years was associated with higher Appetite Disinhibition and Desire to Drink and lower Food Fussiness and Slowness in Eating at 7 years. Consuming SSB ≥1 times/d (compared with a lower intake) was associated with 29 % increase in the odds of Desire to Drink (3rd v. 1st tertile). Pre-schoolers' SSB consumption was associated with higher food approach and less food avoidant behaviours later in childhood. Family characteristics, particularly maternal SSB consumption, explained part of these associations. It is essential to promote the intake of water, instead of sugary drinks, and make parents and caregivers aware of the importance of this exposure, since they have a pivotal role in shaping children's eating behaviours.

'Joining the Dots': Individual, Sociocultural and Environmental Links between Alcohol Consumption, Dietary Intake and Body Weight-A Narrative Review

Alcohol is energy-dense, elicits weak satiety responses relative to solid food, inhibits dietary fat oxidation, and may stimulate food intake. It has, therefore, been proposed as a contributor to weight gain and obesity. The aim of this narrative review was to consolidate and critically appraise the evidence on the relationship of alcohol consumption with dietary intake and body weight, within mainstream (non-treatment) populations. Publications were identified from a PubMed keyword search using the terms 'alcohol', 'food', 'eating', 'weight', 'body mass index', 'obesity', 'food reward', 'inhibition', 'attentional bias', 'appetite', 'culture', 'social'. A snowball method and citation searches were used to identify additional relevant publications. Reference lists of relevant publications were also consulted. While limited by statistical heterogeneity, pooled results of experimental studies showed a relatively robust association between acute alcohol intake and greater food and total energy intake. This appears to occur via metabolic and psychological mechanisms that have not yet been fully elucidated. Evidence on the relationship between alcohol intake and weight is equivocal. Most evidence was derived from cross-sectional survey data which does not allow for a cause-effect relationship to be established. Observational research evidence was limited by heterogeneity and methodological issues, reducing the certainty of the evidence. We found very little qualitative work regarding the social, cultural, and environmental links between concurrent alcohol intake and eating behaviours. That the evidence of alcohol intake and body weight remains uncertain despite no shortage of research over the years, indicates that more innovative research methodologies and nuanced analyses are needed to capture what is clearly a complex and dynamic relationship. Also, given synergies between 'Big Food' and 'Big Alcohol' industries, effective policy solutions are likely to overlap and a unified approach to policy change may be more effective than isolated efforts. However, joint action may not occur until stronger evidence on the relationship between alcohol intake, food intake and weight is established.

Characterization of raft-forming alginate suspensions formed in HCl or model food systems at varying pH levels to better simulate gastric postprandial conditions

OBJECTIVE

Elucidate properties of raft-forming alginates in vitro with varying composition, a system in which the raft was formed (HCl solution; tomato soup; protein-rich beverage), and pH levels for a more accurate representation of postprandial gastric conditions.

SIGNIFICANCE

Knowledge of the impact of the food system and pH on properties of raft-forming alginates may aid in formulation optimization. Recommendations may be made on food that is consumed prior to their consumption to optimize efficacy as a therapeutic agent.

METHODS

Dispersions of sodium alginate, calcium carbonate, and sodium bicarbonate were prepared with levels similar to commercial formulations. Rafts were formed in HCl solution, tomato soup, and a protein-rich beverage at pH 1-4 to assess raft properties.

RESULTS

Significant differences (p < 0.05) in raft mass, strength, resilience, and ability to buffer acid were observed depending on the system in which the rafts were formed. The highest mass was obtained in tomato soup (48.5 ± 9.8 g) compared to the protein-rich beverage and HCl solution (32.5 ± 4.5 g and 23.4 ± 4.8 g, respectively) at pH 1. Rafts formed in the protein-rich beverage exhibited the highest strength. Rafts formed in both food systems had a greater ability to buffer added acid compared to rafts formed in HCl solution.

CONCLUSIONS

In vitro testing of raft forming alginates in HCl solution at low pH may not be sufficient to describe in vivo events, as a strong matrix effect was observed when rafts were formed in model meal systems at representative postprandial pH levels.

The Brown Seaweeds of Scotland, Their Importance and Applications

More than 50% of the UK coastline is situated in Scotland under legislative jurisdiction; therefore, there is a great opportunity for regionally focused economic development by the rational use of sustainable marine bio-sources. We review the importance of seaweeds in general, and more specifically, wrack brown seaweeds which are washed from the sea and accumulated in the wrack zone and their economic impact. Rules and regulations governing the harvesting of seaweed, potential sites for harvesting, along with the status of industrial application are discussed. We describe extraction and separation methods of natural products from these seaweeds along with their phytochemical profiles. Many potential applications for these derivatives exist in agriculture, energy, nutrition, biomaterials, waste treatment (composting), pharmaceuticals, cosmetics and other applications. The chemical diversity of the natural compounds present in these seaweeds is an opportunity to further investigate a range of chemical scaffolds, evaluate their biological activities, and develop them for better pharmaceutical or biotechnological applications. The key message is the significant opportunity for the development of high value products from a seaweed processing industry in Scotland, based on a sustainable resource, and locally regulated.

Metabolite release and rheological properties of sponge cake after in vitro digestion and the influence of a flour replacer rich in dietary fibre

The present study aimed to better understand the metabolite release and rheological characteristics of sponge cake after in vitro digestion and the effect of Eucheuma as a fibre-rich flour replacer. Overall, 22 compounds including amino acids, saccharides, fatty acids, and other metabolites were identified based on nuclear magnetic resonance spectra. Principal component analysis and orthogonal projection to latent structures-discriminant analysis showed that Eucheuma reduced the release of amino acids and fatty acids. The released glucose from the EP20 sample (20% replacement of flour with Eucheuma) decreased by 35.4% in intestinal phases compared with the control cake. Eucheuma's in vitro effects on sponge cake digestion mainly reflected altered flow behaviour index. All samples showed solid-like behaviour and a decrease in viscoelastic moduli after digestion. This study forms the basis for future optimisation of food properties to control their digestive characteristics.

Implementation and in vitro characterization of calcium-free in situ gelling oral reconstituted suspension for potential overweight treatment

In this work, oral granules that were easily dissolved in aqueous dispersion, were prepared. These oral suspensions were formulated with sodium alginate (AlgNa), chitosan (CHI) and sodium carboxymethylcellulose (CMC Na). The gels were formulated by pouring the suspensions into 150 ml of simulated gastric fluid (SGF) pH 1.2 at 37° C. The in-situ gelling mechanism was based on the ionization states of the three biopolymers as a function of the pH of the medium. Fourier transform infrared analysis of gels confirmed the interactions between alginate and chitosan. According to the scanning electron microscopy analysis, the gels were characterized by a firm and homogeneous structure. The obtained values of the elastic storage modulus, G', varied between 10 1   and 10 7 Pa. The eliminated volume of the unabsorbed liquid by the gels fluctuated between 25% and 55% of the total liquid volume. The quality of the gels was improved when a maximum concentration of alginate ( 4   g / 100   ml ) , a minimum concentration of chitosan ( 0.5   g / 100   ml ) and a maximum amount of carboxymethylcellulose ( 4   g / 100   ml ) were used. The value of their elastic modulus, G' was around 10 5 Pa and the residual unabsorbed volume of the liquid was 25% of the total liquid volume. According to the obtained results, the prepared gels could induce a feeling of fullness by stimulating the gastric distension and they could potentially be applied as anti-obesity medication.

Dietary Fibre from Whole Grains and Their Benefits on Metabolic Health

The consumption of whole grain products is often related to beneficial effects on consumer health. Dietary fibre is an important component present in whole grains and is believed to be (at least partially) responsible for these health benefits. The dietary fibre composition of whole grains is very distinct over different grains. Whole grains of cereals and pseudo-cereals are rich in both soluble and insoluble functional dietary fibre that can be largely classified as e.g., cellulose, arabinoxylan, β-glucan, xyloglucan and fructan. However, even though the health benefits associated with the consumption of dietary fibre are well known to scientists, producers and consumers, the consumption of dietary fibre and whole grains around the world is substantially lower than the recommended levels. This review will discuss the types of dietary fibre commonly found in cereals and pseudo-cereals, their nutritional significance and health benefits observed in animal and human studies.

Nondigestible Carbohydrates Affect Metabolic Health and Gut Microbiota in Overweight Adults after Weight Loss

BACKGROUND

The composition of diets consumed following weight loss (WL) can have a significant impact on satiety and metabolic health.

OBJECTIVE

This study was designed to test the effects of including a nondigestible carbohydrate to achieve weight maintenance (WM) following a period of WL.

METHODS

Nineteen volunteers [11 females and 8 males, aged 20-62 y; BMI (kg/m2): 27-42] consumed a 3-d maintenance diet (15%:30%:55%), followed by a 21-d WL diet (WL; 30%:30%:40%), followed by 2 randomized 10-d WM diets (20%:30%:50% of energy from protein:fat:carbohydrate) containing either resistant starch type 3 (RS-WM; 22 or 26 g/d for females and males, respectively) or no RS (C-WM) in a within-subject crossover design without washout periods. The primary outcome, WM after WL, was analyzed by body weight. Secondary outcomes of fecal microbiota composition and microbial metabolite concentrations and gut hormones were analyzed in fecal samples and blood plasma, respectively. All outcomes were assessed at the end of each dietary period.

RESULTS

Body weight was similar after the RS-WM and C-WM diets (90.7 and 90.8 kg, respectively), with no difference in subjectively rated appetite. During the WL diet period plasma ghrelin increased by 36% (P < 0.001), glucose-dependent insulinotropic polypeptide (GIP) decreased by 33% (P < 0.001), and insulin decreased by 46% (P < 0.001), but no significant differences were observed during the RS-WM and C-WM diet periods. Fasting blood glucose was lower after the RS-WM diet (5.59 ± 0.31 mmol/L) than after the C-WM diet [5.75 ± 0.49 mmol/L; P = 0.015; standard error of the difference between the means (SED): 0.09]. Dietary treatments influenced the fecal microbiota composition (R2 = 0.054, P = 0.031) but not diversity.

CONCLUSIONS

The metabolic benefits, for overweight adults, from WL were maintained through a subsequent WM diet with higher total carbohydrate intake. Inclusion of resistant starch in the WM diet altered gut microbiota composition positively and resulted in lower fasting glucose compared with the control, with no apparent change in appetite. This trial was registered at clinicaltrials.gov as NCT01724411.

Destructuring and restructuring of foods during gastric digestion

All foods harbor unique length scale-dependent structural features that can influence the release, transport, and utilization of macro- or micronutrients in the human gastrointestinal tract. In this regard, food destructuring and restructuring processes during gastric passage significantly influence downstream nutrient assimilation and feelings of satiety. This review begins with a synopsis of the effects of oral processing on food structure. Then, stomach-centric factors that contribute to the efficacy of gastric digestion are discussed, and exemplified by comparing the intragastric de- and restructuring of a number of common foods. The mechanisms of how intragastric structuring influences gastric emptying and its relationship to human satiety are then discussed. Finally, recently developed, non-destructive instrumental approaches used to quantitively and qualitatively characterize food behavior during gastric destructuring and restructuring are described.

Wheat bran and oat hulls have dose-dependent effects on ad-libitum feed intake in pigs related to digesta hydration and colonic fermentation

Undigested nutrients and fermentable fibre in the distal ileum and colon stimulate intestinal brakes, which reduce gastric-emptying and digesta-passage-rate, and subsequently limit feed/food-intake. Fibre can also stimulate passage rate potentially increasing feed intake (FI). In order to experimentally determine the relationships between these two hypothesised actions of fibre, five levels of wheat-bran (WB) or oat-hulls (OH) were added to a highly digestible starch-based diet fed to pigs ad-libitum for three weeks. Average-daily-feed-intake (ADFI), faecal short-chain-fatty-acids (SCFA) and related parameters were determined at 7, 14 and 21d. A linear mixed model was fitted to FI and fermentation parameters. Overall, WB diets showed 8-11% lower ADFI (7-14d: p < 0.05; 7-21 & 0-21d: p = 0.053) than OH diets. WB diets produced over 20% more (21d: p < 0.01) SCFA than OH or Control diets. WB at 25% produced 22% more (7d: p < 0.05) SCFA than any other diet. Diets with WB at 25 and 35%, showed higher hydration capacity than any other diet (p < 0.001). OH at 10% had an unusually low FI and a markedly higher hydration capacity. With increasing levels of OH, intake of base diet was 7% more than control at 5% OH, but 8% less than control at 20% OH. With increasing WB content, intake of base diet decreased. From these results, we propose that three mechanisms control the effects of fibre on FI: initial increase in passage rate and feed intake at low concentrations of non-swelling fibres; a depression in FI from high fibre bulk; and reduced feed intake from stimulation of ileal and colonic brakes.

Advances in Research on the Bioactivity of Alginate Oligosaccharides

Alginate is a natural polysaccharide present in various marine brown seaweeds. Alginate oligosaccharide (AOS) is a degradation product of alginate, which has received increasing attention due to its low molecular weight and promising biological activity. The wide-ranging biological activity of AOS is closely related to the diversity of their structures. AOS with a specific structure and distinct applications can be obtained by different methods of alginate degradation. This review focuses on recent advances in the biological activity of alginate and its derivatives, including their anti-tumor, anti-oxidative, immunoregulatory, anti-inflammatory, neuroprotective, antibacterial, hypolipidemic, antihypertensive, and hypoglycemic properties, as well as the ability to suppress obesity and promote cell proliferation and regulate plant growth. We hope that this review will provide theoretical basis and inspiration for the high-value research developments and utilization of AOS-related products.

Design principles of food gels

Naturally sourced gels from food biopolymers have advanced in recent decades to compare favourably in performance and breadth of application to their synthetic counterparts. Here, we comprehensively review the constitutive nature, gelling mechanisms, design approaches, and structural and mechanical properties of food gels. We then consider how these food gel design principles alter rheological and tribological properties for food quality improvement, nutrient-modification of foods while preserving sensory perception, and targeted delivery of drugs and bioactives within the gastrointestinal tract. We propose that food gels may offer advantages over their synthetic counterparts owing to their source renewability, low cost, biocompatibility and biodegradability. We also identify emerging approaches and trends that may improve and expand the current scope, properties and functionalities of food gels and inspire new applications.

Insights on Obesity in Children and Adults: Individualizing Management

For the management of obesity in childhood and adolescence, nonoperative approaches have limited efficacy, including community-based and behavioral interventions and pharmacotherapy approved for use in adults. Roux-en-Y gastric bypass (RYGB) and laparoscopic sleeve gastrectomy are efficacious in reducing weight, body mass index, and comorbidities in adolescents. Understanding the phenotype associated with obesity provides an opportunity to individualize patients' treatments directed at the brain-gut axis. These phenotypes include rapid gastric emptying, increased fasting gastric volume, reduced postprandial incretins, and central mechanisms that impact appetite and satiation including hedonic eating and affective disorders. Further studies are required in adolescents. Identifying phenotypes could enhance the efficacy of behavioral, dietary, and pharmacotherapeutic interventions alone or in combination in children and adolescents.

Acceptability of alginate enriched bread and its effect on fat digestion in humans

Lifestyle interventions and physical activity remain the cornerstone of obesity management, as pharmacological therapies (orlistat) are associated with gastrointestinal (GI) side effects. Combining orlistat with fibers can reduce side effects, improving compliance. Therefore, a fiber that inhibits lipase without side effects could help treat obesity.

The aims of the present work were to assess whether alginate enriched bread could inhibit fat digestion, and assess the acceptability of alginate bread and its effect on GI wellbeing.

A double-blind, randomised, controlled cross-over pilot study (NCT03350958) assessed the impact of an alginate bread meal on; lipid content in ileal effluent and circulating triacylglycerol levels. This was compared against the same meal with non-enriched (control) bread.

GI wellbeing and acceptability of alginate bread was compared to control bread through daily wellbeing questionnaires and food diaries (NCT03477981). Control bread followed by alginate bread were consumed for two weeks respectively.

Consumption of alginate bread reduced circulating triacylglycerol compared to control (2% reduction in AUC) and significantly increased lipid content in ileal effluent (3.8 g ± 1.6 after 210 min).

There were no significant changes to GI wellbeing when comparing alginate bread to control bread. A significant increase in the feeling of fullness occurred with alginate bread compared to baseline and the first week of control bread consumption.

This study showed that sustained consumption of alginate enriched bread does not alter GI wellbeing and can decrease lipolysis, increasing lipid leaving the small intestine.

Further studies are required to demonstrate that reduced fat digestion through the action of alginate can reduce fat mass or body weight.

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Alginate can be incorporated into a highly acceptable loaf at 4%.

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Sustained (two weeks) consumption of alginate bread did not affect GI wellbeing.

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Consumption of alginate bread decreases circulating triglyceride after the meal.

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Consumption of alginate bread increases lipid leaving the ileum after the meal.

Modelling the Association between Core and Discretionary Energy Intake in Adults with and without Obesity

BACKGROUND

Many dietary recommendations for weight control rely on the assumption that greater core food intake will displace intake of energy-dense discretionary foods and beverages. However, there is little evidence to support these assumptions. This study examined the naturalistic relationship between daily core and discretionary energy intake, and with discretionary food and discretionary beverage intake, separately. The impact of weight status on these associations was also examined.

METHOD

One hundred participants completed a four-day (non-consecutive) estimated food diary. Discretionary foods and beverages were identified by reference to the Australian Dietary Guidelines. Non-discretionary items were considered core items. Simultaneous-equation random effects models using disaggregated dietary data controlling for sociodemographic variables were used to determine the association between various dietary components.

RESULT

Core energy intake correlated negatively with discretionary energy intake (cross-equation correlation, ρ = -0.49 (95% CI: -0.57, -0.39)). Its correlation with discretionary foods (-0.47 (-0.56, -0.37)) was stronger than that with discretionary beverages (-0.19 (-0.30, -0.07)) The correlation between core energy intake and discretionary energy intake was significantly stronger in participants who did not have obesity (-0.67 (-0.71, -0.50)) than those with obesity (-0.32 (-0.46, -0.17)) (p = 0.0002).

CONCLUSIONS

Core and discretionary energy intake share an inverse and potentially bidirectional, relationship that appears to be stronger with discretionary foods than discretionary beverages. These relationships were significantly weaker in participants with obesity which may indicate less precise dietary compensation in these individuals. While strategies that promote greater intake of core foods may assist with weight maintenance in individuals of healthy weight, its impact in individuals with obesity may be limited. These strategies should be accompanied by direct messages to reduce commensurately the intake of discretionary items, with special attention paid to discretionary beverage consumption.

Double-Blind, Randomized, Three-Armed, Placebo-Controlled, Clinical Investigation to Evaluate the Benefit and Tolerability of Two Dosages of IQP-AE-103 in Reducing Body Weight in Overweight and Moderately Obese Subjects

Objective

This study was performed to determine the efficacy and tolerability/safety of IQP-AE-103 on body weight reduction in overweight to moderately obese adults.

Methods

A double-blind, randomized, placebo-controlled trial involved one hundred and eight subjects (BMI between 25 and 35 kg/m2) that were randomly assigned to either the low-dose or the high-dose IQP-AE-103 group, or the placebo group. Following a 2-week run-in period, subjects received two capsules of investigational product after three daily main meals for 12 weeks. Subjects were instructed to maintain a nutritionally balanced hypocaloric diet according to the individual's energy requirement. Body weight, body fat, and waist and hip circumference were measured at baseline, and after 2, 4, 8, and 12 weeks. Subjects also rated their feelings of hunger and fullness using visual analogue scales, and food craving on a 5-point scale at the same time intervals. Blood samplings for safety laboratory parameters were taken before and at the end of the study.

Results

After 12 weeks of intake, the high-dose IQP-AE-103 group had a significantly greater weight loss compared with the placebo (5.03 ± 2.50 kg vs. 0.98 ± 2.06 kg, respectively; p < 0.001) and the low-dose group (3.01 ± 2.19 kg; p=0.001). The high-dose group experienced a decrease in body fat of 3.15 ± 2.41 kg compared with a decrease of 0.23 ± 2.74 kg for the placebo group (p < 0.001). High-dose IQP-AE-103 also decreased the feeling of hunger in 66% subjects. A beneficial effect of IQP-AE-103 on the lipid metabolism was also demonstrated in the subgroup of subjects with baseline total cholesterol levels above 6.2 mmol/L. No side effects related to the intake of IQP-AE-103 were reported.

Conclusions

These findings indicate that IQP-AE-103 could be an effective and safe weight loss intervention. This trial is registered with NCT03058367.

The Role of Fiber in Energy Balance

Excessive energy intake is linked with obesity and subsequent diet-related health problems, and it is therefore a major nutritional challenge. Compared with the digestible carbohydrates starch and sugars, fiber has a low energy density and may have an attenuating effect on appetite. This narrative review attempts to clarify the net energy contributions of various fibers, and the effect of fiber on satiety and thus appetite regulation. Fibers, broadly defined as nonstarch polysaccharides, are a varied class of substances with vastly different physicochemical properties depending on their chemical arrangement. Thus, net energy content can vary from more than 10 kJ/g for soluble, nonviscous, and easily fermentable fibers such as those in many fruits, to less than zero for viscous fibers with anti-nutritive properties, such as certain types of fibers found in rye and other cereals. Likewise, some fibers will increase satiety by being viscous or contribute to large and/or swollen particles, which may facilitate mastication and increase retention time in the stomach, or potentially through fermentation and an ensuing satiety-inducing endocrine feedback from the colon. Thus, fibers may clearly contribute to energy balance. The metabolizable energy content is very often considerably lower than the commonly used level of 8 kJ per g fiber, and some fibers may reduce energy intake indirectly through satiety-inducing effects. A more precise characterization of fiber and its physicochemical effects are required before these beneficial effects can be fully exploited in human nutrition.

Alginate and HM-pectin in sports-drink give rise to intra-gastric gelation in vivo

A polysaccharide drink containing 14% maltodextrin/fructose shows in vivo gelling behaviour as evidenced by magnetic resonance imaging.

Changes in Plasma Acylcarnitine and Lysophosphatidylcholine Levels Following a High-Fructose Diet: A Targeted Metabolomics Study in Healthy Women

Background: The consumption of high amounts of fructose is associated with metabolic diseases. However, the underlying mechanisms are largely unknown. Objective: To determine the effects of high fructose intake on plasma metabolomics. Study design: We enrolled 12 healthy volunteers (six lean and six obese women, age 24–35 years) in a crossover intervention study. All participants carried out three diets: (1) low fructose (<10 g/day); (2) high fructose (100 g/day) from natural food sources (fruit); and (3) high fructose (100 g/day) from high fructose syrup (HFS). Outcome measures: The primary outcome was changes in plasma metabolites measured by targeted metabolomics. Results: High compared to low fructose diets caused a marked metabolite class separation, especially because of changes in acylcarnitine and lysophosphatidylcholine levels. Both high fructose diets resulted in a decrease in mean acylcarnitine levels in all subjects, and an increase in mean lysophosphatidylcholine and diacyl-phosphatidylcholine levels in obese individuals. Medium chain acylcarnitines were negatively correlated with serum levels of liver enzymes and with the fatty liver index. Discussion: The metabolic shifts induced by high fructose consumption suggest an inhibition of mitochondrial β-oxidation and an increase in lipid peroxidation. The effects tended to be more pronounced following the HFS than the fruit diet.

Recommendations for characterization and reporting of dietary fibers in nutrition research

Dietary fiber (DF) comprises a wide range of naturally occurring and modified materials with substantial variations in physical and chemical properties and potential physiologic effects. Although nutrition studies testing the effects of DF usually provide extensive detail on the physiologic responses, many still fail to adequately report the type and properties of the DF itself. This weakens the ability to directly replicate and compare studies and to establish structure-function relations. We outline the factors that affect DF functionality and provide 4 overarching recommendations for the characterization and reporting of DF preparations and DF-containing foods in nutrition research. These relate to 1) undertaking characterization methods that reflect the study hypothesis; 2) adequate reporting of DF source, quantity, and composition; 3) measurement of DF rheological properties; and 4) estimation of the DF fermentation rate and extent. Importantly, the food matrix of the test products should also be considered, because this can influence DF functionality and hence the apparent DF efficacy for health-relevant outcomes. Finally, we point out differences in DF functionality to be considered in acute and longer-term trials, the need to design the control treatment according to the research question, and the importance of reporting the amount and type of DF in the background diet.

Just add water: Effects of added gastric distention by water on gastric emptying and satiety related brain activity

BACKGROUND

Gastric distention contributes to meal termination. There is little research on the neural correlates of gastric distention by food. To date, neural measures have not been obtained concurrently with measurements of gastric distention.

OBJECTIVES

1) To study how offering a small versus a large water load following a standardized nutrient load affects gastric distention over time. 2) To assess associations between satiety experiences and brain activity and the degree of gastric distention.

METHOD

19 healthy males (age 22.2 ± 2.5 y, BMI 21.8 ± 1.5 kg/m²) participated in a randomized crossover study with two treatments: ingestion of a 500-kcal 150-mL liquid meal shake followed by a low (LV, 50 mL) or a high volume (HV, 350 mL) water load. At baseline and three times after ingestion satiety was scored, MRI scans were made to determine total gastric content volume (TGV) and functional MRI scans were made to measure cerebral blood flow (CBF).

RESULTS

TGV was significantly higher for HV compared to LV at all time points (p < 0.001) with relative differences between HV and LV of 292 ± 37 mL after ingestion, 182 ± 83 mL at t = 15 min and 62 ± 57 mL at t = 35 min. Hunger decreased (p = 0.023) and fullness increased (p = 0.030) significantly more for HV compared to LV. Ingestion increased CBF in the inferior frontal gyrus and the anterior insula, but there were no differences between treatments. There were no significant correlations between appetite ratings and CBF values.

CONCLUSION

Performing concurrent gastric MRI and CBF measurements can be used to investigate neural correlates of gastric distention. Increased distention did not induce significantly greater brain activation. Future research should further examine the role of the inferior frontal gyrus in satiety.