Effects of HMGCR deficiency on skeletal muscle development.

Pathogenic variants in HMGCR were recently linked to a limb-girdle muscular dystrophy (LGMD) phenotype. The protein product HMG CoA reductase (HMGCR) catalyzes a key component of the cholesterol synthesis pathway. The two other muscle diseases associated with HMGCR, statin-associated myopathy (SAM) and autoimmune anti-HMGCR myopathy, are not inherited in a Mendelian pattern. The mechanism linking pathogenic variants in HMGCR with skeletal muscle dysfunction is unclear. We knocked down Hmgcr in mouse skeletal myoblasts, knocked down hmgcr in Drosophila, and expressed three pathogenic HMGCR variants (c.1327C>T, p.Arg443Trp; c.1522_1524delTCT, p.Ser508del; and c.1621G>A, p.Ala541Thr) in Hmgcr knockdown mouse myoblasts. Hmgcr deficiency was associated with decreased proliferation, increased apoptosis, and impaired myotube fusion. Transcriptome sequencing of Hmgcr knockdown versus control myoblasts revealed differential expression involving mitochondrial function, with corresponding differences in cellular oxygen consumption rates. Both ubiquitous and muscle-specific knockdown of hmgcr in Drosophila led to lethality. Overexpression of reference HMGCR cDNA rescued myotube fusion in knockdown cells, whereas overexpression of the pathogenic variants of HMGCR cDNA did not. These results suggest that the three HMGCR-related muscle diseases share disease mechanisms related to skeletal muscle development.

Exploring Texture and Biomechanics of Food Oral Processing in Fork-Mashable Dishes for Patients with Mastication or Swallowing Impairments.

Texture-modified diets (TMDs) are a primary compensatory treatment for hospitalized older patients with swallowing and mastication disorders. Nevertheless, the lack of a protocol for evaluating their objective textural properties hampers their industrialization and optimal patient care. OBJECTIVES: This study aimed (a) to evaluate the textural properties (maximum force, cohesiveness, and adhesiveness) and biomechanics of food oral processing (mastication cycles, time, and frequency) of ten fork-mashable dishes (Texture E BDA/IDDSI level 6), (b) to explore the impact of oral processing on texture, and (c) to measure the properties of the ready-to-swallow bolus (RSB) in healthy adults. METHODS: The textural properties (maximum force, cohesiveness, and adhesiveness) of ten dishes were analyzed with a texture analyzer before and after oral processing (RSB) in five healthy adults (30 ± 3.9, 3 women). Surface electromyography was used to measure mastication cycles, time, and frequency. RESULTS: The pre-mastication Texture Profile Analysis (TPA)-averaged values of maximum force ranged from 0.65 to 2.73 N, cohesiveness was 0.49-0.87, and adhesiveness was 0.01-0.95 N·s. Masticatory Cycles (46.87-19.13 MC) and time (36.73-15.80 S) from whole samples to RSB greatly and significantly differed among dishes, although frequency did not (1.68-1.11 MC/T). Post-mastication RSB TPA-averaged values of maximum force ranged from 0.70 to 2.24 N; cohesiveness, 0.49-0.73; and adhesiveness, 0.01-1.14 N·s. CONCLUSIONS: Despite all dishes being classified by the same qualitative descriptor (BDA level E/IDDSI level 6), there was a large and significant variation in their textural properties (maximum force, cohesiveness, and adhesiveness) when measured in SI units. In addition, in healthy adults, the masticatory cycles and time to achieve RSB greatly differed, whereas masticatory frequency remained quite constant.

Epilepsy in Duchenne and Becker muscular dystrophies.

OBJECTIVE: Duchenne and Becker muscular dystrophies (DMD and BMD) are dystrophinopathies caused by variants in DMD gene, resulting in reduced or absent dystrophin. These conditions, characterized by muscle weakness, also manifest central nervous system (CNS) comorbidities due to dystrophin expression in the CNS. Prior studies have indicated a higher prevalence of epilepsy in individuals with dystrophinopathy compared to the general population. Our research aimed to investigate epilepsy prevalence in dystrophinopathies and characterize associated electroencephalograms (EEGs) and seizures. METHODS: We reviewed 416 individuals with dystrophinopathy, followed up at three centers between 2010 and 2023, to investigate the lifetime epilepsy prevalence and characterize EEGs and seizures in those individuals diagnosed with epilepsy. Associations between epilepsy and type of dystrophinopathy, genotype, and cognitive involvement were studied. RESULTS: Our study revealed a higher epilepsy prevalence than the general population (1.4%; 95% confidence interval: 0.7-3.2%), but notably lower than previously reported in smaller dystrophinopathy cohorts. No significant differences were found in epilepsy prevalence between DMD and BMD or based on underlying genotypes. Cognitive impairment was not found to be linked to higher epilepsy rates. The most prevalent epilepsy types in dystrophinopathies resembled those observed in the broader pediatric population, with most individuals effectively controlled through monotherapy. INTERPRETATION: The actual epilepsy prevalence in dystrophinopathies may be markedly lower than previously estimated, possibly half or even less. Our study provides valuable insights into the epilepsy landscape in individuals with dystrophinopathy, impacting medical care, especially for those with concurrent epilepsy.

Flours from fermented lentil and quinoa grains as ingredients with new techno-functional properties.

The need to provide novel, nutritious plant-based products requires seeking high-value, sustainable protein sources, like quinoa and lentils, having an increased digestibility and lacking antinutrients. Fungal fermentation has evidenced enhanced nutritional value of flours obtained from these grains. However, research into techno-functional properties, essential to the new product development, is lacking. This study investigated the techno-functional properties of flours made from lentil and quinoa after fermenting them with Pleurotus ostreatus and subjecting them to two drying techniques (lyophilisation and hot air drying). In both cases, the fermentation led to noteworthy improvements in swelling and water holding capacity, especially in those lyophilised than those dried. In contrast, the emulsifying, foaming, thickening, and gelling capacities decreased significantly. The loss of abilities was more severe for dried grains than for lyophilized ones. The thermomechanical analysis of the fermented flours showed lower thickening and gelling potential compared to untreated flours. Microscopy images revealed that the state and structure of starch granules were affected by both fermentation and drying processes. Starch granules in lentils were partly pre-gelatinised and trapped in the cotyledon cell, resulting in limited thickening and gelling abilities. In contrast, in quinoa, starch underwent pre-gelatinisation and retrogradation during the fermentation process, promoting the production of resistant starch and increasing fibre content. This study presents the potential of treated flours as ingredients possessing unique attributes compared to protein and fibre-rich conventional products.

Measuring the Rheological and Textural Properties of Thick Purees Used to Manage Patients with Swallowing Disorders.

Texture-modified diets are the first-line compensatory strategy for older patients with swallowing and mastication disorders. However, the absence of a common protocol to assess textural properties inhibits their standardization and quality control and, thus, patient safety. This study aimed to (a) assess the rheological and textural properties of ten thick purees (Texture C, British Dietetic Association), (b) understand the effect of oral processing, and (c) measure the properties of the ready-to-swallow bolus after oral processing in healthy adults. Shear viscosity at 50 s-1 and 300 s-1 and textural properties (maximum force, cohesiveness, and adhesiveness) of boluses of ten thick purees were analyzed with a rheometer and a texture analyzer before and after oral processing (ready-to-swallow) in five healthy volunteers. Viscosity varied by 81.78% at 50 s-1 (900-4800 mPa·s) among purees before oral processing. Maximum force varied by 60% (0.47-1.2 N); cohesiveness, 18% (0.66-0.82), and adhesiveness, 32% (0.74-1.1 N·s). The high variability of viscosity was also present in ready-to-swallow boluses, 70.32% among purees. Oral processing significantly reduced viscosity in most purees (French omelet, zucchini omelet, turkey stew, red lentils, noodles, and hake fish) and also significantly reduced maximum force (7-36%) and adhesiveness (17-51%) but hardly affected cohesiveness (<5%). All thick purees met the qualitative textural descriptors for Level C texture. However, all ten purees showed significant differences in all parameters measured instrumentally and were affected differently by oral processing. This study demonstrates the need to use instrumental quality control using standardized protocols and SI units to narrow the variability and provide the optimal values for patients with dysphagia who require texture-modified diets.

Origins of thirstiness sensation and current food solutions.

The sensation of thirstiness is the desire to drink water. In certain situations, the ingestion of liquid water can be restricted. As a result, thirstiness is not relieved, resulting in an uncomfortable and distressing situation. The present review describes thirstiness and hydration, the food products and beverages that cause thirstiness, and the beverages and food products currently available to quench thirstiness in individuals with restricted access to liquid ingestion. It also discusses how to measure the effectiveness of calming thirstiness. To diminish thirstiness distress, different alternatives to liquids are proposed. Individuals with swallowing disorders are given thickened water, individuals with restricted water ingestion are given ice cubes or ice popsicles of different flavors, and sportspeople are given energy gels. However, current beverage solutions seem not to relieve thirst fully, although some stimuli like iced water, flavors (especially lemon and mint), or acids seem to work better than plain stimuli and could be added to existing products. Therefore, there is still a need to incorporate these strategies into beverage and food formulations and to test their effectiveness.

Techno-Functional and Rheological Properties of Alternative Plant-Based Flours.

The use of alternative vegetal sources is a proposed strategy to improve the diversity and quality of plant-based products on the market, currently led by soy and pea. This study compares the techno-functional properties of seven vegetable flours (chickpea, lentil, red lentil, white bean, quinoa, amaranth, and oat) and the rheological properties of their flour pastes and gels. All techno-functional properties significantly (α = 0.05) varied depending on the type of flour. Among the flours studied, the highest swelling capacity was for white bean and the lowest for chickpea and red lentil. Water holding capacity was high for white bean and oat flours and low for red lentil. Oat and quinoa flours had the highest oil-holding capacity. Emulsifying and foaming capacities were high for all pulse flours but poor for amaranth and oat flours. However, amaranth and oat provided a much higher viscosity during heating than the rest of the flours. The viscoelastic properties of the flour pastes indicated that they all had a gel structure with storage modulus (G') values over loss modulus (G″) values. From the viscoelastic properties, amaranth and quinoa showed a weak gel structure with low G' and G″ values, and the chickpea, lentil, and red lentil formed pastes with a high elastic contribution (high G' values). In agreement, these three pulse flours were the only ones able to form hard, self-standing gels. These results show the potential of vegetal flours from alternative sources in the development of new plant-based products.

What is the food like that people choke on? A study on food bolus physical properties under different in vitro oral capacities.

People with oral impairments, such as poor denture status, poor muscle strength, and poor salivary secretion, have more difficulties performing oral processes, which results in the risk of choking. In this study, we aimed to understand, in vitro, how different oral impairments can affect the oral processing of food reported as a choking hazard. Six foods that frequently cause choking were selected and studied, varying three in vitro factors at two levels-saliva incorporation amount, cutting activity, and compression action. The median particle size (a50) and the particle size heterogeneity (a75/25) of the food fragmentation, the hardness, and adhesiveness of the bolus formation, and the final cohesiveness of the bolus were studied. The results showed that all the parameters studied varied depending on the food product. High compression reduced a50 (except in mochi that increased) and a75/25 (except in eggs and fish) but increased bolus adhesion and particle aggregation (except for mochi). Regarding cutting activity, when performing a greater number of strokes, the particle size for sausage and egg, and the hardness of the bolus for mochi and sausage were lower. In contrast, for some food products, the bolus adhesiveness (bread) and particle aggregation (pineapple) were higher at a high number of strokes. The amount of saliva also played an important role in the creation of the bolus. When high amounts of saliva were added, the a50 values (mochi) and hardness (mochi, egg, and fish) decreased; and increased the adhesiveness (mochi) and particle aggregation (bread, pineapple, and sausage). When all oral factors are compromised (lack of muscle strength, denture status, and saliva secretion), some food products create a choking hazard as individuals cannot achieve the right particle size, bolus cohesiveness, and mechanical properties of the bolus to be safe to swallow, there is still a need to elaborate a guide, considering all the safety parameters.

Sexual dysfunction worsens both the general and specific quality of life of women with irritable bowel syndrome. A cross-sectional study.

BACKGROUND: Irritable bowel syndrome (IBS) and sexual dysfunction (SxD) lowers quality of life (QOL) separately, but the effect of their overlap in unselected populations has not been studied. OBJECTIVE: To evaluate the QOL of IBS women with and without SxD and compare it with controls. METHODS: In this cross-sectional assessment, we studied 51 IBS women (Rome IV criteria) and 54 controls. SxD was determined using the female sexual function index questionnaire. QOL was evaluated by the Short Form 36 (SF-36) and IBS-QOL questionnaires. RESULTS: SxD prevalence was similar between IBS women (39.22%) and controls (38.89%). Compared with other groups, IBS patients with SxD showed lower scores in all domains as well as in the physical, mental summaries of the SF-36 and almost all domains (except for body image, food avoidance, and social reaction compared with IBS patients without SxD) and the total score of IBS-QOL. CONCLUSIONS: These findings show that SxD worsens both general and specific QOL of women with IBS. The consideration of SxD in patients with IBS will allow us to make a more effective diagnostic and therapeutic approach. Clinical trial registry in Mexico City General Hospital: DI/19/107/03/080. CLINICAL TRIALS REGISTRATION: NCT04716738.

Characterization of Dysphagia Thickeners Using Texture Analysis-What Information Can Be Useful?

Besides shear viscosity, other texture parameters (adhesiveness or cohesiveness) might be relevant for safe swallowing in people suffering from oropharyngeal dysphagia. Shear viscosity is assessed through protocols developed using a viscometer or a rheometer. In contrast, protocols and instruments (capillary break-up rheometer) to assess adhesiveness and cohesiveness are less common and much less developed. Other equipment such as texture analyzers can provide useful information on food properties. Here, we aimed to explore different texture analyzer settings (type of test, probe, and protocol) to characterize four commercial dysphagia thickeners at the shear viscosity levels recommended by manufacturers. Among the tests used (extrusion or penetration) with the different probes (disc, cone and shape holder, sphere, or cylinder), cone extrusion provided information about adhesivity, disc extrusion about sample cohesiveness, and sphere about penetration and sample elasticity. The test speeds used influenced the results, but only one speed is needed as the different speeds provided the same fluid information; for easiness, it is proposed to use 1 mm/s. Comparing the texture analyzer results with viscosity values obtained at different shears, the texture analyzer parameters reflected information that differ from shear viscosity. This information could be relevant for the therapeutic effect of thickening products and food characterization.

Dysphagia thickeners in context of use: Changes in thickened drinks viscosity and thixotropy with temperature and time of consumption.

Dysphagia patients might need to thicken drinks. The viscosity of these thickened drinks varies among commercial thickeners and drinks compromising the ingesta safety. The aim of this study was to investigate how temperature and resting time affect the rheological properties of thickened drinks. Four commercial thickeners were used to thicken water, coffee, orange juice, and milk at two concentration levels used in dysphagia drinks (nectar and pudding). To study the effect of temperature, flow curves of thickened drinks at 10°C and 50°C were obtained and to study the effect of resting time, flow curves of thickened drinks at 25°C were obtained at different times (0, 30, and 60 min). All samples displayed shear-thinning and time-dependent behavior (thixotropy or antithixotropy). The effect of temperature on viscosity values and relative thixotropic area (RTA) depended on the thickener and the drink. Overall, apparent viscosity showed higher values at 50°C than 10°C, especially in thickeners containing starch and in drinks with higher soluble solids (milk and orange juice). This was attributed to the water absorption of pregelatinized starch granules favored by temperature. Antithixotropy was mainly observed at pudding concentration for the starch-containing thickeners, and decreased with temperature. The effect of resting time on apparent viscosity and RTA depended also on the drink and thickener. Mostly, apparent viscosity values increased with resting time and antithixotropic behavior decreased. Both effects, increase in viscosity and decrease of antithixotropy with time, indicated that thickening action was being developed over the resting time.

Oral behavior of emulsified systems with different particle size and thickening agents under simulated conditions.

Food behavior during oral processing plays an essential role in the perception of texture. It depends on different factors, including food structure and composition, as well as its behavior when interacting with saliva. This study aimed to investigate the effect of particle size and thickener type of emulsified systems on physical, rheological, tribological, and oral oily coating properties under oral conditions. Six matrices based on oil-in-water emulsions with different particle sizes (NE-nanoemulsion and CE-conventional emulsions) were prepared using a mixture of emulsifiers (10% w/w) and sunflower oil (10% w/w). Thickened agents were added to the matrices (NE and CE) at different concentrations (3-4.5% w/w of starch-ST or 0.4-0.8% w/w xanthan gum-XG) to obtain equi-viscous samples (NE-EV) with their CE-based counterpart. Results showed a decrease in apparent viscosity values under oral conditions (saliva and shearing at 10 s-1) during the shear time, but this behavior was more evident in starch-based matrices. The lubrication properties of the different matrices depended mainly on the thickener concentration since equi-viscous samples (NE-ST-EV and NE-XG-EV) showed higher coefficient of friction (CoF) values. Finally, oral oily coating was more related to the oil droplets size than to the type of thickener since all NE-based matrices showed a higher amount of coating retained compared to the CE-based ones. Therefore, NE-based matrices could be used as an alternative to increase mouthfeel sensations in food emulsions.

Rescuing Flavor Identity and Dynamic Perception in Puréed Dishes; A Restructuring Solution for the Purée Diet.

With age, difficulties with masticating and swallowing means food consistency and structure must be modified, such as puréeing food. However, elderly consumers have reported that puréed food's taste lacks appeal. This study shows how puréeing food changes the recognition and dynamics of flavors and new strategies to improve them. Further, to measure the identification and dynamics of flavor, a new sensory method was investigated that combined Free Choice and Temporal Order of Sensation (Free-TOS). Three dishes (macaroni, pizza, and potato salad), their purées, and three pasta purées with added flavors (cheese and dry-cured ham; added directly or as an oil in water emulsion or using two types of emulsions (oil in water and water in oil) were assessed by three groups of 60 consumers using Free-TOS. Results showed that in the purée the frequency of mentioned sensations decreased compared with the dish, as it was more difficult to identify flavors. Adding flavors in powder form only allowed a cheese/ham flavor identification, but in the purées with emulsions, it was possible to identify the dry-cured ham flavor. Therefore, this study showed that the Free-TOS method does not need a predetermined attribute list and registers the actual identified flavors and their order of appearance.

Do Consumers Change Their Perception of Liking, Expected Satiety, and Healthiness of a Product If They Know It Is a Ready-to Eat Meal?

A ready-to-eat meal is a prepared meal within a container or package that requires little preparation or heating before consumption. Despite ready-to-eat meals being widely consumed, to date, little information is available on the consumers' perceptions of such products in comparison to a homemade meal. Thus, three groups of eighty participants took part in the present study; each group evaluated five ready-to-eat meals (Pasta, Meatballs, Salad, Beans, and a Sandwich) using one of the following conditions: (i) observation of the packaging, (ii) observation of the meal on a plate (photographs), and (iii) tasting the ready-to-eat product with the packaging being presented alongside the meal. Consumers were asked about their liking, satiety, and healthiness perception. The results showed that both the ready-to-eat pack and sensory quality of the product highly impact liking and healthiness perceptions. Being a ready-to-eat meal in a pack has a negative impact on liking expectations of the meal; however, the sensory quality can either counteract these effects or increase them. Expected satiety of meals depends on the type of meal and varies slightly according to the evaluation condition.

Are mixed meat and vegetable protein products good alternatives for reducing meat consumption? A case study with burgers.

The principal motivations for the worldwide trend towards reducing meat consumption are health, the environment and animal welfare. The present study investigated the willingness of omnivores to introduce mixed (beef-vegetable protein) and 100% vegetable protein products into their diet. The participants (n = 251) were young adult omnivores who consumed meat at least once a week. The stimuli were images of six different products representing two beef burgers, two mixed-protein burgers (50% beef and 50% seitan or soy) and two 100% vegetable protein burgers (seitan and soy). The participants were asked to write down spontaneous associations with each product (Word Association technique) and score their expected liking and purchase intention for them. In addition, they completed a questionnaire (36 statements) to evaluate their attitude towards meat reduction, considering six aspects: diet, habits, ethics, hedonism, health, and the environment. According to their response to these statements, they were classified into three attitude groups: anti- (ANTI, n = 106), intermediate- (INTERM, n = 89), and pro- (PRO, n = 56) meat reduction. All the participants expected to like the 100% beef burger most, the PRO group expected to like all six products to a similar degree and the ANTI group expected to like the mixed product significantly more than the 100% vegetable product, indicating that the introduction of mixed proteins could be a small first step towards meat reduction for those most attached to meat. The associations elicited by the different burgers were mostly the same but were mentioned with different frequencies, which also depended on the attitude group. These distinctive association patterns showed clear connections to the motives underlying each group's attitude towards meat reduction. It may be concluded that mixed products would be a reliable although timid option for consumers who are attached to meat to reduce their meat intake, while any of the products containing vegetable proteins would be an option for consumers who are more favourable towards meat reduction.

Psychometric validation of a Patient-Centred Quality of Cancer Care Questionnaire in Mexico.

OBJECTIVES: To develop and validate a Patient-Centred Quality of Cancer Care Questionnaire in Spanish (PCQCCQ-S) appropriate to the Mexican context. DESIGN: Psychometric validation of a questionnaire. SETTING: Two public oncology hospitals in Mexico City. PARTICIPANTS: 1809 patients with cancer aged ≥18 years. SOURCE OF INFORMATION: Cross-sectional survey. METHODS: The validation procedures comprised (1) content validity through a group of experts and patients; (2) item reduction and evaluation of the factor structure, through an exploratory factor analysis based on the polychoric correlation matrix; (3) internal consistency using Cronbach's alpha; (4) convergent validity between the PCQCCQ-S and supportive care needs scale; (5) correlation analysis between the PCQCCQ-S and quality of life scale by calculating Spearman's rank-correlation coefficient; and (6) differentiation by 'known groups' through the Wilcoxon rank-sum test. RESULTS: The PCQCCQ-S has 30 items with the following five factors accounting for 96.5% of the total variance: (1) timely care; (2) clarity of the information; (3) information for treatment decision-making; (4) activities to address biopsychosocial needs; and (5) respectful and coordinated care. Cronbach's alpha values ranged from 0.73 to 0.90 among the factors. PCQCCQ-S has moderate convergent validity with supportive care needs scale, revealing that higher quality is correlated with lower patient needs. PCQCCQ-S has acceptable ability to differentiate by 'known groups', showing that older patients and those with low levels of education perceived lower total quality of care as compared with their counterparts. CONCLUSION: PCQCCQ-S has acceptable psychometric properties and can be used to measure quality of patient-centred cancer care in Mexico and serve as a reference to develop PCQCCQ-S in other Spanish-speaking countries.

Oral Wine Texture Perception and Its Correlation with Instrumental Texture Features of Wine-Saliva Mixtures.

Unlike solid food, texture descriptors in liquid food are scarce, and they are frequently reduced to the term viscosity. However, in wines, apart from viscosity, terms, such as astringency, body, unctuosity and density, help describe their texture, relating the complexity and balance among their chemical components. Yet there is uncertainty about which wine components (and their combinations) cause each texture sensation and if their instrumental assessment is possible. Therefore, the aim of the present work was to study the effect of wine texture on its main components, when interacting with saliva. This was completed by using instrumental measurements of density and viscosity, and by using two types of panels (trained and expert). For that, six different model-wine formulations were prepared by adding one or multiple wine components: ethanol, mannoproteins, glycerol, and tannins to a de-alcoholised wine. All formulations were mixed with fresh human saliva (1:1), and their density and rheological properties were measured. Although there were no statistical differences, body perception was higher for samples with glycerol and/or mannoproteins, this was also correlated with density instrumental measurements (R = 0.971, p = 0.029). The viscosity of samples with tannins was the highest due to the formation of complexes between the model-wine and salivary proteins. This also provided astringency, therefore correlating viscosity and astringency feelings (R = 0.855, p = 0.030). No correlation was found between viscosity and body perception because of the overlapping of the phenolic components. Overall, the present results reveal saliva as a key factor when studying the wine texture through instrumental measurements (density and viscosity).

Physical effects of dietary fibre on simulated luminal flow, studied by in vitro dynamic gastrointestinal digestion and fermentation.

During the transit through the gastrointestinal tract, fibre undergoes physical changes not usually included in in vitro digestion studies even though they influence nutrient diffusion and might play a role in gut microbiota growth. The aim of this study was to evaluate how physical fibre properties influence the physical properties of gastrointestinal fluids using a gastrointestinal model (stomach, small intestine, ascending colon, transverse colon, and descending colon) (simgi®). Analysis by rheological and particle size characterisation, microbiota composition and short-chain fatty acid (SCFA) determination allows the achievement of this goal. First, the water-holding capacity (WHC), microstructure, and viscosity of eight different fibres plus agar were tested. Based on the results, potato fibre, hydroxypropyl methylcellulose (HPMC), psyllium fibres, and agar (as a control) were selected for addition to a medium growth (GNMF) that was used to feed the stomach/small intestine and colon compartments in the simgi®. During gastrointestinal digestion, GNMF was collected at 5, 30 and 55 minutes of processing at the gastric stage and after the intestinal stage. Then, samples of GNMF with faecal slurry were collected at 0, 24 and 48 h of colonic fermentation. Results showed fibre-dependence on apparent viscosity. Although psyllium was partially broken down in the stomach (decrease in particle size), it was the most viscous at the colonic stage, opposite to the potato fibre, but both led to the highest total SFCA and acetic acid production profile. On a microbiological level, the most relevant increase of bacterial growth was observed in the faecal Lactobacillus species, especially for HPMC and potato fibre, that were not digested until reaching the colon. Besides fibre fermentability, viscosity also influenced microbial growth, and it is necessary to characterise these changes to understand fibre functionality.

Aging-related changes in quantity and quality of saliva: Where do we stand in our understanding?

Saliva is crucial to oral processing of food and consequently is also related to the sensory and textural experience. It is often assumed that the secretion and properties of saliva change with age, which can result in dry mouth conditions, taste aberrations. Such changes may result in reduced nutrient intake and malnutrition besides adversely affecting the quality of life. Based on some recent research findings, this article reviews our current understandings on age-dependent changes on quantity (bulk salivary flow rate) as well as quality of saliva (e.g., composition, viscosity, lubrication) in healthy elderly individuals. The review begins with a short introduction to histological changes of salivary glands upon aging. This is followed by covering different aspects of salivary changes with key articles highlighting decreased flow rate, increased ionic concentration, decreased calcium and mucin content in saliva of elderly subjects consequently affecting the oral coating and flavor perception. We also highlight issues in data associated with respect to variance in saliva collection protocols as well as factors influencing such results other than age, such as health conditions and polypharmacy. Clear gaps in literature have been highlighted with respect to lack of quantitative data in viscoelasticity, rheology, and lubrication properties of saliva in healthy elderly population and the potential impact of changes in these material properties on sensory and textural perception of food and consequently food intake. Such insights will not only have clinical implications for maintaining optimal oral health in elderly population but also serve to optimize food for elderly population. PRACTICAL APPLICATIONS: The population has undergone a fundamental change in its age structure globally, with a rapid increase in elderly population. Innovation of tailored foods is still in its early stage to satisfy the needs of growing aging population. One of the biggest challenges in such food product development is lack of adequate understanding and characterization of endogenous factors, that is, age-related changes in saliva, which may influence oral processing of food and subsequently nutrient intake. Aging affects the salivary glands and alters quantity (flow rate) and quality (e.g., ion and protein composition, rheology, tribology) of saliva. Thus, older adults may suffer from dry mouth, taste aberration, and poor oral hygiene, greatly affecting their quality of life. This review provides insights into how age versus other health conditions influence salivary properties. Understanding of age-dependent changes in salivary rheology and tribology will be of paramount importance to optimize food for elderly population.