Dietary fibre definition revisited - The case of low molecular weight carbohydrates

Impact of resistant starch: Absorption of dietary minerals, glycemic index and oxidative stress in healthy rats

BACKGROUND & AIMS

Resistant starch (RS) is a prebiotic fiber that has been scientifically shown to control the development of obesity. Prebiotic role of RS has also seen to be very important as it helps gut bacteria to regulate fermentation and fatty acid production. This study aimed to check the different levels of RS on glycemic index, oxidative stress and mineral absorption rate in healthy rat models. To evaluate these objectives, the trial was conducted for 40 days of follow up; 10 days were the adjustment period and the collection period over 30 days.

METHODS

Thirty-six healthy female Wistar rats were divided into 4 groups of (9 animals each) NC (Normal Control: without resistant starch), RS0.20 (resistant starch: 0.20 g/kg body weight), RS0.30 (resistant starch: 0.30 g/kg body weight), RS0.40 (resistant starch: 0.40 g/kg body weight). All the diets were isocaloric and isonitroginous.

RESULTS

The impact of different levels of RS on the dry-matter intake (DMI) presented statistically significant results (p ≤ 0.05): DMI was reduced in RS (0.02) fed rats as compared to NC rats in first 3 weeks; and after 4th and 5th weeks, there was a DMI reduction of 28% in RS (0.04) fed rats. Moreover, there was no significant increase in the nutrient intake in all RS diets. The dry-matter (DM) digestibility was statistically significantly (P ≤ 0·05), which increased in all rats fed with different level of RS. The weight loss showed statistically significant results: RS (0.04) exhibited 19 g reduction in weight as compared with NC rats. Significant increase was observed in total oxidant status (TOS), in all the RS fed rats when compared with NC rats. The levels of Mg, Ca, Fe and Zn were shown to be decrease in feces analysis, which proves their better absorbance in gut. Statistically significant increase was observed in antioxidant capacity, whereas significant decrease was observed in the total weight of the animals, showing the role of RS in controlling obesity.

CONCLUSIONS

Overall, significant results were found in all dosage level of RS but long term administration of the higher dosage level (RS0.40) may need to be studied for enhanced results. RS can help improve insulin sensitivity in overweight adults.

Recommendations for the Use of Dietary Fiber to Improve Blood Pressure Control

According to several international, regional, and national guidelines on hypertension, lifestyle interventions are the first-line treatment to lower blood pressure (BP). Although diet is one of the major lifestyle modifications described in hypertension guidelines, dietary fiber is not specified. Suboptimal intake of foods high in fiber, such as in Westernized diets, is a major contributing factor to mortality and morbidity of noncommunicable diseases due to higher BP and cardiovascular disease. In this review, we address this deficiency by examining and advocating for the incorporation of dietary fiber as a key lifestyle modification to manage elevated BP. We explain what dietary fiber is, review the existing literature that supports its use to lower BP and prevent cardiovascular disease, describe the mechanisms involved, propose evidence-based target levels of fiber intake, provide examples of how patients can achieve the recommended targets, and discuss outstanding questions in the field. According to the evidence reviewed here, the minimum daily dietary fiber for adults with hypertension should be >28 g/day for women and >38 g/day for men, with each extra 5 g/day estimated to reduce systolic BP by 2.8 mm Hg and diastolic BP by 2.1 mm Hg. This would support a healthy gut microbiota and the production of gut microbiota-derived metabolites called short-chain fatty acids that lower BP. Awareness about dietary fiber targets and how to achieve them will guide medical teams on better educating patients and empowering them to increase their fiber intake and, as a result, lower their BP and cardiovascular disease risk.

Challenges to Increasing Dietary Fiber in White Flour and Bread

Increasing the intake of dietary fiber from staple foods is a key strategy to improve the health of consumers. White bread is an attractive vehicle to deliver increased fiber as it is widely consumed and available to all socio-economic groups. However, fiber only accounts for about 4% of the dry weight of white flour and bread compared to 10-15% in whole grain bread and flour. We therefore discuss the challenges and barriers to developing and exploiting new types of wheat with high fiber content in white flour. These include defining and quantifying individual fiber components and understanding how they are affected by genetic and environmental factors. Rapid high throughput assays suitable for determining fiber content during plant breeding and in grain-utilizing industries are urgently required, while the impact of fiber amount and composition on flour processing quality needs to be understood. Overcoming these challenges should have significant effects on human health.

Composition and Functional Properties of the Edible Spear and By-Products from Asparagus officinalis L. and Their Potential Prebiotic Effect

Asparagus is a healthy food appreciated for its organoleptic characteristics, nutritional composition and physiological properties. During its industrial processing, a large amount of by-products are generated, since only the apical part of the vegetable is considered edible and a large amount of by-products are generated that could be of nutritional interest. Therefore, the nutritional composition of the edible part and the two by-products of the plant (root and stem) was evaluated, including dietary fiber, inulin, low-molecular-weight carbohydrates, low-molecular-weight polyphenols and macromolecular polyphenols. The hydration properties, oil retention capacity, glucose retardation index and impact on bacterial growth of both probiotic bacteria and pathogenic strains were determined. All samples were high in fiber (>22 g/100 g dw), fructans (>1.5 g/100 g dw) and polyphenolic compounds (>3 g/100 g dw) and had good water-, oil- and glucose-binding capacity. In addition, they promoted the growth of probiotic strains but not pathogenic ones. The effects were more pronounced in the spear by-product samples and appear to be related to the components of dietary fiber. The results indicate that edible spear has potential beneficial effects on host health and microbiota when ingested as part of a healthy diet, while the by-products could be used as supplements and/or as natural ingredients in fiber-enriched foods that require emulsification and are intended to achieve a prebiotic effect.

Nutritional, Fatty Acids, (Poly)phenols and Technological Properties of Flower Powders from Fuchsia hybrida and Alcea rosea

Fuchsia hybrida (pena pena) and Alcea rosea L. (malvagoma) are predominant flowers in the "Horchata" infusion, a traditional beverage in southern Ecuador, to which some medicinal properties are attributed. However, there is very little published information about these two flower species. The current study aimed to obtain two dehydrated powders of these flowers and to determine their chemical composition, physicochemical and technological properties, polyphenols, and fatty acids profile. In both powdered flowers, carbohydrates predominated, with a significant content of dietary fiber and fructose. The fat content was low, mainly comprising polyunsaturated fats (62% pena pena and 52% malvagoma), with a significant presence of omega-3 (C18:3n-3,6,9) and omega-6 (C18:2n-6,9) fatty acids, showing a better n-6/n-3 balance in the malvagoma flowers. Pena pena flowers are highlighted by high anthocyanin and ellagic acid amounts, whereas malvagoma contains a high content of flavanones. In conclusion, the studied powder flowers, could be used in the formulation of new foods or as source of anthocyanins as food colorants.

Dietary Fibre Intake in Chile: 13 Years after the Last National Report

BACKGROUND

The objective is to provide updated data on the intake of total dietary fibre in the population residing in Chile and to identify food sources that contribute most to its intake, as well as its association with different sociodemographic and nutritional status-related determinants.

METHODS

In this descriptive cross-sectional study, a nationwide survey was applied to determine fibre intake using an instrument that has been previously validated in the resident population of Chile.

RESULTS

The sample consisted of a total of 1761 participants. Dietary fibre intake was 12.8 ± 7.1 g/day for the total population, and 90% of participants did not meet the recommendation, with no differences in consumption by sex, geographical area, and the urban/rural population. A lower consumption was found among participants with overweight and obesity. According to food groups, bread was the major contributor to fibre intake, providing 4.39 ± 3.05 g/day, followed by cereals (2.26 ± 2.80 g/day) and vegetables (1.85 ± 1.59 g/day).

CONCLUSIONS

90% of the population consume less fibre than recommended, and bread is the main food source; these data are critical for the development of strategies that are aimed at changing habits in order to improve diet quality.

Nutritional Description of Processed Foods with Fibre-Related Nutrition Claims in Spain: The BADALI Project

Fibre is one of the most beneficial nutrients for health and is very frequently used in nutrition claims (NCs) to promote foods. These claims may lead consumers to believe that products bearing them are healthy and/or healthier than those without them. The main objective of this work is to address this belief. This is the first exhaustive analysis of seven processed food types with fibre-related NCs (six cereal-based and one plant-based meat analogues) comparing them with those without these claims. The Spanish Food Database, BADALI, was used for this study. Results show that as many as 88.7% of processed foods with fibre-related NCs are classified as 'less healthy' according to the Nutrient Profile Model developed by the Pan American Health Organization (PAHO-NPM). When compared to foods without these NCs, similar results were obtained in the whole sample. Most of the observed divergences when analysing individual critical nutrients by food type indicate a deterioration of the nutritional quality. Foods with fibre-related NCs contained more fibre. The more frequent use of whole grain cereals or other fibre-specific ingredients may contribute to this. Some other nutritionally relevant differences were observed and half of them reflected a deterioration of the nutritional quality. In addition, these foods presented a lower prevalence of the organic version, as well as similar rates of mineral and vitamin fortification. Therefore, processed foods with fibre-related NCs are not healthy, nor present a better nutritional profile than those without.

Plant-Based Dietary Fibers and Polysaccharides as Modulators of Gut Microbiota in Intestinal and Lung Inflammation: Current State and Challenges

Recent research has underscored the significant role of gut microbiota in managing various diseases, including intestinal and lung inflammation. It is now well established that diet plays a crucial role in shaping the composition of the microbiota, leading to changes in metabolite production. Consequently, dietary interventions have emerged as promising preventive and therapeutic approaches for managing these diseases. Plant-based dietary fibers, particularly polysaccharides and oligosaccharides, have attracted attention as potential therapeutic agents for modulating gut microbiota and alleviating intestinal and lung inflammation. This comprehensive review aims to provide an in-depth overview of the current state of research in this field, emphasizing the challenges and limitations associated with the use of plant-based dietary fibers and polysaccharides in managing intestinal and lung inflammation. By shedding light on existing issues and limitations, this review seeks to stimulate further research and development in this promising area of therapeutic intervention.