The effect of viscous soluble dietary fiber on nutrient digestion and metabolic responses Ⅱ: In vivo digestion process

Using dietary fiber as stabilizer in dairy products: β-glucan and inulin-type fructans

β-glucan and inulin-type fructans, considering their beneficial effects on health, are the favorite dietary fibers in recent years. This review firstly gives information on the health-promoting effects of these two fibers, and then, using them in dairy products. They can be used in different dairy products, depending on their properties. However, their effect levels and forms may be different. Especially in probiotic products, these fibers can be used as a multi-functional additive because of their satisfactory stability in dairy products. The stabilizer effect can change in dairy products (e.g., ice cream, beverage) with variable composition/formulation. β-glucan and inulin-type fructans develop textural or rheological properties of dairy products that have relatively more standard composition (such as yogurt, cheese), at varying degrees depending on the proportion. Since the additives used to increase the stability of foods or to extend their shelf life are compounds that are beneficial for health, their usage areas should be increased, and their different potential effects should be known. For this reason, in this review, current information about health effects and usage areas of these components discussed in detail. Consequently, the texture improver effect of these two dietary fibers on dairy products is crucial and has no effect (positive/negative) on physicochemical or flavor properties. Although individual studies have reported a reduction in the amount of acetaldehyde in yogurt or effects that may cause undesirable functional properties in mozzarella cheese, most studies have proven that fiber addition does not have an adverse effect on the properties other than texture.

Lowering glycemic levels via gastrointestinal tract factors: the roles of dietary fiber, polyphenols, and their combination

Dietary fiber (DF) and polyphenols (DP) are typical blood sugar-lowering components, and both play distinct yet interconnected roles in exerting their blood sugar-lowering effects. We comprehensively summarized the single and combined effects of DF and DP on blood glucose homeostasis through regulating the relevant factors in the upper gastrointestinal tract (UGT) and lower gastrointestinal tract (LGT). In the UGT, DF slowed down glucose metabolism by enhancing digesta viscosity and hindering enzyme-substrate interaction. DP primarily targeted enzymes and substrates. When combined, DP enhanced the adsorption capacity of DF for glucose. DF weakened DP's inhibitory effect on enzymes. Both DF and DP disrupted glucose intestinal uptake via physical or genomic modulation, but the co-consumption of DF and DP demonstrated a lower inhibitory effect on glucose uptake than DP alone. In the LGT, DF and DP showed synergistic or antagonistic effects on gut microbiota. Remarkably, whole foods exhibited potent prebiotic effects due to their compound-rich matrix, potentially enhancing glucose homeostasis and expanding dietary options for glucose regulation research.

Gastrointestinal Fermentable Polysaccharide Is Beneficial in Alleviating Loperamide-Induced Constipation in Mice

To investigate the role of gastrointestinal (GI) polysaccharide fermentation in alleviating constipation, two polysaccharide fractions were isolated from a soluble fiber extract with determined anti-constipation activity: a 2.04 kDa neutral fraction (SSP-1) contained 99.29% glucose, and a 41.66 kDa acidic fraction (SSP-2) contained 63.85% uronic acid. After mice were given loperamide for 14 d to induce constipation, the GI transit rate increased significantly in the SSP-1 group (p < 0.05) but not in the SSP-2 group. The stool weight in the SSP-2 group was significantly higher than that in SSP-1 (383.60 mg vs. 226.23 mg) (p < 0.05). Both SSP-1 and SSP-2 groups had significantly increased serum gastrin and motilin levels (p < 0.05) and changes in their fecal short-chain fatty acid (SCFA) profiles, while SSP-1 showed better fermentation properties than SSP-2 in terms of statistically higher fecal contents of acetic acid and total SCFAs (p < 0.05). Bioinformatic analysis indicated that SSP-1 upregulated bacteria such as Oscillibacter to improve SCFA metabolism and stimulate GI hormone secretion, while SSP-2 had less influence on the gut microbiota. These results suggest that the neutral polysaccharide with superior GI fermentation properties exerted beneficial effects on constipation, while the less fermentable pectic fraction might act as a stool-bulking agent.

Ultraprocessed plant-based foods: Designing the next generation of healthy and sustainable alternatives to animal-based foods

Numerous examples of next-generation plant-based foods, such as meat, seafood, egg, and dairy analogs, are commercially available. These products are usually designed to have physicochemical properties, sensory attributes, and functional behaviors that match those of the animal-sourced products they are designed to replace. However, there has been concern about the potential negative impacts of these foods on human nutrition and health. In particular, many of these products have been criticized for being ultraprocessed foods that contain numerous ingredients and are manufactured using harsh processing operations. In this article, the concept of ultraprocessed foods is introduced and its relevance to describe the properties of next-generation plant-based foods is discussed. Most commercial plant-based meat, seafood, egg, and dairy analogs currently available do fall into this category, and so can be classified as ultraprocessed plant-based (UPB) foods. The nutrient content, digestibility, bioavailability, and gut microbiome effects of UPB foods are compared to those of animal-based foods, and the potential consequences of any differences on human health are discussed. Some commercial UPB foods would not be considered healthy based on their nutrient profiles, especially those plant-based cheeses that contain low levels of protein and high levels of fat, starch, and salt. However, it is argued that UPB foods can be designed to have good nutritional profiles and beneficial health effects. Finally, areas where further research are still needed to create a more healthy and sustainable food supply are discussed.

Food biopolymer behaviors in the digestive tract: implications for nutrient delivery

Biopolymers are prevalent in both natural and processed foods, serving as thickeners, emulsifiers, and stabilizers. Although specific biopolymers are known to affect digestion, the mechanisms behind their influence on the nutrient absorption and bioavailability in processed foods are not yet fully understood. The aim of this review is to elucidate the complex interplay between biopolymers and their behavior in vivo, and to provide insights into the possible physiological consequences of their consumption. The colloidization process of biopolymer in various phases of digestion was analyzed and its impact on nutrition absorption and gastrointestinal tract was summarized. Furthermore, the review discusses the methodologies used to assess colloidization and emphasizes the need for more realistic models to overcome challenges in practical applications. By controlling macronutrient bioavailability using biopolymers, it is possible to enhance health benefits, such as improving gut health, aiding in weight management, and regulating blood sugar levels. The physiological effect of extracted biopolymers utilized in modern food structuring technology cannot be predicted solely based on their inherent functionality. It is essential to account for factors such as their initial consuming state and interactions with other food components to better understand the potential health benefits of biopolymers.

Postprandial Glycemic Response to Whole Fruit versus Blended Fruit in Healthy, Young Adults

While increased intake of dietary fiber is known to reduce postprandial glycemic response, it is less understood whether the disruption of dietary fiber, in a blender, alters the postprandial glycemic response. We compared the postprandial glycemic response in 20 young, healthy college students (12 female, 8 male) after consuming whole fruit vs. blended fruit. The fruit included gala apple, with the seeds removed, and blackberries. We used a repeated measures two-way ANOVA with fruit treatment as the within-subject variable, sex as the between-subjects factor, and glucose maximum, glucose incremental area under the curve (iAUC), and 60 min glucose as dependent variables. Glucose maximum and glucose iAUC were significantly lower (p < 0.05) in blended fruit compared to whole fruit and 60 min glucose was marginally significantly lower (p = 0.057) in blended fruit compared to whole fruit. Sex was not a significant main effect and sex*treatment was not a significant interaction for any of the dependent variables. We hypothesize that a reduced glycemic response in blended apple and blackberries compared to whole apple and blackberries might be associated with the release of dietary fiber and nutritive components from ground blackberry seeds.

Characterization of ultrasonically extracted flaxseed polysaccharide gum and assessing its lipid-lowering potential in a rat model

Flaxseed polysaccharide gum (FPG) was extracted through the ultrasound-assisted process using water as a solvent with a yield ranging from 8.05 ± 0.32% to 12.23 ± 0.45% by changing different extraction variables. The extracted FPG was analyzed for its functional groups and antioxidant potential. The maximum DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity (≈100%) of FPG was noted at concentrations beyond ≈10 mg·ml^-1. The maximum inhibition percentage through ABTS (2,2'-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid) (72.4% ± 1.9%) was noted at 40 mg·ml^-1, which was observed to be less when compared to DPPH at the same concentration. The total antioxidant potential of the FPG solution at a concentration of 10 mg·ml^-1 was equivalent to 461 mg ascorbic acid, which tends to increase with concentration at a much lower scope. The in vivo trial suggested that the least weight gain was noted in experimental groups G₂ and Gh₂. A significant reduction in total cholesterol was noticed in G₁ (-14.14%) and G₂ (-17.72%) and in Gh₁ (-22.02%) and Gh₂ (-34.68%) after 60 days of the trial compared to the baseline values. The maximum reduction in total triglyceride was observed in Gh₂ (-25.06%) and Gh₁ (-22.01%) after 60 days of the trial. It was an increasing trend in high-density lipoprotein cholesterol (HDL-c) in different experimental groups G₂ (10.51%) than G₁ (5.35%) and Gh₂ (48.96%) and Gh₁ (31.11%), respectively, after 60 days of study interval. Reduction of -5.05% and - 9.45% was observed in G₁ and G₂, while similar results were observed in Gh₁ and Gh₂. Conclusively, results suggested a possible protective role of FPG against hyperlipidemia.

Complexation between burdock holocellulose nanocrystals and corn starch: gelatinization properties, microstructure, and digestibility in vitro

Holocellulose nanocrystals (hCNCs), with hydrodynamic diameters (D_Z) ranging from about 600 to 200 nm, were prepared by treating burdock insoluble dietary fiber (IDF) with enzymes and ultrasonic power. It was revealed that hCNCs improved the viscosity of corn starch (CS) during pasting and inhibited its short-term retrogradation. Besides, the crystallinity, short-range order of the double helix, viscoelastic properties, and microstructure compactness of CS gels improved remarkably in the presence of burdock hCNCs. These effects were both size- and dose-dependent, which primarily originated from the hydrogen bonding between hCNCs and amylopectin or leached amylose. In this regard, the digestion of CS gels containing hCNCs was remarkably retarded because of the reduced accessibility of digestive enzymes to the glycosidic bonds. Therefore, burdock hCNCs, prepared from natural resources using green techniques, hold potential applications in functional foods of a low glycemic index.

Novel freeze-drying matrix for enhancing viability of probiotic supplemented milkshake during simulated in vitro digestion

Probiotics are recognized as essential components to improve health and regulate immune functions. Despite several probiotic formulations, the anticipation for non-fermented probiotic foods is noticeable. The objective of the study was to investigate and develop a stable freeze-dried synbiotic formula that can serve the purpose of a probiotic enricher as well as a thickener in an instant milk-based beverage. The freeze-dried synbiotic formula was assessed for the protective effect of whey protein-polysaccharides for retaining high cell viability during freeze-drying and subsequent storage. Highest survival rates were obtained for WP-15%I (85.90%), WP-15%P (85.43%), and WP-0.6%X (80.23%) combinations. During storage at 4 °C for 75 d, a lower specific rate of cell inactivation was found for WP-0.4%X (-0.0184 day^-1), WP-5%P (-0.0197 day^-1) and WP-5%I (-0.023 day^-1). Subsequent ingestion of synbiotic portions in the gastro-intestinal digestion simulator was studied in two ways to enumerate the retaining cell viability and understanding the importance of co-ingested food. Synbiotic portions reconstituted in milk showed higher probiotic survival through gastrointestinal digestion than water demonstrating the significance of supporting food matrix for improving the survival and efficiency of probiotics.

The effect of guar gum consumption on the lipid profile in type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials

Dyslipidemia is a common encounter in type 2 diabetes mellitus (T2DM) and the current strategies to manage it are still suboptimal. Subsequently, identifying newer molecules with lipid-lowering effects is necessary. A great deal of attention has been given in recent years to fiber supplements, e.g., guar gum. Thus, we screened and evaluated the quality of the evidence regarding the benefits of guar gum supplementation in T2DM and conducted a meta-analysis to assess the effects of this compound on serum lipids in T2DM. We conducted a comprehensive search in PubMed/Medline, Web of Science, Scopus, Google Scholar and Embase, from the inception of these databases until January 2021. In total, 11 papers were included based on the eligible criteria in our meta-analysis. The meta-analysis of the eligible trials demonstrated a significant reduction of total cholesterol (TC) (WMD: -20.32 mg/dL, 95% CI: -27.02, -13.62, P < 0.001) and low-density lipoprotein cholesterol (LDL-C) (WMD: -14.52 mg/dL, 95% CI: -20.69, -8.35, P < 0.001) following guar gum supplementation in T2DM patients. The subgroup analysis based on the dosage (g/day) of this compound revealed that ≥20 g/day of guar gum led to a notable decrease in triglyceride (TG) levels (WMD: -12.55 mg/dL, 95% CI: -23.72, -1.37, P = 0.02) versus < 20 g/day (WMD: -1.84 mg/dL, 95% CI: -32.18, 28.49, P = 0.90). Guar gum supplementation had no effects on high-density lipoprotein cholesterol (HDL-C) (WMD: 0.66 mg/dL, 95% CI: -0.95, 2.28, P = 0.42). Guar gum consumption has lipid-lowering effects when administered to patients with type 2 diabetes mellitus and it is particularly able to reduce TC, LDL-C and TG levels. Further research is however needed to confirm our findings.