Resistant Maltodextrin Research Articles

A review of current analytical methods for the determination of dietary fiber in food

Fiber benefits health and is an essential requirement in the body's daily diet. The definition of fiber has been evolving over the past 70 years. Initially, the definition of fiber focused only on plant cell walls (cellulose, hemicellulose, pectin, cutin, glycoprotein) and intracellular storage and secretion substances (gum, mucilage). More recently, the world has focused on resistant starch and oligosaccharides. The CODEX definition of dietary fiber includes all non-digestible carbohydrate polymers with a degree of polymerization of 3 or higher, provided that they benefit health. Fiber has many components, requiring the development of different methods to analyze components such as fructo-oligosaccharide, galacto-oligosaccharide, polydextrose, resistant maltodextrin, resistant starch, etc. A series of AOAC methods have been developed to explore different types of fiber, and these methods are still valid and widely used. For the analysis of total fiber content, the enzymemass method according to Prosky (AOAC 985.29) was considered the gold standard when it was first published. However, this method only determines a part of the fiber. When adding up the specific fiber components calculated from different methods, some types of fiber are double counting. Therefore, the method for determining total fiber is constantly updated and revised. The Enzymatic-Gravimetric-Liquid Chromatography method has been developed and can fully determine the components of dietary fiber; the newly published updated version is AOAC 2022.01.

Enzyme-assisted hydrolysis and microencapsulation for production of functional food with dietary fructooligosaccharides from Nam Dok Mai mango (Mangifera indica L.)

This research aimed to develop a mango juice microcapsule with high fructooligosaccharides (FOS) content using enzymatic hydrolysis with Novozym® 960 and Pectinex® Ultra SP-L. Enzymatic hydrolysis was done by varying factors which included enzyme concentration (0.1 and 0.2 mL Novozym® 960/100 mL sample and 0.5 and 1.0 mL Pectinex® Ultra SP-L/100 mL sample), incubation temperature (45–55 °C) and incubation time (60 and 120 min). Using 0.2 mL/100 mL sample of Novozym® 960 reduced sugar content by converting 80% of sucrose and increasing FOS levels by 20%. The optimal condition for spray drying increased-FOS mango juice microcapsules were established with 160 °C inlet temperature. Encapsulating agents were; resistant maltodextrin (RM), gum arabic (GA), and a combination of both at 1:1, 2:1, and 3:1 v/v ratios. Microcapsule powders exhibited a light greenish-yellow hue and optimal conditions involved a 3:1 ratio of RM and GA (GRM), which exhibited the highest phenolic compounds, flavonoid content, and antioxidant activity (p ≤ 0.05). Microcapsules stored in vacuum-sealed aluminum bags best maintained physicochemical and microbial quality over a 45-day period. Microencapsulated mango juice has potential to be used in the food industry, including its role in beverage production and as a component in functional foods.

A Comparative Study of Resistant Dextrins and Resistant Maltodextrins from Different Tuber Crop Starches.

The anti-digestibility of resistant dextrin (RD) and resistant maltodextrin (RMD) is usually significantly affected by processing techniques, reaction conditions, and starch sources. The objective of this investigation is to elucidate the similarities and differences in the anti-digestive properties of RD and RMD prepared from three different tuber crop starches, namely, potato, cassava, and sweet potato, and to reveal the associated mechanisms. The results show that all RMDs have a microstructure characterized by irregular fragmentation and porous surfaces, no longer maintaining the original crystalline structure of starches. Conversely, RDs preserve the structural morphology of starches, featuring rough surfaces and similar crystalline structures. RDs exhibite hydrolysis rates of approximately 40%, whereas RMDs displaye rates lower than 8%. This disparity can be attributed to the reduction of α-1,4 and α-1,6 bonds and the development of a highly branched spatial structure in RMDs. The indigestible components of the three types of RDs range from 34% to 37%, whereas RMDs vary from 80% to 85%, with potato resistant maltodextrin displaying the highest content (84.96%, p < 0.05). In conclusion, there are significant differences in the processing performances between different tuber crop starches. For the preparation of RMDs, potato starch seems to be superior to sweet potato and cassava starches. These attributes lay the foundation for considering RDs and RMDs as suitable components for liquid beverages, solid dietary fiber supplements, and low glycemic index (low-GI) products.

Carbohydrate Core-Shell Electrosprayed Microcapsules for Enhanced Oxidative Stability of Vitamin A Palmitate.

Vitamin A is an essential micronutrient that is readily oxidized. In this study, the encapsulation of vitamin A palmitate (AP) within a core-shell carbohydrate matrix by co-axial electrospray and its oxidative stability was evaluated. The electrosprayed core-shell microcapsules consisted of a shell of octenyl succinic anhydride (OSA) modified corn starch, maltose (Hi-Cap), and a core of ethyl cellulose-AP (average diameter of about 3.7 µm). The effect of different compounds (digestion-resistant maltodextrin, soy protein hydrolysate, casein protein hydrolysate, and lecithin) added to the base core-shell matrix formulation on the oxidative stability of AP was investigated. The oxidative stability of AP was evaluated using isothermal and non-isothermal differential scanning calorimetry (DSC), and Raman and Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy methods. The core-shell carbohydrate matrix minimizes the amount of AP present at the microparticle surface, thus protecting AP from oxidation. Furthermore, the most effective oxidation protection was achieved when casein protein hydrolysate was added to the core of the microcapsule due to hydrophobic and hydrogen bond interactions with AP and by the resistant maltodextrin in the shell, which acted as a filler. The utilization of ethanol as a solvent for the dispersion of the core compounds increased the hydrophobicity of the hydrolyzed proteins and contributed to the enhancement of their antioxidant ability. Both the carbohydrate core-shell microcapsule prepared by co-axial electrospray and the addition of oxidation protection compounds enhance the oxidative stability of the encapsulated AP.

Gastrointestinal Tolerability and Acute Glycemic Response of Oligosaccharides and Polysaccharides from Cellulose and Xylan in Healthy Adults: Two Double-Blinded, Randomized, Controlled, Cross-over Trials

Objective The aim of this study was to investigate the gastrointestinal tolerability, glycemic and insulinemic responses of Plant Fiber Extract (PFE), a mixture comprising of oligosaccharides and polysaccharides derived from cellulose and xylan. Methods Two double-blind, randomized, controlled, cross-over trials were conducted in healthy adults. In the first trial, participants (n = 29) consumed either 25, 35 or 45 g per day of PFE or resistant maltodextrin (Control) for 14 days. The occurrence and severity of gastrointestinal (GI) symptoms, stool parameters, and safety outcomes were evaluated with a combination of surveys and blood analysis respectively. In the second trial (n = 20), the post-prandial glycemic and insulinemic responses after the ingestion of 20 g of PFE diluted in water or incorporated into chocolate chips was measured and then compared to that of glucose and regular chocolate, respectively. Results For all timepoints (0, 7 and 14 days), within any given dose group, there was no statistically significant difference in the GI symptoms score between PFE and Control. Further, for each test product (PFE or Control), no difference was observed in the same dose group from days 0 and 14. Stool consistency score and number of participants experiencing loose or watery stools was similar between products. No serious adverse events were reported and neither PFE nor Control significantly altered blood or urine safety parameters. The glycemic and insulinemic responses after PFE ingestion in comparison to glucose were 12% and 8% respectively. The glycemic and insulinemic responses after consuming chocolate containing PFE were 20% of that of regular chocolate. Conclusion PFE was well-tolerated by healthy volunteers in doses up to 45 g/day and it elicited comparatively low glycemic and insulinemic responses when consumed alone or when incorporated into a food product.

Sensory Evaluation, Physico-Chemical Properties, and Aromatic Profile of Pasteurised Orange Juice with Resistant Maltodextrin.

The beneficial health effects of prebiotics have been demonstrated in numerous research papers. However, their incorporation into daily food remains unfamiliar to consumers. This work evaluates the effects of the addition of resistant maltodextrin (RMD) on the sensory attributes of pasteurised orange juice, together with the physico-chemical properties and the aromatic profile. RMD addition increased the sweetness and decreased the acidity and bitterness, resulting in a higher overall panellists' rating of orange juice. It also proportionally increased °Brix together with density and decreased acidity. Colour changes were registered with higher RMD concentrations. Orange pulp presence affected the volume particle size distribution analysis, while RMD addition did not have any effect. The aroma volatile compounds were also analysed. Pulp-added samples showed a higher quantity of alcohol and aldehydes, whereas pulp-free samples registered higher terpene and terpenoid values. Ketones and acids were also quantified. RMD had a moderate impact on volatile compound quantifications, with the orange pulp presence playing a much more decisive role. A correspondence analysis was also performed to relate instrumental and sensory determinations for all samples. This work proves that the addition of RMD to orange juice is technologically feasible while also achieving a good response at the sensory level.

Inhibitory effects of resistant maltodextrin on rat disaccharidases: Overestimation by the method measuring released glucose

Inhibitory effects of resistant maltodextrin on rat disaccharidases: Overestimation by the method measuring released glucose

The Usefulness of Resistant Maltodextrin and Chitosan Oligosaccharide in Management of Gut Leakage and Microbiota in Chronic Kidney Disease.

Microbiota-dysbiosis-induced gut leakage is a pathophysiologic change in chronic kidney disease (CKD), leading to the production of several uremic toxins and their absorption into the bloodstream to worsen the renal complications. We evaluate the benefits of resistant maltodextrin (RMD) and chitosan oligosaccharide (COS) supplements in cell culture and CKD-induced rats. The RMD exerted a significant anti-inflammatory effect in vitro and intestinal occludin and zonula occluden-1 up-regulation in CKD rats compared with inulin and COS. While all prebiotics slightly improved gut dysbiosis, RMD remarkably promoted the relative abundance and the combined abundance of Lactobacillus, Bifidobacteria, Akkermansia, and Roseburia in CKD rats. Supplements of RMD should be advantageous in the treatment of gut leakage and microbiota dysbiosis in CKD.

Feeding with resistant maltodextrin suppresses excessive calorie intake in a high-fat diet, mediated by changes in mouse gut microbiota composition, appetite-related gut hormone secretion, and neuropeptide transcriptional levels

Consuming resistant maltodextrin (RMD) decreases food intake and increase appetite-related gut hormones, but the underlying mechanisms have remained unknown. Therefore, we aimed to elucidate the mechanisms underlying the effects of RMD feeding on food intake (appetite) using Institute of Cancer Research male mice fed with a high-fat diet (HFD-cellulose group) or HFD in which cellulose was replaced with RMD (HFD-RMD group). Feeding mice with an HFD-RMD for approximately 8 weeks inhibited excessive calorie intake and altered the gut microbiota composition. Excessive calorie intake was inhibited for several days in mice fed only with an HFD-cellulose and transplanted with fecal microbiota from the HFD-RMD group (FMT-HFD-RMD group). Moreover, in the HFD-RMD and FMT-HFD-RMD groups, serum active glucagon-like peptide (GLP)-1 and peptide tyrosine tyrosine (PYY) levels were significantly higher, and appetite-related neuropeptide gene transcription in the hypothalamus were significantly altered, compared with the HFD-cellulose and FMT-HFD-cellulose groups. These results suggested that the long-term RMD intake changed the gut microbiota composition, increased the GLP-1 and PYY secretion, and altered the appetite-related neuropeptide gene transcription in the hypothalamus, leading to suppressed excessive calorie intake in an HFD.

Digestion-Resistant Dextrin Derivatives Are Moderately Digested in the Small Intestine and Contribute More to Energy Production Than Predicted from Large-Bowel Fermentation in Rats

Background: Digestion-resistant dextrin derivatives (DRDDs), including resistant maltodextrin (RM), polydextrose, and resistant glucan (RG), have been developed as low-energy foods. However, data on the resistance of DRDDs to small-intestinal digestion are scarce.Objective: We sought to determine the site and extent of DRDD breakdown in the rat intestine and to predict its energy contributions.Methods: In vitro small-intestinal resistance of DRDDs was evaluated by the AOAC method for dietary fiber measurement and by artificial digestion with the use of pancreatic α-amylase and brush-boarder membrane vesicles. In vivo small-intestinal resistance of DRDDs was determined from the feces of male ileorectostomized Sprague-Dawley rats fed a control diet or a diet containing one of the DRDDs at 50 g/kg for 9 d (period 1) and then for 10 d (period 2), during which they received 1 g neomycin/L in their drinking water. Separately, male Sprague-Dawley rats were fed the same diets for 4 wk, and the whole-gut recoveries of DRDDs were determined from feces at days 8-10.Results: Small-intestinal resistances determined in vitro by artificial digestion (RM: 70%; polydextrose: 67%; RG: 69%) were lower than those measured by the AOAC method (RM: 92%; polydextrose: 80%; RG: 82%). In the ileorectostomized rats, fecal dry-matter excretions were consistently greater in the DRDDs than in the control. The small-intestinal resistances of the DRDDs were 68%, 58%, and 62% in period 1 and 66%, 61%, and 67% during period 2 for RM, polydextrose, and RG, respectively. The resistances did not differ among the DRDDs at either time. In the normal rats, food intakes and body weight gains did not differ among the groups. The whole-gut recovery of RM (13%) was lower than that of polydextrose (33%) and RG (29%), which did not differ.Conclusions: DRDDs were more digestible in the rat small intestine than the AOAC method. The energy contribution from small-intestine digestibility, not just large-bowel fermentability, must be considered in determining the energy contribution of DRDDs. Whether humans respond similarly needs to be tested.

High-Shear Granulation of Hygroscopic Probiotic-Encapsulated Skim Milk Powder: Effects of Moisture-Activation and Resistant Maltodextrin.

A fine, hygroscopic, and poorly flowable probiotic powder encapsulating Lactobacillus rhamnosus GG (LGG) was granulated using a high-shear granulation process, wherein a small amount of water (4%, w/w) was used for moisture-activation with or without 10% (w/w) resistant maltodextrin (RM). The process consisted of four steps; premixing, agglomeration, moisture absorption, and drying steps. The moisture content, water activity, and viable cell count were monitored during the granulation. The size, morphology, and flowability of the granules were determined. The powder was successfully converted to about 10-times-larger granules (mass mean diameter = 162-204 µm) by this process, and the granules had a 'snowball' morphology. The LGG cells were well preserved under the high-shear granulation conditions, and the viable cell count of the granules greatly exceeded the minimum therapeutic level recommended for probiotic powders. The addition of RM decreased the moisture content of the granules; improved cell resistance to drying stress; narrowed the particle size distribution, with reductions seen in both very fine and very large particles; and produced more flowable granules. Moisture sorption analysis and differential scanning calorimetry demonstrated that these positive effects of RM on granulation were primarily attributed to its water distribution ability rather than its glass transition-related binding ability.

Comparative analysis of prebiotic effects of four oligosaccharides using in vitro gut model: digestibility, microbiome, and metabolome changes.

Fructooligosaccharides (FOS), Ad-fructooligosaccharides (Ad-FOS), resistant maltodextrin (RMD), and maltooligosaccharides (MOS) are commercially available prebiotic oligosaccharides. In this study, the effects of prebiotics on the human gut microbial ecosystem were evaluated using an in vitro gut model. FOS and Ad-FOS showed tolerance to digestion, whereas RMD and MOS showed moderate digestion by digestive enzymes. In in vitro fecal fermentation, Bifidobacterium spp. increased in the following order: FOS, Ad-FOS, MOS, and RMD, whereas Bacteroides spp. increased in RMD medium. Bacteroides xylanisolvens exhibited cross-feeding by enabling the growth of other beneficial bacteria during co-culture in RMD medium. In metabolome analysis, total short-chain fatty acids (SCFAs) were highly produced in the following order: RMD, FOS, MOS, and Ad-FOS; acetate in the order of FOS, MOS/RMD, and Ad-FOS; butyrate in the order of RMD, MOS, FOS, and Ad-FOS; and propionate only in RMD. In addition, the conversion of betaine to trimethylamine was rarely affected in the following order: MOS, RMD, FOS, and Ad-FOS. Lastly, the four oligosaccharides inhibited the adhesion of pathogenic Escherichia coli to human epithelial cells to a similar extent. The comparative analysis results obtained in this study will provide comprehensive information of these substances to manufacturers and customers.

Effect of agave fructan, resistant maltodextrin and cellulose dietary fibers in gluten-based diets on protein digestibility and nitrogen utilization in vivo

Dietary fiber intake improves the digestion process and decreases glucose and cholesterol levels. However, it could decrease protein digestibility. Cellulose is an insoluble fiber of the cell wall of plants. Resistant maltodextrin is a soluble fiber preceding resistant starch. Agavin is a soluble fiber obtained from agave mezontle and stems. Considering the consumption of low-quality protein diets increases year by year, this research was aimed at assessing the effect of ingesting 5 % cellulose, Agavin and resistant maltodextrin on protein digestibility and nitrogen utilization for growth on 10 % gluten-based and casein-based diets through in vivo assay using Sprague Dawley rats. Food consumption, weight gain, and fecal excretion were measured every third day for 14 days. The nutritional quality and the better acceptance of casein triggered higher rat weight increase. The lack of protein caused lower food consumption and rat weight loss. Gluten-based diets prompted intermediate food intake and low rat weight increase. Zero or five percent of dietary fiber did not cause a relevant effect on rat weight. So, the consumption of 5 % dietary fiber can help improve nutritional habits without affecting nitrogen intake for growth. Finally, Agavin as a dietary fiber represents a suitable option for the agave industry.

The Effects of Soluble Dietary Fibers on Glycemic Response: An Overview and Futures Perspectives.

The properties of each food, composition, and structure affect the digestion and absorption of nutrients. Dietary fiber (DF), especially viscous DF, can contribute to a reduction in the glycemic response resulting from the consumption of carbohydrate-rich foods. Target and control of postprandial glycemic values are critical for diabetes prevention and management. Some mechanisms have been described for soluble DF action, from the increase in chyme viscosity to the production of short-chain fatty acids resulting from fermentation, which stimulates gastrointestinal motility and the release of GLP-1 and PYY hormones. The postprandial glycemic response due to inulin and resistant starch ingestion is well established. However, other soluble dietary fibers (SDF) can also contribute to glycemic control, such as gums, β-glucan, psyllium, arabinoxylan, soluble corn fiber, resistant maltodextrin, glucomannan, and edible fungi, which can be added alone or together in different products, such as bread, beverages, soups, biscuits, and others. However, there are technological challenges to be overcome, despite the benefits provided by the SDF, as it is necessary to consider the palatability and maintenance of their proprieties during production processes. Studies that evaluate the effect of full meals with enriched SDF on postprandial glycemic responses should be encouraged, as this would contribute to the recommendation of viable dietary options and sustainable health goals.

Stability of vitamin C, carotenoids, phenols, and antioxidant capacity of pasteurised orange juice with resistant maltodextrin storage.

Resistant maltodextrin (RMD) was added at increasing concentrations (0%, 2.5%, 5% and 7.5%) before pasteurisation to orange juice to analyse its potential protective effect on the health-related bioactive compounds of pasteurised orange juice throughout its storage time. Samples were characterised in terms of basic physico-chemical properties and bioactive compounds at the beginning of the storage. Higher concentrations of RMD proved to better preserve the bioactive compounds of orange juice, thus obtaining a higher antioxidant capacity (AC). Stability of all samples was determined by measuring the same parameters at days 0, 15, 45, 75, 105, 136 and 170 of storage. °Brix and pH were very stable in all samples along storage, while all bioactive compouds had negative variations. However, RMD addition slightly improved ascorbic acid, vitamin C, total phenols, and total carotenoids retention, improving then its AC. This effect was greater in the 5% RMD-added samples. All bioactive compounds showed a positive Pearson's correlation coefficient with AC. Colour variations were also measured at days 105 and 170. All samples had a positive variation of all colour parameters, being this clearer at day 170. This work enlights the potential functionality of RMD to better preserve the health-related compounds of pasteurised orange juice.

Optimization of flour-replacing ingredients for low-carbohydrate, gluten-free muffins via a mixture design with complete sucrose substitution by d-allulose or d-tagatose

Consumer acceptance testing found wheat flour alternatives can be combined with rare sugars to create acceptable lower sugar, gluten-free muffins. Muffins were developed and optimized using an initial screening procedure. A simplex centroid mixture design defined combinations of wheat-flour alternates. Ninety-one randomized baked blends were analyzed and compared for physical and basic sensory attributes using numerical optimization techniques. Blends of almond flour, whey protein concentrate, and a 50/50 blend of oat fibre and resistant maltodextrin achieved desired structures for high-protein and high-fibre muffins. Combinations of non-dairy coconut creamer, whey protein concentrate, and the same blend of oat fibre and maltodextrin composed the high-fat variant. Optimized flour replacement blends enabled a sugar replacement comparison in a separate categorical design. Vanilla-flavored muffins formulated with monosaccharides (allulose or tagatose) or sucrose (as a control), had sweetness levels augmented with stevia to theoretically equivalent levels. Muffins with allulose or tagatose differed from those containing sucrose in water activity and crust colour (lightness, L*). Overall liking for sucrose substituted formulations compared favorably in a consumer acceptance panel (n = 58). After providing the nutritional composition for sampled products at the conclusion of the sensory analysis, purchase intent of sugar substituted products was comparable to the control muffins.

Bioactive Compounds in Rosehip (Rosa canina) Powder with Encapsulating Agents.

Rosa canina pseudo-fruits contain interesting bioactive compounds. This work aims to evaluate the use of different biopolymers as encapsulating agents on the content of organic acids, minerals, fibers, phenols, carotenoids, and the antioxidant activity of the powdered product. Fruits were ground and freeze-dried with or without biopolymers (maltodextrin, resistant maltodextrin, cyclodextrin, and pea protein). Rosehip formulated purees with encapsulating agents are an interesting food ingredient rich in fiber and minerals that could be used in the food industry in order to obtain different functional foods. Results obtained in this study show that all formulated samples are a good source of potassium, calcium, magnesium, and manganese. Both rosehip without biopolymers and rosehip with pea protein formulations are also a good source of Zn. Formulation with pea protein can be claimed as a good source of Fe. All formulations are food ingredients with a very high content of ascorbic acid. Comparing the encapsulating agents, depending on the studied bioactive compound samples behaved differently. In conclusion, it can be indicated that pea protein is recommended as an encapsulating agent since the rosehip with pea protein sample has the highest content of fiber, minerals, organic acids, and carotenoids among the encapsulating agents studied.

Resistant Maltodextrin Consumption in a Double-Blind, Randomized, Crossover Clinical Trial Induces Specific Changes in Potentially Beneficial Gut Bacteria.

Background: We have previously reported that the addition of resistant maltodextrin (RMD), a fermentable functional fiber, to the diet increases fecal weight as well as the amount of fecal bifidobacteria. Here, we report on the targeted analysis of changes in potentially beneficial gut bacteria associated with the intervention. Objective: The primary objective of this study was to determine the effect of adding 0, 15 and 25 g RMD to the diets of healthy free-living adults on potentially beneficial gut bacteria. Methods: We expanded on our previously reported microbiota analysis in a double-blind, placebo-controlled feeding study (NCT02733263) by performing additional qPCR analyses targeting fecal lactic acid bacteria (LAB), Akkermansia muciniphila, Faecalibacterium prausnitzii and Fusicatenibacter saccharivorans in samples from 49 participants. Results: RMD resulted in an approximately two-fold increase in fecal Fusicatenibacter saccharivorans (p = 0.024 for 15 g/day RMD and p = 0.017 for 25 g/day RMD). For Akkermansia muciniphila and Faecalibacterium prausnitzii, we obtained borderline evidence that showed increased amounts in participants that had low baseline levels of these bacteria (p < 0.1 for 25 g/day RMD). We did not detect any effects of RMD on LAB. Conclusions: RMD supplementation in healthy individuals increases Fusicatenibacter saccharivorans. Albeit to a lesser extent, RMD at the higher intake level may also increase Akkermansia muciniphila and Faecalibacterium prausnitzii in individuals with low baseline levels of those two species. Potential benefits associated with these microbiota changes remain to be established in studies with quantifiable health-related endpoints.

Resistant Maltodextrin Intake Reduces Virulent Metabolites in the Gut Environment: A Randomized Control Study in a Japanese Cohort.

In recent years, there have been many reports on the effects of prebiotics on intestinal health. In particular, the consumption of resistant maltodextrin (RMD) has been reported to be beneficial. However, there has been no comprehensive quantification of the effect of RMD on the intestinal environment. Therefore, this study aimed to quantify the effects of RMD on the intestine, especially the intestinal microbiome and metabolome profiles. A randomized, double-blind, and controlled trial was conducted in 29 Japanese subjects, whose hemoglobin A1c (HbA1c) levels are larger than 6% (Clinical trial no. UMIN000023970, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000027589). The subjects consumed RMD or placebo twice per day for 24 weeks. Blood and fecal samples were collected before and after the intake. The intestinal environment was assessed by a metabologenomics approach, involving 16S rRNA gene-based microbiome analysis and mass spectrometry-based metabolome analysis. The intake of RMD increased the levels of Bifidobacterium and Fusicatenibacter and decreased deoxycholate levels. Additionally, intake of RMD lowered the levels of some opportunistic virulent metabolites, such as imidazole propionate and trimethylamine, in subjects with an initially high amount of those metabolites. RMD may have beneficial effects on the gut environment, such as commensal microbiota modulation and reduction of virulence metabolites, which is known as a causative factor in metabolic disorders. However, the effects of RMD partially depend on the gut environmental baseline.

Oral Intake of Slowly Digestible α-Glucan Such as Resistant Maltodextrin Leads to Increased Secretion of Glucagon-Like Peptide-2 in Rats and Helps Thicken Their Ileal Mucosae.

To investigate whether the oral intake of slowly digestible α-glucan (SDG) could have a trophic (i.e., thickening) effect on their ileal mucosae, for 10 d, rats were given control (non-SDG), 10% isomaltodextrin (IMD) or 10% resistant maltodextrin (RMD) diets. In addition, experimental rat groups were further divided into two groups each and their diets either had or had not 1% sodium carboxymethylcellulose (CMC) added as a thickening agent. In the jejuna and the ilea, compared with control rats, the villus length and the mucosal thickness, but not the crypt depth, were significantly greater in the RMD-fed rats, with the trophic effect being weaker in the IMD-fed rats than in the RMD-fed rats. The colonic crypt depth was significantly greater in SDG groups than in the control group. The concentration of plasma glucagon-like peptide (GLP)-2 in the portal veins of the RMD group but not the IMD group was significantly higher than in the control group, with no effect of CMC supplementation on its concentration. The concentrations of cecal short-chain fatty acids did not significantly increase with SDG supplementation except for propionate concentration of the IMD-supplemented rats, compared with those in the control rats. We concluded that SDGs, especially RMD, thickened the mucosae of the rat distal small intestines. In particular, this effect of RMD but not IMD could have resulted from increased glucose available as a secretagogue of the trophic hormone GLP-2, in the ileum.