Long-chain Inulin Research Articles

Effects of phosphorylation-modified long-chain inulin on wheat starch: Physicochemical properties and retrogradation behaviors

In this research, modification of long-chain inulin (FXL) through phosphorylation (PFXL) to enhance its application in wheat starch (WS) and starch-based products. The impacts of PFXL on the pasting, rheology, microstructure, and retrogradation characteristics of WS were researched. The findings revealed that PFXL significantly reduced both the breakdown and setback values of WS. Additionally, the incorporation of PFXL reduced the viscoelasticity of WS paste and improved its fluidity. Scanning electron microscopy indicated that higher PFXL levels (>5 %) produced small fragments that partially covered the three-dimensional honeycomb structure of WS paste, thereby reducing water loss during short-term storage. PFXL also altered water distribution in WS gels, depending on concentration and storage duration. X-ray diffraction and Fourier-transform infrared spectroscopy suggested that PFXL effectively inhibited amylopectin recrystallization. Compared to FXL, PFXL exhibited a more pronounced ability to inhibit the aging of WS in short- and long-term storage.

Elucidating the mechanism of inulin-induced improvement in the structural and functional properties of High-moisture extruded products

High-moisture extrusion (HME) has increasingly garnered attention in the production of plant-based meat analogs. Nevertheless, the disorganized structural properties and poor functional characteristics of HME extrudates pose significant challenges to the advancement of plant-based alternatives in the food industry. The coextrusion of proteins and polysaccharides has emerged as an effective strategy to improve the sensory qualities of HME meat analogs. Herein, we investigated the effects of the type and addition of inulin on the structural and functional properties of HME extrudates comprising soy protein isolate, soy protein concentrate, and wheat protein. The results indicated that inulin facilitated the conversion of 7S to 11S globulin and induced a transformation from a β-turn angle to a β-folded protein structure, promoting lamellar structure formation and enhancing the overall stability of the protein matrix. Optimal results were achieved with the addition of 6% long-chain and short-chain inulin. In terms of functional characteristics, the incorporation of short-chain inulin resulted in a superior fiber structure and protein digestibility, whereas long-chain inulin enhanced the water-holding capacity, rehydration rate, and thermal stability. Additionally, intermolecular interaction analysis revealed that these inulin-induced improvements in the quality of HME extrudates are primarily attributed to the strengthening of disulfide bonds and hydrogen bonds. These findings offer crucial insights for advancing the quality of plant-based meat analogs, providing valuable directions for future product development in the food industry.

Inulin with different degrees of polymerization as a functional ingredient: Evaluation of flour, dough, and steamed bread characteristics during freezing

In the study, the effects of short-chain inulin (OP), natural inulin (OH), and long-chain inulin (OHP) at substitution levels of 3%, 6%, and 9%, as well as freezing of 0, 15, and 30 days, on the farinograph and extensograph characteristics of flour, the rheological properties, water distribution, and microstructure of dough, as well as the quality of the final steamed bread, were investigated. The findings revealed that inulin led to a reduction in the water absorption of the dough while increasing its stable time. Furthermore, inulin delayed the alteration of freezable water within the frozen dough. Notably, the addition of inulin resulted in a more cohesive and evenly arranged network structure within the frozen dough. Steamed bread supplemented with 6% OP, 6% OH, and 3% OHP consistently dislayed a higher specific volume and spread ratio. These findings offer valuable insights into the utilization of inulin in frozen wheat foods.

The Degree of Inulin Polymerization Is Important for Short-Term Amelioration of High-Fat Diet (HFD)-Induced Metabolic Dysfunction and Gut Microbiota Dysbiosis in Rats.

Inulin, a non-digestible polysaccharide, has gained attention for its prebiotic properties, particularly in the context of obesity, a condition increasingly understood as a systemic inflammatory state linked to gut microbiota composition. This study investigates the short-term protective effects of inulin with different degrees of polymerization (DPn) against metabolic health deterioration and gut microbiota alterations induced by a high-fat diet (HFD) in Sprague Dawley rats. Inulin treatments with an average DPn of 7, 14, and 27 were administered at 1 g/kg of bodyweight to HFD-fed rats over 21 days. Body weight, systemic glucose levels, and proinflammatory markers were measured to assess metabolic health. Gut microbiota composition was analyzed through 16S rRNA gene sequencing. The results showed that inulin27 significantly reduced total weight gain and systemic glucose levels, suggesting a DPn-specific effect on metabolic health. The study also observed shifts in gut microbial populations, with inulin7 promoting several beneficial taxa from the Bifidobacterium genera, whilst inducing a unique microbial composition compared to medium-chain (DPn 14) and long-chain inulin (DPn: 27). However, the impact of inulin on proinflammatory markers and lipid metabolism parameters was not statistically significant, possibly due to the short study duration. Inulin with a higher DPn has a more pronounced effect on mitigating HFD-induced metabolic health deterioration, whilst inulin7 is particularly effective at inducing healthy microbial shifts. These findings highlight the benefits of inulin as a dietary adjuvant in obesity management and the importance of DPn in optimizing performance.

Effect of fibers on starch structural changes during hydrothermal treatment: multiscale analyses, and evaluation of dilution effects on starch digestibility.

Dietary fibers (DFs) may influence the structural, nutritional and techno-functional properties of starch within food systems. Moreover, DFs have favorable effects on the digestive system and potentially a lower glycemic index. These potential benefits may change depending on DF type. Starch processed in the presence of soluble and insoluble fibers can undergo different structural and functional changes, and the present study investigated the effects of short-chain and long-chain inulin and cellulose on the structural and digestive properties of wheat starch. The combined use of differential scanning calorimetry, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) provided insights into the structural changes in starch and inulin at different levels. Short-chain and long-chain inulin had higher water retention capacity and a potential to limit starch gelatinization. The FTIR results revealed an interaction between starch and inulin. Scanning electron microscopy analysis showed morphological changes in starch and inulin after the hydrothermal treatment. Cellulose fiber was not affected by the hydrothermal treatment and had no influence on starch behavior. The structural differences observed through XRD, FTIR and scanning electron microscopy analyses between starch with and without inulin fibers did not significantly impact starch digestibility, except for the dilution effect caused by adding DFs. The present study highlights the importance of utilizing different analytical tools to assess changes in food samples at different scales. Although short-chain and long-chain inulin could potentially limit starch gelatinization, the duration of the heat treatment (90 °C for 10 min) was sufficient to ensure complete starch gelatinization. The dilution effect caused by adding fibers was the primary reason for the effect on starch digestibility. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Study of the structural characterization, physicochemical properties and antioxidant activities of phosphorylated long-chain inulin with different degrees of substitution

In this study, phosphorylated derivatives of long-chain inulin with different substitution degrees were prepared. The synthesized samples were named PFXL-1, PFXL-2, PFXL-3, and PFXL-4 according to their degree of substitution (from low to high). The structures of FXL and PFXL were characterized by infrared spectroscopy and nuclear magnetic resonance spectroscopy, and the results indicated the successful introduction of phosphate groups. FXL and PFXL were composed of two types of sugar, fructose and glucose, with a molar ratio of 0.977:0.023. The SEM results showed that phosphorylation changed the morphology of FXL from an irregular mass to small spherical aggregates. The XRD pattern showed that the crystallinity was reduced by the introduction of phosphate groups. The Mw of FXL was 2649 g/mol, and the Mw of PFXL-4 increased the most (2965 g/mol). Additionally, PFXL was more stable and uniform, and the absolute value of the PFXL potential reached 7.83 mV. Phosphorylation decreased the weight loss rate of FXL and improved the viscoelastic properties and antioxidant activity of FXL. This study presents a method for the modification of FXL, demonstrating that phosphorylation can enhance its physicochemical properties and physiological activity and suggesting its potential as a functional food and quality modifier.

Inulin alleviates atherosclerosis through improving lipid metabolism, inflammation, and gut microbiota in ApoE-knockout mice: the short-chain is more efficacious.

Atherosclerosis (AS) is considered the underlying cause of many diseases, particularly cardiovascular and cerebrovascular diseases. Inulin, a type of fructan, has shown potential in improving atherosclerosis, although there are conflicting findings. It is hypothesized that the polymerization degree of inulin may largely influence its therapeutic effectiveness. Therefore, this study aimed to investigate the effects and mechanisms of short-chain and long-chain inulin in AS. ApoE-/- mice fed a high fat diet (HFD) were used to establish an atherosclerosis model. These mice received daily oral administration of either short-chain or long-chain inulin for 12weeks. Plasma lipid metabolism-related indices were measured using biochemical analysis, and plasma immunological indices were analyzed via ELISA. The aorta, aortic root regions, liver tissue, adipose tissue, and colon tissue were examined through various staining techniques, including ORO staining, hematoxylin and eosin staining, Alcian blue staining, and immunofluorescent or immunohistochemical assays. Microbiome analysis was conducted in the cecal content. The results indicated that both short-chain and long-chain inulin substantially reduced the formation of atherosclerotic plaques. Inulin also improved plasma lipid concentrations and hepatic lipid metabolism, and partially alleviated both localized (atherosclerotic lesions) and systemic inflammation. Short-chain inulin was more effective than long-chain inulin in reducing atherosclerotic plaques formation, enhancing lipid metabolism and reducing inflammation. Additionally, both types of inulin showed similar effectiveness in enhancing intestinal epithelial barrier integrity, gut microbiota composition and functionality. These findings suggest that inulin has a protective role against atherosclerosis by enhancing lipid metabolism, reducing inflammation, and improving intestinal barrier and gut microbiota. As a dietary intervention, short-chain inulin is more effective than long-chain inulin, offering clinical implications for using inulin as a therapeutic agent for atherosclerosis.

Effects of Different Types of Dietary Fibers on Lipid Metabolism and Bile Acids in Weaned Piglets.

The aim of this study was to investigate the effects of dietary fiber on the serum biochemistry, bile acid profile, and gut microbiota in piglets. Twenty-four pigs (initial body weight: 10.53 ± 1.23 kg) were randomly divided into three treatments with eight replicate pens of one pig per pen for 21 d. The dietary treatments consisted of the following: (1) a fiber-free diet (NS); (2) a fiber-free diet + 3% fructooligosaccharides (SI); (3) a fiber-free diet + 3% dietary fiber mixture (fructooligosaccharides, long-chain inulin, and microcrystalline cellulose at the ratio 1:1:1; MIX). The results showed that compared with the NS group, the 3% SI diet reduced the serum total cholesterol (TC) concentration of the piglets (p < 0.05). The metabolomics results showed that the 3% SI diet increased the level of taurohyocholic acid (THCA) and α-muricholic acid, and the 3% MIX diet increased the level of THCA and cholic acid (p < 0.05). The use of 3% SI or MIX decreased the glycodeoxycholic acid (GDCA) level in the bile of the piglets (p < 0.05). The correlation analysis shows that the GDCA was positively related to the TC. The 16S rRNA gene sequencing results showed that UCG-002 and Holdemanella were enriched in the SI group, while Bacteroides was enriched in the MIX group. The microbial function prediction indicated that SI supplementation tended to elevate the relative abundance of gut bacteria capable of expressing bile acid-metabolizing enzymes. To sum up, the regulatory effect of dietary fiber on lipid metabolism is related to bile acids in piglets. Compared with MIX, SI is more likely to regulate bile acids through the gut microbiota.

Effect of salt and kansui on rheology, water mobility and physicochemical properties of long-chain inulin non-fermented dough and its noodles quality

Salt and kansui are usually added to flour to enhance the quality of flour products. However, the technical roles in long-chain inulin (FXL) dough formation are not well understood. The physicochemical properties and texture changes of FXL dough and noodles after adding salt and kansui were studied. The data revealed that the salt and kansui increased the G′, and G″, disulfide bond content, and the β-sheet content of the FXL dough. SEM results showed that low salt and kansui contents had different effects on the gluten network, especially 1% kansui, which had the best effect on the gluten network structure. Samples supplemented with 1.5% kansui significantly increased hardness and cooking loss (p < 0.05), with values of 84.53 N and 5.48%, respectively. Salt and kansui increased the crystallinity of starch measured by XRD. Therefore, adding salt and kansui may be a feasible approach to alleviate fibre enriched flour products.

Structural characteristics variations of dough incorporated with long-chain inulin modified by phosphorylation

In the study, long-chain inulin (FXL) was modified by phosphorylation (PFXL) to obtain new characteristics for improving the quality of dough. The secondary structure, disulfide bond content, surface hydrophobicity, and microstructure of gluten in dough, as well as the emulsification properties of gluten, were investigated. The results showed that the PFXL could affect the gluten structure through hydrogen bonding interactions and hydrophobic interactions, thus increasing the contents of β-sheets structure, α-helices structure and the disulfide bond, and decreasing the surface hydrophobicity of the dough. And the emulsification activity and stability of gluten were also improved. A more stable and ordered gluten network structure was promoted to form mainly through a liquid lamellar film formed by PFXL. Generally, the phosphorylation modification for FXL is an effective alternative to increasing the additive amount of dietary fiber in the dough and improving its quality.

Effect of inulin polymerization degree on nutritional and technological characteristics of gluten free bread

Introduction: Wheat bread is the staple food all over the world. Gluten sensitivity in some people has led to the development of gluten-free ones. Inulin is a soluble dietary fiber with beneficial nutritional effects is able to restore the function of gluten in gluten-free products by increasing water absorption and creating a structure. The function of gluten depends on its polymerization degree. This study is aimed to investigate the effect of inulin polymerization degree on the technological and nutritional characteristics of rice-acorn flour based gluten-free bread.&#x0D; Methods: This study is an experimental type. To investigate the effect of the inulin polymerization degree on technological and nutritional characteristics of rice:acorn flour based gluten-free bread, the textural, physicochemical, sensory characteristics and inulin stability of samples enriched inulin with different polymerization degree were assessed. All tests were done in triplicate. Data analysis was done with SPSS 25 software&#x0D; Results: Results indicated that the optimized technological characteristics and lowest inulin loss ratio (31% w/w-1) is found at gluten-free bread samples containing 30% w/w-1 of acorn flour and long-chain inulin fermented by MF-SD (A30R70SL). Long-chain inulin is found to be able to restore gases produced during the fermentation and expanded through cooking process, which seems to be induced by its potential ability to form a gel.&#x0D; Conclusion: Using long-chain inulin is recommended to achieve desirable technological characteristics and high nutritional value in the formulation of gluten-free bread.

Phenotypic and genomic analysis of inulin consumption byLactiplantibacillus plantarumstrains from Sichuan pickle

To investigate the capability, properties, and molecular mechanism of inulin fermentation by lactic acid bacteria (LAB) from Sichuan pickle. A total of 79 LAB strains were purified from 30 aged Sichuan pickle brine samples, and only 21 Lactiplantibacillus plantarum strains (26.58%, 21/79) derived from 15 samples grew well through utilizing inulin as a carbon source. The fermentation tests through using long-chain inulin (lc-inulin) as a carbon source showed that only 6 L. plantarum strains grew well, while other 15 strains could only utilize short-chain oligofructose (FOS), and thin-layer chromatography analysis evidenced a strain specificity of inulin consumption patterns. Lactiplantibacillus plantarum YT041 is a vigorous inulin fermenter, and whole genome sequencing data revealed that sacPTS1 and fosRABCDXE operons might be associated with the fermentation of FOS and lc-inulin, respectively. The phenotype of inulin consumption is commonly present in LAB from Sichuan pickle, which is strain-specific and largely depends on their specific ecological niche and degree of polymerization.

Effects of an inulin and microcrystalline cellulose hybrid hydrogel on the short-term low temperature storage characteristics of pork sausage models

Herein, we applied plant-based fibrous ingredients to reduced-fat emulsifying pork sausage models to partially achieve improvable storage quality and wellness purpose. The hybrid hydrogel comprised of long-chain inulin, microcrystalline cellulose (IMC), and glucolactone was incorporated into 90% of minced lean pork to constitute 5% and 10% respectively of total mass of lean, IMC gel, and pork backfat, corresponding to the addition of pork backfat as 5% and 0%. After 20-day storage at 4 °C, compared to control without IMC gel, addition of IMC gel evidently reinforces hardness, chewiness, and water holding capacity in the matrices of sausage models. Furthermore, IMC gel causes noticeable increases in metmyoglobin content and thiobarbituric acid reactive substance (TBARS) value, and a decrease in peroxide value (POV), implying deep lipid oxidation and fostering the oxidation stability. IMC gel brings about distinct decreases of α-helix conformation and aliphatic groups (methyl and methylene), and evident increases of β-fold conformation and gauche-gauche-gauche disulfide bond conformation. Dynamic rheology shows that IMC gel combined with backfat (5%:5%) is beneficial to the maintenance of higher viscoelasticity than that (10%:0%). Scanning electron microscopy similarly displays that the sausage model using the formulation (5%:5%) possesses more promising appearances of emulsion-filled composite crosslinking networks than the control (0%:10%) and the sausage model using the formulation (10%:0%). The findings demonstrated that IMC gel as a fat replacer may offer potential advantages in upscaling healthier reduced-fat sausage quality.

Influences of Na2CO3, NaHCO3, K2CO3 on the rheological, water distribution, and microstructural properties of 5% long-chain inulin dough and quality of steamed bread

Inulin is rich in nutrition and can be used to produce functional flour products. Adding alkali to the dough system is an effective way to improve the quality of dough products. In this study, the effects of Na2CO3, NaHCO3 and K2CO3 on the rheology, water distribution, microstructure properties and steamed bread quality of 5% long inulin dough (FXL) were investigated. The addition of alkali improved the viscoelastic properties and the content of β-sheets in the FXL dough and made the weakly bound water move toward tightly bound water and free water. At the same time, the addition of alkali made the microstructure of the FXL dough tighter, but excess alkali (0.6 g/100 g) had a negative effect. The addition of alkali reduced the crystallinity. Alkali also gave steamed bread a pale yellow appearance, reducing volume and hardness compared to the control group. These results can contribute to a better exploration of the application potential of alkali in functional flour products to improve the quality of fortified flour products.

Inulin for surimi gel fortification: Performance and molecular weight-dependent effects

Inulin is a prebiotic carbohydrate widely used in food industry due to its health benefits and unique rheological properties. For the first time, this study explores the potential of natural inulin as a sustainable food additive to enhance surimi gel characteristics, specifically focusing on understanding its molecular weight effects. The good solubility of inulin facilitates the conversion of α-helix to other secondary conformations which are favorable for protein denaturation and aggregation during gelation. Moreover, the abundant –OH groups at the surface of inulin can boost the chemical forces within surimi proteins to reinforce the gel network. Compared to short-chain inulin, long-chain inulin can alleviate proteolysis, enhance hydrophobic interactions and intertwine with myosin molecules, thereby reinforcing the gel network. A more viscous long-chain inulin solution formed within surimi gels fills the space between aggregated proteins and facilitates the lock of water molecules, improving the water-holding capacity (WHC). Thus, an addition of 12 % long-chain inulin leads to an enhanced hardness of surimi gel from 943 to 1593 and improved WHC from 72 % to 85 %. A new inulin-myosin interaction mechanism model is also proposed to provide useful guidelines for surimi processing and expanding the application of inulin within the food industries.

Soluble corn arabinoxylan has desirable material properties for high incorporation in expanded cereal extrudates

Incorporation of soluble dietary fiber to cereal extrudates is a practical approach to improve its nutrition values, but it can be technically challenging as a reduction in extrudate quality commonly occurs at a high incorporation level. In the present study, we incorporated soluble corn arabinoxylan (CAX) into cornmeal at a high level (25% w/w) and produced expanded extrudates with a comparable microstructure to cornmeal without added fibers. For a comparison, wheat arabinoxylan (WAX)- and long chain inulin-incorporated cornmeal extrudates had low degrees of expansion and high bulk density. CAX-incorporated cornmeal had comparable melt viscosities as the cornmeal control at shear rates higher than 100 s −1 and an endothermic transition occurring at the same temperature range (130–170 °C), both similar to cornmeal alone. On the other hand, WAX-incorporated cornmeal instead had an exothermic transition at 130–170 °C, and a substantially higher melt viscosity than cornmeal. Long chain inulin-incorporated cornmeal had two overlapped endothermic transitions at 130–170 °C and a markedly lower melt viscosity than cornmeal. The superior functionality of CAX in corn extrudates was attributed to its highly branched xylan backbone extensively substituted by complex sidechains and charged structure. CAX had a hypothesized ellipsoid-shaped conformation that presumably would not engage in intermolecular entanglements, resulting in a low viscous near-Newtonian flow behavior. In summary, addition of CAX to cornmeal did not cause major changes in melt viscosity and endothermic transition of the pre-extrusion material, nor to the quality of resulting extrudates. • Corn arabinoxylan (CAX)-incorporated (25%) cornmeal extrudates had good expansion. • CAX performed better in extrusion than wheat arabinoxylan or long-chain inulin. • CAX-incorporated cornmeal had desirable thermal and rheological properties. • Branched structure of CAX appeared to contribute to its functionality in extrusion.

Global, distinctive, and personal changes in molecular and microbial profiles by specific fibers in humans

Dietary fibers act through the microbiome to improve cardiovascular health and prevent metabolic disorders and cancer. To understand the health benefits of dietary fiber supplementation, we investigated two popular purified fibers, arabinoxylan (AX) and long-chain inulin (LCI), and a mixture of five fibers. We present multiomic signatures of metabolomics, lipidomics, proteomics, metagenomics, a cytokine panel, and clinical measurements on healthy and insulin-resistant participants. Each fiber is associated with fiber-dependent biochemical and microbial responses. AX consumption associates with a significant reduction in LDL and an increase in bile acids, contributing to its observed cholesterol reduction. LCI is associated with an increase in Bifidobacterium. However, at the highest LCI dose, there is increased inflammation and elevation in the liver enzyme alanine aminotransferase. This study yields insights into the effects of fiber supplementation and the mechanisms behind fiber-induced cholesterol reduction, and it shows effects of individual, purified fibers on the microbiome.

Spaghetti Enriched with Inulin: Effect of Polymerization Degree on Quality Traits and α-Amylase Inhibition

Inulin is considered a dietary fiber and represents a noteworthy ingredient for food biofortification due to its health effects and its neutral taste. The aim of the work was the evaluation of the quality of pasta produced using whole-meal flours of two ancient Sicilian landraces (Senatore Cappelli-CAP and Timilia—TIM) fortified with two types of inulin (long-chain topinambur inulin IT and low-chain chicory inulin IC), at two different levels of substitution (2 and 4%) to evaluate its possible effect on α-amylase inhibition. The color indices L* and a* were mainly influenced by cultivars, while IT improved the sensory attributes, mainly the elasticity sensation, and influenced less the other sensory attributes: adhesiveness, color, odor, taste, and Over Quality Score for both landraces. The cooking quality was linked mainly to the landrace used, due to the very different gluten matrix of CAP and TIM. IC and IT showed promising α-Amy inhibitory activity with comparable IC50 values of 0.45 ± 0.04 and 0.50 ± 0.06 mg/mL. The enrichment of spaghetti with inulin with an inhibitory effect on α-amylase determined the hypoglycemic properties of pasta, thus lowering the corresponding IC50 value.

Effect of inulin with different degrees of polymerization on dough rheology, gelatinization, texture and protein composition properties of extruded flour products

The quality deterioration of extruded flour products has caused serious food waste with huge economic losses. To ameliorate the status, the effect of inulin with different degrees of polymerization on rheology, gelatinization properties of dough, and textural and protein composition properties of extruded flour products was investigated. When short-chain inulin (FS) and long-chain inulin (FXL) were incorporated, the empirical rheological properties of the dough were significantly improved. Besides, the storage and loss modulus of dough dynamic rheology with the incorporation of 8 g/100 g FS or FXL increased to the maximum value and exhibited the best gelatinization characteristics. Textural analysis showed that 4 g/100 g FS and 2 g/100 g FXL extruded flour products yielded minimum hardness and maximum elasticity, with increased moisture content. According to the secondary structure and SDS-PAGE measurement, the protein polymerization increased after inulin addition, which enhanced the strength of gluten. Principal component analysis also showed that there was significant effect of FS and FXL on the dough and extruded flour products. The results obtained can be used to better understand the functionality and food applications of inulin with different degrees of polymerization.

Fiber mixture-specific effect on distal colonic fermentation and metabolic health in lean but not in prediabetic men

ABSTRACT Infusions of the short-chain fatty acid (SCFA) acetate in the distal colon improved metabolic parameters in men. Here, we hypothesized that combining rapidly and slowly fermentable fibers will enhance distal colonic acetate production and improve metabolic health. In vitro cultivation studies in a validated model of the colon were used to identify fiber mixtures that yielded high distal colonic acetate production. Subsequently, in two randomized crossover studies, lean and prediabetic overweight/obese men were included. In one study, participants received supplements of either long-chain inulin+resistant starch (INU+RS), INU or maltodextrin (PLA) the day prior to a clinical investigation day (CID). The second trial studied beta glucan+RS (BG+RS) versus BG and PLA. During each CID, breath hydrogen, indirect calorimetry, plasma metabolites/hormones were assessed during fasting and postprandial conditions. Additionally, fecal microbiota composition and SCFA were determined. In prediabetic men, INU+RS increased plasma acetate compared to INU or PLA (P < .05), but did not affect metabolic parameters. In lean men, INU+RS increased breath hydrogen and fasting plasma butyrate, which was accompanied by increased energy expenditure, carbohydrate oxidation and PYY and decreased postprandial glucose concentrations (all P < .05) compared to PLA. BG+RS increased plasma butyrate compared to PLA (P < .05) in prediabetic individuals, but did not affect other fermentation/metabolic markers in both phenotypes. Fiber-induced shifts in fecal microbiota were individual-specific and more pronounced with INU+RS versus BG+RS. Administration of INU+RS (not BG+RS) the day prior to investigation improved metabolic parameters in lean but not in prediabetic individuals, demonstrating that effects were phenotype- and fiber-specific. Further research should study whether longer-term supplementation periods are required to elicit beneficial metabolic health in prediabetic individuals. Trial registration numbers: Clinical trial No. NCT03711383 (Inulin study) and Clinical trial No. NCT03714646 (Beta glucan study).