Amalia Yanni

Oat β-glucan enrichment improved bread quality and sensory acceptance while reducing blood pressure, fasting glucose and LDL-C after an 8-week intervention in mildly hypercholesterolemic subjects with overweight/obesity.

Background: Growing evidence suggests that the structural integrity of plant tissues is an important determinant of starch digestibility and postprandial metabolic responses in cereals, legumes, and starch-rich foods. This narrative review evaluates the influence of botanical tissue architecture and the degree of milling on physicochemical properties, product quality, starch digestibility, and metabolic responses in cereal- and legume-based foods. Methods: The evidence was critically synthesized from studies on physicochemical characterization, in vitro starch digestibility, acute postprandial and long-term human intervention studies, and relevant systematic reviews and meta-analyses. Results: The preservation of intact cells, cellular aggregates, and coarser flour fractions limits water penetration and delays starch swelling and gelatinization, whereas extensive milling increases starch damage and susceptibility to enzymatic hydrolysis. Botanical origin further influences these effects, with legumes generally exhibiting lower starch digestibility than cereals because of their thicker and less permeable cell walls. Increasing the proportion of coarse flour fractions may also impair loaf volume, texture, processing performance, and consumer acceptability. Acute postprandial human intervention studies typically report attenuated glycemic responses following consumption of structurally preserved cereal- and legume-based foods, with several studies also showing improved insulinemic and incretin responses. However, human evidence is more heterogeneous than the relatively consistent in vitro evidence for slower starch hydrolysis with greater preservation of cellular structure, and these effects do not necessarily translate into lower postprandial glycemic responses. Evidence regarding appetite regulation and long-term metabolic outcomes remains limited or inconsistent. Conclusions: Cellular integrity and botanical structure are important but under-recognized determinants of carbohydrate functionality. Preserving plant tissue structure by controlling the degree of milling may contribute to the modulation of starch digestibility and postprandial metabolic responses. Integrating structural characteristics alongside nutrient composition may support the development of healthier cereal- and legume-based foods while maintaining technological functionality, consumer acceptability, and metabolic health.

Food and its constituents influence human physiology and metabolism, thereby playing a crucial role in overall health

Yeast β-glucans are bioactive polysaccharides derived primarily from the cell walls of Saccharomyces cerevisiae. They are widely recognized for their immunomodulatory, antioxidant, and anti-inflammatory actions as well as for their probiotic effects. Their addition to food products has gained growing interest owing to their ability to promote health as well as to enhance sensorial and technological attributes of foods. The aim of this narrative review is to present the health benefits of yeast β-glucans according to the mechanisms taking place, compare them to other biomolecules with analogous health-promoting effects, and summarize the existing knowledge on their incorporation into various food matrices. Focus is also given to clinical trials using foods enriched with yeast β-glucans as well as in vitro digestion studies of such foods. In addition, research interest extends to the methods of yeast β-glucan assessment in food products. Despite the promising results so far, significant challenges remain, including variability in study design, limited translational evidence from in vitro studies, and the lack of standardized protocols for determination across various food categories. Overall, the reviewed literature supports their growing potential as valuable components in the design of functional foods. Ongoing research and advancement should prioritize well-designed human trials, standardized production protocols and deeper structure–function relationship investigation in order to further reveal their contribution across a wide range of applications, reinforcing both consumer health and innovation within the food industry.

Purpose: The study investigates whether postprandial amino acid responses differ between normalweight (NW) and overweight/obese (OW) individuals following consumption of plant protein-enriched wheat biscuits with the same protein content but different protein composition. It highlights the importance of developing functional snack products with specific amino acid profile that could benefit individuals with overweight/obesity. Methods: Thirty volunteers (15 NW and 15 OW) participated in an acute, randomized crossover trial, in which they consumed two plant protein–enriched wheat biscuits differing in amino acid profile—one enriched in L-arginine (arginine biscuit, ArgB) and the other in branched-chain amino acids (branched-chain amino acids biscuit, BCAAsB)—as well as a conventional wheat biscuit (CB) in separate sessions with one week intervals. Postprandial amino acids (AAs) responses were measured for 180 min following ingestion. Fasting and postprandial AAs concentrations were determined by Ultra-High Performance Liquid Chromatography coupled with Time-of-Flight Mass Spectrometry (UHPLC-ToF–MS). Results: OW subjects exhibited higher fasting concentrations of methionine, tryptophan and tyrosine (p < 0.05) while NW subjects, higher levels of glutamine (p < 0.05). Postprandial responses of all the determined AAs to enriched biscuits were higher in the NW compared to the OW group with incremental areas under the curve (iAUCs) of alanine, glutamine and threonine reaching statistical significance (p < 0.05). In the OW group, ingestion of BCAAsB resulted also in lower iAUC values of asparagine and serine, while consumption of ArgB led to a lower iAUC of glycine and a higher iAUC of taurine compared to the NW group (p < 0.05). Conclusion: Ingestion of plant protein-enriched wheat biscuits by OW subjects resulted in lower postprandial responses of alanine, glutamine and threonine compared to NW. AAs composition of BCAAs-enriched biscuit resulted also in lower responses of asparagine and serine while that of the L-arg-enriched biscuit, in lower glycine but higher taurine responses in OW compared to NW subjects. Depletion of all the above-mentioned AAs has been recorded in obesity. Higher taurine concentrations can lead in beneficial effects since taurine improves glycemic control and insulin sensitivity and it has shown potential anti-obesity properties. These findings underscore the challenge of designing protein-rich foods that could elicit beneficial metabolic responses for overweight/obese individuals.

Consumption of bakery products prepared with finely milled flour is associated with elevated postprandial glycemia, increased hunger, and reduced satiety. The milling process disrupts the plant cell walls of cereal grains and legumes, enhancing the accessibility of encapsulated starch to digestive enzymes. This study investigates the effects of flour origin (wheat and chickpea) and particle size in three wholemeal breads on physicochemical properties, postprandial glucose, insulin, glucagon-like peptide-1 (GLP-1) responses, and subjective appetite sensations in healthy individuals. In the test breads, 30% of refined wheat flour was substituted with cracked whole wheat (1.8–2.0 mm) to make whole grain bread (WGB), finely milled chickpea flour (CFM), or larger particle-chickpea flour (1.4–1.8 mm, CLP). Wheat bread (WB) served as the control. In all three test breads, 28% of refined wheat flour was substituted with wholemeal wheat flour. Compared to WB and WGB, CFM and CLP had a harder and more chewy texture, and a lower specific volume (p < 0.05). WGB, CFM, and CLP had reduced porosity and lightness (L*) compared to WB (p < 0.05). In a randomized crossover study (RCT), fifteen normoglycemic individuals participated in four separate sessions. The glucose incremental area under the curve (iAUC) was lower for CLP compared to those of both WB and CFM (p < 0.05). While insulin responses were similar across all breads, GLP-1 iAUC was significantly higher following CLP consumption compared to WB (p < 0.05), whereas no significant differences were observed among the other test breads in the postprandial GLP-1 response. CLP consumption resulted in a lower iAUC for hunger and desire to eat, and a higher iAUC for fullness, as evaluated using Visual Analogue Scales (VAS), compared to WB (p < 0.05). Incorporation of large-particle chickpea flour into bread can effectively reduce postprandial glycemia, increase GLP-1 secretion and contribute to the enhancement of satiety. Such formulations may offer promising dietary strategies for glycemic control and appetite regulation.

The aim of this study was to examine the effect of free or immobilized Lacticaseibacillus rhamnosus OLXAL-1 cells on oat flakes on the gut microbiota and metabolic and inflammatory markers in a streptozotocin (STZ)-induced Type-1 Diabetes Mellitus (T1DM) animal model. Forty-eight male Wistar rats were assigned into eight groups (n = 6): healthy or diabetic animals that received either a control diet (CD and DCD), an oat-supplemented diet (OD and DOD), a diet supplemented with free L. rhamnosus OLXAL-1 cells (CFC and DFC), or a diet supplemented with immobilized L. rhamnosus OLXAL-1 cells on oat flakes (CIC and DIC). Neither L. rhamnosus OLXAL-1 nor oat supplementation led to any significant positive effects on body weight, insulin levels, plasma glucose concentrations, or lipid profile parameters. L. rhamnosus OLXAL-1 administration resulted in a rise in the relative abundances of Lactobacillus and Bifidobacterium, as well as increased levels of lactic, acetic, and butyric acids in the feces of the diabetic animals. Additionally, supplementation with oat flakes significantly reduced the microbial populations of E. coli, Enterobacteriaceae, coliforms, staphylococci, and enterococci and lowered IL-1β levels in the blood plasma of diabetic animals. These findings suggested that probiotic food-based strategies could have a potential therapeutic role in managing dysbiosis and inflammation associated with T1DM.

Background/Objectives: The gut microbiota is linked to the pathogenesis of type 1 diabetes mellitus (T1DM), while supplementation with probiotics may result in positive alterations in the composition of the gut microbiome. This research aimed to map the changes in the gut microbiome and blood markers of streptozotocin-induced diabetic rats after a dietary intervention with free or immobilized cells of the presumptive probiotic Pediococcus acidilactici SK on pistachio nuts. Methods: Twenty-four male Wistar rats were studied and divided into four groups (healthy or diabetic) which received the free or the immobilized P. acidilactici SK cells on pistachio nuts for 4 weeks. Blood, fecal, and intestinal tissue samples were examined. Results: The diabetic rats exhibited an elevated concentration of HDL-c, while the inflammatory IL-1β levels were significantly lower in the diabetic animals that received the immobilized cells compared to the group that received the free cells. The dietary intervention with immobilized cells led to decreased counts of fecal staphylococci and enterococci in the diabetic animals, while the diet with both free and immobilized P. acidilactici SK cells rendered levels of these populations in normal values in the feces and intestinal tissue of the diabetic animals. Noticeably, the Lactobacillus and Bifidobacterium genera were elevated after the supplementation with immobilized P. acidilactici SK cells on pistachio nuts. Conclusions: Dietary supplementation with P. acidilactici SK cells (in free or in immobilized form) beneficially affected the gut microbiota/microbiome of streptozotocin-induced diabetic rats, leading to the alleviation of dysbiosis and inflammation and control over their lipid levels.

The present study aimed to investigate the effect of a dietary intervention including free or immobilized cells of the presumptive probiotic Pediococcus acidilactici ORE5 on Corinthian currants, a food with beneficial impact in the condition of Type-1 Diabetes Mellitus (T1DM), on the microbiome composition of STZ-induced diabetic rats. Twenty four male Wistar rats were divided into four groups (n = 6 per group): healthy animals, which received the free (H_FP) or the immobilized Pediococcus acidilactici ORE5 cells (H_IPC), and diabetic animals, which received the free (D_FP) or the immobilized Pediococcus acidilactici ORE5 cells(D_IPC) for 4 weeks (10⁹ cfu/day, in all groups). At the end of the dietary intervention, the D_IPC group exerted a lower concentration of the inflammatory cytokine IL-1 beta compared to D_FP. Consumption of immobilized P. acidilactici ORE5 cells on Corinthian currants by diabetic animals led to increased loads of fecal lactobacilli and lower Enterobacteriaceae, coliforms, and Escherichia coli levels, while Actinobacteria phylum, Akkermansia, and Bifidobacterium genera abundances were increased, and fecal lactic acid was elevated. Overall, the results of the present research demonstrated that functional ingredients could ameliorate gut dysbiosis present in T1DM and could be used to design dietary patterns aiming at T1DM management. However, well-designed clinical trials are necessary, in order to confirm the beneficial effects in humans.

Type-1 Diabetes Mellitus (T1D) onset and development is closely linked with imbalance of gut microbiome, while supplementation with probiotics may result in positive alterations in gut microbiome composition. In the present study, the effect of a dietary intervention including free or immobilized cells of the presumptive probiotic Pediococcus acidilactici ORE5 on Corinthian currants, a food with beneficial impact in the condition of diabetes, was investigated. Male Wistar rats were studied which were divided into 4 groups: healthy animals, which received the free (H_FP) or the immobilized cells (H_IPC), and diabetic animals, which received the free (D_FP) or the immobilized cells (D_IPC), for 4 weeks (109 cfu/day, in all groups). At the end of the dietary intervention, D_IPC group exerted lower concentration of the inflammatory cytokine IL-1b compared to D_FP. Consumption of immobilized on Corinthian currants P. acidilactici ORE5 cells by diabetic animals led to increased loads of fecal lactobacilli and lower levels of Enterobacteriaceae, coliforms, and E. coli, while Actinobacteria phylum, Akkermansia, and Bifidobacterium genera abundances were increased, and fecal lactic acid was elevated. Overall, the results of the present research demonstrated that functional ingredients can ameliorate gut dysbiosis present in T1D and could be used to design dietary patterns aiming at T1D management. However, well-designed clinical trials are necessary, in order to confirm the beneficial effects in humans.