Impaired Carbohydrate Metabolism among Women with Chronic Low Back Pain and the Role of Dietary Carbohydrates: A Randomized Controlled Cross-Over Experiment.

Background: Impaired glucose regulation is suggested to be related to chronic low back pain (CLBP), although it is not clear how they interact with each other. Thus, the primary aim of this study was to investigate differences in postprandial glycemic responses (PPGRs) (the first sign of impaired glucose metabolism) to high- (sucrose) and low-glycemic index (GI) (isomaltulose) beverages in normoglycemic women with CLBP and healthy controls (HCs) and explore whether any group that showed greater PPGRs to high-GI beverage intake would benefit when the high-GI beverage was replaced with a low-GI beverage. Secondly, this study aimed to explore the association between PPGR and pain in patients with CLBP. Methods: This study was registered at clinicaltrials.org (NCT04459104) before the start of the study. In this study, 53 CLBP patients and 53 HCs were recruited. After 11-12 h of fasting, each participant randomly received isomaltulose or sucrose. Blood glucose levels were measured during the fasting state and 15, 30, 45, 60, 90, and 120 min after the beverage intake, and each participant underwent experimental pain measures. Results: Compared to the HCs, the CLBP group showed significantly higher PPGRs to sucrose (p < 0.021). Additionally, the CLBP group showed a significantly higher decrease in PPGR (p = 0.045) when comparing PPGR to sucrose with PPGR to isomaltulose. Correlation analysis revealed a positive association between self-reported pain sensitivity and PPGR to sucrose, while there was no association found between any experimental pain measures and glycemic responses. Conclusions: Overall, these findings suggest that normoglycemic CLBP patients might have a higher risk of developing impaired glucose tolerance than the HCs and might benefit more when high-GI foods are replaced with low-GI ones.

The Synergistic Effect of Compound Sugar with Different Glycemic Indices Combined with Creatine on Exercise-Related Fatigue in Mice.

In this study, a compound sugar (CS) with different glycemic index sugars was formulated via hydrolysis characteristics and postprandial glycemic response, and the impact of CS and creatine emulsion on exercise-related fatigue in mice was investigated. Thirty-five C57BL/6 mice were randomly divided into five groups to supply different emulsions for 4 weeks: initial emulsion (Con), glucose emulsion (62 mg/10 g MW glucose; Glu), CS emulsion (62 mg/10 g MW compound sugar; CS), creatine emulsion (6 mg/10 g MW creatine; Cr), and CS and creatine emulsion (62 mg/10 g MW compound sugar, 6 mg/10 g MW creatine, CS-Cr). Then, the exhaustion time of weight-bearing swimming and forelimb grip strength were measured to evaluate the exercise capacity of mice, and some fatigue-related biochemical indexes of blood were determined. The results demonstrated that the ingestion of CS significantly reduced the peak of postprandial blood glucose levels and prolonged the energy supply of mice compared to ingesting an equal amount of glucose. Mouse exhaustion time was 1.22-fold longer in the CS group than in the glucose group. Additionally, the supplementation of CS increased the liver glycogen content and total antioxidant capacity of mice. Moreover, the combined supplementation of CS and creatine increased relative forelimb grip strength and decreased blood creatine kinase activity. The findings suggested that the intake of CS could enhance exercise capacity, and the combined supplementation of CS and creatine has a synergistic effect in improving performance.

Determining the effects of Candida utilis-fermented pea starch vs. unfermented pea starch, alone or in whole diets, on palatability and glycemic response in dogs and cats.

Current research suggests yeast fermentation has the potential to improve palatability of pea-based diets for both cats and dogs. However, to be useful, fermentation should not compromise other healthy attributes of peas such as a low glycemic response. Fermentation of uncooked pea starch with Candida utilis (ATCC 9950) appeared to increase crude protein, crude fiber content, inorganic compounds (phosphorus and iron) and phenols. Whole diets were designed with fermented and unfermented pea starch to assess palatability, food intake, and glycemic responses in unacclimated, mixed sex Beagle dogs and mixed breed cats (n = 8 and n = 7, respectively). For palatability testing, a control diet was formulated with 30% corn starch as well as test diets with 30% inclusion of fermented or unfermented pea starch (all lab-made), then compared to a commercial diet containing pea starch (Legacy/Horizon). Fermentation had little effect on rapidly digestible starch either in uncooked starch form or when incorporated into whole diets, but did decrease resistant starch by 15% and increase slowly digestible starch by 20%. Palatability tests using either two choices or four choices at a time revealed a significant preference for the fermented pea starch diet (p < 0.01) in both species. For the glycemic responses, a total of four different pea products were included: unfermented pea starch, fermented pea starch, and 30% inclusion of unfermented and fermented pea starch in whole formulated diets. There were no significant changes in glycemic responses with the fermented pea diet compared to the unfermented diet, demonstrating that healthful low glycemic properties of pea starch were retained after C. utilis fermentation. Overall, C. utilis-fermentation technique was successfully adapted to pea starch where it resulted in increased palatability and food intake in dogs and cats, with potential to positively contribute to overall health benefits for both species.

α-Glucan-type exopolysaccharides with varied linkage patterns: Mitigating post-prandial glucose spike and prolonging the glycemic response.

Microbial exopolysaccharides (EPSs) are traditionally known as prebiotics that foster colon health by serving as microbiota nutrients, while remaining undigested in the small intestine. However, recent findings suggest that α-glucan structures in EPS, with their varied α-linkage types, can be hydrolyzed by mammalian α-glucosidases at differing rates. This study explores α-glucan-type EPSs, including dextran, alternan, and reuteran, assessing their digestive properties both in vitro and in vivo. Notably, while fungal amyloglucosidase - a common in vitro tool for carbohydrate digestibility analysis - shows limited efficacy in breaking down these structures, mammalian intestinal α-glucosidases can partially degrade them into glucose, albeit slowly. In vivo experiments with mice revealed that various EPSs elicited a significantly lower glycemic response (p < 0.05) than glucose, indicating their nature as carbohydrates that are digested slowly. This leads to the conclusion that different α-glucan-type EPSs may serve as ingredients that attenuate post-prandial glycemic responses. Furthermore, rather than serving as mere dietary fibers, they hold the potential for blood glucose regulation, offering new avenues for managing obesity, Type 2 diabetes, and other related-chronic diseases.

Effect of cinnamon spice on continuously monitored glycemic response in adults with prediabetes: a 4-week randomized controlled crossover trial.

BACKGROUND: Previous clinical studies showing that cinnamon spice lowers blood glucose concentrations had inconsistent results. OBJECTIVES: To determine the effect of daily cinnamon spice supplementation in an amount commonly used for seasoning on glucose concentrations in adults with obesity and prediabetes. METHODS: Following a 2-wk run-in period of maintaining a low polyphenol/fiber diet, 18 participants with obesity and prediabetes underwent a 10-wk randomized, controlled, double-blind, crossover trial (mean age 51.1 y; mean fasting plasma glucose 102.9 mg/dL). The participants were randomly assigned to take cinnamon (4 g/d) or placebo for 4-wk, followed by a 2-wk washout period, and then crossed over to the other intervention for an additional 4-wk. Glucose changes were measured with continuous glucose monitoring. Oral glucose tolerance testing immediately following ingestion of cinnamon or placebo was performed at 4-time points to assess their acute effects both at the baseline and end of each intervention phase. Digestive symptom logs were obtained daily. RESULTS: There were 694 follow-up days with 66,624 glucose observations. When compared with placebo, 24-h glucose concentrations were significantly lower when cinnamon was administered [mixed-models; effect size (ES) = 0.96; 95 % confidence interval (CI): -2.9, -1.5; P < 0.001]. Similarly, the mean net-area-under-the-curve (netAUC) for glucose was significantly lower than for placebo when cinnamon was given (over 24 h; ES = -0.66; 95 % CI: 2501.7, 5412.1, P = 0.01). Cinnamon supplementation resulted in lower glucose peaks compared with placebo (Δpeak 9.56 ± 9.1 mg/dL compared with 11.73 ± 8.0 mg/dL; ES = -0.57; 95 % CI: 0.8, 3.7, P = 0.027). Glucose-dependent-insulinotropic-polypeptide concentrations increased during oral glucose tolerance testing + cinnamon testing (mixed-models; ES = 0.51; 95 % CI: 1.56, 100.1, P = 0.04), whereas triglyceride concentrations decreased (mixed-models; ES = 0.55; 95 % CI: -16.0, -1.6, P = 0.02). Treatment adherence was excellent in both groups (cinnamon: 97.6 ± 3.4 % compared with placebo: 97.9 ± 3.7 %; ES = -0.15; 95 % CI: -1.8, 0.2, P = 0.5). No differences were found in digestive symptoms (abdominal pain, borborygmi, bloating, excess flatus, and stools/day) between cinnamon and placebo groups. CONCLUSIONS: Cinnamon, a widely available and low-cost supplement, may contribute to better glucose control when added to the diet in people who have obesity-related prediabetes. This trial was registered at clinicaltrials.gov as NCT04342624.

Glucagon-Like Peptide 1 (GLP-1) Receptor Variants and Glycemic Response to Liraglutide: A Pharmacogenetics Study in Iranian People with Type 2 Diabetes Mellitus.

INTRODUCTION: Pharmacogenetics studies suggest that genetic variants have a possible influence on the inter-individual differences in therapeutic response to glucagon-like peptide 1 receptor agonists (GLP-1 RAs). We aimed to examine the potential role of genetic variability of glucagon-like peptide 1 receptor (GLP-1R) on glycemic response to GLP-1 RAs in a population of Iranian people with type 2 diabetes mellitus (T2DM). METHODS: In this study, we analyzed the data from participants in a non-inferiority randomized clinical trial between 2019 and 2020. Patients received liraglutide 1.8 mg/day subcutaneously for 24 weeks. They were stratified by the baseline hemoglobin A1c (HbA1c) into four categories: 7-7.99, 8-8.99, 9-9.99, and ≥ 10%. In each category, subjects with HbA1c reduction greater than the median ΔHbA1c value for that group were defined as optimal responders. The pooled number of optimal/suboptimal responders in the four groups was used for the comparison. We evaluated two genetic variants of GLP-1R, rs6923761 and rs10305420, using Sanger sequencing. Logistic regression analyses were performed to examine the associations of the GLP-1R variants with the glycemic response in different genetic models. RESULTS: Out of 233 participants, 120 individuals were optimal responders. Median HbA1c reduction was - 2.5% in the optimal responder group compared with - 1.0% in the suboptimal responder group (P < 0.001). In genetic models, rs10305420 T allele homozygosity was associated with optimal glycemic response to liraglutide compared with heterozygous and wild-type homozygous states (recessive model: OR 3.28, 95% CI 1.41-7.65, P = 0.006; codominant model: OR 2.52, 95% CI 1.03-6.13, P = 0.04). No significant association was found between rs6923761 variant and HbA1c reduction. CONCLUSION: GLP-1R rs10305420 polymorphism can explain some of the inter-individual differences in glycemic response to liraglutide in a population of Iranian people with T2DM.

Effect of 100% Orange Juice and a Volume-Matched Sugar-Sweetened Drink on Subjective Appetite, Food Intake, and Glycemic Response in Adults.

Dietary recommendations to reduce the consumption of free sugars often group 100% fruit juice with other sugar-containing beverages. The objective of this study was to determine the effect of consuming 100% orange juice compared to an orange drink on next-meal food intake (FI), glycemic response, average appetite, emotions, and sensory characteristics in normal-weight adults. Thirty-six normal-weight adults (age: 26.8 ± 0.9 years) consumed, in random order and at least 5 days apart, three 240 mL test beverages as follows: (a) 100% orange juice, (b) orange drink, or (c) water. Subjective sweetness and pleasantness were determined immediately after test beverage consumption. Glycemic response, average appetite, and subjective emotions were measured every 15 min for 60 min. Food intake was determined at a pizza lunch 60 min later. Rest-of-day glycemic response and energy intake (EI) were determined using a continuous glucose monitor and food record, respectively. Lunch FI (p = 0.054) and total EI (p = 0.01) were both lower after 100% orange juice compared with the orange drink. Caloric compensation was 84% after 100% orange juice and -25% after the orange drink (p = 0.047). Average appetite was not significantly different between the test beverages (p > 0.05). Blood glucose iAUC adjusted for available carbohydrate was lower after 100% orange juice compared with the orange drink (p < 0.001). Rest-of-day blood glucose concentrations were lower after 100% orange juice compared with the orange drink (p = 0.03) and water control (p < 0.001). In conclusion, consumption of 100% orange juice as a preload resulted in higher caloric compensation, lower total daily EI, and lower blood glucose concentrations compared to the orange drink.

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.

Complementary Nutritional Improvements of Cereal-Based Products to Reduce Postprandial Glycemic Response.

High glycemic response (GR) is part of cardiometabolic risk factors. Dietary polyphenols, starch digestibility, and dietary fibers could play a role in modulating GR. We formulated cereal products with high dietary fibers, polyphenols, and slowly digestible starch (SDS) contents to test their impact on the glycemic index (GI) and insulin index (II). Twelve healthy subjects were randomized in a crossover-controlled study to measure the GI and II of four biscuits according to ISO-26642(2010). Two types of biscuits were enriched with dietary fibers and polyphenols and high in SDS, and two similar control biscuits with low levels of these compounds were compared. The subjects consumed 50 g of available carbohydrates from the biscuits or from a glucose solution (reference). Glycemic and insulinemic responses were monitored for 2 h after the start of the consumption. The two enriched biscuits led to low GI and II (GI: 46 ± 5 SEM and 43 ± 4 SEM and II: 54 ± 5 SEM and 45 ± 3 SEM) when controls had moderate GI and II (GI: 57 ± 5 SEM and 58 ± 5 SEM and II: 61 ± 4 SEM and 61 ± 4 SEM). A significant difference of 11 and 15 units between the GI of enriched and control products was obtained. These differences may be explained by the polyphenol contents and high SDS levels in enriched products as well as potentially the dietary fiber content. This study provides new proposals of food formulations to induce beneficial health effects which need to be confirmed in a longer-term study in the context of the SINFONI consortium.

Starch-ascorbyl palmitate inclusion complex, a type 5 resistant starch, reduced in vitro digestibility and improved in vivo glycemic response in mice.

The prevalence of type 2 diabetes (T2D) has become a major public health concern worldwide. Slowly digested or indigestible carbohydrates such as resistant starch (RS) are associated with a low glycemic index (GI) and the decreased risk of developing T2D. Recently, starch inclusion complexes (ICs) have raised attention due to their thermally stable structure and high RS content. In this study, starch-ascorbyl palmitate (AP) ICs were produced using two different methods with hydrothermal treatments performed, and their in vitro digestion kinetics and in vivo glycemic response in C57BL/6J mice were investigated to determine their potential as a new type of RS, i.e., RS5. After treatments of annealing followed by acid hydrolysis (ANN-ACH), IC samples produced by both methods retained V-type crystalline structure. Either in their raw or treated conditions, V6h-AP ICs prepared using the "empty" V-type method exhibited a more favorable hydrolysis pattern as compared to its counterpart produced by the DMSO method in terms of a lower hydrolysis rate and equilibrium concentration (C∞) (p < 0.05). From the in vitro results, the ANN-ACH treated V6h-AP IC exhibited an estimated GI (eGI) value of 54.83, falling within the range of low GI foods and was the lowest among all tested samples (p < 0.05). Consistent with the in vitro digestion kinetics, the in vivo results showed that mice fed with ANN-ACH V6h-AP IC exhibited a modest glycemic response as evidenced by the lowest increase in postprandial blood glucose and AUC blood glucose (p < 0.05). In addition, the in vivo GI of the ANN-ACH V6h-AP IC (39.53) was the lowest among all the sample treatments and was even lower than that of the RS2 comparison (56, p < 0.05), indicating its more pronounced effect in modulating the postprandial glycemic response in mice and great potential as a new RS5.

Individual Postprandial Glycemic Responses to Meal Types by Different Carbohydrate Levels and Their Associations with Glycemic Variability Using Continuous Glucose Monitoring.

This study aimed to investigate individual postprandial glycemic responses (PPGRs) to meal types with varying carbohydrate levels and examine their associations with 14-day glycemic variability using continuous glucose monitoring (CGM) in young adults. In a two-week intervention study with 34 participants connected to CGM, four meal types and glucose 75 g were tested. PPGRs were recorded for up to 2 h with a 15 min interval after meals. Data-driven cluster analysis was used to group individual PPGRs for each meal type, and correlation analysis was performed of 14-day glycemic variability and control with related factors. Participants had a mean age of 22.5 years, with 22.8% being male. Four meal types were chosen according to carbohydrate levels. The mean glucose excursion for all meal types, except the fruit bowl, exhibited a similar curve with attenuation. Individuals classified as high responders for each meal type exhibited sustained peak glucose levels for a longer duration compared to low responders, especially in meals with carbohydrate contents above 50%. A meal with 45% carbohydrate content showed no correlation with either 14-day glycemic variability or control. Understanding the glycemic response to carbohydrate-rich meals and adopting a meal-based approach when planning diets are crucial to improving glycemic variability and control.

Association of Met420del Variant of Metformin Transporter Gene SLC22A1 with Metformin Treatment Response in Ethiopian Patients with Type 2 Diabetes.

Objective: This study aimed to evaluate whether the M420del variants of SLC22A1 (rs72552763) is associated with metformin treatment response in Ethiopian patients with type 2 diabetes mellitus (T2DM). Patients and Methods: A prospective observational cohort study was conducted on 86 patients with T2DM who had been receiving metformin monotherapy for <1 year. Patients showing ≥0.5% reduction in HbA1c levels from baseline within 3 months and remained low for at least another 3 months were defined as responders while those patients with <0.5% reduction in HbA1c levels and/or those whom started a new class of glucose-lowering drug(s) because of unsatisfactory reduction were defined as non-responders. In addition, good glycemic control was observed when HbA1c ≤7.0%, and the above values were regarded as poor. Genotyping of rs72552763 SNP was performed using TaqMan® Drug Metabolism Enzyme Genotyping Assay and its association with metformin response and glycemic control were assessed by measuring the change in HbA1c and fasting blood glucose levels using Chi-square, logistic regression and Mann-Whitney U-test. Statistical significance was set at p <0.05. Results: The minor allele frequency of the rs72552763 SNP of SLC22A1 was 9.3%. Metformin response was significantly higher in deletion_GAT (del_G) genotypes as compared to the wild-type GAT_GAT (G_G) genotypes. Furthermore, a significantly lower median treatment HbA1 level was found in del_G genotypes as compared to G_G genotypes. However, the association of rs72552763 with metformin response was not replicated at the allele level. In contrast, the minor del_allele was significantly associated with good glycemic control compared to the G_allele, though not replicated at del_G genotypes level. Conclusion: This study demonstrated that metformin response was significantly higher in study participants with a heterozygous carrier of M420del variants of SLC22A1 as compared to the wild-type G_G genotypes after 3 months of treatment.

A Feasible Approach to Developing Fiber-Enriched Bread Using Pomegranate Peel Powder: Assessing Its Nutritional Composition and Glycemic Index.

The consumption of dietary fiber (DF) has been associated with a reduced incidence of non-communicable diseases. Despite various strategies implemented worldwide to increase DF intake, it remains low. Therefore, the development of new fiber-rich food products that are widely consumed could be a strategy to improve DF intake. In this study, an agro-industrial by-product, pomegranate peel powder (PPP), was used as an innovative source of DF and antioxidant. The objective was to develop a bread enriched with DF, antioxidants, and sensory characteristics by partially replacing wheat flour (WF) with PPP at levels of 0%, 2.5%, 5%, 7.5%, and 10%. Bread with 2.5% and 5% PPP was chosen for a clinical trial to evaluate glycemic response (GR) in healthy subjects and determine the bread's glycemic index (GI). As the percentage of PPP increased, both the DF and total polyphenol content increased significantly. The highest overall acceptability was achieved with bread containing up to 5% PPP. Consumption of bread with 2.5% and 5.0% PPP significantly reduced the GI compared to the control bread, while the decrease in GR was not significant. PPP could be a potential food and low-cost ingredient to improve the bread's nutritional quality through its contribution to DF and antioxidants.

[Staple food habits on glycemic response: a controlled feeding trial].

OBJECTIVE: To study the effects of staple food on the glycemic responses through a controlled feeding trial. METHODS: In November 2020, two groups of volunteers with different staple food habits(the rice group, n=35, and the wheat group, n=35), were recruited from Changzhi Medical College in Shanxi Province. They were subjected to a two-stage feeding trial, in which their staple food habits were maintained in the first stage(staple food fortification period, 4 weeks) and then swapped in the second stage(staple food swap period, 4 weeks), while keeping the rest of the dietary components same. A continuous glucose monitoring system was used to monitor the glycemic response of glucose, steamed buns and steamed rice, equivalent to 50 g of available carbohydrate(CHO). Blood glucose level up to 120 minutes postprandial, incremental area under the curve(iAUC) and glycemic index(GI) were analyzed. RESULTS: During the staple food fortification period, the glycemic response to steamed buns at 15 min(5.43±0.69 vs.5.14±0.50 mmol/L, P=0.047), 30 min(6.63±0.98 vs.6.10±0.70 mmol/L, P=0.012), 45 min(6.81±1.15 vs.6.21±0.67 mmol/L, P=0.011) and 60 min postprandial(6.03±0.96 vs.5.56±0.59 mmol/L, P=0.017) in the rice group were higher than the wheat group, and the trends for blood glucose fluctuation during the 120 minutes after consuming steamed buns were different between the two groups. During the staple food swap period, the 120 min iAUC(83.24±30.15 vs.69.32±26.25 mmol·min/L, P=0.032) and GI(88±24 vs.75±33, P=0.041) of the rice group to steamed buns were higher than the wheat group. Comparing the differences between the two groups in the staple food exchange period and the staple food intensification period, the rice group had an increased glycemic response to steamed buns(P=0.007), while the wheat group had an increased glycemic response to glucose(P<0.001), steamed buns(P<0.001) and steamed rice(P=0.018). The 120 min iAUC of steamed buns in the rice group increased(83.24±30.15 vs.70.12±26.02 mmol·min/L, P=0.029), and the 120 min iAUC of rice in the wheat group(69.75±32.32 vs.54.87±20.43 mmol·min/L, P=0.040) increased. CONCLUSION: Even to the same food, there are significant differences in the glycemic responses of people with different staple food habits, and short-term changes in the intake of staple food will lead to differences in the glycemic response.

Structural changes of thermally treated starch during digestion and the impact on postprandial glucose homeostasis.

Intake of foods upon thermal treatment is typically associated with an elevated postprandial glycemic response, which is one of the risk factors for type 2 diabetes development and progression. In this study, rice starch was thermally treated using aqueous phase (boil), air phase (bake), and lipid phase (fry). Peak blood glucose levels in C57 mice increased by 16.94 %, 12.60 %, and 8.1 % after ingestion of thermally treated starch (20.23, 19.48, and 18.70 mmol/L), compared with raw starch (17.30 mmol/L). The insulin response to the intake of thermally treated starch increased (4.73 %-6.83 % higher than the control), whereas the concentration of GLP-1, a hormone used to promote insulin secretion, decreased (1.54 %-8.56 % lower than the control). Furthermore, thermally treated starch accelerated food absorption by enhancing gastrointestinal digestion, exacerbating postprandial glucose fluctuation at the next meal. Structural characterization showed thermal treatment reduced starch branching density and degree of structure order, which were not conducive to preventing the attack of enzymes. During digestion, they were highly hydrolyzed into low-molecular-weight fragments, and the proportion of ultrashort chains substantially increased. These findings provide a better understanding of the fine structure of starch that promotes hypoglycemia and initially explain how diets high in thermally treated starch impair glucose balance.

Effect of the Pasta Making Process on Slowly Digestible Starch Content.

The rate at which starch is digested in the human intestine elicits different glycemic responses and reflects the glycemic index (GI) of foods. In vitro measurement of starch digestibility can reflect the GI of food. Differences in starch digestibility among four durum wheat pasta samples, couscous, and bread were evaluated to better describe the role of the pasta making process in affecting starch digestibility. Statistical differences in RDS (rapidly digestible starch), SDS (slowly digestible starch), and RS (resistant starch) of products were found (p < 0.05). As expected, pasta samples showed the highest value of SDS/av starch compared to couscous and bread. Fusilli and cavatelli samples presented the highest SDS/av starch ratio (55.80 ± 3.06% and 53.91 ± 3.50%, respectively), then came spaghetti 49.39 ± 2.83% and penne 45.93 ± 1.19%, while couscous presented the lowest value of SDS/av starch (2.64 ± 0.50%), followed by bread (11.78 ± 2.63%). Our study confirmed that the pasta making process efficiently mediates an increase in SDS/Av starch content, which has been specifically quantified above 40%, therefore strongly related to a lowered glycemic response in vivo. Our results strengthened the concept that pasta is a good source of SDS, which makes it useful for glycemic control.

Effects of resistant starch on glycemic response, postprandial lipemia and appetite in subjects with type 2 diabetes.

PURPOSE: Resistant starch (RS) content has exhibited beneficial effects on glycemic control; however, few studies have investigated the effects of this substance on postprandial responses and appetite in subjects with type 2 diabetes (T2D). Here, we aimed to examine the effects of RS from two sources on glycemic response (GR), postprandial lipemia, and appetite in subjects with T2D. METHODS: In a randomized and crossover study, 17 subjects with T2D consumed native banana starch (NBS), high-amylose maize starch (HMS) or digestible maize starch (DMS) for 4 days. On day 5, a 6-h oral meal tolerance test (MTT) was performed to evaluate glycemic and insulinemic responses as well as postprandial lipemia. Besides, subjective appetite assessment was measured using a visual analogue scale. RESULTS: NBS induced a reduction on fasting glycemia, glycemia peak and insulinemic response during MTT. However, no modifications on postprandial lipemia were observed after RS treatments. Both NBS and HMS reduced hunger and increased satiety. CONCLUSION: NBS supplementation induced more beneficial effects on glycemic metabolism than HMS even when all interventions were matched for digestible starch content. RS intake did not modify postprandial lipemia, however, positively affected subjective appetite rates. TRIAL REGISTRATION: This trial was retrospectively registered at www.anzctr.org.au (ACTRN12621001382864) on October 11, 2021.

Slow digestion properties of long-sized isomaltooligosaccharides synthesized by a transglucosidase from Thermoanaerobacter thermocopriae.

Isomaltooligosaccharides (IMOs) are widely used as prebiotic ingredients that promote colon health; however, recent studies revealed that these are slowly hydrolyzed to glucose within the small intestine. Here, novel α-glucans with a higher number of α-1,6 linkages were synthesized from maltodextrins using the Thermoanaerobacter thermocopriae-derived transglucosidase (TtTG) to decrease susceptibility to hydrolysis and improve slow digestion properties. The synthesized long-sized IMOs (l-IMOs; 70.1% of α-1,6 linkages), comprising 10-12 glucosyl units, exhibited slow hydrolysis to glucose when compared to commercial IMOs under treatment with mammalian α-glucosidase level. In male mice, the ingestion of l-IMOs significantly decreased the post-prandial glycemic response compared to other samples (p < 0.05). Therefore, enzymatically synthesized l-IMOs can be applied as functional ingredients for the modulation of blood glucose homeostasis in obesity, Type 2 diabetes, and other chronic diseases.

Cooked Rice-Based and Wheat-Based Food Structure Influenced Digestion Kinetics and Glycemic Response in Growing Pigs.

BACKGROUND: How starch-based food structure can affect the rate and extent of digestion in the small intestine and resulting glycemic response is not properly understood. One possible explanation is that food structure influences gastric digestion, which subsequently determines digestion kinetics in the small intestine and glucose absorption. However, this possibility has not been investigated in detail. OBJECTIVES: Using growing pigs as a digestion model for adult humans, this study aimed to investigate how physical structure of starch-rich foods affects small intestinal digestion and glycemic response. METHODS: Male growing pigs (21.7 ± 1.8 kg, Large White × Landrace) were fed one of the 6 cooked diets (250-g starch equivalent) with varying initial structures (rice grain, semolina porridge, wheat or rice couscous, or wheat or rice noodle). The glycemic response, small intestinal content particle size and hydrolyzed starch content, ileal starch digestibility, and portal vein plasma glucose were measured. Glycemic response was measured as plasma glucose concentration collected from an in-dwelling jugular vein catheter for up to 390 min postprandial. Portal vein blood samples and small intestinal content were measured after sedation and euthanasia of the pigs at 30, 60, 120, or 240 min postprandial. Data were analyzed with a mixed-model ANOVA. RESULTS: The plasma glucose Δmaxoverall and iAUCoverall for couscous and porridge diets (smaller-sized diets) were higher than that of intact grain and noodle diets (larger-sized diets): 29.0 ± 3.2 compared with 21.7 ± 2.6 mg/dL and 5659 ± 727 compared with 2704 ± 521 mg/dL⋅min, for the smaller-sized and larger-sized diets, respectively (P < 0.05). Ileal starch digestibility was not significantly different between the diets (P ≥ 0.05). The iAUCoverall was inversely related to the starch gastric emptying half-time of the diets (r = -0.90, P = 0.015). CONCLUSIONS: Starch-based food structure affected the glycemic response and starch digestion kinetics in the small intestine of growing pigs.

A New Approach to Personalized Nutrition: Postprandial Glycemic Response and its Relationship to Gut Microbiota.

A prolonged and elevated postprandial glucose response (PPGR) is now considered a main factor contributing for the development of metabolic syndrome and type 2 diabetes, which could be prevented by dietary interventions. However, dietary recommendations to prevent alterations in PPGR have not always been successful. New evidence has supported that PPGR is not only dependent of dietary factors like the content of carbohydrates, or the glycemic index of the foods, but is also dependent on genetics, body composition, gut microbiota, among others. In recent years, continuous glucose monitoring has made it possible to establish predictions on the effect of different dietary foods on PPGRs through machine learning methods, which use algorithms that integrate genetic, biochemical, physiological and gut microbiota variables for identifying associations between them and clinical variables with aim of personalize dietary recommendations. This has allowed to improve the concept of personalized nutrition, since it is now possible to recommend through these predictions specific dietary foods to prevent elevated PPGRs that are highly variable among individuals. Additional components that can enrich the predictive algorithms are findings of nutrigenomics, nutrigenetics and metabolomics. Thus, this review aims to summarize the evidence of the components that integrate personalized nutrition focused on the prevention of PPGRs, and to show the future of personalized nutrition by laying the groundwork for the development of individualized dietary management and its impact on the improvement of metabolic diseases.