Effects of dietary fiber on glycemic control and insulin sensitivity in patients with type 2 diabetes: A systematic review and meta-analysis

Applications of bacterial cellulose in the food industry and its health-promoting potential

Bacterial cellulose (BC) is a naturally occurring biomaterial with a wide range of potential applications in the food industry because of its exceptional mechanical qualities, unique nanofiber structure, high purity, and outstanding biocompatibility. Beyond its physical attributes, BC has gained interest recently due to research demonstrating its potential health benefits as a functional food ingredient. This article examines the many uses of BC in the food business, with a focus on how it may enhance food texture, operate as a bioactive carrier, and have promise in the packaging sector. Further research was done on the health-promoting properties of BC in functional foods, particularly with regard to its functions as a blood glucose regulator, and gastrointestinal health. This review seeks to bring fresh ideas for the study of bioactive components in the food industry by providing a summary of the existing research and demonstrating the possible role of BC in food. It also suggests future paths for research.

Foxtail millet bran dietary fibres foster in vitro beneficial gut microbes and metabolites while suppressing pathobionts

Foxtail millet bran soluble dietary fibre (MBSDF) is a dietary compound with various bioactivities, potentially modulated by the gut microbiota. To elucidate this bioregulatory mechanism, this study focused on the structureal composition and in vitro fermentation characteristics of MBSDF. The results revealed that MBSDF has a molecular weight of 18.26 kDa. The main chain is connected through a glycosidic bond in the form of →4)-α-D-Glcp-(1 → 4)-β-D-Xylp-(1→, being branched by →4, 6)-α-D-Glcp-(1 → O-6 and →3, 4)-β-D-Xylp-(1 → O3 bonds. After 24 h fermentation, the carbohydrate utilisation rate reached 59.15 %, with a decreased molecular weight and monosaccharide composition molar mass ratio. Meanwhile, a increase was observed in the short-chain fatty acid, accompanied by an increased relative abundance of Faecalibacterium, Bifidobacterium and Lactobacillus and suppressed growth of pathogenic Enterococcus. Interestingly, the modulation of gut homeostasis probably occurs via butyrate metabolism pathway. Collectively, MBSDF can selectively regulate the gut microbiota and their metabolites.

Pumpkin Soluble Dietary Fiber instead of Insoluble One Ameliorates Hyperglycemia via the Gut Microbiota-Gut-Liver Axis in db/db Mice

Pumpkin extract has been shown to alleviate hyperglycemic symptoms by improving glucose metabolism disorders. However, the specific active components responsible for its hypoglycemic effects and the underlying molecular mechanisms remain unclear. In this study, db/db mice underwent a 4-week dietary intervention with two pumpkin flours (PF1 and PF2), total dietary fiber (TDF), soluble dietary fiber (SDF), and insoluble dietary fiber (IDF), with acarbose serving as a positive control. Our results revealed that pumpkin components significantly altered the gut microbiota, characterized by a reduction in diabetes-related bacteria and an increase in short-chain fatty acid (SCFA)-producing bacteria, including Bacteroides, Akkermansia, and Lachnospiraceae_NK4A136 group. Additionally, pumpkin components significantly increased fecal SCFA levels and upregulated the expression of SCFA receptor GPR43, potentially promoting GLP-1 secretion. Notably, pumpkin components significantly reduced fasting blood glucose and serum insulin levels and inhibited gluconeogenesis. This effect may be ascribed to the inhibition of the cAMP/PKA/CREB signaling pathway coupled with the activation of the PI3K/AKT signaling pathway. Our research indicated that pumpkin flour and dietary fiber alleviated hyperglycemia through the gut-liver axis, with SDF contributing the most to the hypoglycemic effect. These findings suggest that pumpkin components may serve as an adjunct nutritional intervention to ameliorate hyperglycemia.

The effect of high-fibre diets on glycaemic control in women with diabetes in pregnancy: A systematic review and meta-analysis

Dietary fibre improves glycaemic control in type 2 diabetes, but its therapeutic role in women with diabetes in pregnancy is unclear. We assessed the effect of dietary fibre on markers of glycaemic control in women with diabetes in pregnancy.

METHODS

We searched four databases (Cochrane Library, MEDLINE, Embase and Web of Science) to identify RCTs exploring the effect of dietary fibre, high-fibre diets or fibre supplementation on fasting blood glucose (FBG), 2-h postprandial blood glucose (PBG) and requirement for insulin therapy, among other glycaemic makers in pregnant women with diabetes. Data were pooled for each outcome to calculate change from baseline mean (SD) and overall mean difference (MD) between control and intervention groups.

RESULTS

Of 1462 identified studies, data from 20 eligible trials containing 1061 participants were pooled. On meta-analysis, a higher fibre intake was associated with reduced FBG (MD: -0.35 mmol/L, 95% CI: -0.53, -0.18, p < 0.01), PBG (MD: -0.90 mmol/L, 95% CI: -1.39, -0.40, p < 0.01) and requirement for insulin (OR: 0.24, 95% CI: 0.13, 0.46, p < 0.01). There was significant heterogeneity for FBG and PBG (>90%), attributable to differences in Intervention type for PBG (Dietary Approach to Stop Hypertension [DASH] diet, low glycaemic index, supplement; p < 0.01) and study duration (for FBG: p = 0.002; not for PBG). Studies were mostly scored as high risk of bias due to lack of blinding (Cochrane Risk of Bias Tool v.2.0).

CONCLUSION

High-quality dietary intervention studies in pregnancy are lacking. Our results suggest that high-fibre diets improve fasting and postprandial glycaemia and reduce the likelihood of requiring insulin in women with diabetes in pregnancy.

Differently Processed Low Doses of β-Glucan from Oat Bran Similarly Attenuate Postprandial Glycemic Response

Incorporating β-glucan-rich oat bran (OB) can attenuate postprandial glycemic response (PPGR) in solid foods, but its effect in liquid matrices is unclear. This study investigated the ability of differently processed low-dose-β-glucan-containing beverages to lower PPGR, and the mechanisms of action. Twenty participants consumed five malt beverages made from cocoa powder: intact OB (Intact), OB treated with enzymatic hydrolysis (EnzymA, EnzymB) or extrusion (Extr), or no OB (Ctrl). Four-hour postprandial incremental areas under the curve (iAUC) and peak incremental concentrations (iCmax) of glucose, insulin, glucagon-like peptide 1 (GLP-1), gastric inhibitory polypeptide (GIP), and paracetamol were evaluated. The molecular weight (MW) and extractability of the β-glucan in all the test products were also assessed. The three-hour glucose iAUC significantly decreased by -26%, -28%, -32%, and -38% in Intact, EnzymA, EnzymB, and Extr, respectively, and the insulin levels of the oat-containing products were also significantly lower compared to Ctrl. Intact and Extr elicited a lower insulin iCmax and GLP-1 3 h iAUC compared to Ctrl. However, the GIP and paracetamol levels were not changed. All the processed OBs improved β-glucan extractability and lowered the MW of β-glucan compared to Intact. In conclusion, low-dose oat β-glucan in a beverage significantly reduced PPGR, with effects maintained across different oat processing methods.

Hypoglycemic effects of white hyacinth bean polysaccharide on type 2 diabetes mellitus rats involvement with entero-insular axis and GLP-1 via metabolomics study

The present study aimed to investigate the potential effects of white hyacinth bean polysaccharide (WHBP) against type 2 diabetic mellitus (T2DM) which was established by high-glucose/high-fat for 8 weeks, combined with a low-dose streptozotocin (STZ) injection. Our results showed that WHBP behaved the hypoglycemic effect by attenuating fasting blood glucose in vivo. WHBP-mediated anti-diabetic effects associated with the attenuation of insulin resistance and pancreatic impairment, as evidenced by the mitigation of pathological changes, inflammatory response and oxidative stress in the pancreas of T2DM rats. Meanwhile, gut protection was also shown during WHBP-mediated anti-diabetic effects, and glucagon-like peptide-1 (GLP-1), a mediator of the entero-insular axis, was observed to be elevated in both gut and pancreas of WHBP groups when compared to DM group, suggesting that hypoglycemic effects of WHBP were implicated in gut-pancreas interaction. Subsequently, untargeted metabolomics analysis performed by UPLC-QTOF/MS and showed that WHBP administration significantly adjusted the levels of 40 metabolites when compared to DM group. Further data concerning pathway analysis showed that WHBP administration significantly regulated the phenylalanine metabolism, tryptophan metabolism, arginine and proline, isoleucine metabolism, and glycerophospholipid metabolism in T2DM rats. Together, our results suggested that WHBP performed hypoglycemic effects and pancreatic protection linked to entero-insular axis involvement with GLP-1 and reversed metabolic disturbances in T2DM rats.

The Role of Dietary Ingredients and Herbs in the Prevention of Non-Communicable Chronic Liver Disease

BACKGROUND

Liver diseases are among the most commonly diagnosed conditions, with the main risk factors being inappropriate lifestyles, including poor diet, excessive alcohol consumption, low physical activity and smoking, including electronic cigarettes. Non-communicable chronic liver diseases also often develop as a result of accompanying overweight and obesity, as well as type 2 diabetes.

METHODS

The literature on risk factors for non-communicable chronic liver diseases, which show a high strong influence on their occurrence, was analysed.

RESULTS

Measures to prevent non-communicable chronic liver disease include the selection of suitable food ingredients that have proven protective effects on the liver. Such ingredients include dietary fibre, probiotics, herbs, various types of polyphenols and fatty acids (omega-3).

CONCLUSIONS

Because of their liver-protective effects, nutritionists recommend consuming vegetables, fruits, herbs and spices that provide valuable ingredients with anti-inflammatory and anti-cancer effects. These components should be provided with food and, in the case of probiotics, supplementation appears to be important. As a preventive measure, a diet rich in these nutrients is therefore recommended, as well as one that prevents overweight and other diseases that can result in liver disease.

Impact of the Mediterranean Diet on Athletic Performance, Muscle Strength, Body Composition, and Antioxidant Markers in Both Athletes and Non-Professional Athletes: A Systematic Review of Intervention Trials

Background: The Mediterranean Diet (MD) has gained attention for its potential benefits in enhancing athletic performance and overall health. This systematic review aims to evaluate the effects of the MD on athletic performance, strength, body composition, and metabolic markers in both athletes and non-professional athletes. Methods: The review included seven studies with a total of 116 participants, ranging from professional handball players to non-professional strength athletes. The studies assessed various aspects of athletic performance, including strength, power, endurance, and body composition. Results: The main key findings from the review showed that MD may improve muscle endurance and power, as well as anaerobic performance in CrossFit athletes, and MD was associated with enhanced strength performance, including increased vertical jump height, hand grip strength, and shuttle run performance. The results on the impact on body composition were mixed, with some studies showing improvements in fat-free mass and skeletal muscle mass, while others found no significant changes. The MD also demonstrated positive effects on several markers, such as increased plasma total antioxidant activity and decreased markers of oxidative stress and inflammation. Conclusions: In conclusion, while the MD seems to represent a viable dietary strategy for enhancing athletic performance and overall health, more rigorous studies are necessary to clarify its impact across diverse athletic populations.

Interventions to improve glycaemic control in people living with, and at risk of developing type 2 diabetes

Type 2 diabetes mellitus is one of the most prevalent health conditions worldwide, affecting millions of individuals and posing significant public health challenges. Understanding the nature of type 2 diabetes, its causes, symptoms and treatments is crucial for managing and preventing its complications. Many different dietary strategies are used by individuals to treat and manage diabetes. This review provides an overview of popular dietary strategies that have evidence for improving long-term glycaemic control or achieving diabetes remission, as well as strategies that may be useful to reduce postprandial hyperglycaemia, which may be of use in the prevention of diabetes, but also as strategies for those already diagnosed but trying to manage their condition better. Recent clinical trials have provided evidence that in people living with type 2 diabetes who also live with overweight or obesity, using a total diet replacement weight loss programme results in significant and substantial weight loss, and as a result, many people can achieve remission from their diabetes. There has been considerable interest in whether similar effects can be achieved without reliance on formula foods, using real diet approaches. Reduced or low-carbohydrate diet approaches hold some promise, with observational or preliminary findings suggesting beneficial effects, but evidence from robust trials or systematic reviews of randomized controlled trials is still lacking. The Mediterranean dietary pattern, low in saturated fat and high in monounsaturated fat, also has some potential, with evidence to suggest some people can lose weight and achieve remission using this approach, which may be easier to adhere to longer term than more intensive total diet replacement and low-carbohydrate strategies. Plant-based diets that advocate for the elimination of animal-based and/or animal-derived foods have increased in popularity. There is evidence from epidemiological studies that people who follow these diets have a lower risk of developing type 2 diabetes, and evidence from trials and systematic reviews of trials that changing to a dietary pattern lower in animal-based and animal-derived foods has benefits on glycaemic control and other markers of cardiovascular disease. While these approaches all provide food or nutrient prescriptions, approaches that incorporate periods of fasting do not provide rules on the types of foods that can or cannot be consumed, but rather provide time windows of when to eat. Evidence suggests that these approaches can be as effective in achieving energy restriction and weight loss as approaches that advocate continuous energy restriction, and there is evidence for benefits on glycaemic control independent of weight loss. Finally, popular dietary strategies that may be useful to use or combine to help prevent postprandial hyperglycaemia include reducing the glycaemic index or glycaemic load of the diet, high-fibre diets, eating foods in a meal in the order vegetables > protein > carbohydrates, preloading or combining acids such as vinegar or lemon juice with meals and engaging in low-intensity aerobic exercise immediately after meals.

Impact of Combined Prebiotic Galacto-Oligosaccharides and Bifidobacterium breve-Derived Postbiotic on Gut Microbiota and HbA1c in Prediabetic Adults: A Double-Blind, Randomized, Placebo-Controlled Study

The complex interactions between intestinal microbiota and metabolic disorders are well-documented, with implications for glucose metabolism, energy expenditure, and intestinal permeability. Prebiotics induce beneficial changes in gut microbiota composition in prediabetes, while postbiotics can enhance gut barrier function, complementing each other to improve glucose metabolism and insulin sensitivity. This study investigated the effects of a 12-week dietary fibre (DF) supplement on gut health, metabolic function, and diet. The supplement contained konjac glucomannan (KGM), galacto-oligosaccharides (GOSs), and exopolysaccharides (EPSs) from Bifidobacterium breve. In a randomised, double-blind, placebo-controlled, parallel-group clinical trial, 53 prediabetic volunteers were randomly assigned to either a daily DF supplement (YMETA) or a placebo (cellulose microcrystalline) for 12 weeks, followed by a 4-week follow-up. Measurements included gut microbiota composition, glycated haemoglobin (HbA1c), fasting plasma glucose (FPG), plasma lipids, anthropometry, body composition, blood pressure, and dietary intake. The intervention group showed a significant increase in alpha diversity and butyrate-producing bacteria, with reductions in HbA1c and FPG levels below prediabetes thresholds. No significant changes were observed in the placebo group. This study suggests that manipulating the human gut microbiome through dietary interventions could be a promising therapeutic approach to managing prediabetes and preventing or delaying diabetes.

Polysaccharides from Medicinal Plants: Bridging Ancestral Knowledge with Contemporary Science

Plants are a core part of cultural identity, as part of a diet, decorations, ceremonies, or as medicinal agents. Empirical knowledge regarding plants and their healing potential has existed worldwide for centuries. With the advance of science and technology, not only is the refinement of such sources or isolation of specific compounds possible, but these compounds can also be characterized based on their natural occurrence. Besides their importance for plant metabolism and structure, polysaccharides have been demonstrated to have substantial positive human health impacts on inflammation, metabolism, oxidative stress, and others. As an inherent part of plant cell walls, many polysaccharides from medicinal herbs, such as fructans, glucans, and pectins, have been extracted and analyzed for their structure and function. However, a review summarizing a significant portion of these studies was still unavailable. This review helps to fill the knowledge gap between polysaccharide bioactivity, their structure, and their plant matrix sources, focusing on historical medicinal usage.

Unraveling the Microbiome-Human Body Axis: A Comprehensive Examination of Therapeutic Strategies, Interactions and Implications

This review scrutinizes the intricate interplay between the microbiome and the human body, exploring its multifaceted dimensions and far-reaching implications. The human microbiome, comprising diverse microbial communities inhabiting various anatomical niches, is increasingly recognized as a critical determinant of human health and disease. Through an extensive examination of current research, this review elucidates the dynamic interactions between the microbiome and host physiology across multiple organ systems. Key topics include the establishment and maintenance of microbiota diversity, the influence of host factors on microbial composition, and the bidirectional communication pathways between microbiota and host cells. Furthermore, we delve into the functional implications of microbiome dysbiosis in disease states, emphasizing its role in shaping immune responses, metabolic processes, and neurological functions. Additionally, this review discusses emerging therapeutic strategies aimed at modulating the microbiome to restore host-microbe homeostasis and promote health. Microbiota fecal transplantation represents a groundbreaking therapeutic approach in the management of dysbiosis-related diseases, offering a promising avenue for restoring microbial balance within the gut ecosystem. This innovative therapy involves the transfer of fecal microbiota from a healthy donor to an individual suffering from dysbiosis, aiming to replenish beneficial microbial populations and mitigate pathological imbalances. By synthesizing findings from diverse fields, this review offers valuable insights into the complex relationship between the microbiome and the human body, highlighting avenues for future research and clinical interventions.

Nutritional Profiles and Their Links to Insulin Resistance and Anthropometric Variables in a Female Cohort

This study investigates the relationship between dietary habits and metabolic health among women, emphasizing the role of anthropometric parameters as proxies for insulin resistance. We analyzed data from 443 women categorized into two groups based on the presence or absence of clinically diagnosed insulin resistance. Our assessments included dietary quality, socio-demographic characteristics, and a series of anthropometric measurements such as body weight, Body Mass Index (BMI), Waist-Hip Ratio (WHR), Abdominal Volume Index (AVI), and Body Adiposity Index (BAI). The results indicated significant disparities in these parameters, with the insulin-resistant group exhibiting higher average body weight (78.92 kg vs. 65.04 kg, p < 0.001), BMI (28.45 kg/m2 vs. 23.17 kg/m2, p < 0.001), and other related measures, suggesting a strong influence of dietary patterns on body composition and metabolic risk. The study underscores the importance of dietary management in addressing insulin resistance, advocating for personalized dietary strategies to improve metabolic health outcomes in women. This approach highlights the need for integrating dietary changes with lifestyle modifications and socio-demographic considerations to combat metabolic risks effectively.

Partially defatted coconut flour as a functional ingredient in replacement of refined wheat flour for development of fiber rich muffins

In the current study, partially defatted coconut flour (PDCF) was prepared using deoiled cake obtained after virgin coconut oil processing. The proximate analysis of PDCF revealed the presence of 5.21% moisture, 14.03% fat, 21.34% protein, 46.39% fiber and 3.27% ash, along with prominent functional properties. Herein, muffins were prepared by incorporation of PDCF as a replacement of refined wheat flour (RWF) at 0, 25, 50, 75 and 100% flour blend. Significant changes in batter rheology were observed after 25 to 100% replacement of RWF with PDCF, which indicated a decrease in peak viscosity and final viscosity by 65.05 to 83.59% and 61.57 to 85.17% respectively, an increase in specific gravity of batter by 0.857-0.929 g/L. The prepared muffins had significant variations in colour of crust and crumb regions as represented by changes in L*a*b*, Hue angle (h°) and Chroma (C) and textural properties such as hardness, springiness, guminess, cohesiveness, chewiness, and resilience. Incorporation of 50% PDCF significantly (P < 0.05) increased the overall acceptability of the muffins (with a maximum score of 8.5), with a fiber content of 5.53 ± 0.23% and protein content of 7.57 ± 0.30%. Storage stability studies performed at 25 ± 2 °C for seven days revealed an increase in microbial count, and reduction in textural properties but both to be in acceptable regime.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05857-2.

The effects of pomegranate consumption on glycemic indices in adults: A systematic review and meta-analysis

BACKGROUND AND AIM

Epidemiologic studies have shown that type 2 diabetes (T2D) is more prevalent worldwide; therefore, improving glycemic indices to prevent or control T2D is vital. Randomized controlled trials (RCTs) on the effects of pomegranate consumption on glycemic indices have shown inconsistent results. Therefore, we aim to evaluate the impact of pomegranate consumption on fasting blood glucose (FBG), fasting insulin, hemoglobin A1c (HbA1c), and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) in adults.

METHODS

A systematic literature search was performed using electronic databases, including PubMed, Web of Science, and Scopus, up to May 2023 to identify eligible RCTs evaluating the effect of pomegranate consumption on glycemic indices. Heterogeneity tests of the included trials were performed using the I2 statistic. Random effects models were assessed based on the heterogeneity tests, and pooled data were determined as the weighted mean difference with a 95 % confidence interval.

RESULTS

Of 1999 records, 32 eligible RCTs were included in the current study. Our meta-analysis of the pooled findings showed that pomegranate consumption significantly reduced FBG (WMD: -2.22 mg/dL; 95 % CI: -3.95 to -0.50; p = 0.012), fasting insulin (WMD: -1.06 μU/ml; 95%CI: -1.79 to -0.33; p = 0.004), HbA1c (WMD: -0.22 %; 95% CI: -0.43 to -0.01; p = 0.037), and HOMA-IR (WMD: -0.30; 95%CI: -0.61 to -0.00; p = 0.046).

CONCLUSION

Overall, the results demonstrated that pomegranate consumption benefits glycemic indices in adults. However, further research with long-term interventions is required.

PROSPERO REGISTRATION CODE

CRD42023422780.

Total and different dietary fiber subtypes and the risk of all-cause, cardiovascular, and cancer mortality: a dose-response meta-analysis of prospective cohort studies

We aimed to conduct a comprehensive review of the association between dietary fiber and the risk of mortality. We did a systematic search in PubMed, Scopus, and Web of Science up to November 2022 to find prospective cohort studies of the relationship between total and subtypes of dietary fiber and the risk of all-cause, cardiovascular (CVD), and cancer mortality in the general population. The hazard ratios (HRs) and 95% CIs were calculated using a random-effects model. A total of 28 studies with 1 613 885 participants were included. Higher intake of total and subtypes of dietary fiber including cereal, vegetable, legume, soluble, and insoluble fiber, but not fruit fiber, was associated with a lower risk of all-cause mortality, with HRs ranging from 0.77 for insoluble fiber to 0.93 for legume fiber. Similar findings were observed for CVD mortality, where higher intake of total and all subtypes of dietary fiber was each associated with a lower risk. Higher intake of total, cereal, vegetable, and insoluble fiber was also associated with a lower risk of cancer mortality. No association was found between the intake of fruit, legume, and soluble fiber and cancer mortality. Dose-response meta-analyses suggested an inverse association between total fiber intake and the risk of all-cause, CVD, and cancer mortality. The certainty of evidence was rated moderate for the association of total fiber with all-cause, CVD, and cancer mortality. In conclusion, our findings highlight the potential advantages of consuming a wide range of dietary fiber subtypes against all-cause, CVD, and cancer mortality. Registry and registry number: PROSPERO (CRD42021226816).

The association between ultra-processed foods and conventional markers of cardiovascular risk in an adult Iranian population

BACKGROUND AND AIMS

According to the NOVA classification system, ultra-processed foods result from extensive industrial processing and use ingredients derived from food and non-food products, which can negatively impact on cardiovascular disease risk factors. Despite this, few studies have investigated UPFs in Middle Eastern populations regardless of high consumption in this region.

METHODS AND RESULTS

This cross-sectional study was conducted on data from the Prospective Epidemiological Research Studies in Iran Kharemeh cohort (n = 6611). Food frequency questionnaires were assessed and the ratio of total UPFs energy/total energy intake was calculated. Data was categorized into tertiles of UPF consumption using the NOVA classification system. Kruskal-Wallis tests were used to assess differences in nutrient and food intakes between tertiles and logistic regression analysis was applied to assess the associations between UPFs and CVD risk factors. After adjustment for potential confounders the logistic regression analysis revealed significant positive relationships between intakes of UPFs and waist circumference (WC) (T2: OR; 1.34, 95% CI; 1.13-1.60 - T3: OR; 1.41, 95% CI; 1.18-1.69, P ˂0.001), low-density lipoprotein cholesterol (LDL-C) (T2: OR; 1.20, 95% CI; 1.05-1.37 - T3: OR; 1.27, 95% CI; 1.11-1.45, P ˂0.001), non-high-density lipoprotein cholesterol (non-HDL) (T2: OR; 1.21, 95% CI; 1.07-1.37 - T3: OR; 1.24, 95% CI; 1.10-1.41, P ˂0.001) and LDL-C to HDL-C ratio (T2: OR; 1.15, 95% CI; 1.02-1.31 - T3: OR; 1.21, 95% CI; 1.07-1.38, P = 0.002).

CONCLUSION

The consumption of UPFs was positively associated with WC and atherogenic blood lipids. However, increased intakes of fiber and unsaturated fats were also found in those consuming more UPFs, which was not expected. These findings offer insights into an understudied population and warrant further research.

Effects of anthocyanin supplementation in diet on glycemic and related cardiovascular biomarkers in patients with type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials

Purpose

This study is the first systematic review and meta-analysis based on RCTs on the effects of anthocyanins on patients with type 2 diabetes mellitus (T2DM) and the effect on T2DM-related cardiovascular disease.

Methods

RCTs published in English from five electronic databases were evaluated for glycated hemoglobin (HbA1c), fasting blood glucose (FBG), 2-h postprandial blood glucose, fasting insulin, model assessment for insulin resistance, triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, systolic blood pressure, and diastolic blood pressure. The quality of the studies was rated (Cochrane Risk of Bias tool) and weighted mean differences were calculated (DerSimonian-Laird model with random effects). Leave-one-out sensitivity, subgroup, and publication bias analyses were conducted. The strength of the evidence was rated according to the GRADE guidelines.

Results

In all, 13 RCTs were analyzed out of the 239 identified studies, with a duration longer than 4 weeks (703 participants with T2DM). Our findings indicate that a median dose of 320 mg/day anthocyanins, either from fruit extracts or pure supplements, for a median intervention length of 8 weeks significantly reduced HbA1c [Weighted Mean Difference (WMD) -0.31, p = 0.00], FBG (WMD -0.63, p = 0.00), 2-h postprandial glucose (WMD -1.60, p = 0.00), TG (WMD -0.45, p = 0.01), and LDL (WMD -0.26 p = 0.02). However, the effects of anthocyanins on fasting insulin, HOMA-IR, TC, HDL cholesterol, systolic blood pressure, and diastolic blood pressure in patients with T2DM were not statistically significant. Anthocyanins from fruit extracts or powder exhibited a higher reduction of HbA1c compared to pure anthocyanin supplements.

Conclusion

The significant improvements in glycemic parameters and lipid profile, suggest the benefits of anthocyanins, especially from fruit extract or powder, in the management of T2DM, and their ability to delay the onset of lipid disorder-related diseases such as cardiovascular disease associated with T2DM. The mechanism behind this reduction in glycemic markers could be attributed to the antioxidant and anti-inflammatory activity of anthocyanins. Further research with well-designed RCTs is required to determine the optimal dosage of anthocyanins for the treatment of T2DM and to comprehend the consequences.

The effect of spirulina sauce on glycemic index, lipid profile, and oxidative stress in type 2 diabetic patients: A randomized double-blind clinical trial

We aimed to evaluate the effect of spirulina sauce on glycemic indices, lipid profile, oxidative stress markers, and anthropometric measurement in type 2 diabetic patients. Forty patients were randomly assigned to receive 20 g/day spirulina sauce (containing 2 g of spirulina) or placebo for 2 months. Anthropometric and biochemical indices were measured at the beginning and end of the intervention. Fasting blood glucose (mean difference (MD): -15.3 mg/dL, 95% confidence (CI): -44.2 to 13.60, p = .26), HbA1c (MD: 0.13%, 95% CI: -0.83 to 0.57, p = .75), insulin (MD: -1.46 μIU/mL, 95% CI: -4.0 to 1.09, p = .28), and HOMA-IR (MD: -0.35, 95% CI: -2.0 to 1.32, p = .68) did not change significantly between groups. QUICKI increased significantly (MD: 0.025, 95% CI: 0.006 to 0.045, p = .03). Among the lipid profile, triglyceride (TG) (MD: -68.6 mg/dL, 95% CI: -107.21 to -29.98, p < .001), total cholesterol (MD: -29.55 mg/dL, 95% CI: -55.28 to -3.81, p = .02), and LDL (MD: -17.7 mg/dL, 95% CI: -33.24 to -2.15, p = .01) were significantly decreased in the spirulina group compared to the control; whereas, the change in HDL was non-significant. No significant change was observed in body composition and anthropometric measurements, except waist circumference, which was reduced (MD: -2.65 cm, 95% CI: -3.91 to -1.38, p = .001). Hunger index significantly decreased and fullness increased marginally significantly. Although malondialdehyde was significantly reduced, no change was observed in total antioxidant capacity (TAC). Spirulina sauce was not effective for glycemic control in type 2 diabetes; however, could be useful for controlling appetite and ameliorating lipid profile.

Gut microbiota-derived tryptamine and phenethylamine impair insulin sensitivity in metabolic syndrome and irritable bowel syndrome

The incidence of metabolic syndrome is significantly higher in patients with irritable bowel syndrome (IBS), but the mechanisms involved remain unclear. Gut microbiota is causatively linked with the development of both metabolic dysfunctions and gastrointestinal disorders, thus gut dysbiosis in IBS may contribute to the development of metabolic syndrome. Here, we show that human gut bacterium Ruminococcus gnavus-derived tryptamine and phenethylamine play a pathogenic role in gut dysbiosis-induced insulin resistance in type 2 diabetes (T2D) and IBS. We show levels of R. gnavus, tryptamine, and phenethylamine are positively associated with insulin resistance in T2D patients and IBS patients. Monoassociation of R. gnavus impairs insulin sensitivity and glucose control in germ-free mice. Mechanistically, treatment of R. gnavus-derived metabolites tryptamine and phenethylamine directly impair insulin signaling in major metabolic tissues of healthy mice and monkeys and this effect is mediated by the trace amine-associated receptor 1 (TAAR1)-extracellular signal-regulated kinase (ERK) signaling axis. Our findings suggest a causal role for tryptamine/phenethylamine-producers in the development of insulin resistance, provide molecular mechanisms for the increased prevalence of metabolic syndrome in IBS, and highlight the TAAR1 signaling axis as a potential therapeutic target for the management of metabolic syndrome induced by gut dysbiosis.

Effect of Adding Fermented Proso Millet Bran Dietary Fiber on Micro-Structural, Physicochemical, and Digestive Properties of Gluten-Free Proso Millet-Based Dough and Cake

The increasing demand for functional foods has pushed the food industry to produce fiber-enriched products. In this study, rheological, microstructural, physicochemical, and functional characteristics were investigated for whole proso millet dough and cake, fortified with fermented proso millet bran dietary fiber flour (F-DF). Results showed that proso millet flour is less absorbent and stable than the control group. Adding proso millet flour and F-DF reduced the elasticity of the dough and increased its hardness, but had no significant effect on viscosity, cohesion, and resilience. The microstructure analysis exhibited an unformed continuous network formation in proso millet dough. Analyses suggested that proso millet flour combined with the fermented dietary fiber group had significantly higher total phenol content (0.46 GAE mg/g), DPPH• scavenging activity (66.84%), and ABTS•+ scavenging activity (87.01%) than did the other group. In addition, F-DF led to a significant reduction in the predicted released glucose contents of reformulated cakes. In summary, cakes prepared with the involvement of whole proso millet flour and F-DF exhibited less adverse sensory impact and possessed the potential to decrease postprandial blood glucose levels resulting purely from cake consumption.

In vitro simulated fecal fermentation of mixed grains on short-chain fatty acid generation and its metabolized mechanism

In vitro simulated digestion and fecal fermentation were performed to investigate the influence of mixed grains on gut microbes. In addition, the key metabolic pathways and enzymes associated with short-chain fatty acids (SCFAs) were explored. The mixed grains exhibited an observable regulatory effect on the composition and metabolism of intestinal microorganisms, especially in probiotics, such as Bifidobacterium spp., Lactobacillus spp., and Faecalibacterium spp. WR (wheat + rye), WB (wheat + highland barley) and WO (wheat + oats) tended to generate lactate and acetate, which are related to Sutterella, Staphylococcus, etc. WQ (wheat + quinoa) induced high propionate and butyrate accumulation by consuming lactate and acetate, mainly through Roseburia inulinivorans, Coprococcus catus and Anaerostipes sp., etc. Moreover, bacteria enriched in different mixed grain groups regulated the expression of pivotal enzymes in metabolic pathways and then affected the generation of SCFAs. These results provide new knowledge on the characteristics of intestinal microbial metabolism in different mixed grain substrates.

Predicting weight loss success on a new Nordic diet: an untargeted multi-platform metabolomics and machine learning approach

Background and aim

Results from randomized controlled trials indicate that no single diet performs better than other for all people living with obesity. Regardless of the diet plan, there is always large inter-individual variability in weight changes, with some individuals losing weight and some not losing or even gaining weight. This raises the possibility that, for different individuals, the optimal diet for successful weight loss may differ. The current study utilized machine learning to build a predictive model for successful weight loss in subjects with overweight or obesity on a New Nordic Diet (NND).

Methods

Ninety-one subjects consumed an NND ad libitum for 26 weeks. Based on their weight loss, individuals were classified as responders (weight loss ≥5%, n = 46) or non-responders (weight loss <2%, n = 24). We used clinical baseline data combined with baseline urine and plasma untargeted metabolomics data from two different analytical platforms, resulting in a data set including 2,766 features, and employed symbolic regression (QLattice) to develop a predictive model for weight loss success.

Results

There were no differences in clinical parameters at baseline between responders and non-responders, except age (47 ± 13 vs. 39 ± 11 years, respectively, p = 0.009). The final predictive model for weight loss contained adipic acid and argininic acid from urine (both metabolites were found at lower levels in responders) and generalized from the training (AUC 0.88) to the test set (AUC 0.81). Responders were also able to maintain a weight loss of 4.3% in a 12 month follow-up period.

Conclusion

We identified a model containing two metabolites that were able to predict the likelihood of achieving a clinically significant weight loss on an ad libitum NND. This work demonstrates that models based on an untargeted multi-platform metabolomics approach can be used to optimize precision dietary treatment for obesity.

Carbohydrates for glycemic control: functional and microbiome aspects

PURPOSE OF REVIEW

Glycemia goals are used as indicators of control and progression in prediabetes and diabetes. Adopting healthy eating habits is essential. It is worth considering the quality of carbohydrates to help with dietary glycemic control. The present article aims to review recent meta-analyses published in the years 2021-2022 on the effects of dietary fiber and low glycemic index/load (LGI/LGL) foods on glycemic control and how gut microbiome modulation contributes to glycemic control.

RECENT FINDINGS

Data involving more than 320 studies were reviewed. The evidence allows us to infer that LGI/LGL foods, including dietary fiber intake, are associated with reduced fasting glycemia and insulinemia, postprandial glycemic response, HOMA-IR, and glycated hemoglobin, which are more evident in soluble dietary fiber. These results can be correlated with changes in the gut microbiome. However, the mechanistic roles of microbes or metabolites implicated in these observations continue to be explored. Some controversial data highlight the need for more homogeneity between studies.

SUMMARY

The properties of dietary fiber are reasonably well established for their glycemic homeostasis effects, including the fermentation aspects. Findings of gut microbiome correlations with glucose homeostasis can be incorporated into clinical nutrition practice. Target dietary fiber interventions on microbiome modulation can offer options to improve glucose control and contribute to personalized nutritional practices.

Increasing Our Understanding of How Dietary Components Can Affect Cellular Mechanisms That Regulate Aging and Slow the Onset of Frailty and Chronic Diseases

The current average life expectancy at birth is well over 80 years [...].

Acute Effects of Dietary Fiber in Starchy Foods on Glycemic and Insulinemic Responses: A Systematic Review of Randomized Controlled Crossover Trials

Dietary fiber (DF) consumption has been associated with improved glycemic control in epidemiological and long-term interventional studies. However, its acute effects are not yet clear. This systematic review aims to elucidate the postprandial effects of DF in starchy products on glycemia and insulinemia. An electronic search of databases was conducted, and forty-one records met the inclusion criteria and underwent a risk-of-bias assessment. It was shown that soluble DF does not clearly affect glycemia in individuals with normal weight, while resistant starch may be more effective in flattening glycemic responses. Concerning insulinemia, both soluble DF and resistant starch have mixed results, with either favorable or no effects. Data on insoluble DF and glucose metabolism are scarce. The same mixed results for glycemia can be seen in healthy volunteers with overweight/obesity, while resistant starch seems to improve insulinemic responses. Finally, more studies need to examine the acute effects of DF in starchy foods on glucose metabolism and insulin secretion in individuals facing glucose abnormalities. Additionally, more studies are needed to prove whether ingesting high-fiber carbohydrate-containing products per se can result in blunted glycemic and insulinemic responses and which DF type and amount are more effective.

Effect of Insoluble Dietary Fiber Extracted from Feijoa (Acca sellowiana (O. Berg) Burret.) Supplementation on Physicochemical and Functional Properties of Wheat Bread

This study aimed to assess the effects of insoluble dietary fiber (IDF) from feijoa supplementation on the physicochemical and functional properties of wheat bread. The results showed that feijoa IDF (FJI) had the typical structures of hydrolysis fiber, polysaccharide functional groups, and crystal structure of cellulose. The gradual increase of FJI levels (from 2 to 8%) in wheat bread resulted in increased total DF, ash, and protein contents, accompanied by a reduction in moisture, carbohydrates, and energy value. The inclusion of FJI in the bread crumb caused a rise in both redness (a*) and yellowness (b*) values while decreasing the brightness (L*) relative to the control specimen. In addition, adding FJI up to 2% significantly increased total phenolic and flavonoid contents and antioxidant activity, as well as flavor score of supplemented bread samples, while additions above 2% resulted in undesirable taste and texture. FJI addition caused higher bile acid, NO2-, and cholesterol adsorption capacities. Moreover, FJI addition up to 4% significantly reduced glucose adsorption capacities at different in vitro starch digestion intervals. The findings revealed that FJI offers great potential as an ideal functional ingredient in food processing.

Association between dietary patterns and biomarkers in connection with diabetes mellitus in adolescents: A systematic review

AIMS

To perform a systematic review to investigate the association between adolescents' a posteriori dietary patterns with diabetes-related biomarkers (fasting blood glucose, fasting insulinemia, glycated hemoglobin and homeostatic model assessment insulin resistance index (HOMA-IR)).

DATA SYNTHESIS

Review registered with PROSPERO under number CRD42020185369. Studies with adolescents aged 10-19 years that identified dietary patterns by a posteriori methods were included. The databases used included: PubMed, SCOPUS, Web of Science, Food Science and Technology Abstracts, CINAHL, SPORTDiscus, Lilacs/BVS, The Cochrane Central Register of Controlled Trials, ProQuest Dissertations&Theses Global and Capes Theses Bank and Brazilian Digital Library of Theses and Dissertations. Risk of bias was assessed via the Agency for Healthcare Research and Quality tool. Eight cross-sectional studies that evaluated 6438 adolescents (55.5% females) were included. For fasting blood glucose, the results were inconsistent and some studies found no association for the dietary patterns called traditional (57%), Western (42%) and healthy (28%). For the fasting insulinemia and HOMA-IR outcomes, the Western dietary pattern showed a positive association or higher means in 60% and 50% of the studies, respectively. No studies that evaluated glycated hemoglobin were found.

CONCLUSION

Fasting insulinemia and HOMA-IR outcomes were positively associated with the Western dietary patterns. The studies reviewed did not present consistent evidence of an association with western, healthy and traditional dietary patterns with fasting blood glucose, as the results were conflicting or did not show statistical significance.

Effect of kimchi intake on body weight of general community dwellers: a prospective cohort study

The impact of kimchi intake on weight management has been a topic of interest. We aimed to conduct an epidemiological study to investigate the association between kimchi intake and weight loss. Participants were selected from the Health Examinees cohort study. Kimchi intake was assessed by a 106-item semi-quantitative food frequency questionnaire, including four types of kimchi. Obesity was defined according to the Korean Society for the Study of Obesity guidelines. We performed a correlation analysis among all participants (N = 58 290) and conducted a prospective risk assessment analysis among participants with a baseline BMI value ≥25 kg m^-2 (N = 20 066). In the correlation analysis, higher kimchi consumption was found to be associated with a lower increment in BMI change (men, β 0.169, 95% CI (0.025, 0.313); women, β 0.140, 95% CI (0.046, 0.236)) compared with the lower group. The risk assessment analysis indicated that moderate kimchi consumption is associated with normal weight development in men (Q3, hazard ratio, 1.28, 95% CI (1.06, 1.54)). Baechu [cabbage] kimchi intake also showed a significant association among men participants (all p for trend <0.05). In conclusion, moderate kimchi intake was associated with weight loss among middle-aged and older Koreans, especially in men.

Konjac Glucomannan: An Emerging Specialty Medical Food to Aid in the Treatment of Type 2 Diabetes Mellitus

There are many factors causing T2DM; thus, it is difficult to prevent and cure it with conventional treatment. In order to realize the continuous intervention of T2DM, the treatment strategy of combining diet therapy and traditional medication came into being. As a natural product with the concept of being healthy, konjac flour and its derivatives are popular with the public. Its main component, Konjac glucomannan (KGM), can not only be applied as a food additive, which greatly improves the taste and flavor of food and extends the shelf life of food but also occupies an important role in T2DM. KGM can extend gastric emptying time, increase satiety, and promote liver glycogen synthesis, and also has the potential to improve intestinal flora and the metabolic system through a variety of molecular pathways in order to positively regulate oxidative stress and immune inflammation, and protect the liver and kidneys. In order to establish the theoretical justification for the adjunctive treatment of T2DM, we have outlined the physicochemical features of KGM in this article, emphasizing the advantages of KGM as a meal for special medical purposes of T2DM.

The Effect of Regular Consumption of Reformulated Breads on Glycemic Control: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Bread is a major source of grain-derived carbohydrates worldwide. High intakes of refined grains, low in dietary fiber and high in glycemic index, are linked with increased risk for type 2 diabetes mellitus (T2DM) and other chronic diseases. Hence, improvements in the composition of bread could influence population health. This systematic review evaluated the effect of regular consumption of reformulated breads on glycemic control among healthy adults, adults at cardiometabolic risk or with manifest T2DM. A literature search was performed using MEDLINE, Embase, Web of Science and the Cochrane Central Register of Controlled Trials. Eligible studies employed a bread intervention (≥2 wk) in adults (healthy, at cardiometabolic risk or manifest T2DM) and reported glycemic outcomes (fasting blood glucose, fasting insulin, HOMA-IR, HbA1c, and postprandial glucose responses). Data were pooled using generic inverse variance with random-effects model and presented as mean difference (MD) or standardized MD between treatments with 95% CIs. Twenty-two studies met the inclusion criteria (n = 1037 participants). Compared with "regular" or comparator bread, consumption of reformulated intervention breads yielded lower fasting blood glucose concentrations (MD: -0.21 mmol/L; 95% CI: -0.38, -0.03; I² = 88%, moderate certainty of evidence), yet no differences in fasting insulin (MD: -1.59 pmol/L; 95% CI: -5.78, 2.59; I² = 38%, moderate certainty of evidence), HOMA-IR (MD: -0.09; 95% CI: -0.35, 0.23; I² = 60%, moderate certainty of evidence), HbA1c (MD: -0.14; 95% CI: -0.39, 0.10; I² = 56%, very low certainty of evidence), or postprandial glucose response (SMD: -0.46; 95% CI: -1.28, 0.36; I² = 74%, low certainty of evidence). Subgroup analyses revealed a beneficial effect for fasting blood glucose only among people with T2DM (low certainty of evidence). Our findings suggest a beneficial effect of reformulated breads high in dietary fiber, whole grains, and/or functional ingredients on fasting blood glucose concentrations in adults, primarily among those with T2DM. This trial was registered at PROSPERO as CRD42020205458.

Effects of okra (Abelmoschus esculentus (L.) Moench) on glycemic markers in animal models of diabetes: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

Okra (Abelmoschus esculentus (L.) Moench) is traditionally used by different populations of Africa, América, Asia, and Europa to control diabetes. Although its action has been evaluated in several preclinical rodent trials, they have not been systematically analyzed.

OBJECTIVE

To evaluate the effectiveness of using okra in the treatment of diabetes in experimental rodent models.

MATERIAL AND METHODS

Controlled and randomized rodent animal trials with induced diabetes published between January 2000 and January 2021 were searched in the PubMed, Scopus, Scielo, and Web of Science databases. The search strategy included studies comprising the descriptors: animal species, diabetes induction method, intervention time, part of okra fruit used (whole, seeds, or peels), and dose as well as observed effects on biochemical and metabolic parameters. The systematic review was carried out according to the PRISMA statement, Cochrane bias risk tool (SYRCLE's RoB tool), and registered for systematic review protocols (PROSPERO).

RESULTS

A total of 326 articles were identified and after the exclusion of studies with gestational animal models, non-rodent animals, and non-diabetic animals, 11 studies involving 388 rodents were selected for the synthesis of results. The diabetes induction methods included streptozotocin, streptozotocin-nicotinamide, alloxan monohydrate, insulin resistance by high-fat diets or formulation described in AIN - 76, and feeding with high-fat food. Both Wistar albino rats, Sprague-Dawley males, and rats of both sexes of the Long-Evans lineage as well as male albino mice and C57BL females were included in the experiments. Studies showed that extracts of the fruit, the fresh fruit, or its various fractions had positive effects on the following markers: glycated hemoglobin, cholesterol, HOMA-IR, oral glucose tolerance test, and blood glucose, in acute (2 and 24 h), and chronic (up to 4 months) treatment.

CONCLUSION

An important hypoglycemic effect of okra in its various fractions on induced diabetes was observed by different authors. Moreover, okra promoted improvement in metabolic markers such as insulin sensitivity, lipid profile, and bodyweight loss.

Remission as an Emerging Therapeutic Target in Type 2 Diabetes in the Era of New Glucose-Lowering Agents: Benefits, Challenges, and Treatment Approaches

Type 2 diabetes mellitus (T2DM) is a progressive disease with a growing prevalence, associated with an increased risk of complications. The introduction of new classes of antidiabetic drugs into clinical practice has dramatically changed the landscape of diabetes therapy. However, despite the progress made in the pharmacotherapy of T2DM, mitigating the burden of the disease on individuals, societies and health care systems remains a challenge. Remission has recently emerged as a therapeutic target in T2DM, achievable through a wide range of interventions. Recent studies have shown that extensive lifestyle changes, such as weight reduction, bariatric surgery, and intensive glucose lowering therapy, can prompt the remission of diabetes, but some unanswered questions remain regarding its long-term effects on diabetic complications. Metabolic surgery and novel classes of glucose-lowering medications are currently the most effective interventions to induce weight loss and by extension remission in patients with diabetes; however, the ideal strategy to achieve the long-term maintenance of remission remains doubtful. In this narrative review, we discuss the available therapeutic approaches to target the remission of diabetes through personalized multimodal care, based on the latest evidence.

Physicochemical properties of dietary fiber of bergamot and its effect on diabetic mice

Bergamot (Citrus medica L. var. sarcodactylis) contains different bioactive compounds, and their effects remain unclear. Therefore, the structural and bio-function of bergamot dietary fiber were investigated. A sequential extraction procedure was utilized to obtain soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) from bergamot. The main monosaccharide in SDF and IDF is arabinose. SDF had a porous structure, which enhanced the water and oil holding capacity, as well as the cholesterol and glucose adsorption capacity, which was superior to that of IDF. In db/db diabetic mice, SDF and IDF regulated glucose tolerance and controlled blood glucose levels. Reduction of serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol in SDF and IDF could be observed. In summary, SDF and IDF from bergamot effectively promoted health in patients with diabetes.

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

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

Associations between dietary fiber intake and cardiovascular risk factors: An umbrella review of meta-analyses of randomized controlled trials

Although several meta-analyses have revealed the beneficial effects of dietary fiber intake on human health, some have reported inconsistent findings. The purpose of this work was to perform an umbrella meta-analysis to evaluate the relevant evidence and elucidate the effect of dietary fiber intake on glycemic control, lipid profiles, systematic inflammation, and blood pressure. Eligible studies were searched in several electronic databases, including Web of Science, PubMed, Scopus, and the Cochrane Library, up to March 2022. A total of 52 meta-analyses involving 47,197 subjects were identified to assess the pooled effect size. Overall, higher dietary fiber intake was significantly associated with reductions in parameters involving glycemic control, including fasting plasma glucose (ES = -0.55, 95% CI: -0.73, -0.38, P < 0.001), fasting plasma insulin (ES = -1.22, 95% CI: -1.63, -0.82, P < 0.001), homeostasis model assessment of insulin resistance (HOMA-IR) (ES = -0.43, 95% CI: -0.60, -0.27, P < 0.001), and glycosylated hemoglobin (HbA1c) (ES = -0.38, 95% CI: -0.50, -0.26, P < 0.001). In terms of lipid profiles, higher dietary fiber intake was associated with significant reductions in the serum level of total cholesterol (ES = -0.28, 95% CI: -0.39, -0.16, P < 0.001) and low-density lipoprotein cholesterol (ES = -0.25, 95% CI: -0.34, -0.16, P < 0.001), but not triglycerides (ES = -0.001, 95% CI: -0.006, 0.004, P = 0.759) and high-density lipoprotein cholesterol (ES = -0.002, 95% CI: -0.004, 0.000, P = 0.087). Higher dietary fiber intake was also significantly associated with improved tumor necrosis factor-alpha serum levels (ES = -0.78, 95% CI: -1.39, -0.16, P = 0.013), while no significant effect was observed for C-reactive protein (ES = -0.14, 95% CI: -0.33, 0.05, P = 0.156). Finally, blood pressure was also significantly improved following higher dietary fiber intake (systolic blood pressure: ES = -1.72, 95% CI: -2.13, -1.30, P < 0.001; diastolic blood pressure: ES = -0.67, 95% CI: -0.96, -0.37, P < 0.001). Subgroup analysis revealed that the study population and type of dietary fiber could be partial sources of heterogeneity. In conclusion, the present umbrella meta-analysis provides evidence for the role of dietary fiber supplementation in the improvement of established cardiovascular risk factors.

Effect of oats and oat ß-glucan on glycemic control in diabetes: a systematic review and meta-analysis of randomized controlled trials

Introduction

Current health claims recognize the ability of oat ß-glucan to lower blood cholesterol; however, its ability to improve glycemic control is less certain. We undertook a systematic review and meta-analysis of randomized controlled trials (RCTs) to update the evidence on the effect of oats and oat ß-glucan on glycemic control in individuals with diabetes.

Research design and methods

MEDLINE, EMBASE and Cochrane were searched (June 2021) for RCTs of ≥2 weeks investigating the effect of oat ß-glucan on glycemic control in diabetes. The outcomes were hemoglobin A1c (HbA1c), fasting glucose, 2-hour postprandial glucose (2h-PG) from a 75 g oral glucose tolerance test, homeostatic model assessment of insulin resistance (HOMA-IR) and fasting insulin. Independent reviewers extracted the data and assessed the risk of bias. Data were pooled using the generic inverse variance method. Heterogeneity was assessed (Cochran Q) and quantified (I2). Pooled estimates were expressed as mean difference (MD) with 95% CI. The certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations approach.

Results

Eight trial comparisons (n=407) met the eligibility criteria. All trials were in adults with type 2 diabetes who were predominantly middle-aged, overweight and treated by antihyperglycemic medications or insulin. A median dose of 3.25 g of oat ß-glucan for a median duration of 4.5 weeks improved HbA1c (MD, −0.47% (95% CI −0.80 to −0.13), pMD=0.006), fasting glucose (−0.75 mmol/L (−1.20 to –0.31), pMD<0.001), 2h-PG (−0.42 mmol/L (−0.70 to –0.14), pMD=0.003) and HOMA-IR (−0.88 (−1.55 to –0.20), pMD=0.011). There was a non-significant reduction in fasting insulin (−4.30 pmol/L (−11.96 to 3.35), pMD=0.271). The certainty of evidence was high for fasting glucose, moderate for HOMA-IR and fasting insulin (downgraded for imprecision), and low for HbA1c and 2h-PG (downgraded for imprecision and inconsistency).

Conclusions

Consumption of oats and oat ß-glucan results in generally small improvements in established markers of fasting and postprandial glycemic control beyond concurrent therapy in adults with type 2 diabetes. The current evidence provides a very good indication for reductions in fasting glucose and less of an indication for reductions in HbA1c, 2h-PG, fasting insulin and HOMA-IR in this population.

Trial registration number

NCT04631913.

Could Dietary Modification Independent of Energy Balance Influence the Underlying Pathophysiology of Type 2 Diabetes? Implications for Type 2 Diabetes Remission

High-quality clinical trial data demonstrate that remission is possible for people living with type 2 diabetes (T2D) if they lose a large amount of weight (≥ 10 kg). Durable remission appears predicated on the long-term maintenance of weight loss. Unfortunately, long-term follow-up data from lifestyle-based weight loss programmes show that, on average, most people regain at least some of the weight lost. In addition, restoration of a diminished first-phase insulin response also appears necessary for durable remission, and this becomes less likely as T2D progresses. A pragmatic approach to enhance the effects of weight loss on durable remission is to consider whether dietary components could help control blood glucose, independent of caloric balance. This manuscript reviews current evidence on weight-neutral effects of diet on blood glucose, including high-protein, low-carbohydrate, high-fibre and plant-based diets, with a particular focus on the effect of nutrition on the underlying pathophysiology of T2D, including the first-phase insulin response. The importance of mechanistic data in enhancing our understanding of dietary strategies in T2D remission is described, and suggestions are made for future advances in remission research.

Fiber-Rich Cranberry Pomace as Food Ingredient with Functional Activity for Yogurt Production

In this study, different amounts (from 2% to 4.5%) of dietary fiber-rich cranberry pomace (CP) were added to yogurt before or after fermentation to increase dietary fiber content without changing the textural properties of the product. The addition of CP reduced whey loss, improved the firmness and viscosity, increased the total phenol compound content and the antioxidant capacity values (DPPH•, ABTS, and ORAC) of the yogurt in a dose-dependent manner, and had no significant effect on the viability of the yogurt culture bacteria. For all CP-supplemented yogurt samples, the bioaccessibility index of the polyphenols after in vitro intestinal phase digestion was approximately 90%. However, yogurt with CP added before fermentation exhibited a significantly (p < 0.05) lower degree of protein hydrolysis post-gastric and post-intestinal than the yogurt with CP added after fermentation. Yogurt supplemented with 4.5% CP could be considered a good antioxidant dairy product and a good source of dietary fiber.

The effects of dietary supplements and natural products targeting glucose levels: an overview

Identifying effective dietary supplements and medicinal herbs has attracted the attention of clinicians and researchers to complement the standard treatment in controlling diabetes mellitus. In the present overview, we aimed to collect studies with the highest level of evidence to shed light on detecting the most effective dietary supplements and medicinal herbs for controlling glycemic status. For the current overview, four electronic databases, including PubMed, Scopus, Web of Science, and Cochrane Library, were systematically searched from inception to 31 December 2020 and then updated until 1 October 2021 to obtain eligible meta-analyses on either dietary supplements or medicinal herbs and their effects on glycemic status. Fasting blood sugar (FBS) and Hemoglobin A1C (HbA1C) were considered as primary outcomes. Finally, ninety-one meta-analyses on dietary supplements (n = 55) and herbs (n = 36) were included. Evidence showed positive effects of chromium, zinc, propolis, aloe vera, milk thistle, fenugreek, cinnamon, ginger, and nettle on FBS and/or HbA1C. However, mostly the heterogeneity (I2) was high. Other supplements and herbs also showed no reduction in glucose levels or their effects were small. Although some dietary supplements and medicinal herbs showed a significant reduction in FBS and/or HbA1C, mostly their effects from the clinical point of view were not remarkable. In addition, due to high heterogeneity, publication bias, and a limited number of included studies in most cases further clinical trials are needed for making decision on anti-diabetic supplement efficacy.