Resistant Starch Intake Research Articles

The Impact of Yoyo Dieting and Resistant Starch on Weight Loss and Gut Microbiome in C57Bl/6 Mice.

Cyclic weight loss and subsequent regain after dieting and non-dieting periods, a phenomenon termed yoyo dieting, places individuals at greater risk of metabolic complications and alters gut microbiome composition. Resistant starch (RS) improves gut health and systemic metabolism. This study aimed to investigate the effect of yoyo dieting and RS on the metabolism and gut microbiome. C57BL/6 mice were assigned to 6 diets for 20 weeks, including control, high fat (HF), yoyo (alternating HF and control diets every 5 weeks), control with RS, HF with RS, and yoyo with RS. Metabolic outcomes and microbiota profiling using 16S rRNA sequencing were examined. Yoyo dieting resulted in short-term weight loss, which led to improved liver health and insulin tolerance but also a greater rate of weight gain compared to continuous HF feeding, as well as a different microbiota profile that was in an intermediate configuration between the control and HF states. Mice fed HF and yoyo diets supplemented with RS gained less weight than those fed without RS. RS supplementation in yoyo mice appeared to shift the gut microbiota composition closer to the control state. In conclusion, yoyo dieting leads to obesity relapse, and increased RS intake reduces weight gain and might help prevent rapid weight regain via gut microbiome restoration.

Unveiling the Benefits of Resistant Starch in Legumes: Overview of Current and Future Prospective

AbstractResistant starch has gained substantial attention in recent years due to its potential health benefits. Among the various sources of RS, legumes have appeared as a prominent and promising contributor. Legumes like beans, lentils, and chickpeas, comprise a unique composition that promotes the resistant starch formation during cooking and processing. The review begins by presenting an overview of resistant starch and its classification based on its structure and digestibility. The mechanisms by which legume‐based resistant starch impacts human health are discussed, including its potential role in controlling postprandial glucose and insulin responses, improve satiety, boost colonic health, and influence lipid metabolism. The promising role of resistant starch from legumes in controlling chronic diseases like obesity, cardiovascular disorders, and type 2 diabetes is also explored. This review briefly covers the recent advancements in regulating the starch biosynthesis pathway through the utilization of RNA interference (RNAi) and CRISPR/Cas9 techniques. In summary, the association between resistant starch and legumes offers a compelling pathway to enhance human health and mitigate the risk of chronic diseases. Legumes as a regular part of the diet can be a viable and effective approach to augment resistant starch intake and harness its potential health‐promoting effects.

Resistant starch intake facilitates weight loss in humans by reshaping the gut microbiota

Emerging evidence suggests that modulation of gut microbiota by dietary fibre may offer solutions for metabolic disorders. In a randomized placebo-controlled crossover design trial (ChiCTR-TTRCC-13003333) in 37 participants with overweight or obesity, we test whether resistant starch (RS) as a dietary supplement influences obesity-related outcomes. Here, we show that RS supplementation for 8 weeks can help to achieve weight loss (mean −2.8 kg) and improve insulin resistance in individuals with excess body weight. The benefits of RS are associated with changes in gut microbiota composition. Supplementation with Bifidobacterium adolescentis, a species that is markedly associated with the alleviation of obesity in the study participants, protects male mice from diet-induced obesity. Mechanistically, the RS-induced changes in the gut microbiota alter the bile acid profile, reduce inflammation by restoring the intestinal barrier and inhibit lipid absorption. We demonstrate that RS can facilitate weight loss at least partially through B. adolescentis and that the gut microbiota is essential for the action of RS.

Maternal fiber-rich diet promotes early-life intestinal development in offspring through milk-derived extracellular vesicles carrying miR-146a-5p

BackgroundsThe intestinal development in early life is profoundly influenced by multiple biological components of breast milk, in which milk-derived extracellular vesicles (mEVs) contain a large amount of vertically transmitted signal from the mother. However, little is known about how maternal fiber-rich diet regulates offspring intestinal development by influencing the mEVs.ResultsIn this study, we found that maternal resistant starch (RS) consumption during late gestation and lactation improved the growth and intestinal health of offspring. The mEVs in breast milk are the primary factor driving these beneficial effects, especially enhancing intestinal cell proliferation and migration. To be specific, administration of mEVs after maternal RS intake enhanced intestinal cell proliferation and migration in vivo (performed in mice model and indicated by intestinal histological observation, EdU assay, and the quantification of cyclin proteins) and in vitro (indicated by CCK8, MTT, EdU, and wound healing experiments). Noteworthily, miR-146a-5p was found to be highly expressed in the mEVs from maternal RS group, which also promotes intestinal cell proliferation in cells and mice models. Mechanically, miR-146a-5p target to silence the expression of ubiquitin ligase 3 gene NEDD4L, thereby inhibiting DVL2 ubiquitination, activating the Wnt pathway, and promoting intestinal development.ConclusionThese findings demonstrated the beneficial role of mEVs in the connection between maternal fiber rich diet and offspring intestinal growth. In addition, we identified a novel miRNA-146a-5p-NEDD4L-β-catenin/Wnt signaling axis in regulating early intestinal development. This work provided a new perspective for studying the influence of maternal diet on offspring development.Graphical

P825 Comprehensive dietitian-delivered dietary advice effectively achieves dietary change in adults with Ulcerative Colitis, whereas generalised written dietary advice does not

Abstract Background Diet is an important consideration in microbial therapy trials. It is unclear whether provision of generalised written dietary advice is sufficient to induce dietary change as part of a therapeutic regimen or whether personalised diet advice is required. This study examines the effectiveness of different dietary advice modes provided in dietary and faecal microbiota transplantation (FMT) studies in adults with mild-moderately active ulcerative colitis (UC). Methods This observational study examined before and after dietary intake data from three prospective dietary and FMT studies held from 2018 to 2021 at a South Australian tertiary inflammatory bowel disease service. In all studies, adults ≥18 years with mild-moderately active UC completed 3 or 7-day weighed food diaries measuring habitual diet at 0 and 8 weeks after provision of dietitian-developed dietary advice. In studies one and two, a medical officer provided participants a written UC healthy eating pamphlet. The pamphlet contained generalised dietary recommendations for UC, targeting reduction of total and animal protein and increasing fermentable fibres including resistant starch to recommended serve sizes. In study three, a research dietitian provided a 1-week guided meal plan, diet manual with recipes and verbal personalised dietary counselling advising on the same recommendations and strategies. In all studies, participants were encouraged to eat to appetite. Dietary intake, including key nutrients of interest (protein and fermentable fibres), at weeks 0 and 8 was assessed using Foodworks 10TM nutritional analysis software and analysed using paired statistical tests. Results Across studies one and two, 28 adults with mild-moderately active UC received written dietary advice. In study three, 30 adults received personalised verbal and written dietary advice. Outlined in Table 1, verbal and written advice significantly reduced total protein and animal protein intakes by 20% (p=0.007) and 34% (p=0.002) respectively. Total fibre and resistant starch intakes significantly increased by 64% (p<0.001) and 353% (p<0.001) respectively. Comparatively, written advice alone had no significant change on any key nutrient intakes. Neither dietary advice mode significantly changed energy or micronutrient intakes. Conclusion Written dietary advice alone was insufficient to achieve dietary change. In contrast, verbal and written dietary advice with the same intended change on dietary intake, delivered by a research dietitian effectively achieved dietary changes. This emphasises that comprehensive written and verbal dietary education delivered by a dietitian should be included in microbial-modulating study designs where dietary change is an intended outcome.

Association of Dietary Resistant Starch Intake with Obesity and Metabolic Syndrome in Korean Adults.

Research findings on the relationship between dietary resistant starch (RS) intake and metabolic diseases using population-based data are very scarce. This study examined the association of dietary RS intake with obesity and metabolic syndrome in Korean adults. A total of 12,491 adults (5292 men and 7199 women) were selected from the 2016-2018 Korea National Health and Nutrition Examination Survey data. The individual RS intake (g) was calculated by linking the 1-day 24 h recall data with the RS content database for common Korean foods. Obesity was defined as a BMI ≥ 25.0 kg/m2. Metabolic syndrome was defined as having three or more of the following: abdominal obesity, elevated triglycerides, low HDL cholesterol, elevated fasting blood glucose, and elevated blood pressure. Odds ratios (ORs) with 95% confidence intervals (CIs) for obesity and metabolic syndrome across quartiles (Qs) of RS intake were calculated using multiple logistic regression analysis. In men, the highest quartile of RS intake showed a significantly lower OR for metabolic syndrome compared to the lowest quartile after adjusting for covariates (OR = 0.71, 95% CI = 0.56-0.92, p-trend = 0.0057). Dietary RS intake in men was also inversely associated with obesity (Q4 vs. Q1: OR = 0.80, 95% CI = 0.67-0.97, p-trend = 0.0329) and elevated triglycerides (Q4 vs. Q1: OR = 0.80, 95% CI = 0.66-0.98, p-trend = 0.0314). In women, RS intake was not associated with metabolic syndrome. Our findings may serve as useful data for developing guidelines for RS intake and conducting further cohort and clinical studies to investigate the health effects of RS.

Development of a database to estimate dietary intake of resistant starch in Koreans

Development of a database to estimate dietary intake of resistant starch in Koreans

Creating high-resistant starch rice by simultaneous editing of SS3a and SS3b.

Creating high-resistant starch rice by simultaneous editing of SS3a and SS3b.

Postprandial glucose-lowering effects by sago (Metroxylon sagu Rottb.) resistant starch in spontaneously type 2 diabetes, Goto-Kakizaki rat.

Introduction: The beneficial effects of resistant starch (RS) consumption on health in terms of reducing postprandial hyperglycaemia are evident. However, the potential of local Sarawak sago RS in regulating glucose has not been extensively studied. Objectives: This study aims to identify glucose-lowering effects of Sarawak sago RS, namely native (RS2) and chemically modified (RS4). Methodology: An oral glucose tolerance test (OGTT) was performed before and after 1 month treatment with sago RS2 and RS4 in spontaneously type 2 diabetes (T2D), Goto-Kakizaki (GK) rat. The mechanisms involved were further explored by screening the in vitro inhibitory activities of α-glucosidase and dipeptidyl peptidase (DPP)-IV. Histopathology examination for pancreas, kidney and liver tissues was done in response to sago RS intake using haematoxylin and eosin (H&E) staining. Results and discussion: The incremental area under the curve (iAUC) for blood glucose in RS-treated groups was decreased and significant in RS2-treated group (p < 0.05). Improved iAUC for insulin and higher glucagon-like peptide (GLP-1) levels were observed in all RS-treated groups (p < 0.05). Both sago RS may have potential roles in regulating glucose via α- glucosidase and DPP-IV inhibitory activities by reducing intestinal glucose absorption. For histopathology, although insignificant, sago RS2 and RS4 attenuated lesion scores of pancreatic tissue whereas the liver and kidney tissues significantly showed lesser lesion scores compared to the control diabetic group suggesting the potential of RS in reducing cell degeneration. Conclusion: Findings of this study indicates that RS2 showed greater glucose-lowering effect when compared to RS4, thus the therapeutic potential in the T2D management should be further explored.

Meta-analysis reveals gut microbiome and functional pathway alterations in response to resistant starch.

Resistant starch (RS) has the ability to improve the structure of the gut microbiota, regulate glucolipid metabolism and maintain the health of the human body, and has been extensively studied by many scholars in recent years. However, previous studies have provided a wide range of results on the differences in the gut microbiota after RS intake. In this article, we performed a meta-analysis of a total of 955 samples of 248 individuals from the seven studies included to compare the gut microbiota of the baseline and the end-point of RS intake. At the end-point, RS intake was related to a lower gut microbial α-diversity and higher relative abundance of Ruminococcus, Agathobacter, Faecalibacterium and Bifidobacterium, and the functional pathways of the gut microbiota related to the carbohydrate metabolism, lipid metabolism, amino acid metabolism and genetic information processing were higher. Different types of resistant starch and different populations led to varied responses on the gut microbiome. The altered gut microbiome may contribute to improve the blood glucose level and insulin resistance, which may be a potential treatment route for diabetes, obesity and other metabolic diseases.

Diet and the gut-lung axis in cystic fibrosis – direct & indirect links

ABSTRACT Cystic fibrosis (CF) is a multisystem, autosomal, recessive disease primarily affecting the lungs, pancreas, gastrointestinal tract, and liver. Whilst there is increasing evidence of a microbial ‘gut-lung axis’ in chronic respiratory conditions, there has been limited analysis of such a concept in CF. We performed a comprehensive dietary and microbiota analysis to explore the interactions between diet, gastrointestinal microbiota, respiratory microbiota, and clinical outcomes in children with CF. Our results demonstrate significant alterations in intestinal inflammation and respiratory and gastrointestinal microbiota when compared to age and gender matched children without CF. We identified correlations between the gastrointestinal and respiratory microbiota, lung function, CF pulmonary exacerbations and anthropometrics, supporting the concept of an altered gut-lung axis in children with CF. We also identified significant differences in dietary quality with CF children consuming greater relative proportions of total, saturated and trans fats, and less relative proportions of carbohydrates, wholegrains, fiber, insoluble fiber, starch, and resistant starch. Our findings position the CF diet as a potential modulator in gastrointestinal inflammation and the proposed gut-lung axial relationship in CF. The dietary intake of wholegrains, fiber and resistant starch may be protective against intestinal inflammation and should be explored as potential therapeutic adjuvants for children with CF.

The association of dietary resistance starch intake with all-cause and cause-specific mortality.

Several studies have estimated daily intake of resistant starch (RS), but no studies have investigated the relationship of RS intake with mortality. We aimed to examine associations between RS intake and all-cause and cause-specific mortality. Data from US National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018 with 24-h dietary recall data was used in current study. The main exposure in this study was RS intake, and the main outcome was the mortality status of participants until December 31, 2019. The multivariable Cox proportional hazards regression models were developed to evaluate the hazard ratios (HRs) and 95% confidence interval (95% CI) of cardiovascular disease (CVD), cancer, and all-cause mortality associated with RS intake. A total of 42,586 US adults [mean (SD) age, 46.91 (16.88) years; 22,328 (52.43%) female] were included in the present analysis. During the 454,252 person-years of follow-up, 7,043 all-cause deaths occurred, including 1,809 deaths from CVD and 1,574 deaths from cancer. The multivariable-adjusted HRs for CVD, cancer, and all-cause mortality per quintile increase in RS intake were 1 (95%CI, 0.97-1.04), 0.96 (95%CI, 0.93-1), and 0.96 (95%CI, 0.95-0.98), respectively. The associations remained similar in the subgroup and sensitivity analyses. Higher RS intake is significantly associated with lower cancer and all-cause mortality, but not significantly with CVD mortality. Future studies focusing on other populations with different food sources of RS and RS subtypes are needed to access the dose-response relationship and to improve global dietary recommendations.

Resistant starch type-4 intake alters circulating bile acids in human subjects.

Resistant starch (RS) type 4 (RS4) is a type of RS, a class of non-digestible prebiotic dietary fibers with a range of demonstrated metabolic health benefits to the host. On the other hand, bile acids (BA) have recently emerged as an important class of metabolic function mediators that involve host-microbiota interactions. RS consumption alters fecal and cecal BA in humans and rodents, respectively. The effect of RS intake on circulating BA concentrations remains unexplored in humans. Using available plasma and stool samples from our previously reported double-blind, controlled, 2-arm crossover nutrition intervention trial (Clinicaltrials.gov: NCT01887964), a liquid-chromatography/mass-spectrometry-based targeted multiple reaction monitoring, and absolute quantifications, we assessed BA changes after 12 weeks of an average 12 g/day RS4-intake. Stool BA concentrations were lower post RS4 compared to the control, the two groups consuming similar macronutrients (n = 14/group). Partial least squares-discriminant analysis revealed distinct BA signatures in stool and plasma post interventions. The increased circulating BA concentrations were further investigated using linear mixed-effect modeling that controlled for potential confounders. A higher plasma abundance of several BA species post RS4 was observed (fold increase compared to control in parenthesis): taurocholic acid (1.92), taurodeoxycholic acid (1.60), glycochenodeoxycholic acid (1.58), glycodeoxycholic acid (1.79), and deoxycholic acid (1.77) (all, p < 0.05). Distinct microbiome ortholog-signatures were observed between RS4 and control groups (95% CI), derived using the Piphillin function-prediction algorithm and principal component analysis (PCA) of pre-existing 16S rRNA gene sequences. Association of Bifidobacterium adolescentis with secondary BA such as, deoxycholic acid (rho = 0.55, p = 0.05), glycodeoxycholic acid (rho = 0.65, p = 0.02), and taurodeoxycholic acid (rho = 0.56, p = 0.04) were observed in the RS4-group, but not in the control group (all, p > 0.05). Our observations indicate a previously unknown in humans- RS4-associated systemic alteration of microbiota-derived secondary BA. Follow-up investigations of BA biosynthesis in the context of RS4 may provide molecular targets to understand and manipulate microbiome-host interactions.

Effects of Resistant Starch on Patients with Chronic Kidney Disease: A Systematic Review and Meta-Analysis

Background Chronic kidney disease (CKD) is a main health problem associated with increased risk of cardiovascular disease, morbidity, and mortality. Recent studies shown that the progression of CKD may be related to the change of intestinal flora. Resistant starch (RS) is a type of dietary fiber that can act as a substrate for microbial fermentation. Some studies have found that the supplementation of RS can improve the intestinal flora disorder in CKD patients. However, the specific effect of RS on CKD patients remains controversial. Objective We designed this meta-analysis to identify and assess the effects of RS on patients with CKD. Methods A comprehensive search of MEDLINE, Embase, Web of Science, and Cochrane systematic review databases was conducted in January 2020, and all new trials were updated in August 2021. Randomized trials were collected to assess the effects of RS on patients with CKD. The weighted average effect size of the net change was calculated by using the random-effects model. Results The meta-analysis included 8 studies involving 301 participants. RS intake significantly reduced serum indolephenol sulfate (IS), blood phosphorus, IL-6, and uric acid levels in dialysis patients. The mean difference (MD) of serum IS (P = 0.0002) in the dialysis subgroup was -12.57 μmol/L (95% CI: -19.28, -5.86 μmol/L). The MD of blood phosphorus (P = 0.03) was -0.39 mg/dl (95% CI: -0.78, -0.01 mg/dl). The MD of serum uric acid (P = 0.004) between the dialysis subgroup and the nondialysis subgroup was -31.58 mmol/L (95% CI: -52.99, -10.17 mmol/L). The mean difference (MD) of IL-6 (P = 0.02) in the dialysis subgroup was -1.16 μmol/L (95% CI: -2.16, -0.16 μmol/L). However, there was no significant change of RS on hs-CRP, serum creatinine, blood urea nitrogen (BUN), blood paracresol sulfate, and blood lipid. Conclusions The intake of RS reduced the serum IS, serum phosphorus, IL-6, and uric acid levels significantly in dialysis patients, while hs-CRP, serum creatinine, BUN, serum paracresol sulfate, and blood lipid showed no significant changes.

Resistant starch: A promising ingredient and health promoter

Resistant starch (RS) consists of a glucose plant polymer that is extremely abundant in nature and easily obtained through simple technological processes in the food industry. Its molecular conformation, as well as its specific localization within the plant tissues, makes this molecule sterically inaccessible to the activity of amylolytic enzymes, which can degrade any other type of starch. Such a characteristic allows resistant starch to act as dietary fiber when ingested by humans, and it is used as a substrate by the gut microbiota. By metabolizing the resistant starch, the microbiota can produce organic fatty acids of low molecular weight, mainly butyrate, propionate, and acetate, also known as short-chain fatty acids (SCFA). Besides being a valuable energy source for colonocytes, SCFA promotes a plethora of beneficial and systemic effects on human metabolism. Researchers worldwide have been investigating the broad spectrum of benefits generated by the inclusion of resistant starch in the diet, including its effect on counteracting metabolic diseases. The worldwide abundance, easy access, and variety of industrial applications of resistant starch make it a functional food of great interest to the scientific community and for the development of new dietetic approaches capable of promoting health for the world’s population. This review will cover physiological aspects associated with RS intake and its impact on microbiota and health, especially to counteract chronic non-communicable diseases.

Resistant Starch Intake Is Low in Australian Adults With Irritable Bowel Syndrome Who Follow a Low FODMAP Diet

ObjectivesThis observational study aimed to assess dietary intake, including resistant starch (RS) in adults with Irritable Bowel Syndrome (IBS), who follow a habitual diet low in Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols (FODMAP) (LFD).MethodsTwenty-six participants in Perth, Western Australia with IBS (23 females, aged mean ± SD 37 ± 13 years with a Body Mass Index of 23 ± 3 kg/m2) had FODMAP content assessed using the Monash University Comprehensive Nutrition Assessment Questionnaire and dietary RS from 3-d weighed food diary analysed using published RS values for Australian foods incorporated into a dietary database analysed using FoodWorks 10 (Xyris, QLD, Australia). Descriptive statistics and correlation analysis were performed using SPSS v27(IBM, 2017).ResultsOut of all participants 35% (n = 9) were on a LFD > 1 year, median 12 months (Interquartile range = 21.8 months), and 77% (n = 20) were at the personalized phase. Median FODMAP intake was 9.6 ± 9.4 g/d and positively associated with the length of time on a LFD, partial correlation (adjusted with BMI and age) was 0.541 (P = 0.003). A therapeutic FODMAP intake <12 g/d (unvalidated) was achieved by 73% (n = 19) of participants. Energy from fat mean ± SD 38.1 ± 9.6% and saturated fat 12.4 ± 3.9% were above Australian recommendations at 20–35% and <10%, respectively. Mean energy contributed by carbohydrates, 36 ± 9.2% was below recommendations (45–65%). Despite the avoidance of plant-based foods high in FODMAP, dietary fibre intake was 20.7 ± 7.4 g/d, equivalent to national Australian studies of adults but less than dietary targets (male 38 g, female 28 g). Habitual RS consumption was 2.1 ± 1.2 g/d, lower than estimations of both typical Australian diets (3.7 (1.9–5.6) g/d) and a LFD study providing all meals (6.9 (3.6–10.3 g/d). Consumptions of vegetables and fruit were 3.9 ± 2.9 and 0.3 ± 1.6 serves/d respectively, and less than the Australian recommendations of 5–6 and 2 serves/d respectively.ConclusionsThis is the first study in IBS patients to measure RS intake in habitual LFD. Australian adults with IBS consuming a LFD should integrate additional RS sources when personalising their LFD. On the premise that food consumed will not exacerbate IBS symptoms, patients on a LFD should increase the intake of vegetables and fruits based on personal tolerance.Funding SourcesEdith Cowan University.

Intake of Resistant Starch Reduces Colonic Inflammation in the Colon of Obese, C57BL/6 Mice Fed a High Fat Diet

ObjectivesIntake of fiber has beneficial effects for gut health which may be due to short chain fatty acid (e.g., butyrate) production during colonic fermentation. In contrast, obesity and obesogenic diets are linked to increased colonic inflammation. We tested the hypothesis that increasing fiber intake reduces colonic inflammation in C57BL/6 mice fed an obesogenic diet.MethodsFour-week-old male C57BL/6 mice were assigned to 5 dietary groups (n = 22/group) for 24 weeks: (1) AIN93G as a control diet (AIN); (2) a high fat diet (HFD, 45% energy fat); (3) HFD + 5% resistant starch from corn (RS); (4) HFD + 10%RS; or (5) HFD + 20%RS. We used biochemical, gas chromatography with flame-ionization detection, and histological approaches to determine the effect of RS on the inflammatory status in the colon of C57BL/6 mice fed HFD.ResultsAll animals receiving HFD exhibited increases in body mass and body fat composition compared to the AIN group irrespective of RS dosage. However, the HFD + RS groups exhibited an increase in fecal butyrate content in a RS dose-dependent manner over the HFD group with 2.1- and 3.3-fold increase in the HFD + 10%RS and HFD + 20%RS groups, respectively. Consistent with butyrate's beneficial effects, there were concomitant > 0.5-fold decreases in inflammatory cell infiltration and b-catenin protein staining in the colon of animals receiving 20% RS supplementation relative to the HFD group.ConclusionsThese data indicate that even under obesogenic conditions in a mouse model, RS consumption reduces colonic inflammation.Funding SourcesThis work was supported by U.S. Department of Agriculture, Agricultural Research Service, research project 3062-51,000-056-00D.

Additional Resistant Starch from One Potato Side Dish per Day Alters the Gut Microbiota but Not Fecal Short-Chain Fatty Acid Concentrations.

The composition of the gut microbiota and their metabolites are associated with cardiometabolic health and disease risk. Intake of dietary fibers, including resistant starch (RS), has been shown to favorably affect the health of the gut microbiome. The aim of this research was to measure changes in the gut microbiota and fecal short-chain fatty acids as part of a randomized, crossover supplemental feeding study. Fifty participants (68% female, aged 40 ± 13 years, BMI 24.5 ± 3.6 kg/m2) completed this study. Potato dishes (POT) contained more RS than refined grain dishes (REF) (POT: 1.31% wet basis (95% CI: 0.94, 1.71); REF: 0.73% wet basis (95% CI: 0.34, 1.14); p = 0.03). Overall, potato dish consumption decreased alpha diversity, but beta diversity was not impacted. Potato dish consumption was found to increase the abundance of Hungatella xylanolytica, as well as that of the butyrate producing Roseburia faecis, though fecal butyrate levels were unchanged. Intake of one potato-based side dish per day resulted in modest changes in gut microbiota composition and diversity, compared to isocaloric intake of refined grains in healthy adults. Studies examining foods naturally higher in RS are needed to understand microbiota changes in response to dietary intake of RS and associated health effects.

Does a high dietary intake of resistant starch affect glycaemic control and alter the gut microbiome in women with gestational diabetes? A randomised control trial protocol

BackgroundGestational Diabetes Mellitus (GDM) is prevalent with lasting health implications for the mother and offspring. Medical nutrition therapy is the foundation of GDM management yet achieving optimal glycaemic control often requires treatment with medications, like insulin. New dietary strategies to improve GDM management and outcomes are required.Gut dysbiosis is a feature of GDM pregnancies, therefore, dietary manipulation of the gut microbiota may offer a new avenue for management. Resistant starch is a fermentable dietary fibre known to alter the gut microbiota and enhance production of short-chain fatty acids. Evidence suggests that short-chain fatty acids improve glycaemia via multiple mechanisms, however, this has not been evaluated in GDM.MethodsAn open-label, parallel-group design study will investigate whether a high dietary resistant starch intake or resistant starch supplement improves glycaemic control and changes the gut microbiome compared with standard dietary advice in women with newly diagnosed GDM. Ninety women will be randomised to one of three groups - standard dietary treatment for GDM (Control), a high resistant starch diet or a high resistant starch diet plus a 16 g resistant starch supplement. Measurements taken at Baseline (24 to 30-weeks’ gestation), Day 10 and Day 56 (approximately 36 weeks’ gestation) will include fasting plasma glucose levels, microbial composition and short-chain fatty acid concentrations in stool, 3-day dietary intake records and bowel symptoms questionnaires. One-week post-natal data collection will include microbial composition and short-chain fatty acid concentrations of maternal and neonatal stools, microbial composition of breastmilk, birthweight, maternal and neonatal outcomes. Mixed model analysis of variance will assess change in glycaemia and permutation-based multivariate analysis of variance will assess changes in microbial composition within and between intervention groups. Distance-based linear modelling will identify correlation between change in stool microbiota, short-chain fatty acids and measures of glycaemia.DiscussionTo improve outcomes for GDM dyads, evaluation of a high dietary intake of resistant starch to improve glycaemia through the gut microbiome needs to be established. This will expand the dietary interventions available to manage GDM without medication.Trial registrationAustralian New Zealand Clinical Trial Registry, ACTRN12620000968976p. Registered 28 September 2020

Effects of Resistant Starch Interventions on Metabolic Biomarkers in Pre-Diabetes and Diabetes Adults.

Simple lifestyle changes can prevent or delay the onset of type 2 diabetes mellitus (T2DM). In addition to maintaining a physically active way of life, the diet has become one of the bases in managing TD2M. Due to many studies linking the ability of resistant starch (RS) to a substantial role in enhancing the nutritional quality of food and disease prevention, the challenge of incorporating RS into the diet and increasing its intake remains. Therefore, we conducted this review to assess the potential benefits of RS on metabolic biomarkers in pre-diabetes and diabetes adults based on available intervention studies over the last decade. Based on the conducted review, we observed that RS intake correlates directly to minimize possible effects through different mechanisms for better control of pre-diabetic and diabetic conditions. In most studies, significant changes were evident in the postprandial glucose and insulin incremental area under the curve (iAUC). Comparative evaluation of RS consumption and control groups also showed differences with inflammatory markers such as TNF-α, IL-1β, MCP-1, and E-selectin. Only RS2 and RS3 were extensively investigated and widely reported among the five reported RS types. However, a proper comparison and conclusion are deemed inappropriate considering the variations observed with the study duration, sample size, subjects and their metabolic conditions, intervention doses, and the intervention base products. In conclusion, this result provides interesting insights into the potential use of RS as part of a sustainable diet in diabetes management and should be further explored in terms of the mechanism involved.