Dietary supplementation with resistant starch contributes to intestinal health

Resistant starch inhibits high-fat diet-induced oncogenic responses in the colon of C57BL/6 mice

The beneficial effects of dietary fiber for colon health may be due to short chain fatty acids (SCFAs), such as butyrate, produced by colonic bacterial fermentation. In contrast, obesogenic diet induced obesity is linked to increased colon cancer incidence. We hypothesize that increasing fiber intake promotes healthy microbiome and reduces bacterial dysbiosis and oncogenic signaling in the colon of mice fed an obesogenic diet. About 5-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 enriched dietary fiber (RSF) from maize; (4) HFD+10%RSF; or (5) HFD+20%RSF. Compared to the AIN group, mice receiving the HFD exhibited more than 15% increase in body mass and body fat composition irrespective of RSF dosage. However, the HFD+RSF groups exhibited an increase (>300%) of fecal butyrate but a decrease (>45%) of secondary bile acids in a RSF dose-dependent manner over the HFD group. Similarly, there were concomitant decreases (>25%) in pro-inflammatory plasma cytokines (TNFα, IL-6 and MCP-1), β-catenin and Ki67 protein staining in the colon of the HFD+20%RSF group relative to the HFD group. Furthermore, the abundance of colonic Proteobacteria, signatures of dysbiosis, was decreased (>63%) in a RSF dose-dependent manner compared to the HFD. Collectively, these data indicate that RSF not only increases butyrate but also reduces secondary bile acids, bacterial dysbiosis and β-catenin in the colon of mice fed a HFD.

Characterization and Nutritional Intervention Effects of Canna edulis Type 5 Resistant Starch in Hyperlipidemia Mice

Numerous reports have indicated that the type 3 resistant starch (RS3) derived from Canna edulis can regulate lipid metabolism. However, it remains unclear whether the type 5 resistant starch (RS5) exhibits similar effects. In this study, RS5 was prepared from Canna edulis native starch and lauric acid through a hydrothermal method for the first time, and its nutritional intervention effects on hyperlipidemia in mice were investigated. The Canna edulis type 5 resistant starch (Ce-RS5) prepared using Canna edulis native starch and lauric acid exhibited a high compound index and resistant starch content, along with decreased swelling power and enhanced starch granule stability. The crystallinity of Ce-RS5 was decreased, and its crystal structure displayed a B+V pattern. Microscopically, the surface appeared rough with deepened grooves, and the granules were loose. Feeding mice with 1.5 g/kg and 3 g/kg of Ce-RS5 significantly reduced their body weight, positively regulated their blood lipid levels, and improved liver damage and fat accumulation. Additionally, Ce-RS5 promoted the abundance of beneficial gut bacteria, such as norank_f_Muribaculaceae, and inhibited the abundance of harmful bacteria like Colidextribacter. This study provides the first evidence of the hypolipidemic and weight loss effects of Ce-RS5 in hyperlipidemia mice.

Randomized controlled trial protocol to analyze the effects of rice with different contents of resistant starch on chronic constipation

The trend of the aging population worldwide is becoming increasingly severe. As people age, constipation becomes increasingly common in older adults, causing varying degrees of physical and psychological harm to them. Dietary intervention is a common nonpharmacological therapy. Resistant starch is a type of dietary fiber that can regulate the gut microbiota and alleviate chronic constipation. However, few studies have explored the effects of different types of rice on chronic constipation in older adults. This protocol aims to evaluate the effects of rice with different contents of resistant starch on chronic constipation in old adults. This trial is a double-blind, two-arm randomized controlled trial. Older adults with chronic constipation residing in long-term care facilities will be recruited. Participants will be randomly assigned to receive A rice (resistant starch: 11-20%) or receive B rice (resistant starch: 0.1-0.5%). Both groups will adopt the serving of individual dishes, and the nutrition experts calculated the consumption of rice in the two groups according to the different conditions of each older person to ensure that the number of calories in the meal remained unchanged and that the other dietary components remained unchanged. The intervention will last for a total of 24 weeks. Participants will undergo follow-up via questionnaires at 6, 12, and 24 weeks during the intervention. The primary outcome will be constipation symptoms assessed by the Wexner questionnaire. The secondary outcomes will be quality of life, depression, anxiety and sleep quality. This is the first randomized controlled trial on the effects of rice with different contents of resistant starch on chronic constipation in older adults. It is expected that this study, if proven effective in relieving constipation symptoms in older adults, will provide evidence-based constipation care for medical staff.Trial registration number: retrospectively registered on Chinese Clinical Trial Registry.

Prebiotics: Comprehensive analysis of sources, structural characteristics and mechanistic roles in disease regulation

Prebiotics are nondigestible components that comprise short-chain carbohydrates, primarily oligosaccharides, which are converted into beneficial compounds by probiotics. Various plant substances with prebiotic properties provide substantial health benefits and are used to prevent different diseases and for medical and clinical applications. Consuming prebiotics gives impeccable benefits since it aids in gut microbial balance. Prebiotic research is primarily concerned with the influence of intestinal disorders. The proposed review will describe recent data on the sources, structures, implementation of prebiotics and potential mechanisms in preventing and treating various disorders, with an emphasis on the gut microbiome. Prebiotics have a distinctive impact on the gastro intestine by explicitly encouraging the growth of probiotic organisms like Bifidobacteria and Lactobacilli. This in turn augments the body's inherent ability to fend off harmful pathogens. Prebiotic carbohydrates may also provide other non-specific advantages due to their fermentation in the large intestine. Additional in vivo research is needed to fully comprehend the interactions between prebiotics and probiotics ingested by hosts to improve their nutritional and therapeutic benefits.

Short-chain fatty acids reverses gut microbiota dysbiosis-promoted progression of glioblastoma by up-regulating M1 polarization in the tumor microenvironment

Glioblastoma (GBM), known as the most malignant and common primary brain tumor of the central nervous system, has finite therapeutic options and a poor prognosis. Studies have shown that host intestinal microorganisms play a role in the immune regulation of parenteral tumors in a number of different ways, either directly or indirectly. However, the potential impact of gut microbiota on tumor microenvironment, particularly glioma immunological milieu, has not been clarified exactly. In this study, by using an orthotopic GBM model, we found gut microbiota dysbiosis caused by antibiotic cocktail treatment boosted the tumor process in vivo. An obvious change that followed gut microbiota dysbiosis was the enhanced percentage of M2-like macrophages in the TME, in parallel with a decrease in the levels of gut microbial metabolite, short-chain fatty acids (SCFAs) in the blood and tumor tissues. Oral supplementation with SCFAs can increase the proportion of M1-like macrophages in the TME, which improves the outcomes of glioma. In terms of mechanism, SCFAs-activated glycolysis in the tumor-associated macrophages may be responsible for the elevated M1 polarization in the TME. This study will enable us to better comprehend the "gut-brain" axis and be meaningful for the development of TAM-targeting immunotherapeutic strategies for GBM patients.

The Therapeutic Potential of the Specific Intestinal Microbiome (SIM) Diet on Metabolic Diseases

Exploring the intricate crosstalk between dietary prebiotics and the specific intestinal microbiome (SIM) is intriguing in explaining the mechanisms of current successful dietary interventions, including the Mediterranean diet and high-fiber diet. This knowledge forms a robust basis for developing a new natural food therapy. The SIM diet can be measured and evaluated to establish a reliable basis for the management of metabolic diseases, such as diabetes, metabolic (dysfunction)-associated fatty liver disease (MAFLD), obesity, and metabolic cardiovascular disease. This review aims to delve into the existing body of research to shed light on the promising developments of possible dietary prebiotics in this field and explore the implications for clinical practice. The exciting part is the crosstalk of diet, microbiota, and gut-organ interactions facilitated by producing short-chain fatty acids, bile acids, and subsequent metabolite production. These metabolic-related microorganisms include Butyricicoccus, Akkermansia, and Phascolarctobacterium. The SIM diet, rather than supplementation, holds the promise of significant health consequences via the prolonged reaction with the gut microbiome. Most importantly, the literature consistently reports no adverse effects, providing a strong foundation for the safety of this dietary therapy.

The impact of slowly digestible and resistant starch on glucose homeostasis and insulin resistance

PURPOSE OF REVIEW

This review will summarize recent studies assessing the effect of slowly digestible starch (SDS) and resistant starch (RS) on glucose metabolism in healthy, prediabetic or type 2 diabetic adults.

RECENT FINDINGS

Currently, a particular interest in starch and its digestibility has arisen, with data showing a positive effect of SDS and RS on the glucose homeostasis of healthy, at-risk, prediabetic and type 2 diabetic patients but research is ongoing.

SUMMARY

Carbohydrates (CHO) and especially starch play a major role in the prevention and management of metabolic diseases such as type 2 diabetes (T2D). This largely depends on the quality and the digestibility (rate and extent) of the ingested starchy products, beyond their quantity. SDS have been poorly studied but display a beneficial effect on reducing glucose excursions in healthy and insulin-resistant subjects and a relevant potential to improve glucose control in type 2 diabetic individuals. As for RS, the results appear to be encouraging but remain heterogeneous, depending the nature of the RS and its role on microbiota modulation. Further studies are needed to confirm the present results and investigate the potential complementary beneficial effects of SDS and RS on long-term glucose homeostasis to prevent cardiometabolic diseases.

Flow field-flow fractionation coupled with multidetector: A robust approach for the separation and characterization of resistant starch

The unique properties of resistant starch (RS) have made it applicable in the formulation of a broad range of functional foods. The physicochemical properties of RS play a crucial role in its applications. Recently, flow field-flow fractionation (FlFFF) has attracted increasing interest in the separation and characterization of different categories of RS. In this review, an overview of the theory behind FlFFF is introduced, and the controllable factors, including FlFFF channel design, sample separation conditions, and the choice of detector, are discussed in detail. Furthermore, the applications of FlFFF for the separation and characterization of RS at both the granule and molecule levels are critically reviewed. The aim of this review is to equip readers with a fundamental understanding of the theoretical principle of FlFFF and to highlight the potential for expanding the application of RS through the valuable insights gained from FlFFF coupled with multidetector analysis.

Resistant Starch-Encapsulated Probiotics Attenuate Colorectal Cancer Cachexia and 5-Fluorouracil-Induced Microbial Dysbiosis

5-Fluorouracil (5-FU) is commonly used as the primary chemotherapy for colorectal cancer (CRC). However, it can lead to unwanted chemoresistance. Resistant starch (RS), which functions similarly to fermentable dietary fiber, has the potential to reduce the risk of CRC. The effects of RS on improving CRC-associated cachectic symptoms and 5-FU chemotherapy-induced microbial dysbiosis remain unknown. Female BALB/cByJNarl mice were randomly divided into four groups: one tumor group (with CT26 colonic carcinoma but no treatment) and three CT26 colonic carcinoma-bearing groups that were administered 20 mg/kg 5-FU (T+5-FU group), a probiotic cocktail (4 × 108 CFUs) plus chemotherapy (T+5-FU+Pro), or resistant-starch-encapsulated probiotics plus chemotherapy (T+5-FU+RS-Pro). T+5-FU and T+5-FU+RS-Pro administration significantly suppressed tumor growth and activated apoptotic cell death in CT26-bearing mice. 5-FU-induced increases in inflammatory cytokines and NF-κB signaling were mitigated by the Pro or RS-Pro supplementation. A gut microbial composition comparison indicated that the abundance of intestinal bacteria in the T and T+5-FU groups decreased significantly, while the groups receiving Pro or RS-Pro maintained a greater abundance and healthy gut microbiota composition, suggesting that RS can reduce the microbial dysbiosis that occurs during 5-FU chemotherapy. The use of RS-Pro before chemotherapy should be considered for the regulation of chemotherapy-associated cachectic symptoms, inflammation, and chemotherapy-induced microbial dysbiosis.