Effects of BARLEYmax and high-β-glucan barley line on short-chain fatty acids production and microbiota from the cecum to the distal colon in rats

A Comprehensive Review on Dietary Polysaccharides as Prebiotics, Synbiotics, and Postbiotics in Infant Formula and Their Influences on Gut Microbiota

Human milk contains an abundance of nutrients which benefit the development and growth of infants. However, infant formula has to be used when breastfeeding is not possible. The large differences between human milk and infant formula in prebiotics lead to the suboptimal intestinal health of infant formula-fed infants. This functional deficit of infant formula may be overcome through other dietary polysaccharides that have been characterized. The aim of this review was to summarize the potential applications of dietary polysaccharides as prebiotics, synbiotics, and postbiotics in infant formula to better mimic the functionality of human milk prebiotics for infant gut health. Previous studies have demonstrated the influences of dietary polysaccharides on gut microbiota, SCFA production, and immune system development. Compared to prebiotics, synbiotics and postbiotics showed better application potential in shaping the gut microbiota, the prevention of pathogen infections, and the development of the immune system. Moreover, the safety issues for biotics still require more clinical trials with a large-scale population and long time duration, and the generally accepted regulations are important to regulate related products. Pectin polysaccharides has similar impacts to human milk oligosaccharides on gut microbiota and the repairing of a damaged gut barrier, with similar functions also being observed for inulin and β-glucan. Prebiotics as an encapsulation material combined with probiotics and postbiotics showed better potential applications compared to traditional material in infant formula.

Harnessing Prebiotics to Improve Type 2 Diabetes Outcomes

The gut microbiota, a complex ecosystem of microorganisms in the human gastrointestinal tract (GI), plays a crucial role in maintaining metabolic health and influencing disease susceptibility. Dysbiosis, or an imbalance in gut microbiota, has been linked to the development of type 2 diabetes mellitus (T2DM) through mechanisms such as reduced glucose tolerance and increased insulin resistance. A balanced gut microbiota, or eubiosis, is associated with improved glucose metabolism and insulin sensitivity, potentially reducing the risk of diabetes-related complications. Various strategies, including the use of prebiotics like inulin, fructooligosaccharides, galactooligosaccharides, resistant starch, pectic oligosaccharides, polyphenols, β-glucan, and Dendrobium officinale have been shown to improve gut microbial composition and support glycemic control in T2DM patients. These prebiotics can directly impact blood sugar levels while promoting the growth of beneficial bacteria, thus enhancing glycemic control. Studies have shown that T2DM patients often exhibit a decrease in beneficial butyrate-producing bacteria, like Roseburia and Faecalibacterium, and an increase in harmful bacteria, such as Escherichia and Prevotella. This review aims to explore the effects of different prebiotics on T2DM, their impact on gut microbiota composition, and the potential for personalized dietary interventions to optimize diabetes management and improve overall health outcomes.

Translating Human and Animal Model Studies to Dogs' and Cats' Veterinary Care: Beta-Glucans Application for Skin Disease, Osteoarthritis, and Inflammatory Bowel Disease Management

The inclusion of beta-glucans in dog and cat food is associated with numerous beneficial effects on the health of these animals. In this regard, there is an effort to elucidate the potential of this nutraceutical in chronic patients. Since there is a lack of a review on the topic, this review article aims to compile and discuss the evidence found to date. Atopic dermatitis, inflammatory bowel disease, and osteoarthritis are diseases of significant clinical relevance in dogs and cats. In general, the pathophysiology of these chronic conditions is related to immune-mediated and inflammatory mechanisms. Therefore, the immunomodulation and anti-inflammatory effects of beta-glucans are highlighted throughout this review. The available information seems to indicate that the studies on beta-glucans' impact on allergic processes in dogs indicate a reduction in clinical signs in atopic dermatitis cases. Additionally, while beta-glucans show promise as a safe supplement, particularly for osteoarthritis, further clinical trials are imperative, especially in uncontrolled environments. Beta-glucans emerge as a potential nutraceutical offering immune benefits for inflammatory bowel disease patients, although extensive research is required to define its optimal origin, molecular weight, dosage, and specific applications across animals suffering from this disease.

Glycolysis characteristics of intracellular polysaccharides from Agaricus bitorquis (Quél.) sacc. Chaidam and its effects on intestinal flora from different altitudes of mice in vitro fermentation

The glycolysis characteristics and effects on intestinal flora of polysaccharides from Agaricus bitorquis (Quél.) Sacc. Chaidam (ABIPs) in vitro fermentation by different altitudes of mice feces was examined, including low, medium, and high altitudes groups (LG, MG, and HG). In vitro, fermentation of ABIPs forty-eight hours resulted in a remarkable decrease in total sugar content and improvement of short-chain fatty acids (SCFAs) (mainly acetate, propionate, and butyrate), which simultaneously induced the composition of monose and uronic acids and SCFAs continuously change. Besides, ABIPs influenced the abundance and composition of the intestinal flora, generally increasing the abundance of probiotic bacteria (such as Bifidobacterium and Faecalibacterium) and decreasing the abundance of harmful bacteria (such as Phenylobacterium and Streptococcus) in all groups, with the highland biology core genus Blautia significantly enriched in LG and MG groups. It was also found that ABIPs enhanced pathways associated with biosynthesis and metabolism. In addition, correlation analysis speculated that the metabolism of SCFAs by ABIPs may be associated with genera such as Anaerostipes, Roseburia, and Weissella. ABIPs may protect organismal health by regulating hypoxic intestinal flora composition and metabolic function, and more superior fermentation performance was observed in MG compared to other groups.

Integrated microbiota and metabolite profiling analysis of prebiotic characteristics of Phellinus linteus polysaccharide in vitro fermentation

Phellinus linteus polysaccharide (PLP) had received increasing attention due to its multiple biological activities. Herein, the extraction, characterization and in vitro fermentation of PLP were studied to explore its physiochemical properties and the interaction mechanism between the gut microbiota and PLP. The results obtained demonstrated that PLP was mainly composed of 9 monosaccharides, with three gel chromatographic peaks and molecular weights (M_w) of 308.45 kDa, 13.58 kD and 3.33 kDa, respectively. After 48 h fermentation, the M_w, total sugar, reducing sugar, pH and monosaccharides composition were decreased. Furthermore, PLP regulated the composition of gut microbiota, such as promoting the proliferation of beneficial bacteria such as Bacteroides, Prevotella and Butyricimonas, while preventing the growth of pathogenic bacteria such as Escherichia-Shigella, Morganella and Intestinimonas. Gut microbiota metabolites regulated by PLP such as short-chain fatty acids were the main regulators that impact the host health. Bioinformatics analysis indicated that butyrate, bile acid and purine metabolism were the main metabolic pathways of PLP regulating host health, and the Bacteroides was the key genus to regulate these metabolic pathways. In conclusion, our finding suggested that PLP may be used as a prebiotic agent for human health because of its ability to regulate gut microbiota.

β-glucans: a potential source for maintaining gut microbiota and the immune system

The human gastrointestinal (GI) tract holds a complex and dynamic population of microbial communities, which exerts a marked influence on the host physiology during homeostasis and disease conditions. Diet is considered one of the main factors in structuring the gut microbiota across a lifespan. Intestinal microbial communities play a vital role in sustaining immune and metabolic homeostasis as well as protecting against pathogens. The negatively altered gut bacterial composition has related to many inflammatory diseases and infections. β-glucans are a heterogeneous assemblage of glucose polymers with a typical structure comprising a leading chain of β-(1,4) and/or β-(1,3)-glucopyranosyl units with various branches and lengths as a side chain. β-glucans bind to specific receptors on immune cells and initiate immune responses. However, β-glucans from different sources differ in their structures, conformation, physical properties, and binding affinity to receptors. How these properties modulate biological functions in terms of molecular mechanisms is not known in many examples. This review provides a critical understanding of the structures of β-glucans and their functions for modulating the gut microbiota and immune system.

Interaction between β-glucans and gut microbiota: a comprehensive review

Gut microbiota (GMB) in humans plays a crucial role in health and diseases. Diet can regulate the composition and function of GMB which are associated with different human diseases. Dietary fibers can induce different health benefits through stimulation of beneficial GMB. β-glucans (BGs) as dietary fibers have gained much interest due to their various functional properties. They can have therapeutic roles on gut health based on modulation of GMB, intestinal fermentation, production of different metabolites, and so on. There is an increasing interest in food industries in commercial application of BG as a bioactive substance into food formulations. The aim of this review is considering the metabolizing of BGs by GMB, effects of BGs on the variation of GMB population, influence of BGs on the gut infections, prebiotic effects of BGs in the gut, in vivo and in vitro fermentation of BGs and effects of processing on BG fermentability.

Gut microbiota-derived short-chain fatty acids regulate gastrointestinal tumor immunity: a novel therapeutic strategy?

Tumor immune microenvironment (TIME), a tumor-derived immune component, is proven to be closely related to the development, metastasis, and recurrence of tumors. Gut microbiota and its fermented-metabolites short-chain fatty acids (SCFAs) play a critical role in maintaining the immune homeostasis of gastrointestinal tumors. Consisting mainly of acetate, propionate, and butyrate, SCFAs can interact with G protein-coupled receptors 43 of T helper 1 cell or restrain histone deacetylases (HDACs) of cytotoxic T lymphocytes to exert immunotherapy effects. Studies have shed light on SCFAs can mediate the differentiation and function of regulatory T cells, as well as cytokine production in TIME. Additionally, SCFAs can alter epigenetic modification of CD8⁺ T cells by inhibiting HDACs to participate in the immune response process. In gastrointestinal tumors, the abundance of SCFAs and their producing bacteria is significantly reduced. Direct supplementation of dietary fiber and probiotics, or fecal microbiota transplantation to change the structure of gut microbiota can both increase the level of SCFAs and inhibit tumor development. The mechanism by which SCFAs modulate the progression of gastrointestinal tumors has been elucidated in this review, aiming to provide prospects for the development of novel immunotherapeutic strategies.

A single administration of barley β-glucan and arabinoxylan extracts reduces blood glucose levels at the second meal via intestinal fermentation

Diet with barley may suppress the glycemic response after consuming the next meal ("second meal effect"). This study aimed to investigate the second meal effect and its mechanism. Mice were given a single dose of β-glucan or arabinoxylan, the primary sources of soluble fiber in barley. A single dose of β-glucan or arabinoxylan extract, followed 6 h later by a 20% glucose solution (second meal), suppressed blood glucose elevation. Arabinoxylan and β-glucan increased the levels of short-chain fatty acids (SCFAs) in the ileum and cecum, respectively. Total GLP-1 secretion in the blood increased with β-glucan and showed an increasing trend with arabinoxylan. These results suggest barley β-glucan and arabinoxylan are fermented in the intestinal tract to generate SCFAs, which may induce GLP-1 secretion and control blood glucose levels during the second meal.

Arabinoxylan as well as β-glucan in barley promotes GLP-1 secretion by increasing short-chain fatty acids production

Barley is rich in soluble dietary fiber including β-glucan and arabinoxylan. Barley β-glucan is fermented by gut bacteria and, thereby contributes to an effect on intestinal bacterial composition and short-chain fatty acids (SCFAs). It also increases GLP-1 secretion via SCFAs receptor. However, few studies have focused on barley arabinoxylan. Therefore, we have investigated the effects of arabinoxylan from barley on intestinal fermentability and GLP-1 secretion. C57BL/6J mice were fed a high-fat diet containing arabinoxylan-dominant barley flour without β-glucan (bgl) and high β-glucan-containing barley flour (BF) for 12 weeks. We conducted oral glucose tolerance test (OGTT) to measure insulin and GLP-1 concentrations. The concentration of SCFAs in the cecum contents was also determined. Furthermore, we measured mRNA expression assay GLP-1 secretion using real-time PCR. The OGTT result showed that GLP-1 concentrations at 60 min were increased in mice fed bgl and BF. Acetic acid and total SCFAs concentrations in the cecum contents were increased in both the barley groups, and butyric acid was increased in the bgl group. Furthermore, the bgl and BF groups had increased Gpr43, a receptor for SCFAs, and NeuroD which is involved in L cell differentiation. These results show arabinoxylan as well as β-glucan is involved in the SCFAs-mediated increase in GLP-1 secretion upon barley consumption.

Effect of β-1,3/1,6-glucan on gut microbiota of yellow-feathered broilers

β-1,3/1,6-glucan as a prebiotic improves immune performance in animals. These functions are closely related to the effect of β-1,3/1,6-glucan on gut microbiota structure. However, the effect of β-1,3/1,6-glucan on the gut microbiota structure of broilers is unclear. The aim of this study was to confirm the effects of β-1,3/1,6-glucan on the cecal microflora structure of yellow-feathered broilers. This study monitored the antimicrobial resistance (AMR) level of Escherichia coli in feces of yellow-feathered broilers by standard broth dilution method and mastered the AMR level of chickens selected. The effects of β-1,3/1,6-glucan on gut microbiota were investigated by 16S rRNA sequencing. The results showed that the number of isolated multidrug-resistant E. coli strains accounted for 98.41%. At 14, 21, and 28 days of age, supplemented of 0.2%, 0.1%, and 0.1% β-1,3/1,6-glucan in yellow-feathered broiler diets significantly altered gut microbial composition, and beneficial bacteria Alistipes, Bacteroides and Faecalibacterium were significantly increased. These findings provide guidance and recommendations for β-1,3/1,6-glucan as a broiler feed additive to improve the growth of broilers.

Docosahexaenoic acid-rich fish oil alleviates hepatic steatosis in association with regulation of gut microbiome in ob/ob mice

It remains to study whether docosahexaenoic acid-rich fish oil (DHA-FO) improves hepatic lipid metabolism by leptin-independent mechanisms. We used ob/ob mice as a model to investigate the effects of DHA-FO on hepatic steatosis. DHA-FO inhibited lipid droplets (LD) formation in liver of ob/ob mice. Probably because DHA-FO consumption prevented the accumulation of oleic acid, and suppressed the synthesis of triglycerides and cholesteryl esters. These beneficial effects might be concerned with the promotion of short chain fatty acids (SCFAs) production. Furthermore, DHA-FO could reverse gut bacteria dysbiosis, including increasing the abundance of SCFAs producers (e.g. Akkermansia and unclassified_Muribaculaceae), and suppressing the proliferation of conditional pathogenic bacteria, such as unclassified_Lachnospiraceae. DHA-FO also promoted colonic microbial function ("Glycerolipid metabolism") associated with lipid metabolism. As a potential ingredient for functional food, DHA-FO reduced LD accumulation, which might be associated with modulation of obesity-linked gut microbiome in ob/ob mice.

Immunomodulatory and Anticancer Activities of Barley Bran Grown in Jordan: An in vitro and in vivo Study

The Mediterranean diet is regarded as one of the most healthful dietary patterns in the world, owing to a combination of foods high in antioxidants and anticancer constituents. Barley bran is one of the components of the Mediterranean diet. It has nutritional and beneficial effects in different pathological conditions. Many studies were achieved to assess the nutritious values of barley bran, but there is no research indicating immunomodulatory and anticancer activities of barley bran grown in Jordan. The present study aims to examine and assess the potential immunomodulatory and anti-tumor activities of ethanol, n-hexane, aqueous/methanol, and water extracts obtained from barley bran. The Maceration method was utilized to prepare ethanol, n-hexane, aqueous/methanol, and water extracts. Various phytochemical groups were determined by using qualitative phytochemical tests. The antiproliferative activity of extracts was determined against MCF-7, HCT-116, A549, and EMT6/p by the MTT assay. The Folin-Ciocalteu reagent was used to detect the total phenolic content in extracts. Furthermore, immunomodulatory activity was assessed by determining the effect of extracts on splenocytes proliferation in the presence and absence of mitogens. The nitro blue tetrazolium assay and the neutral red method were used to assess the effect of each extract on the phagocytic activity of macrophages and pinocytosis, respectively. For the in vivo part, three different concentrations (10, 20, and 30% w/v) of barley bran were used to test the prophylactic effect in four Balb/C mice groups inoculated with EMT6/p cell-line subcutaneously. Also, serum samples were collected to assess the effect on cytokines (IFN-gamma, IL-2, IL-4, and IL-10). Barley bran extracts inhibited cancer cell proliferation. According to immunoassays, n-hexane and aqueous/methanol extracts could significantly rise lymphocyte proliferation and pinocytosis activity of macrophages. The activity of phagocytosis was increased by n-hexane and ethanol extracts. For the in vivo part, the average tumor size and weight of mice given the 30% barley bran group was significantly reduced (p < 0.05) compared with the control group. During our study, higher levels of TH1 cytokines (IFN- γ, IL-2) and lower levels of TH2 cytokine (IL-4) and T regulatory cytokine (IL-10) were obtained due to consumption of barley bran in food. Barley bran can be used as a prophylactic agent because it has anti-cancer and immunomodulatory activities.

Immunomodulatory Properties of Polysaccharide-Rich Young Green Barley (Hordeum vulgare) Extract and Its Structural Characterization

Young green barley (YGB) water extract has revealed a beneficial impact on natural killer (NK) cells' ability to recognize and eliminate human colon cancer cells, without any side effects for normal colon epithelial cells. The direct anticancer effect of the tested compounds has been also shown. The mixture of oligosaccharides found in this extract was characterized by chemical analyses and via FT-IR spectroscopy and MALDI-TOF MS techniques. The YGB preparation contained 26.9% of proteins and 64.2% of sugars, mostly glucose (54.7%) and fructose (42.7%), with a small amount of mannose (2.6%) and galactose (less than 0.5%). Mass spectrometry analysis of YGB has shown that fructose oligomers contained from 3 to 19 sugar units. The number of fructans was estimated to be about 10.2% of the dry weight basis of YGB. The presented results suggest the beneficial effect of the consumption of preparations based on young barley on the human body, in the field of colon cancer prevention.

Consumption of barley flour increases gut fermentation and improves glucose intolerance via the short-chain fatty acid receptor GPR43 in obese male mice

The ameliorative effect of barley intake on glucose intolerance is attenuated when Gpr43 is deficient.

Combined effects of BARLEYmax and cocoa polyphenols on colonic microbiota and bacterial metabolites in vitro

BARLEYmax, a barley variety, and cocoa polyphenols (CPPs) have been reported to affect bacterial metabolites in the colon. This study aimed to evaluate the combined effects of BARLEYmax and CPPs supplementation on fecal microbiota in vitro using pig feces for 48 h. The relative abundances of the family Clostridiaceae and the genus Clostridium and ammonia-nitrogen production were decreased by both BARLEYmax and CPP supplementation, and there was a positive correlation between their abundances and the ammonia-nitrogen concentration. Although acetate and n-butyrate production was decreased by CPP supplementation, their concentrations were maintained at a higher level in the BARLEYmax + CPP group than in the cellulose (control) and cellulose + CPP groups. Therefore, this study demonstrated that a combination of BARLEYmax and CPPs may be beneficial in maintaining higher short-chain fatty acid production and the elimination of potentially harmful factors.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-021-00959-z.

Fiber-Rich Barley Increases Butyric Acid-Producing Bacteria in the Human Gut Microbiota

Butyric acid produced in the intestine by butyric acid-producing bacteria (BAPB) is known to suppress excessive inflammatory response and may prevent chronic disease development. We evaluated whether fiber-rich barley intake increases BAPB in the gut and concomitantly butyric acid in feces. Eighteen healthy adults received granola containing functional barley (BARLEYmax^®) once daily for four weeks. Fecal DNA before intake, after intake, and one month after intake was analyzed using 16S rRNA gene sequencing to assess microbial diversity, microbial composition at the order level, and the proportion of BAPB. Fecal butyric acid concentration was also measured. There were no significant differences in diversities and microbial composition between samples. The proportion of BAPB increased significantly after the intake (from 5.9% to 8.2%). However, one month after stopping the intake, the proportion of BAPB returned to the original value (5.4%). Fecal butyric acid concentration increased significantly from 0.99 mg/g feces before intake to 1.43 mg/g after intake (p = 0.028), which decreased significantly to 0.87 mg/g after stopping intake (p = 0.008). As BAPB produce butyric acid by degrading dietary fiber, functional barley may act as a prebiotic, increasing BAPB and consequently butyric acid in the intestine.

Fluid resuscitation via colon alleviates systemic inflammation in rats with early-stage severe acute pancreatitis

Fluid resuscitation via colon (FRVC) is a complementary therapeutic procedure for early-stage cases of severe acute pancreatitis (SAP). The expression of intestinal dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) regulates systemic inflammation. This study aimed to investigate the effect of FRVC on the expression of DC-SIGN in the colon tissue of SAP rats and its effect on the early response of systemic inflammatory and multiple organ injury. SAP was induced in rats via retrograde injection of sodium taurocholate into the biliopancreatic duct. DC-SIGN expression of appeared in the proximal and distal colon. Histological characteristics and inflammatory cytokines were examined to compare the effect of FRVC and intravenous fluid resuscitation (IVFR). The results showed that DC-SIGN expression in the proximal colon increased in a time-dependent manner in the early-stage of SAP rats. FRVC inhibited DC-SIGN expression in the proximal colon. Both FRVC and IVFR alleviated histological injuries of the pancreas and colon. However, FRVC had an advantage over IVFR in alleviating lung injury and reducing serum TNF-α, IL-6 and LPS. These results suggest that FRVC treatment might help suppress systemic inflammation and prevent subsequent organ failure in early-stage SAP rats likely through inhibiting DC-SIGN expression in the proximal colon.

Extraction and characterisation of arabinoxylan from brewers spent grain and investigation of microbiome modulation potential

Purpose

Brewers’ spent grain (BSG) represents the largest by-product of the brewing industry. Its utilisation as an animal feed has become less practical today; however, its high fibre and protein content make it a promising untapped resource for human nutrition. BSG contains mainly insoluble fibre. This fibre, along with protein, is trapped with the complex lignocellulosic cell structure and must be solubilised to release components which may be beneficial to health through modulation of the gut microbiota.

Methods

In this study, the application of a simultaneous saccharification and fermentation process for the extraction and solubilisation of arabinoxylan from BSG is demonstrated.

Results

Processing of the BSG was varied to modulate the physicochemical and molecular characteristic of the released arabinoxylan. The maximum level of arabinoxylan solubilisation achieved was approximately 21%, compared to the unprocessed BSG which contained no soluble arabinoxylan (AX). Concentration of the solubilised material produced a sample containing 99% soluble AX. Samples were investigated for their microbiome modulating capacity in in-vitro faecal fermentation trials. Many samples promoted increased Lactobacillus levels (approx. twofold). One sample that contained the highest level of soluble AX was shown to be bifidogenic, increasing the levels of this genus approx. 3.5-fold as well as acetate (p = 0.018) and propionate (p < 0.001) production.

Conclusion

The findings indicate that AX extracted from BSG has prebiotic potential. The demonstration that BSG is a source of functional fibre is a promising step towards the application of this brewing side-stream as a functional food ingredient for human nutrition.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02570-8.

High β-Glucan Barley Supplementation Improves Glucose Tolerance by Increasing GLP-1 Secretion in Diet-Induced Obesity Mice

The aim of this study was to investigate the underlying mechanism for the improvement of glucose tolerance following intake of high β-glucan barley (HGB) in terms of intestinal metabolism. C57BL/6J male mice were fed a fatty diet supplemented with HGB corresponding to 5% of dietary fiber for 83 days. An oral glucose tolerance test was performed at the end of the experimental period. The concentration of short-chain fatty acids (SCFAs) in the cecum was analyzed by GC–MS (gas chromatography–mass spectrometry). The mRNA expression levels related to L cell function in the ileum were measured by real-time PCR. Glucagon-like peptide-1 (GLP-1) levels in the portal vein and cecal content were assessed by enzyme-linked immunosorbent assay. GLP-1-producing L cells of the ileum were quantified by immunohistochemistry. HGB intake improved glucose tolerance and increased the cecal levels of SCFAs, acetate, and propionate. The number of GLP-1-positive L cells in the HGB group was significantly higher than in the control group. GLP-1 levels in the portal vein and cecal GLP-1 pool size in the HGB group were significantly higher than the control group. In conclusion, we report improved glucose tolerance after HGB intake induced by an increase in L cell number and subsequent rise in GLP-1 secretion.

Novel Resistant Starch Type 4 Products of Different Starch Origins, Production Methods, and Amounts Are Not Equally Fermented when Fed to Sprague-Dawley Rats

SCOPE

The possible mechanisms of production of four novel resistant starch type 4 (RS4) products for total cecal fermentation in an in vivo rodent model are evaluated.

METHODS AND RESULTS

Forty weanling rats are randomly assigned to five groups (n = 8) for a 3-week study. Starches are the RS type 4 products, as 10% of weight of RS diets (RSA-RSD), and AMIOCA starch (100% amylopectin) comprises 53.6% weight of control (CON) and 43.6% weight of RS diets. The RS products vary by percent purity and origin (potato, corn, tapioca). At euthanasia, cecal contents, serum, GI tract, and abdominal fat are collected. RSB, RSC, and RSD fed rats have greater empty cecum weights, lower cecal content pH, higher cecal content wet weight, and higher total cecal content acetate and propionate than the CON and RSA fed rats. Two other indicators of fermentation, total cecal contents butyrate and glucagon-like peptide 1, do not have significant ANOVA F values, which require more subjects for 80% power.

CONCLUSION

RS4 products that are produced from different starch origins with varying amounts of RS4 content and different methods of production are not uniformly fermented in an in vivo model.