Effects of early dietary intervention with a fermentable fibre on colonic microbiota activity and mucin gene expression in newly weaned rats

Increase Dietary Fiber Intake Ameliorates Cecal Morphology and Drives Cecal Species-Specific of Short-Chain Fatty Acids in White Pekin Ducks

The current study was to investigate the modulatory effects of total dietary fiber (TDF) levels on cecal morphology and the response of microbiota to maintain gut health for duck growth. A total of 192 14-day-old male white Pekin ducks were randomly allocated to three dietary groups and fed diets, containing 12.4, 14.7, and 16.2% TDF, respectively, until 35 days under the quantitative feed intake. Each dietary group consisted of eight replicate cages of eight birds. The results revealed that 14.7 and 16.2% TDF groups significantly promoted growth performance and improved villus height, the ratio of villus to crypt, muscle layer thickness, and goblet cells per villus of cecum in ducks. qPCR results showed that the transcriptional expression of Claudin-1, Muc2, IGF-1, and SLC16A1 was significantly upregulated in cecum in 14.7 and 16.2% TDF groups. Meanwhile, the concentration of IGF-1 in circulating was significantly increased in 14.7 and 16.2% TDF groups while that of DAO was significantly decreased in 16.2% TDF group. Furthermore, the concentrations of butyrate, isobutyrate, valerate, and isovalerate in cecum were conspicuously improved in 14.7 and 16.2% TDF groups while that of propionate was significantly decreased. In addition, the concentrations of butyrate, isobutyrate, valerate, and isovalerate in cecum presented negative correlations with the concentration of DAO in circulating. 16S rRNA gene sequencing results showed that the 14.7% TDF group importantly elevated the microbial richness. Simultaneously, butyrate-producing bacteria like the family Lachnospiraceae, Oscillospiraceae, and Erysipelatoclostridiaceae were enriched as biomarkers in the 16.2% TDF group. Correlation network analysis revealed that the associations between specific bacteria and short-chain fatty acids (SCFAs) induced by different TDF levels, and the correlations among bacteria were also witnessed. For example, the genus Monoglobus and CHKCI002 showed a positive correlation with butyrate, and there was a positively coexistent association between Monoglobus and CHKCI002. In summary, these data revealed that increasing the TDF level could enhance the cecal morphology and drive cecal species-specific of SCFAs in ducks.

Increased fermentable carbohydrate intake alters colonic mucus barrier function through glycation processes and increased mast cell counts

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder for which dietary interventions can be a useful treatment. In recent years, the low-FODMAP approach is gaining traction in this regard. The fermentation of these non-absorbed carbohydrates by the gut microbiota can generate toxic glycating metabolites, such as methylglyoxal. These metabolites can have harmful effects by their role in the generation of advanced glycation end products (AGEs), which activates Receptor for AGEs (AGER). Mast cells can be stimulated by AGEs and play a role in IBS. We have treated mice with lactose or fructo-oligosaccharides (FOS), with or without co-administration of pyridoxamine and investigated the colonic mucus barrier. We have found that an increased intake of lactose and fructo-oligosaccharides induces a dysregulation of the colonic mucus barrier, increasing mucus discharge in empty colon, while increasing variability and decreasing average thickness mucus layer covering the fecal pellet. Changes were correlated with increased mast cell counts, pointing to a role for the crosstalk between these and goblet cells. Additionally, AGE levels in colonic epithelium were increased by treatment with the selected fermentable carbohydrates. Observed effects were prevented by co-treatment with anti-glycation agent pyridoxamine, implicating glycation processes in the negative impact of fermentable carbohydrate ingestion. This study shows that excessive intake of fermentable carbohydrates can cause colonic mucus barrier dysregulation in mice, by a process that involves glycating agents and increased mucosal mast cell counts.

Cinnamaldehyde Promotes the Intestinal Barrier Functions and Reshapes Gut Microbiome in Early Weaned Rats

Cinnamaldehyde is an aromatic aldehyde isolated from the essential oil of cinnamon. It has been proved to possess various bioactivities such as anti-inflammation, anti-bacteria and antihypertensive. Nevertheless, early weaning could lead to intestinal stress, causing a range of intestinal health problems. The aim of this study is to explore the effects of cinnamaldehyde on gut barrier integrity, inflammatory responses, and intestinal microbiome of early weaned rats. In this study, treatment with cinnamaldehyde (100 or 200 mg/kg bodyweight/day) for 2 weeks significantly promoted the production of mucins in the colonic epithelial tissue of rats. Cinnamaldehyde supplementation significantly upregulated the expression of Muc2, TFF3 and the tight junction proteins (ZO-1, claudin-1, and occludin). Hematoxylin and eosin staining results showed that colonic histopathological changes were recovered by cinnamaldehyde supplementation. The mRNA expression of IL-6 and TNF-α were significantly decreased in the cinnamaldehyde groups while the TNF-α protein levels were significantly decreased in the two cinnamaldehyde groups. Cinnamaldehyde treatment obviously attenuated the activation of NF-κB signaling pathway in rat colonic tissue and suppressed the production of inflammatory cytokines. Furthermore, cinnamaldehyde supplementation remodeled the gut microbiome structure, at the genus level, Akkermansia, Bacteroides, Clostridium III, Psychrobacter, Intestinimonas were increased, whereas those of Ruminococcus, Escherichia/Shigella were obviously decreased in the cinnamaldehyde treated groups. These findings indicated that cinnamaldehyde could effectively enhance intestinal barrier integrity, ameliorate inflammatory responses and remodel gut microbiome in early weaned rats.

Goat and cow milk differ in altering microbiota composition and fermentation products in rats with gut dysbiosis induced by amoxicillin

Antibiotics are effective treatments for bacterial infections, however, their oral administration can have unintended consequences and may alter the gut microbiota composition. In this study, we examined the influence of antibiotics on the induction of gut dysbiosis and then evaluated the potential of cow and goat milk to restore the microbiota composition and metabolism in newly weaned rats. In the first study (gut dysbiosis model), rats were treated with amoxicillin, a mixture of antibiotics (ampicillin, gentamicin and metronidazole) or no antibiotics (control). Antibiotics reduced the rat body weights, food intakes and faecal outputs compared to the control group. Gut length was significantly decreased after the antibiotic intake. The bacterial populations (Bifidobacterium spp., Lactobacillus spp. and total bacteria) and short-chain fatty acids (SCFAs; acetic, butyric and propionic) concentrations in rat caecum, colon and faeces were significantly altered by the antibiotic treatments. In the second study, we examined the effects of cow and goat milk in restoring bacterial populations and metabolism in rats with gut dysbiosis induced by amoxicillin. Goat milk significantly increased the numbers of Bifidobacterium spp. and Lactobacillus spp. and decreased the numbers of Clostridium perfringens in the caecum and colon of rats treated with amoxicillin. Whereas, rats fed cow milk had higher Lactobacillus spp. and lower C. perfringens in the gut. Caecal and colonic SCFAs (acetic, butyric and propionic) concentrations differed significantly between rats fed cow and goat milk diets. Overall, goat and cow milk varied in their effects on the immature gut following antibiotic-induced dysbiosis in a rat model.

Kiwifruit Skin and Flesh Contributions to Fecal Bulking and Bacterial Abundance in Rats

Changes in fecal bulk and bacterial abundance due to separately consumed skin and flesh of four kiwifruit cultivars was determined using a rat model designed to estimate the fecal bulking potential of human foods. Dry matter contribution by skin to 100 g of fresh kiwifruit was less than 5% in all cultivars, whereas flesh dry matter contributed up to 20% of fresh fruit weight. Dietary fiber was 35-49% of skin compared with 8-23% of flesh on a dry weight basis. The skin significantly increased whole fruit fecal bulking, but the total bulk per 100 g kiwifruit was less than 10% of daily fecal bulk recommended for optimal gut health. Kiwifruit (skin or flesh) substantially increased the abundance of Lachnospiraceae and Lactobacillus spp. within the gut. Fermentation and prebiosis therefore probably play a greater role than fermentation-resistant dietary fiber in gut health benefits of kiwifruit.

Cellulose and cellulose derivatives: Different colloidal states and food-related applications

Development of new sources and isolation processes has recently enhanced the production of cellulose in many different colloidal states. Even though cellulose is widely used as a functional ingredient in the food industry, the relationship between the colloidal states of cellulose and its applications is mostly unknown. This review covers the recent progress on illustrating various colloidal states of cellulose and the influencing factors with special emphasis on the correlation between the colloidal states of cellulose and its applications in food industry. The associated unique colloidal states of cellulose like high aspect ratio, crystalline structure, surface charge, and wettability not only promote the stability of colloidal systems, but also help improve the nutritional aspects of cellulose by facilitating its interactions with digestive system. Further studies are required for the rational control and improvement of the colloidal states of cellulose and producing food systems with enhanced functional and nutritional properties.

Short Chain Fatty Acids Enhance Expression and Activity of the Umami Taste Receptor in Enteroendocrine Cells via a Gαi/o Pathway

The short chain fatty acids (SCFAs) acetate, butyrate and propionate, are produced by fermentation of non-digestible carbohydrates by the gut microbiota and regulate appetite, adiposity, metabolism, glycemic control, and immunity. SCFAs act at two distinct G protein coupled receptors (GPCRs), FFAR2 and FFAR3 and are expressed in intestinal enteroendocrine cells (EECs), where they mediate anorectic gut hormone release. EECs also express other GPCRs that act as nutrient sensors, thus SCFAs may elicit some of their health-promoting effects by altering GPCR expression in EECs and enhance gut sensitivity to dietary molecules. Here, we identify that exposure of the murine EEC STC-1 cell line or intestinal organoids to physiological concentrations of SCFAs enhances mRNA levels of the umami taste receptors TASR1 and TASR3, without altering levels of the SCFA GPCRs, FFAR2 and FFAR3. Treatment of EECs with propionate or butyrate, but not acetate, increased levels of umami receptor transcripts, while propionate also reduced CCK expression. This was reversed by inhibiting Gαi/o signaling with pertussis toxin, suggesting that SCFAs act through FFAR2/3 to alter gene expression. Surprisingly, neither a FFAR3 nor a FFAR2 selective ligand could increase TASR1/TASR3 mRNA levels. We assessed the functional impact of increased TASR1/TASR3 expression using unique pharmacological properties of the umami taste receptor; namely, the potentiation of signaling by inosine monophosphate. Activation of umami taste receptor induced inositol-1-phosphate and calcium signaling, and butyrate pretreatment significantly enhanced such signaling. Our study reveals that SCFAs may contribute to EEC adaptation and alter EEC sensitivity to bioactive nutrients.

Soluble Fiber and Insoluble Fiber Regulate Colonic Microbiota and Barrier Function in a Piglet Model

The main purpose of the present study was to assess the effect of soluble and insoluble fiber on colonic bacteria and intestinal barrier function in a piglet model. A total of 24 piglets (25 ± 1 d old; 7.50 ± 0.31 kg) were randomly allotted to 4 treatments: basal diet (control, CON), 1% insoluble dietary fiber (IDF) diet, 1% soluble dietary fiber (SDF) diet, and 0.5% insoluble fiber + 0.5% soluble dietary fiber (MDF) diet. The trial lasted 28 days. SDF-fed piglets showed a higher (P < 0.05) bacterial a-diversity (observed_species, chao1, and ACE) and a higher relative abundance of Proteobacteria and Actinobacteria, Solobacterium, Succinivibrio, Blautia, and Atopobium in colonic digesta than CON, IDF, and MDF groups (P < 0.05). At the same time, Bacteroidetes, Euryarchaeota, Phascolarctobacterium, Coprococcus_1, and Prevotella_1 were significantly increased in the IDF group when compared with CON, SDF, and MDF groups (P < 0.05). Furthermore, Bacteroidetes and Enterobacteriaceae, Selenomonas, Phascolarctobacterium, and Alloprevotella(P < 0.05) were significantly higher in the MDF group than those in the other three groups (P < 0.05). SDF diet increased the concentrations of short-chain fatty acid (SCFA) in colonic digesta (P < 0.05) when compared with the CON group and enhanced weight index of the colon (P < 0.05) than the CON and IDF groups. Furthermore, compared with the CON group, SDF, IDF, and MDF diets all upregulated the mRNA expressions of claudin-1 (CLDN-1) in colonic mucosa (P < 0.05), SDF and IDF diets upregulated the mRNA expressions of mucin 2 (MUC2) (P < 0.05), SDF diet increased mRNA expressions of zonula occludens 1 (ZO-1) and occludin (OCLN), while the IDF group enhanced the secretory immunoglobulin A (sIgA) concentrations (P < 0.05), respectively. IDF and MDF diets decreased expressions of TNF-α(P < 0.05). We concluded that the influence of soluble fiber on colonic microbiota was more extensive than that of insoluble fiber. Moreover, soluble fiber could more effectively improve colonic barrier function by upregulating gene expressions of the gut barrier.

Effects of Blackcurrant and Dietary Fibers on Large Intestinal Health Biomarkers in Rats

This study examined the effects of anthocyanin-rich blackcurrant extract and dietary fibers individually and their combinations on biomarkers of large intestinal health in rats. After six weeks of feeding, rats fed diets with blackcurrant gained significantly less body weight and reduced their food intake resulting in a lower food efficiency compared with those rats fed control diets. Combining dietary fiber (apple or broccoli) with blackcurrant in the diet was more effective in reducing the body weight gain and food intake. Cecal bacterial populations and short-chain fatty acids differed between the experimental diets. Blackcurrants significantly altered the bacterial populations by increasing the abundance of Bacteroides-Prevotella-Porphyromonas group and Lactobacillus spp., while decreasing the abundance of Bifidobacterium spp. and Clostridium perfringens. Propionic acid concentrations were increased by the diets with blackcurrant. Butyric acid concentrations were increased by dietary fiber supplementation. Dietary fiber increased the number of goblet cells in the colon. Diets with blackcurrant were more effective in altering the biomarkers of large intestinal health than those without blackcurrant.

Functionality and nutritional aspects of microcrystalline cellulose in food

Microcrystalline cellulose (MCC) is among the most commonly used cellulose derivatives in the food industry. In order assess the recent advances of MCC in food product development and its associated nutraceutical implications, google scholar and database of journals subscribed by Jiangnan university, China were used to source literature. Recently published research articles that reported physicochemical properties of MCC for food application or potential application in food and nutraceutical functions were reviewed and major findings outlined. The selected literature reviewed demonstrated that the material has been extensively explored as a functional ingredient in food including meat products, emulsions, beverages, dairy products, bakery, confectionary and filling. The carbohydrate polymer also has many promising applications in functional and nutraceutical food industries. Though widely used as control for many dietary fiber investigations, MCC has been shown to provide positive effects on gastrointestinal physiology, and hypolipidemic effects, influencing the expression of enzymes involved in lipid metabolism. These techno-functional and nutraceutical properties of MCC are influenced by the physicochemical of the material, which are defined by the raw material source and processing conditions. Apart from these functional properties, this review also highlighted limitations and gaps regarding the application of material in food and nutritional realms. Functional, Nutritional and health claims of MCC.

Of the milk sugars, galactose, but not prebiotic galacto-oligosaccharide, improves insulin sensitivity in male Sprague-Dawley rats

BACKGROUND

Consumption of dairy products reduces risk of type 2 diabetes. Milk proteins and fats exhibit anti-diabetic properties but milk sugars have been studied little in this context. Galactose from milk lactose is readily converted to glycogen in the liver but its effects on insulin sensitivity have not been assessed. Prebiotic oligosaccharides from milk alter gut microbiota and can thereby influence host metabolism. Our objective was to assess the effect on insulin sensitivity of dietary galactose compared to glucose and fructose, and fermentable galacto-oligosaccharides compared to non-fermentable methylcellulose.

METHODS

Diets containing 15% of dry matter from glucose, fructose, galactose, galacto-oligosaccharides, or methylcellulose were fed to 36 rats per diet for 9 weeks. Hyperinsulinemic-euglycemic clamps with [3-3H]glucose infusion and a steady-state 2-[1-14C]deoxyglucose bolus injection were used to assess insulin sensitivity and glucose uptake indices. Tissue was collected in fed, fasted and fasted, insulin-stimulated states.

RESULTS

Galactose increased glucose infusion rate during the clamp by 53% and decreased endogenous glucose production by 57% compared to glucose and fructose. Fed-state hepatic glycogen content was greater with galactose compared to glucose and fructose, consistent with a potentiation of the insulin effect on glycogen synthase by dephosphorylation. Galactose decreased the fecal Firmicutes:Bacteroidetes ratio while galacto-oligosaccharides increased abundance of fecal Bifidobacterium spp. 481-fold compared to methylcellulose, and also increased abundance of Lactobacillus spp. and Bacteroidetes. Galacto-oligosaccharides did not affect glucose infusion rate or endogenous glucose production during basal or clamp periods compared to methylcellulose.

CONCLUSIONS

Galactose at 15% of daily intake improved hepatic insulin sensitivity in rats compared to glucose and fructose. Galactose caused an increase in fed-state hepatic glycogen content and a favourable shift in gut microbial populations. Intake of galacto-oligosaccharides improved the gut microbial profile but did not improve insulin sensitivity.

Produto a base de yacon e modulação da microbiota, perfil de ácidos graxo e lipídico em ratas ovariectomizadas

RESUMO Objetivo: Este trabalho avaliou a modulação da microbiota gastrointestinal, do perfil de ácidos orgânicos e de lipídeos em ratas Wistar ovariectomizadas, sendo que algumas receberam dieta suplementada com 6% de fruto-oligossacarídeos e inulina, a partir do produto a base de yacon, e outras não. Métodos: Analisou-se o peso do ceco, pH e ácidos orgânicos, microbiota do conteúdo cecal, colesterol total e frações. Resultados: No grupo que recebeu a dieta suplementada durante todo o experimento ocorreu modulação benéfica da microbiota intestinal em função da fermentação dos fruto-oligossacarídeos/inulina, bem como aumento do perfil de lactato (p<0,05) e do nível de lipoproteina alta densidade (p<0,05). Conclusão: Isso sugere que o hábito de consumo contínuo do yacon tem potencial para modular a microbiota intestinal, o perfil de ácidos orgânicos e para diminuir as dislipidemias.

Mucin-Microbiota Interaction During Postnatal Maturation of the Intestinal Ecosystem: Clinical Implications

The mucus layer and gut microbiota interplay contributes to host homeostasis. The mucus layer serves as a scaffold and a carbon source for gut microorganisms; conversely, gut microorganisms, including mucin degraders, influence mucin gene expression, glycosylation, and secretion. Conjointly they shield the epithelium from luminal pathogens, antigens, and toxins. Importantly, the mucus layer and gut microbiota are established in parallel during early postnatal life. During this period, the development of gut microbiota and mucus layer is coupled with that of the immune system. Developmental changes of different mucin types can impact the age-dependent patterns of intestinal infection in terms of incidence and severity. Altered mucus layer, dysbiotic microbiota, and abnormal mucus-gut microbiota interaction have the potential for inducing systemic effects, and accompany several intestinal diseases such as inflammatory bowel disease, colorectal cancer, and radiation-induced mucositis. Early life provides a pivotal window of opportunity to favorably modulate the mucus-microbiota interaction. The support of a health-compatible mucin-microbiota maturation in early life is paramount for long-term health and serves as an important opportunity for clinical intervention.

The fate of (13)C-labelled and non-labelled inulin predisposed to large bowel fermentation in rats

The fate of stable-isotope (13)C labelled and non-labelled inulin catabolism by the gut microbiota was assessed in a healthy rat model. Sprague-Dawley male rats were randomly assigned to diets containing either cellulose or inulin, and were fed these diets for 3 days. On day (d) 4, rats allocated to the inulin diet received (13)C-labelled inulin. The rats were then fed the respective non-labelled diets (cellulose or inulin) until sampling (d4, d5, d6, d7, d10 and d11). Post feeding of (13)C-labelled substrate, breath analysis showed that (13)C-inulin cleared from the host within a period of 36 hours. Faecal (13)C demonstrated the clearance of inulin from gut with a (13)C excess reaching maximum at 24 hours (d5) and then declining gradually. There were greater variations in caecal organic acid concentrations from d4 to d6, with higher concentrations of acetic, butyric and propionic acids observed in the rats fed inulin compared to those fed cellulose. Inulin influenced caecal microbial glycosidase activity, increased colon crypt depth, and decreased the faecal output and polysaccharide content compared to the cellulose diet. In summary, the presence of inulin in the diet positively influenced large bowel microbial fermentation.

α-Galactosides present in lupin flour affect several metabolic parameters in Wistar rats

The aim of this study is to evaluate the influence of α-galactosides present in a lupin diet on metabolic parameters in growing Wistar rats.

Galacto-oligosaccharides and Colorectal Cancer: Feeding our Intestinal Probiome

Prebiotics are ingredients selectively fermented by the intestinal microbiota that promote changes in the microbial community structure and/or their metabolism, conferring health benefits to the host. Studies show that β (1-4) galacto-oligosaccharides [β (1-4) GOS], lactulose and fructo-oligosaccharides increase intestinal concentration of lactate and short chain fatty acids, and stool frequency and weight, and they decrease fecal concentration of secondary bile acids, fecal pH, and nitroreductase and β-glucuronidase activities suggesting a clear role in colorectal cancer (CRC) prevention. This review summarizes research on prebiotics bioassimilation, specifically β (1-4) GOS, and their potential role in CRC. We also evaluate research that show that the impact of prebiotics on host physiology can be direct or through modulation of the gut intestinal microbiome, specifically the probiome (autochtonous beneficial bacteria), we present studies on a potential role in CRC progression to finally describe the current state of β (1-4) GOS generation for industrial production.

Influence of green and gold kiwifruit on indices of large bowel function in healthy rats

The effects of kiwifruit on large bowel health were investigated in healthy rats. Four-week old Sprague-Dawley rats were given diets containing 10% homogenized green kiwifruit, gold kiwifruit or 10% glucose solution (control) over 4 or 6 wk. Green kiwifruit increased the fecal output compared to control. Growth of certain bacterial species in cecum was influenced by both green and gold kiwifruit. A significant increase in cecal Lachnospiraceae in rats fed the green kiwifruit diet was observed at week 4. At week 6, green and gold kiwifruit diets assisted in improving colonic barrier function by upregulating the expression of mucin (MUC)-2, MUC3, Toll-like receptor (TLR)-4 or trefoil factor-3 genes. Gold kiwifruit consumption increased the colonic goblet cells per crypt at week 6. Significant negative correlations between E. coli and β-defensin 1 and TLR4 expression were observed. Consuming green and gold kiwifruit for 6 wk significantly altered the biomarkers of large bowel health; indicating that regularly consuming kiwifruit helps attain optimal digestive health.

Exposure to a galactooligosaccharides/inulin prebiotic mix at different developmental time points differentially modulates immune responses in mice

Prebiotics constitute emerging tools to alleviate immune pathologies. This study aimed to evaluate the effect of prebiotic exposure during perinatal and postweaning periods on immune and gut regulations. Mice were fed either a galactooligosaccharides/inulin prebiotic mix-enriched diet or a control diet during the perinatal and/or postweaning periods. Biomarkers related to gut barrier function (SCFA, heat shock proteins, zonula occludens protein-1, and mucin-2) and immune mechanisms (IgA, IgE, IgG1, IgG2a, IL-10, TGF-β, IL-4, IL-17A, and IFN-γ) were analyzed. The milk of dams fed the prebiotic diet was more concentrated in both IgA and TGF-β when prebiotics were introduced during both the perinatal and postweaning periods; IL-10, IgA, and IgG2a were increased in pups; and expression of intestinal markers was more pronounced. Postweaning exposure to prebiotics alone induced higher INF-γ and TGF-β levels, whereas IgA levels fell. Combined exposure periods (perinatal/postweaning) to prebiotics increased tolerance-related immunoglobulins in pups and reinforced gut barrier functions.