Dietary Oligosaccharides Research Articles

Oligosaccharide feed supplementation reduces plasma insulin in geldings with Equine Metabolic Syndrome

BackgroundThe prevalence of Equine Metabolic Syndrome and insulin dysregulation is increasing in the horse population. Insulin dysregulation is a risk factor for laminitis, which has significant welfare consequences for the horse. Current treatment strategies for Equine Metabolic Syndrome have variable effects on insulin sensitivity. Findings suggest that gut microbiota plays an important role in gastrointestinal barrier protection and metabolic diseases. Dietary supplementation with oligosaccharides has been shown to increase the production of short-chain fatty acids and induce changes in the gut microbiota, with an increase in insulin sensitivity.ObjectivesWe hypothesized that dietary oligosaccharide supplementation would ameliorate insulin dysregulation in horses with Equine Metabolic Syndrome.Study designFifteen horses were included in a cross-over study including two feed supplementations periods with oligosaccharide supplementation or calcium carbonate. Before and after each period plasma insulin, endotoxin, serum amyloid A, and blood glucose concentrations were measured during an oral sugar test and fecal samples were collected.ResultsOligosaccharide supplementation significantly reduced insulin in geldings (p = 0.02). Overall, none of the dominating bacterias changed significantly in relative Δ-abundance. In the gut microbiota of mares, the Akkermansia genus and Clostridiaceae family were significantly more abundant. Within-sample bacterial diversity of horses with insulin concentrations > 60 mIU/L was significantly greater when compared to horses < 60 mIU/L. Horses with insulin concentrations > 60 mIU/L and horses with previous laminitis had a significantly greater beta diversity.Main limitationsCut-off values for oligosaccharide feed supplementation/placebo dosing instead of dosing by g/kg body weight; owner compliance; single blood sample in oral sugar test; inter-horse variationConclusionsThis study demonstrated that oligosaccharide supplementation could improve insulin dysregulation in geldings with Equine Metabolic Syndrome suggesting that sex susceptibility might be a factor to consider. Additionally, a tendency of reduction of obesity-associated bacteria was observed. Furthermore, the diversity of the gut microbiota was significantly dependent on laminitis status and insulin concentrations. However, more studies on the effects of oligosaccharide supplementation on insulin dysregulation are needed to improve the dietary management of horses with Equine Metabolic Syndrome.

Dynamic genetic adaptation of Bacteroides thetaiotaomicron during murine gut colonization

To understand how a bacterium ultimately succeeds or fails in adapting to a new host, it is essential to assess the temporal dynamics of its fitness over the course of colonization. Here, we introduce a human-derived commensal organism, Bacteroides thetaiotaomicron (Bt), into the guts of germ-free mice to determine whether and how the genetic requirements for colonization shift over time. Combining a high-throughput functional genetics assay and transcriptomics, we find that gene usage changes drastically during the first days of colonization, shifting from high expression of amino acid biosynthesis genes to broad upregulation of diverse polysaccharide utilization loci. Within the first week, metabolism becomes centered around utilization of a predominant dietary oligosaccharide, and these changes are largely sustained through 6weeks of colonization. Spontaneous mutations in wild-type Bt also evolve around this locus. These findings highlight the importance of considering temporal colonization dynamics in developing more effective microbiome-based therapies.

Effect of Chromium Nanoparticles and Switching from a High-Fat to a Low-Fat Diet on the Cecal Microenvironment in Obese Rats.

Previous studies showed that chromium nanoparticles (Cr-NPs) might be used as dietary compounds against some obesity-related disorders; however, there is little information on how these compounds influence the gut microenvironment. The aim of this study was to investigate whether the negative effects of a high-fat diet in the large intestine of rats might be mitigated by switching to a low-fat diet and supplementation with Cr-NPs. Microbiota sequencing analysis revealed that the main action of the Cr-NPs was focused on changing the gut microbiota's activity. Supplementation with nanoparticles decreased the activity of β-glucuronidase and enzymes responsible for the hydrolysis of dietary oligosaccharides and, thus, lowered the concentration of short-chain fatty acids in the cecum. In this group, there was also an elevated level of cecal lithocholic acid. The most favorable effect on the regulation of obesity-related disorders was observed when a high-fat diet was switched to a low-fat diet. This dietary change enhanced the production of short-chain fatty acids, reduced the level of secondary bile acids, and increased the microbial taxonomic richness, microbial differences, and microbial enzymatic activity in the cecum. To conclude, supplementation of a high-fat diet with Cr-NPs primarily had an effect on intestinal microbial activity, but switching to a low-fat diet had a powerful, all-encompassing effect on the gut that improved both microbial activity and composition.

Effect of Rotavirus Infection and 2'-Fucosyllactose Administration on Rat Intestinal Gene Expression.

Viral infections are described as modifying host gene expression; however, there is limited insight regarding rotavirus (RV) infections. This study aimed to assess the changes in intestinal gene expression after RV infection in a preclinical model, and the effect of 2-fucosyllactose (2'-FL) on this process. From days 2 to 8 of life, rats were supplemented with the dietary oligosaccharide 2'-FL or vehicle. In addition, an RV was inoculated on day 5 to nonsupplemented animals (RV group) and to 2'-FL-fed animals (RV+2'-FL group). Incidence and severity of diarrhea were established. A portion from the middle part of the small intestine was excised for gene expression analysis by microarray kit and qPCR. In nonsupplemented animals, RV-induced diarrhea upregulated host antiviral genes (e.g., Oas1a, Irf7, Ifi44, Isg15) and downregulated several genes involved in absorptive processes and intestinal maturation (e.g., Onecut2, and Ccl19). The 2'-FL-supplemented and infected animals had less diarrhea; however, their gene expression was affected in a similar way as the control-infected animals, with the exception of some immunity/maturation markers that were differentially expressed (e.g., Ccl12 and Afp). Overall, assessing the expression of these key genes may be useful in the evaluation of the efficacy of nutritional interventions or treatments for RV infection.

Synergistic effects of alginate oligosaccharide and cyanidin-3-O-glucoside on the amelioration of intestinal barrier function in mice

Emerging evidence shows that dietary oligosaccharides are important prebiotics that can improve intestinal flora, while dietary polyphenols can act directly on intestinal cells. However, information about their synergistic effects on gut health is still limited. In this study, alginate oligosaccharide (AOS) and cyanidin-3-O-glucoside (C3G) were selected as a common marine plant oligosaccharide and terrestrial plant polyphenol, respectively, to study their effects on intestinal health. The results show that, in comparison to their individual applications, the combination of AOS and C3G (mass ratio, 3:1) displayed a stronger ability to up-regulate the expression of tight junction proteins, while enhanced intestinal epithelial barrier was also observed and levels of mucin-2 and β-defensins were simultaneously increased in the intestinal mucus. Interestingly, the secretion of immunoglobulin A and immune-related cytokines were approximately doubled by the AOS + C3G mixture. In addition, the AOS + C3G mixture was found to be more conducive to the positive transformation of intestinal flora, which stimulated the growth of beneficial bacteria Akkermansia, Lachnospiraceae and Feacalibaculum while inhibiting the growth of harmful bacteria Helicobacter and Turicibacter. The data generated herein thus suggests that dietary oligosaccharides and dietary polyphenols may be more beneficial to intestinal health when applied in combination than their individual effects alone.

Fermentable Fibers or Oligosaccharides Reduce Urinary Nitrogen Excretion by Increasing Urea Disposal in the Rat Cecum

The availability of fermentable carbohydrates could influence the digestive degradation and disposal of blood urea. The effects of a poorly fermented cellulosic oat fiber, a soluble fermentable fiber (gum arabic) or one of two oligosaccharides (fructooligosaccharide or xylooligosaccharide) on nitrogen excretion were compared with a wheat starch-based control diet in male Wistar rats. The fibers and oligosaccharides were added to the semipurified diets at 7.5 g/100 g in place of wheat starch. The diets contained 13 g casein/100 g. Oat fiber did not cause an enlargement of the cecum. In contrast, gum arabic and the oligosaccharides elicited a 35–60% enlargement of the cecal wall and a 2 to 2.6-fold mean increase in the cecal pool of short chain fatty acids. Compared with rats fed the oat fiber-based diet, urea flux from blood to cecum was nearly 50% greater and more than 120% greater in those fed the gum arabic and oligosaccharide diets, respectively. In those groups, net nitrogen retention in the cecum more than doubled (nitrogen retention was calculated as the difference between net urea nitrogen flux into the cecum and ammonia nitrogen reabsorption). As a percentage of total excreted nitrogen, fecal nitrogen was 20% in the oat fiber group and 27–29% in the gum arabic and oligosaccharide groups, compared with only 10% in fiber-free controls. Results indicate that under these dietary conditions, the addition of oligosaccharides to the diet induced a 20 to 30% decrease in blood urea and renal nitrogen excretion relative to the control, indicating a potential for oligosaccharide diet therapy in chronic renal disease.

Infant Gut Microbial Metagenome Mining of α-l-Fucosidases with Activity on Fucosylated Human Milk Oligosaccharides and Glycoconjugates.

ABSTRACTThe gastrointestinal microbiota members produce α-l-fucosidases that play key roles in mucosal, human milk, and dietary oligosaccharide assimilation. Here, 36 open reading frames (ORFs) coding for putative α-l-fucosidases belonging to glycosyl hydrolase family 29 (GH29) were identified through metagenome analysis of breast-fed infant fecal microbiome. Twenty-two of those ORFs showed a complete coding sequence with deduced amino acid sequences displaying the highest degree of identity with α-l-fucosidases from Bacteroides thetaiotaomicron, Bacteroides caccae, Phocaeicola vulgatus, Phocaeicola dorei, Ruminococcus gnavus, and Streptococcus parasanguinis. Based on sequence homology, 10 α-l-fucosidase genes were selected for substrate specificity characterization. The α-l-fucosidases Fuc18, Fuc19A, Fuc35B, Fuc39, and Fuc1584 showed hydrolytic activity on α1,3/4-linked fucose present in Lewis blood antigens and the human milk oligosaccharide (HMO) 3-fucosyllactose. In addition, Fuc1584 also hydrolyzed fucosyl-α-1,6-N-acetylglucosamine (6FN), a component of the core fucosylation of N-glycans. Fuc35A and Fuc193 showed activity on α1,2/3/4/6 linkages from H type-2, Lewis blood antigens, HMOs and 6FN. Fuc30 displayed activity only on α1,6-linked l-fucose, and Fuc5372 showed a preference for α1,2 linkages. Fuc2358 exhibited a broad substrate specificity releasing l-fucose from all the tested free histo-blood group antigens, HMOs, and 6FN. This latest enzyme also displayed activity in glycoconjugates carrying lacto-N-fucopentaose II (Lea) and lacto-N-fucopentaose III (Lex) and in the glycoprotein mucin. Fuc18, Fuc19A, and Fuc39 also removed l-fucose from neoglycoproteins and human α-1 acid glycoprotein. These results give insight into the great diversity of α-l-fucosidases from the infant gut microbiota, thus supporting the hypothesis that fucosylated glycans are crucial for shaping the newborn microbiota composition.IMPORTANCE α-l-Fucosyl residues are frequently present in many relevant glycans, such as human milk oligosaccharides (HMOs), histo-blood group antigens (HBGAs), and epitopes on cell surface glycoconjugate receptors. These fucosylated glycans are involved in a number of mammalian physiological processes, including adhesion of pathogens and immune responses. The modulation of l-fucose content in such processes may provide new insights and knowledge regarding molecular interactions and may help to devise new therapeutic strategies. Microbial α-l-fucosidases are exoglycosidases that remove α-l-fucosyl residues from free oligosaccharides and glycoconjugates and can be also used in transglycosylation reactions to synthesize oligosaccharides. In this work, α-l-fucosidases from the GH29 family were identified and characterized from the metagenome of fecal samples of breastfed infants. These enzymes showed different substrate specificities toward HMOs, HBGAs, naturally occurring glycoproteins, and neoglycoproteins. These novel glycosidase enzymes from the breast-fed infant gut microbiota, which resulted in a good source of α-l-fucosidases, have great biotechnological potential.

Dietary Oligosaccharides Differentially Modulate Microbiome, Enteric Glia, and Epithelial Barrier Function in the Neonatal Jejunum and Colon

In our pig intestinal ischemia model, a neonatal defect in epithelial barrier restitution in the jejunum can be rescued by ischemic mucosal homogenate from weaned pigs. This is associated with an immature enteric glial cell (EGC) network, a known driver of restitution that matures postnatally partly in response to microbial colonization, which can be modulated with dietary prebiotic fiber. Therefore, we hypothesized that dietary oligosaccharide supplementation accelerates postnatal microbial colonization and EGC network maturation in the jejunum and colon, thus enhancing restitution after ischemic injury. After 24‐hours of colostrum, piglets were fed control or oligosaccharide‐supplemented formula (control‐fed or prebiotic‐fed) for 21 days and fecal swabs were sequenced for 16S rDNA. Intestinal samples were collected for western blot, imaging, and EGC culture. Surgically ischemia‐injured jejunal and colonic mucosal samples from select day 14 pigs were recovered ex vivo while monitoring epithelial barrier function by transepithelial electrical resistance (TEER). Migration abilities, calcium responses to ATP, paracrine effects on IPEC‐J2 cell restitution, and protein secretome were assessed in jejunal and colonic EGC cultures. Colonic microbial taxa changed in a time‐ and diet‐dependent manner with the prebiotic‐fed taxa clustering by day 7 and becoming progressively more tightly clustered over time (P<.050). TEER and histology of uninjured jejunum and colon were unaffected by diet. Following ischemia, low initial TEER recovered to control levels in the control‐fed colon but not prebiotic‐fed colon (diet and injury interaction, P=.038), while diet had no effect on jejunal TEER recovery. Prebiotic‐fed colon had lower levels of the EGC markers glial fibrillary acidic protein (GFAP) and S‐100B at day 21 (P<.050), and subjectively reduced density of GFAP+ and S‐100B+ EGC were noted in preliminary volume imaging of prebiotic‐fed jejunal submucosa at days 14 and 21. EGC from prebiotic‐fed colonic submucosa showed decreased chemotactic motility toward sterile‐filtered colonic contents (P=.010), decreased intracellular calcium response to ATP (P=.0075), and their co‐culture with IPEC‐J2 enhanced epithelial restitution versus monoculture (P=.032). Oppositely, EGC from prebiotic‐fed jejunal submucosa showed increased intracellular calcium response (P=.050) and their co‐culture with IPEC‐J2 did not enhance restitution as efficiently (P=.33) as those from control‐fed jejunal submucosa (P=.019). For future study, prebiotic‐fed colonic submucosal EGC differentially secreted 13 proteins of interest versus control‐fed. Preliminary results indicate dietary oligosaccharides in neonates exert different effects in the jejunum versus the colon on EGC network development and phenotype, and on epithelial restitution in vivo and in vitro. Ongoing work to understand microbiome‐ EGC‐epithelial interactions during postnatal development may lead to novel preventative and clinical practices to improve intestinal health in vulnerable neonates.

Oligosaccharide equine feed supplement, Immulix, has minor impact on vaccine responses in mice

Several mammalian species are vaccinated in early life, but little is known about the effect of diet on vaccine response. Oligosaccharides are increasingly proposed as dietary supplement for young individuals due to their anti-inflammatory potential elicited through modulation of gut microbiota (GM). Also, diet, e.g. the size of the fat fraction, is known to modulate the GM. We tested if an oligosaccharide diet (Immulix) and/or increased dietary fat content affected antibody titers to a tetanus vaccine in 48 BALB/cJTac mice through GM modulation. Female mice had significantly higher IgG titers with higher variation compared to male mice. The effects of Immulix and/or increased fat content were minor. Immulix negatively affected IgG titers in male mice four weeks after secondary vaccination but upregulated Il1b gene expression in the spleen. Immulix had a downregulating effect on expression of Cd4 and Foxp3 in ileum only if the mice were fed the diet with increased fat. The diet with increased dietary fat increased Il1b but decreased Cd8a gene expression in the spleen. Immulix and diet affected GM composition significantly. Increased dietary fat content upregulated Lactobacillus animalis but downregulated an unclassified Prevotella spp. Immulix decreased Lactobacillales, Streptococcaceae and Prevotellaceae but increased Bacteroides. It is concluded that in spite of some minor influences on immune cell markers, cytokines and IgG titers Immulix feeding or increased dietary fat content did not have any biologically relevant effects on tetanus vaccine responses in this experiment in mice.

Effects of dietary oligosaccharides on serum biochemical index, intestinal morphology, and antioxidant status in broilers.

In order to determine the effect of different oligosaccharides on growth performance, intestinal health, and antioxidant status of broilers, 240 1-day-old XiangHuang broilers were randomly distributed to 4 treatments with 6 replicates each. Birds were fed corn-soybean-based diets (CON), and birds in xylo-oligosaccharides (XOS), fructo-oligosaccharides (FOS), and iso-maltooligosaccharide (IMO) groups were given the basal diet supplemented with 200 mg/kg XOS, FOS, and IMO, respectively. Result showed that average daily gain (ADG) during the whole 5weeks in FOS group was greater than that in control group (p < 0.05). Both breast and thigh muscle percentages were higher for birds fed XOS versus CON (p < 0.05). Oligosaccharides supplementation increased jejunal villus height compared with control group (p < 0.05). Malondialdehyde (MDA) concentration in breast muscle was lower for birds fed diet containing FOS versus CON (p < 0.05). Activities of total superoxide dismutase (T-SOD) in serum and thigh muscle were higher in IMO than in control group (p < 0.05). Serum T-SOD and breast muscle's glutathione peroxidase (GSH-Px) activity was higher in XOS compared with control group (p < 0.05). Conclusion, dietary oligosaccharides such as XOS, FOS, and IMO could improve intestinal health and antioxidant ability of muscle without affect growth performance in broilers.

Microbiological Characteristics of Intestinal Biocenosis of Ambulator Patients Having Behavioral Risk Factors for Chronic Non-Communicable Diseases

The earliest correction of behavioral risk factors for chronic non-communicable diseases will reduce the rates of premature mortality of the population. Currently, the relationship between the altered spectrum of intestinal microflora in various indicators of suboptimal health status and body mass index is not sufficiently studied. When they are in a state of suboptimal health status, patients consider themselves healthy and do not go to the doctor for a long time, which makes it difficult to implement early preventive measures in this group of patients. Goal. To determine the qualitative and quantitative composition of the intestinal microflora before and 1 month after taking a metaprebiotic complex containing dietary fiber (inulin) and oligosaccharides (oligofructose) in outpatient patients who consider themselves healthy, have behavioral risk factors for chronic non-communicable diseases or chronic non-communicable diseases in remission, and/or do not consult a doctor within the last 3 months. Materials and methods. Outpatient patients were examined (114 people: 36 men, 78 women aged 18 to 72 years). A survey was conducted, including a detailed active collection of complaints (including using the international SHSQ-25 questionnaire) and anamnesis, as well as a thorough physical examination with an anthropometric study. Using the MALDI-ToF mass spectrometry method, the degree of microbiotic disorders, the structure of the intestinal microflora were determined with the identification of microorganisms isolated from feces before and after taking the course of the metaprebiotic complex with various indicators of suboptimal status and body mass index. Results. New data were obtained on the intestinal biocenosis of patients who consider themselves healthy at different levels of suboptimal status. When using a metaprebiotic complex containing inulin and oligofructose, an improvement in the composition of the intestinal microflora was found due to a decrease in the frequency of release of conditionally pathogenic enterobacteria and other gram-negative microorganisms (median degree of contamination: from 0.45 (0.3-0.98) to 0.3(0.21-0.7) at low suboptimal status and from 0.5(0.7-1.7) to 0.31 (0.2-1.3) at high) and increase the frequency of enterococcal excretion (median degree of contamination: from 5,58 (4,16-7,0) tо 6,3 (4,8-7,8) at low suboptimal status and from от 4,5 (2,8-6,3) tо 5,1 (3,8-6,4) at high). Conclusion. The importance of studying the microbiotic complex of the intestine in increasing the indicators of suboptimal health status and body mass index in patients who consider themselves healthy is proved, which will allow for the earliest detection and rational individual prevention of chronic non-communicable diseases.

An Oligosaccharide Rich Diet Increases Akkermansia spp. Bacteria in the Equine Microbiota.

Some oligosaccharides induce growth of anti-inflammatory bacterial species and induce regulatory immunity in humans as well as animals. We have shown that the equine gut microbiota and the immune-microbial homeostasis largely stabilize within the first 50 days of life. Furthermore, we have previously established that certain bacterial species in the equine gut correlated with regulatory immunity. Accordingly, we hypothesized that an oligosaccharide rich diet fed to foals during the first 50 days would increase the abundance of bacterial species associated with regulatory immunity, and that this would influence immune responses in the foals. Eight pregnant mares and their foals were fed an oligosaccharide rich diet from 4 weeks before expected parturition until 49 days post-partum. Six mares and foals served as control. Fecal microbiota from mares and foals was characterized using 16S rRNA gene amplicon high throughput sequencing. On Day 49 the test foals had significantly higher abundances of Akkermansia spp. Blood sampled from the foals in the test group on Day 7, 28, and 49 showed non-significant increases in IgA, and decreases in IgG on Day 49. In BALB/cBomTac mice inoculated with gut microbiota from test and control foals we found increased species richness, increased relative abundance of several species identified as potentially anti-inflammatory in horses, which were unclassified Clostridiales, Ruminococcaceae, Ruminococcus, Oscilospira, and Coprococcus. We also found increased il10 expression in the ileum if inoculated with test foal microbiota. We conclude that an oligosaccharide diet fed to foals in the “window of opportunity,” the first 50 days of life, increases the abundance of anti-inflammatory species in the microbiota with potentially anti-inflammatory effects on regulatory immunity.

Dietary Phytogenics and Galactomannan Oligosaccharides in Low Fish Meal and Fish Oil-Based Diets for European Sea Bass (Dicentrarchus labrax) Juveniles: Effects on Gill Structure and Health and Implications on Oxidative Stress Status.

An effective replacement for fish meal (FM) and fish oil (FO) based on plant-based raw materials in the feed of marine fish species is necessary for the sustainability of the aquaculture sector. However, the use of plant-based raw materials to replace FM and FO has been associated with several negative health effects, some of which are related to oxidative stress processes that can induce functional and morphological alterations in mucosal tissues. This study aimed to evaluate the effects of dietary oligosaccharides of plant origin (5,000 ppm; galactomannan oligosaccharides, GMOS) and a phytogenic feed additive (200 ppm; garlic oil and labiatae plant extract mixture, PHYTO) on the oxidative stress status and mucosal health of the gills of juvenile European sea bass (Dicentrarchus labrax). The experimental diets, low FM and FO diets (10%FM/6%FO) were supplemented with GMOS from plant origin and PHYTO for 63 days. GMOS and PHYTO did not significantly affect feed utilization, fish growth, and survival. GMOS and PHYTO downregulated the expression of β-act, sod, gpx, cat, and gr in the gills of the fish compared with that in fish fed the control diet. The expression of hsp70 and ocln was upregulated and downregulated, respectively, in the GMOS group compared with that in the control group, whereas the expression of zo-1 was downregulated in the PHYTO group compared with that in the GMOS group. The morphological, histopathological, immunohistochemical, and biochemical parameters of the fish gills were mostly unaffected by GMOS and PHYTO. However, the PHYTO group had lower incidence of lamellar fusion than did the control group after 63 days. Although the tissular distribution of goblet cells was unaffected by GMOS and PHYTO, goblet cell size showed a decreasing trend (−11%) in the GMOS group. GMOS and PHYTO significantly reduced the concentration of PCNA+ in the epithelium of the gills. The above findings indicated that GMOS and PHYTO in low FM/FO-based diets protected the gill epithelia of D. labrax from oxidative stress by modulating the expression of oxidative enzyme-related genes and reducing the density of PCNA+ cells in the gills of the fish.

Improvement of colonic healing and surgical recovery with perioperative supplementation of inulin and galacto-oligosaccharides

Anastomotic leak (AL) is a major complication in colorectal surgery. Recent evidence suggests that the gut microbiota may affect healing and may cause or prevent AL. Butyrate is a beneficial short-chain fatty acid (SCFA) that is produced as a result of bacterial fermentation of dietary oligosaccharides and has been described as beneficial in the maintenance of colonic health. To assess the impact of oligosaccharides on colonic anastomotic healing in mice, we propose to modulate the microbiota with oligosaccharides to increase butyrate production via enhancement of butyrate-producing bacteria and, consequently, improve anastomotic healing in mice. Animal experiments were conducted in mice that were subjected to diets supplemented with inulin, galacto-oligosaccharides (GOS) or cellulose, as a control, for two weeks before undergoing a surgical colonic anastomosis. Macroscopic and histological assessment of the anastomosis was performed. Extent of epithelial proliferation was assessed by Ki-67 immunohistochemistry. Gelatin zymography was used to evaluate the extent of matrix metalloproteinase (MMP) hydrolytic activity. Inulin and GOS diets were associated with increased butyrate production and better anastomotic healing. Histological analysis revealed an enhanced mucosal continuity, and this was associated with an increased re-epithelialization of the wound as determined by increased epithelial proliferation. Collagen concentration in peri-anastomotic tissue was higher with inulin and GOS diets and MMP activity, a marker of collagen degradation, was lower with both oligosaccharides. Inulin and GOS diets were further associated with lower bacterial translocation. Dietary supplementation with inulin and GOS may improve anastomotic healing and reinforce the gut barrier in mice.

Cranberry Proanthocyanidins and Dietary Oligosaccharides Synergistically Modulate Lactobacillus plantarum Physiology.

Plant-based foods contain bioactive compounds such as polyphenols that resist digestion and potentially benefit the host through interactions with their resident microbiota. Based on previous observations, we hypothesized that the probiotic Lactobacillus plantarum interacts with cranberry polyphenols and dietary oligosaccharides to synergistically impact its physiology. In this study, L. plantarum ATCC BAA-793 was grown on dietary oligosaccharides, including cranberry xyloglucans, fructooligosaccharides, and human milk oligosaccharides, in conjunction with proanthocyanidins (PACs) extracted from cranberries. As a result, L. plantarum exhibits a differential physiological response to cranberry PACs dependent on the carbohydrate source and polyphenol fraction introduced. Of the two PAC extracts evaluated, the PAC1 fraction contains higher concentrations of PACs and increased growth regardless of the oligosaccharide, whereas PAC2 positively modulates its growth during xyloglucan metabolism. Interestingly, fructooligosaccharides (FOS) are efficiently utilized in the presence of PAC1, as this L. plantarum strain does not utilize this substrate typically. Relative to glucose, oligosaccharide metabolism increases the ratio of secreted acetic acid to lactic acid. The PAC2 fraction differentially increases this ratio during cranberry xyloglucan fermentation compared with PAC1. The global transcriptome links the expression of putative polyphenol degradation genes and networks and metabolic phenotypes.

Structure and evolution of the bifidobacterial carbohydrate metabolism proteins and enzymes.

Bifidobacteria have attracted significant attention because they provide health-promoting effects in the human gut. In this review, we present a current overview of the three-dimensional structures of bifidobacterial proteins involved in carbohydrate uptake, degradation, and metabolism. As predominant early colonizers of the infant's gut, distinct bifidobacterial species are equipped with a panel of transporters and enzymes specific for human milk oligosaccharides (HMOs). Interestingly, Bifidobacterium bifidum and Bifidobacterium longum possess lacto-N-biosidases with unrelated structural folds to release the disaccharide lacto-N-biose from HMOs, suggesting the convergent evolution of this activity from different ancestral proteins. The crystal structures of enzymes that confer the degradation of glycans from the mucin glycoprotein layer provide a structural basis for the utilization of this sustainable nutrient in the gastrointestinal tract. The utilization of several plant dietary oligosaccharides has been studied in detail, and the prime importance of oligosaccharide-specific ATP-binding cassette (ABC) transporters in glycan utilisations by bifidobacteria has been revealed. The structural elements underpinning the high selectivity and roles of ABC transporter binding proteins in establishing competitive growth on preferred oligosaccharides are discussed. Distinct ABC transporters are conserved across several bifidobacterial species, e.g. those targeting arabinoxylooligosaccharide and α-1,6-galactosides/glucosides. Less prevalent transporters, e.g. targeting β-mannooligosaccharides, may contribute to the metabolic specialisation within Bifidobacterium. Some bifidobacterial species have established symbiotic relationships with humans. Structural studies of carbohydrate-utilizing systems in Bifidobacterium have revealed the interesting history of molecular coevolution with the host, as highlighted by the early selection of bifidobacteria by mucin and breast milk glycans.

Size matters: TLR4-mediated effects of α-(1,5)-linear arabino-oligosaccharides in macrophage-like cells depend on their degree of polymerization

Linear arabino-oligosaccharides (LAOS) produced from controlled enzymatic hydrolysis of arabinans from sugar beet are well-known because of their chain-length dependent prebiotic effects. However, it is not clear if these α-(1,5)-linked arabinose oligosaccharides can interact directly with immune system cells, as well as if its degree of polymerization (DP) influences possible biological effects. Four high purity LAOS with distinct DP were tested in macrophage-like cells exposed or not to LPS. Results shown that LAOS interact with Toll-like receptor (TLR) 4 in a chain length-dependent manner. LAOS with higher DP induce stimulatory effects mainly through the TLR4/MyD88 pathway, thereby enhancing the release of tumor necrosis factor alpha (TNF-α), interleukin (IL-) 1β, 6, 12, and chemokines including MCP-1, RANTES, IL-8, and IP-10. Notably, LAOS with lower DP appears to have an opposite effect to those counterparts with higher DP, as they does not induce the secretion of cytokines and chemokines in macrophages-like cells, while also inhibit TLR4-mediated effects induced by both lipopolysaccharide and LAOS with higher DP. These findings provide not only insights into potential biological effects of LAOS, but also reveal that controlled enzymatic hydrolysis of sugar beet arabinans may lead to dietary oligosaccharides with desired biological properties.

Effects of dietary chitosan oligosaccharides on oxidative stress and inflammation response in liver and spleen of yellow-feather broilers exposed to high ambient temperature

Heat stress jeopardised animal health by inducing oxidative stress and inflammation. This study was done to investigate the effects of chitosan oligosaccharides (COS) on oxidative stress and inflammation response in liver and spleen of yellow-feather broilers under high ambient temperature. A total of 144 35-day-old female Chinese indigenous yellow-feather broilers (body weight 450.21 ± 10.05 g) were randomly allocated into 3 dietary treatments with 6 replication pens, each pen had 8 broilers. The treatments were: Control, basal diet; COS100, basal diet with 100 mg/kg COS; COS200, basal diet with 200 mg/kg COS. During day 22 to 42 (57 to 77 days of age), broilers in the COS200 group had higher (p < .05) ADFI than broilers in the Control group. Broilers in the COS200 group had lower (p < .05) serum alanine aminotransferase, aspartate aminotransferase, and tumour necrosis factor-α levels, and spleen malondialdehyde (MDA) content, but had higher (p < .05) liver superoxide dismutase activity and serum interleukin-10 level than broilers in the Control group. Broilers in the COS100 and COS200 groups had lower (p < .05) serum and liver MDA content, and serum interleukin-1β level, but had higher (p < .05) serum glutathione peroxidase activity than broilers in the Control group. In conclusion, dietary COS supplementation can alleviate heat stress-induced oxidative stress and inflammation response in liver and spleen by decreasing lipid peroxidation, increasing anti-oxidant enzyme activities and IL-10 level. HIGHLIGHTS Dietary COS decreased serum ALT, AST, IL-1β, TNF-α and MDA. Dietary COS increased serum GSH-Px and IL-10, liver SOD, and spleen GSH-Px.

Dietary Oligofructose Alone or in Combination with 2'-Fucosyllactose Differentially Improves Recognition Memory and Hippocampal mRNA Expression.

Mounting evidence suggests that dietary oligosaccharides promote brain development. This study assessed the capacity of oligofructose (OF) alone or in combination with 2′-fucosyllactose (2′-FL) to alter recognition memory, structural brain development, and hippocampal gene expression. Beginning on postnatal day (PND) 2, male pigs received one of three milk replacers formulated to contain OF, OF + 2′-FL, or no oligosaccharides (CON). Pigs were tested on the novel object recognition task using delays of 1 or 48 h at PND 22. At PND 32–33, magnetic resonance imaging (MRI) procedures were used to assess structural brain development and hippocampal tissue was collected for analysis of mRNA expression. Pigs that consumed the OF diet demonstrated increased recognition memory after a 1 h delay, whereas those consuming diets containing OF + 2′-FL displayed increased recognition memory after a 48 h delay. Pigs fed OF or OF + 2′-FL exhibited a larger relative volume of the olfactory bulbs compared with CON pigs. Provision of OF or OF + 2′-FL altered gene expression related to dopaminergic, GABAergic, cholinergic, cell adhesion, and chromatin remodeling processes. Collectively, these data indicate that dietary OF and OF + 2′-FL differentially improve cognitive performance and affect olfactory bulb structural development and hippocampal gene expression.

RETRACTED: Dietary oligosaccharides attenuate DSS-induced colitis in mice, induce PGlyRP3 expression, and inhibit NF-κB and MEK/ERK signaling

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editors. The Editors of Cellular Immunology have been informed by Elsevier that the article had been submitted to another journal while under consideration at "Cellular Immunology", which is a case of double submission. Based on the above infringement and its deleterious impact on the mutual trust necessary for the evaluation of scientific work - the corresponding authors had stated that the article was not submitted to another journal - it was decided to retract this article.