Oligomannan Prebiotic Attenuates Immunological, Clinical and Behavioral Symptoms in Mouse Model of Inflammatory Bowel Disease

Effects of oligosaccharides on performance, intestinal morphology, microbiota and immune reactions in laying hens challenged with dextran sodium sulfate

The aim of this study was to determine the effect of oligosaccharide extract from bamboo shoot (BOS) on the performance, intestinal morphology, microbiota and immune reaction of laying hens challenged with dextran sodium sulfate (DSS). Thirty-two White Leghorn hens (480 days old) were divided into 4 groups (8 hens each) with similar mean body weights: C (basal diet), D (basal diet + DSS), B (5 g/kg BOS diet), and BD (5 g/kg BOS diet + DSS). They were administered a single oral dose of 4 mL of distilled water/kg body weight with or without 0.45 g of DSS for 7 consecutive days from the 14th d to the 21st d of the experiment. The important findings were that (1) The egg yolk ratio was decreased by DSS treatment, but it was improved by BOS treatment, which also increased the egg shell ratio. (2) The diversity of intestinal microbiota and relative abundance of 4 bacteria genera were increased by BOS treatment. (3) Intestinal morphology was not affected by DSS and BOS, but the leukocytes accumulation in the liver was increased by DSS treatment and suppressed by BOS treatment. (4) Dietary BOS treatment influenced the mRNA expression of Th-1 and Treg cytokines in the liver and Th-17 cytokines in both intestine and liver of laying hens. These results suggest that BOS may enhance egg quality, Th-1 and Th-17 immune function without causing tissue damage under normal condition, and may suppress the excessive inflammatory responses during inflammation.

Updating the Classification of Chronic Inflammatory Enteropathies in Dogs

Chronic inflammatory enteropathies (CIEs) in dogs are currently classified based on response to sequential treatment trials into food-responsive (FREs); antibiotic-responsive (AREs); immunosuppressant-responsive (IREs); and non-responsive enteropathies (NREs). Recent studies have reported that a proportion of NRE dogs ultimately respond to further dietary trials and are subsequently misclassified. The FRE subset among CIEs is therefore probably underestimated. Moreover, alterations in the gut microbiota composition and function (dysbiosis) have been shown to be involved in CIE pathogenesis in recent research on dogs. Metronidazole and other antibiotics that have been used for decades for dogs with AREs have been demonstrated to result in increased antimicrobial resistance and deleterious effects on the gut microbiota. As a consequence, the clinical approach to CIEs has evolved in recent years toward the gradual abandonment of the use of antibiotics and their replacement by other treatments with the aim of restoring a diverse and functional gut microbiota. We propose here to refine the classification of canine CIEs by replacing the AREs category with a microbiota-related modulation-responsive enteropathies (MrMREs) category.

Supplementing maternal diet with milk oligosaccharides and probiotics helps develop the immune system and intestinal flora of offsprings

Intestinal flora is very important for improving the development of the immune system in newborns. Maternal diet during pregnancy and lactation is one of the key factors affecting the growth and development of offspring. The objective of the present study was to examine whether supplementation of maternal diet with milk oligosaccharides and Bifidobacterium could influence the development of the intestinal flora and immune system of neonatal mice. In total, 30 pregnant Institute of Cancer Research (ICR) mice were randomly divided into six groups: a control group (basal diet) and five intervention groups (basal diet supplemented with different doses of 2'-fucosyllactose [2'-FL] and Bifidobacterium Bb12) during the pregnancy period. All female mice were monitored for physical health during gavage. After delivery, the number of mice in each litter, any deformity, and the development of the offspring were recorded. The spleen, blood, and fecal samples of six groups of 10-12 day-old offspring were collected. The results demonstrated that maternal milk oligosaccharides and probiotics conferred protective effects against lipopolysaccharide (LPS)-induced immunosuppression in mice offspring by significantly enhancing the immune organ indexes, splenocyte proliferation, immunoglobulin (immunoglobulin G, A, M) production as well as improving the macrophage phagocytosis (p < .05). The abundance of Lactobacilli and Bifidobacteria in the feces of offspring mice in the intervention groups was significantly higher than that of the offspring mice in the control group (p < .05). These findings suggest that the combination of 2'-FL and Bifidobacterium Bb12 displayed synergistic interactions between the two components that could promote the development of the immune system of the offsprings and improve their microbiota through maternal ingestion.

Reduction in mucosa thickness is associated with changes in immune function in the colon mucosa during the weaning transition in Holstein bull dairy calves

This study aims to characterize changes in the structure and the molecules related to immune function in the colon mucosa in dairy calves during the weaning transition (weaned at week 6 of age). Colon mucosa thickness, measured at week 5 to 8 and 12 of age, decreased for 2 weeks after weaning, but then recovered. Colon mucosa's transcriptome profiling at week 5, 7, and 12 of age was obtained using RNA-sequencing. Functional analysis showed that pathways related to immune function were up-regulated postweaning. A weighted gene co-expression network analysis identified 17 immune function related genes, expressed higher postweaning, which were negatively correlated with colon mucosa thickness, suggesting that these genes may be involved in colon mucosa inflammation and recovery from mucosa thickness decrement during the weaning transition. As such, it is important to determine the function of immune cells in the colon mucosa during the weaning transition in dairy calves.

Red osier dogwood extract versus Trimethoprim-sulfadiazine (Part 1). Effects on the growth performance, blood parameters, gut histomorphometry, and Salmonella excretion of broiler chickens orally challenged with Salmonella Enteritidis

The poultry industry has not been spared from the prevalent incidence of diseases caused by invasive pathogens, especially Salmonella. Due to the pressing need to identify a suitable antibiotic alternative for use in poultry production, this study investigated the efficacy of red osier dogwood (ROD) extract on the growth, blood parameters, gut morphology, and Salmonella excretion in broiler chickens orally challenged with Salmonella Enteritidis (SE). A 4 × 2 factorial experiment was conducted based on 2 main factors, namely dietary treatments, and SE challenge. A total of 404, one-day-old male Ross broiler chicks were randomly assigned to 4 dietary treatments; 1) Negative control (NC), 2) NC + 0.075 ppm of Trimethoprim-sulfadiazine (TMP/SDZ)/kg of diet, 3) NC + 0.3% ROD extract, and 4) NC + 0.5% ROD extract. The absence of SE in the fecal samples obtained from chick delivery boxes was confirmed on d 0. On d 1, half of the birds were orally gavaged with 0.5 mL of phosphate-buffered saline each (noninfected group) and the remaining with 0.5 mL of 3.1 × 105 CFU/mL SE (infected group) in all treatment groups. Dietary treatments were randomly assigned to 8 replicate cages at 6 birds/cage. On 1-, 5-, 12-, and 18-day postinfection (DPI), cloacal fecal samples were collected on the 6 birds/cage to assess SE excretion. Average weight gain (AWG), average feed intake (AFI), feed conversion ratio (FCR), and mortality were determined weekly. On d 21, 10 chickens/treatment were euthanized to perform hematology, gut histomorphometry, serum immunoglobulins G and M (IgG and IgM), and superoxide dismutase measurements. Both ROD extract levels did not affect (P > 0.05) growth performance; however, the SE-infected birds showed increased (P < 0.05) AFI and FCR throughout the experimental period. Regardless of the SE-infection, both ROD extract levels improved (P < 0.05) duodenal villus height: crypt depth compared to other treatments. 0.5% ROD extract improved (P < 0.05) ileal villus width (VW) of noninfected birds and ileal crypt depth of infected birds, but it decreased (P < 0.05) the ileal VW of infected birds, compared to other treatments. The SE-infected birds showed lower (P < 0.05) lymphocytes (L) but increased (P < 0.05) heterophils (H), H:L, and monocytes (MON). Both ROD extract levels did not affect (P > 0.05) white blood cell differential, while dietary 0.3% ROD extract increased (P < 0.05) MON of the birds, regardless of infection model. Regardless of infection model, both TMP/SDZ and 0.5% ROD extract reduced the concentration of IgM in the serum, compared to the control and 0.3% ROD (P = 0.006). Conclusively, both ROD extract levels improved duodenal histomorphology and body defense against SE infection in broiler chickens; however, the 0.3% ROD extract was better.

Casein Reactivates Dopaminergic Nerve Injury and Intestinal Inflammation with Disturbing Intestinal Microflora and Fecal Metabolites in a Convalescent Parkinson's Disease Mouse Model

Parkinson's disease (PD) is the fastest-growing neurodegenerative disease, with pathogenic causes elusive and short of effective treatment options. Investigations have found that dairy products positively correlate with the onset of PD, but the mechanisms remain unexplored. As casein is an antigenic component in dairy products, this study assessed if casein could exacerbate PD-related symptoms by stimulating intestinal inflammation and unbalanced intestinal flora and be a risk factor for PD. Using a convalescent PD mouse model induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), the results showed casein reduced motor coordination, caused gastrointestinal dysfunction, reduced dopamine content, and induced intestinal inflammation. Meanwhile, casein disturbed gut microbiota homeostasis by increasing the Firmicutes/Bacteroidetes ratio, decreasing α-diversity, and caused abnormal alterations in fecal metabolites. However, these adverse effects of casein attenuated much when it had hydrolyzed by acid or when antibiotics inhibited the intestinal microbiota of the mice. Therefore, our results suggested that casein could reactivate dopaminergic nerve injury and intestinal inflammation and exacerbate intestinal flora disorder and its metabolites in convalescent PD mice. These damaging effects might be related to disordered protein digestion and gut microbiota in these mice. These findings will provide new insights into the impact of milk/dairy products on PD progression and supply information on dietary options for PD patients.

Nondigestible Functional Oligosaccharides: Enzymatic Production and Food Applications for Intestinal Health

Nondigestible functional oligosaccharides are of particular interest in recent years because of their unique prebiotic activities, technological characteristics, and physiological effects. Among different types of strategies for the production of nondigestible functional oligosaccharides, enzymatic methods are preferred owing to the predictability and controllability of the structure and composition of the reaction products. Nondigestible functional oligosaccharides have been proved to show excellent prebiotic effects as well as other benefits to intestinal health. They have exhibited great application potential as functional food ingredients for various food products with improved quality and physicochemical characteristics. This article reviews the research progress on the enzymatic production of several typical nondigestible functional oligosaccharides in the food industry, including galacto-oligosaccharides, xylo-oligosaccharides, manno-oligosaccharides, chito-oligosaccharides, and human milk oligosaccharides. Moreover, their physicochemical properties and prebiotic activities are discussed as well as their contributions to intestinal health and applications in foods.

Heterologous Expression, Purification and Characterization of an Alkalic Thermophilic β-Mannanase CcMan5C from Coprinopsis cinerea

A endo-1,4-β-mannanase (CcMan5C) gene was cloned from Coprinopsis cinerea and heterologously expressed in Pichia pastoris, and the recombinant enzyme was purified by Ni-affinity chromatography and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF-MS). CcMan5C hydrolyzed only locust bean gum galactomannan (LBG) but not α-mannan from S. cerevisiae or Avicel cellulose, oat spelt xylan, or laminarin from Laminaria digitata. CcMan5C exhibited distinctive catalytic features that were different from previously reported β-mannanases. (1) CcMan5C is the first reported fungal β-mannase with an optimal alkalic pH of 8.0-9.0 for hydrolytic activity under assay conditions. (2) CcMan5C is the first reported alkalic fungal β-mannase with an optimal temperature of 70 °C for hydrolytic activity under assay conditions. (3) The organic solvents methanol, ethanol, isopropanol, and acetone at concentrations of 10% or 20% did not inhibit CcMan5C activity, while 10% or 20% isopropanol and acetone even enhanced CcMan5C activity by 9.20-34.98%. Furthermore, CcMan5C tolerated detergents such as Tween 20 and Triton X-100, and its activity was even enhanced to 26.2-45.6% by 1% or 10% Tween 20 and Triton X-100. (4) CcMan5C solution or lyophilized CcMan5C exhibited unchanged activity and even increasing activity after being stored at -20 °C or -80 °C for 12 months and retained above 50% activity after being stored at 4 °C for 12 months. These features make CcMan5C a suitable candidate for the detergent industry and paper and pulp industry.

Inflammatory CSF profiles and longitudinal development of cognitive decline in sporadic and GBA-associated PD

Inflammation modifies the incidence and progression of Parkinson's disease (PD). By using 30 inflammatory markers in CSF in 498 people with PD and 67 people with dementia with Lewy bodies (DLB) we show that: (1) levels of ICAM-1, Interleukin-8, MCP-1, MIP-1 beta, SCF and VEGF were associated with clinical scores and neurodegenerative CSF biomarkers (Aβ1-42, t-Tau, p181-Tau, NFL and α-synuclein). (2) PD patients with GBA mutations show similar levels of inflammatory markers compared to PD patients without GBA mutations, even when stratified by mutation severity. (3) PD patients who longitudinally developed cognitive impairment during the study had higher levels of TNF-alpha at baseline compared to patients without the development of cognitive impairment. (4) Higher levels of VEGF and MIP-1 beta were associated with a longer duration until the development of cognitive impairment. We conclude that the majority of inflammatory markers is limited in robustly predicting longitudinal trajectories of developing cognitive impairment.

The synbiotic mixture of Bacillus licheniformis and Saccharomyces cerevisiae extract aggravates dextran sulfate sodium induced colitis in rats

BACKGROUND

Uncertain effects of probiotics and/or prebiotics have been reported in experimental and clinical colitis. This study aims to examine the effects of a synbiotic combination comprising Bacillus licheniformis DSM 17236 and Saccharomyces cerevisiae cell wall extract on dextran sulfate sodium (DSS)-induced colitis in Sprague Dawley rats.

METHODS

Acute colitis was induced in rats by oral administration of DSS 3.5% for 7 days. Fifty rats were divided equally into five groups; one control group and the other groups were induced with colitis and treated with or without the tested synbiotic, mixed with diet, for 28 days and sulfasalazine (100 mg/kg) via intragastric tube once daily for 14 days.

RESULTS

Symptomatically, the synbiotic administration raised the disease activity index (DAI) to comparable scores of the DSS group, specially from the 2nd to 7th days post DSS intoxication. It also induced a significant (p < 0.05) amplification of WBCs, myeloperoxidase (MPO), malondialdehyde (MDA), nuclear factor kappa B (NF-kB) expression and proinflammatory cytokines tumor necrosis factor alpha (TNFα), interferon gamma (INFγ), and interleukin-1 beta (IL-1β) while depressed the antioxidant enzymes glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) when compared with the DSS and control groups. The DSS intoxicated and Synbiotic+DSS groups showed desquamations of the covering epithelium, noticeable diffuse leukocytic infiltrations, sever catarrhal enteritis, ischemic colitis with diffuse coagulative necrosis of the entire colonic mucosa. Contrarily, sulfasalazine proved to be effective in the reduction of the tested inflammatory markers and the pathological degenerative changes of the DSS ulcerative colitis.

CONCLUSION

The examined synbiotic did not ameliorate but aggravated the DSS-induced colitis, so it should be subjected to intensive experimental and clinical testing before their use in animals and human.

Effects of combined prebiotic, probiotic, IgG and amino acid supplementation on the gut microbiome of patients with inflammatory bowel disease

Background: The effects of the Total Gut Restoration (TGR) system supplementation on the gut microbiome were evaluated. Materials & methods: A mucosal in vitro simulation of the human gastrointestinal tract (M-SHIME®) system was inoculated with fecal samples from patients with inflammatory bowel disease. Chambers were supplemented for 5 days with the TGR system (five probiotic Bacillus strains, prebiotic mixture, immunoglobulin concentrate, amino acids and prebiotic flavonoids). Results: Compared with unsupplemented controls, supplementation was associated with a significant increase in short-chain fatty acid production, and changes to the microbiome were observed. Supernatants from supplemented chambers improved intestinal barrier function, increased IL-6 and IL-10 production and decreased MCP1 production versus control in Caco-2/THP1 coculture. Conclusion: Daily TGR supplementation facilitated changes to the gut microbiome of patients with inflammatory bowel disease.

The Role of the Human Gut Microbiome in Inflammatory Bowel Disease and Radiation Enteropathy

The human gut microbiome plays a key role in regulating host physiology. In a stable state, both the microbiota and the gut work synergistically. The overall homeostasis of the intestinal flora can be affected by multiple factors, including disease states and the treatments given for those diseases. In this review, we examine the relatively well-characterised abnormalities that develop in the microbiome in idiopathic inflammatory bowel disease, and compare and contrast them to those that are found in radiation enteropathy. We discuss how these changes may exert their effects at a molecular level, and the possible role of manipulating the microbiome through the use of a variety of therapies to reduce the severity of the underlying condition.

Manno-oligosaccharides from cassia seed gum ameliorate inflammation and improve glucose metabolism in diabetic rats

Functional oligosaccharides show anti-diabetic effects through inflammation regulation with improved glucose metabolism. In this study, novel prebiotics of manno-oligosaccharides from cassia seed gum (CMOS) were incorporated into the diet of streptozotocin (STZ) plus high-fat and high-sugar diet (HFSD)-induced rats. After feeding for 8 weeks, CMOS (300-1200 mg per kg b.w. per d) significantly ameliorated the fasting blood glucose level (7.1-8.2 mmol L^-1) as compared with that of the model group (14.2 mmol L^-1), where the area under the oral glucose tolerance test curve was decreased by 20.0%-24.5%. Meanwhile, CMOS prevented STZ plus HFSD-induced damage to islet tissue with a clear and integrated morphology and reduced the glucagon/insulin area ratio (by 97.9% for 300 mg per kg b.w. per d CMOS). CMOS also reduced metabolic endotoxemia and maintained intestinal integrity with recovered mRNA expression of Zo-1 and occludin to the normal comparable level. Upon 16S rDNA sequencing, it was found that CMOS regulated the microbiota composition in the cecum with an increased relative abundance of Bifidobacteria, while that of Shigella was decreased. The molecular mechanisms involved in the anti-diabetic effects of CMOS were further studied. CMOS reduced the mRNA expression of Tlr2 and Tlr4 in the intestines of STZ plus HFSD-induced rats. Meanwhile, Nlrp3 associated inflammasome activation in the intestine and liver with glucose metabolism disorder was inhibited by CMOS, resulting in reduced interleukin-1β secretion (by 38.8-46.4% for CMOS of 300-1200 mg per kg b.w. per d) and inflammation. Furthermore, CMOS regulated the AKT/IRS/AMPK signaling pathway and improved glucose metabolism in the liver. Findings obtained here implicated that CMOS could modulate metabolic-inflammation as a functional dietary supplement.

Shugan Hewei Decoction Alleviates Cecum Mucosal Injury and Improves Depressive- and Anxiety-Like Behaviors in Chronic Stress Model Rats by Regulating Cecal Microbiota and Inhibiting NLRP3 Inflammasome

Chronic stress is a significant cause of depression, anxiety, and intestinal mucosal injury. Gut microbiota disturbances are also associated with these disorders. Shugan Hewei Decoction (SHD), which is a traditional Chinese medicine formula developed by our team, has shown superior therapeutic effects in the treatment of depression, anxiety, and functional gastrointestinal diseases caused by chronic stress. In this study, we investigated the modulatory effect of SHD on the cecal microbiota and cecum mucosal NOD-like receptor protein 3 (NLRP3) inflammasome in a chronic unpredictable stress (CUS)/social isolation rat model. After the SHD intervention, the CUS model rats showed improvements in their depressive- and anxiety-like behaviors, as well as sustained body weight growth and improved fecal characteristics. SHD improved the cecal microbiota diversity and changed the abundance of six microbial genera. A Spearman's correlation analysis showed a strong correlation between the NLRP3 inflammasome and CUS-perturbed cecal biomarker microbiota. SHD regulated the excessive expression of NLRP3, ASC, caspase-1, interleukin-1β (IL-1β), and IL-18 in the serum and cecum mucosa induced by CUS, as well as the activation of the Toll-like receptor 4/nuclear factor-κB signaling cascades. Our results reveal the pharmacological mechanisms of SHD and provide a validated therapeutic method for the treatment of depression, anxiety, and cecum mucosal injury.

Association of Heterophil/Lymphocyte Ratio with Intestinal Barrier Function and Immune Response to Salmonella enteritidis Infection in Chicken

Simple Summary

Salmonella represents a serious threat to the poultry industry and human health. The heterophil/lymphocyte (H/L) ratio indicates the robustness and immune system status of the chicken. Thus, the H/L ratio has been used for the selection of chickens that are resistant to Salmonella. However, the mechanisms conferring the resistance ability to the chickens with a low H/L ratio compared to those with a high H/L ratio remain unclear. Therefore, the present study aimed to investigate the association of the H/L ratio with the intestinal barrier function and immune response to Salmonella enteritidis infection in chicken. First, we enumerated the number of goblet cells in the ileum and caecum, measured the ileal villi morphology, and the expression of immune genes in the ileum and caecum of non-infected and SE-infected chickens at 7- and 21-days post-infection. Then, we assessed the correlation with the H/L ratio. The H/L ratio was negatively correlated to the number of goblet cells, IL-1β, IL-8, and IFN-γ ileal expressions, indicating that the individuals with a low H/L ratio displayed enhanced intestinal barrier and immunity. These results suggest that the H/L ratio is associated with intestinal immunity and could be a potential resistance indicator in chickens.

Abstract

The heterophil/lymphocyte (H/L) ratio has been extensively studied to select poultry that are resistant to environmental stressors. Chickens with a low H/L ratio are superior to the chickens with a high H/L ratio in survival, immune response, and resistance to Salmonella infection. However, this disease resistance ability is likely to be associated with enhanced intestinal immunity. Therefore, to expand our understanding of these underlying resistance mechanisms, it is crucial to investigate the correlation between the H/L ratio as a blood immune indicator in live chickens and the intestinal barrier function and immunity. Jinxing yellow chickens H/L line one-day-old were divided into non-infected (NI) and Salmonella enteritidis infected (SI) at 7-days old. After dividing the birds into NI and SI, blood samples were taken for H/L ratios determination, and subsequently, birds from the SI group were infected with Salmonella enteritidis (SE). We assessed the effects of SE infection on the (i) goblet cells number from the ileum and caecum gut-segments, (ii) ileal mucosa morphology, and (iii) immune gene mRNA expressions from the ileum and caecum of NI and SI chickens at 7 and 21 days-post-infection (dpi). We found that the H/L ratio was negatively correlated with most intestinal immune indices, particularly with the goblet cells number and with IL-1β, IL-8, and IFN-γ ileal expressions. In conclusion, these results suggest that the H/L ratio is associated with the intestinal barrier and immune response for SE clearance and that the chickens with a low H/L ratio displayed enhanced intestinal immunity. This study expands the current knowledge that is related to using the H/L ratio to select and breed resistant broiler chickens.

Metabolite and transcriptome analyses revealed the modulation of fructo-oligosaccharide on ileum metabolism of Taiping chickens

AIM

The metabolic markers and differentially expressed genes (DEGs) related to fructo-oligosaccharide (FOS) were screened, and the response of FOS to the ileum metabolic pathway of Taiping chickens was analysed.

METHODS AND RESULTS

Prebiotic are widely used in agricultural breeding for care and maintenance of animal health, especially FOS. Metabonomics evaluation of ileum of Taiping chicken ultra-performance liquid chromatography-quadruple time of-flight high-sensitivity mass spectrometry showed that 93 differentially altered metabolites were identified and divided into eight categories, of which organic acids and derivatives was the most important one. Transcriptomic analysis showed that DEGs were mainly enriched in drug metabolism-cytochrome p450, metabolism of xenobiotics by cytochrome p450, retinol metabolism and fat digestion and absorption. Integrated analysis of metabolite profiles and gene expression revealed that the significantly up-regulated GSTT1 was significantly correlated with most of the different lipid metabolites, suggesting that GSTT1 may play an important role in FOS regulation of lipid metabolism.

CONCLUSIONS

The results of this study suggest that supplementation of FOS can have a positive effect on gut metabolites, which may contribute to the overall health with indigenous chickens.

SIGNIFICANCE AND IMPACT OF THE STUDY

Insight into the responses of intestinal prebiotics of Taiping chicken is helpful to understand the role of prebiotics in maintaining intestinal microflora balance and improving immune response and productivity of poultry from the molecular and metabolic levels.

Konjac Glucomannan Oligosaccharides Prevent Intestinal Inflammation Through SIGNR1-Mediated Regulation of Alternatively Activated Macrophages

SCOPE

Konjac glucomannan oligosaccharides (KMOS) are prebiotics and may improve intestinal immunity through modulation of macrophage function. However, the underlying molecular mechanisms were unclear.

METHODS AND RESULTS

Using a mouse model of dextran sulfated sodium (DSS)-induced acute colitis, the study demonstrates here that KMOS (400 mg^-1 kg^-1 d^-1 ) can ameliorate intestinal inflammation in a macrophage dependent manner. Oral exposure to KMOS prevents DSS-induced intestinal pathology, improves epithelial integrity, and decreases accumulation of colonic inflammatory leukocytes and cytokines. The therapeutic effects of KMOS are dependent on the function of macrophages, as depletion of macrophages abolished the effects. In colonic lamina propria of DSS-treated mice, as well as in vitro culture of bone marrow derived macrophages (BMDMs), KMOS skews reprogramming of classically activated macrophages (CAM/M1) into alternatively activated macrophages (AAM/M2). The study further determines that the activation of SIGNR1/phospho-c-Raf (S338)/phospho-p65 (S276)/acetyl-p65 (K310) pathway is responsible for KMOS-induced AAM/M2 polarization. Blockage of SIGNR1 abolishes KMOS-induced AAM/M2 polarization of activated macrophages, expression of phospho-p65 (S276) in colonic macrophages, and alleviation of DSS-induced colitis in mice, suggesting that SIGNR1 is critical for macrophage responses to KMOS.

CONCLUSIONS

This study reveals a SIGNR1-mediated macrophage-dependent pathway that supports regulatory function of KMOS in host immunity and intestinal homeostasis.

Hemicellulose-Derived Oligosaccharides: Emerging Prebiotics in Disease Alleviation

The gut microbiota in the human body is an important component that plays a pivotal role in the ability of the host to prevent diseases and recover from these diseases. If the human microbiome changes for any reason, it affects the overall functioning of the host. Healthy and vigorous gut microbiota require dietary fiber supplementation. Recently, oligosaccharides have been found to play a significant role in the modulation of microbiota. Several such oligosaccharides, i.e., xylooligosaccharides (XOS), mannooligosaccharides (MOS), and arabino-xylooligosaccharides (AXOS), are derived from hemicellulosic macromolecules such as xylan, mannan, and arabino-xylan, respectively. These oligosaccharides serve as substrates for the probiotic production of health-promoting substances (short-chain fatty acids, branched chain amino acids etc.), which confer a variety of health benefits, including the prevention of some dreaded diseases. Among hemicellulose-derived oligosaccharides (HDOs), XOS have been largely explored, whereas, studies on MOS and AXOS are currently underway. HDOs, upon ingestion, help reduce morbidities by lowering populations of harmful or pathogenic bacteria. The ATP-binding cassette (ABC) transporters are mainly utilized for the uptake of oligosaccharides in probiotics. Butyrate generated by the selective fermentation of oligosaccharides, along with other short-chain fatty acids, reduces gut inflammation. Overall, oligosaccharides derived from hemicelluloses show a similar potential as conventional prebiotics and can be supplemented as functional foods. This review summarizes the role of HDOs in the alleviation of autoimmune diseases (inflammatory bowel disease, Crohn's disease), diabetes, urinary tract infection, cardiovascular diseases, and antimicrobial resistance (AMR) through the modulation of the gut microbiota. The mechanism of oligosaccharide utilization and disease mitigation is also explained.

Evidence of a Myenteric Plexus Barrier and Its Macrophage-Dependent Degradation During Murine Colitis: Implications in Enteric Neuroinflammation

BACKGROUND & AIMS

Neuroinflammation in the gut is associated with many gastrointestinal (GI) diseases, including inflammatory bowel disease. In the brain, neuroinflammatory conditions are associated with blood-brain barrier (BBB) disruption and subsequent neuronal injury. We sought to determine whether the enteric nervous system is similarly protected by a physical barrier and whether that barrier is disrupted in colitis.

METHODS

Confocal and electron microscopy were used to characterize myenteric plexus structure, and FITC-dextran assays were used to assess for presence of a barrier. Colitis was induced with dextran sulfate sodium, with co-administration of liposome-encapsulated clodronate to deplete macrophages.

RESULTS

We identified a blood-myenteric barrier (BMB) consisting of extracellular matrix proteins (agrin and collagen-4) and glial end-feet, reminiscent of the BBB, surrounded by a collagen-rich periganglionic space. The BMB is impermeable to the passive movement of 4 kDa FITC-dextran particles. A population of macrophages is present within enteric ganglia (intraganglionic macrophages [IGMs]) and exhibits a distinct morphology from muscularis macrophages, with extensive cytoplasmic vacuolization and mitochondrial swelling but without signs of apoptosis. IGMs can penetrate the BMB in physiological conditions and establish direct contact with neurons and glia. Dextran sulfate sodium-induced colitis leads to BMB disruption, loss of its barrier integrity, and increased numbers of IGMs in a macrophage-dependent process.

CONCLUSIONS

In intestinal inflammation, macrophage-mediated degradation of the BMB disrupts its physiological barrier function, eliminates the separation of the intra- and extra-ganglionic compartments, and allows inflammatory stimuli to access the myenteric plexus. This suggests a potential mechanism for the onset of neuroinflammation in colitis and other GI pathologies with acquired enteric neuronal dysfunction.

Mannan oligosaccharide attenuates cognitive and behavioral disorders in the 5xFAD Alzheimer's disease mouse model via regulating the gut microbiota-brain axis

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by cognitive deficits and psychiatric symptoms. The gut microbiota-brain axis plays a pivotal role during AD development, which could target nutritional intervention. The prebiotic mannan oligosaccharide (MOS) has been reported to reshape the gut microbiome and enhanced the formation of the neuroprotective metabolites short-chain fatty acids (SCFAs). Here, we found that an 8-week treatment of MOS (0.12%, w/v in the drinking water) significantly improved cognitive function and spatial memory, accompanied by attenuated the anxiety- and obsessive-like behaviors in the 5xFAD transgenic AD mice model. MOS substantially reduced the Aβ accumulation in the cortex, hippocampus, and amygdala of the brain. Importantly, MOS treatment significantly balanced the brain redox status and suppressed the neuroinflammatory responses. Moreover, MOS also alleviated the HPA-axis disorders by decreasing the levels of hormones corticosterone (CORT) and corticotropin-releasing hormone (CRH) and upregulated the norepinephrine (NE) expressions. Notably, the gut barrier integrity damage and the LPS leak were prevented by the MOS treatment. MOS re-constructed the gut microbiota composition, including increasing the relative abundance of Lactobacillus and reducing the relative abundance of Helicobacter. MOS enhanced the butyrate formation and related microbes levels. The correlation analysis indicated that the reshaped gut microbiome and enhanced butyrate formation are highly associated with behavioral alteration and brain oxidative status. SCFAs supplementation experiment also attenuated the behavioral disorders and Aβ accumulation in the AD mice brain, accompanied by balanced HPA-axis and redox status. In conclusion, the present study indicated that MOS significantly attenuates the cognitive and mental deficits in the 5xFAD mice, which could be partly explained by the reshaped microbiome and enhanced SCFAs formation in the gut. MOS, as a prebiotics, can be translated into a novel microbiota-targeted approach for managing metabolic and neurodegenerative diseases.

Biological functions of NLRP3 inflammasome: A therapeutic target in inflammatory bowel disease

Cases of inflammatory bowel disease (IBD), a debilitating intestinal disorder with complex pathological mechanisms, have been increasing in recent years, straining the capacity of healthcare systems. Thus, novel therapeutic targets and innovative agents must be developed. Notably, the NLRP3 inflammasome is upregulated in patients with IBD and/or in animal experimental models. As an innate immune supramolecular assembly, the NLRP3 inflammasome is persistently activated during the pathogenesis of IBD by multiple stimuli. Moreover, this protein complex regulates pro-inflammatory cytokines. Thus, targeting this multiprotein oligomer may offer a feasible way to relieve IBD symptoms and improve clinical outcomes. The mechanisms by which the NLRP3 inflammasome is activated, its role in IBD pathogenesis, and the drugs administered to target this protein complex are reviewed herein. This review establishes that the use of inflammasome-targeting drugs are effective for IBD treatment. Moreover, this review suggests that the value and potential of naturally sourced or derived medicines for IBD treatment must be recognized and appreciated.

Periplaneta americana Oligosaccharides Exert Anti-Inflammatory Activity through Immunoregulation and Modulation of Gut Microbiota in Acute Colitis Mice Model

The incidence and prevalence of inflammatory bowel disorders (IBD) are increasing around the world due to bacterial infection, abnormal immune response, etc. The conventional medicines for IBD treatment possess serious side effects. Periplaneta americana (P. americana), a traditional Chinese medicine, has been used to treat arthritis, fever, aches, inflammation, and other diseases. This study aimed to evaluate the anti-inflammatory effects of oligosaccharides from P. Americana (OPA) and its possible mechanisms in vivo. OPA were purified and biochemical characterization was analyzed by HPGPC, HPLC, FT-IR, and GC–MS. Acute colitis mice model was established, the acute toxicity and anti-inflammatory activity were tested in vivo. The results showed OPA with molecular mass of 1.0 kDa were composed of 83% glucose, 6% galactose, 11% xylose, and the backbone was (1→4)-Glcp. OPA had potent antioxidant activities in vitro and significantly alleviated the clinical symptoms of colitis, relieved colon damage without toxic side effects in vivo. OPA exhibited anti-inflammatory activity by regulating Th1/Th2, reducing oxidative stress, preserving intestinal barrier integrity, and inhibiting TLR4/MAPK/NF-κB pathway. Moreover, OPA protected gut by increasing microbial diversity and beneficial bacteria, and reducing pathogenic bacteria in feces. OPA might be the candidate of complementary and alternative medicines of IBD with low-cost and high safety.

Response of the ileum transcriptome to fructo-oligosaccharides in Taiping chickens

The aim of this study was to investigate the effects of fructo-oligosaccharide (FOS) supplementation intake of Taiping chickens (Gallus gallus domesticus) and its stimulating effects on ileum. 120 healthy chickens were randomly divided into two groups; control group (CT) and fructo-oligosaccharides group (FOS). At the 60th day of age, ileum mucosa of three chickens per group were collected and performed transcriptome profiling of Taiping chicken ileum mucosa using the Hiseq™ 2500 sequencing platform. Compared with CT group, 50 genes were differentially expressed in the FOS group. Ten of the differently expressed genes were further validated by RT-qPCR. In addition, gene ontology and Kyoto encyclopedia of genes and genomes analyses revealed that these differentially expressed genes were mainly enriched to drug metabolism-cytochrome P450, metabolism of xenobiotics by cytochrome P450, retinol metabolism, fat digestion and absorption, herpes simplex infection and valine, leucine and isoleucine biosynthesis. The results of this study provided the help to our understanding application of fructo-oligosaccharides in indigenous chicken production and provide a theoretical basis for the genetic development of indigenous chickens.

Structure, preparation, modification, and bioactivities of β-glucan and mannan from yeast cell wall: A review

In order to solve the antibiotic resistance, the research on antibiotic substitutes has received an extensive attention. Many studies have shown that β-glucan and mannan from yeast cell wall have the potential to replace antibiotics for the prevention and treatment of animal diseases, thereby reducing the development and spread of antibiotic-resistant bacterial pathogens. β-Glucan and mannan had a variety of biological functions, including improving the intestinal environment, stimulating innate and acquired immunity, adsorbing mycotoxins, enhancing antioxidant capacity, and so on. The biological activities of β-glucan and mannan can be improved by chemically modifying its primary structure or reducing molecular weight. In this paper, the structure, preparation, modification, and biological activities of β-glucan and mannan were reviewed, which provided future perspectives of β-glucan and mannan.

Prebiotic mannooligosaccharides: Synthesis, characterization and bioactive properties

Functional oligosaccharides are non-digestible food ingredients that confer numerous health benefits. Among these, mannooligosaccharides (MOS) are emerging prebiotics that have characteristic potential bio-active properties. Microbial mannanases can be used to break down mannan rich agro-residues to yield MOS. Various applications of MOS as health promoting functional food ingredient may open up newer opportunities in food and feed industry. Enzymatic hydrolysis is the widely preferred method over chemical hydrolysis for MOS production. Presently, commercial MOS is being derived from yeast cell wall mannan and is widely used as prebiotic in feed supplements for poultry and aquaculture. Apart from stimulating the growth of probiotic microflora, MOS impart anticancer and immunomodulatory effects by inducing different gene markers in colon cells. This review summarizes recent developments and future prospects of enzymatic synthesis of MOS from various mannans, their structural characteristics and their potential health benefits.

Regulation of the intestinal microbiota: An emerging therapeutic strategy for inflammatory bowel disease

The rapid development of metagenomics, metabolomics, and metatranscriptomics provides novel insights into the intestinal microbiota factors linked to inflammatory bowel disease (IBD). Multiple microorganisms play a role in intestinal health; these include bacteria, fungi, and viruses that exist in a dynamic balance to maintain mucosal homeostasis. Perturbations in the intestinal microbiota disrupt mucosal homeostasis and are closely related to IBD in humans and colitis in mice. Therefore, preventing or correcting the imbalance of microbiota may serve as a novel prevention or treatment strategy for IBD. We review the most recent evidence for direct or indirect interventions targeting intestinal microbiota for treatment of IBD in order to overcome the current limitations of IBD therapies and shed light on personalized treatment options.

Review article: bugs, inflammation and mood-a microbiota-based approach to psychiatric symptoms in inflammatory bowel diseases

BACKGROUND

Psychiatric co-morbidities including depression and anxiety are common in inflammatory bowel diseases (IBD). Emerging evidence suggests that interactions between the gut microbiota and brain may play a role in the pathogenesis of psychiatric symptoms in IBD.

AIM

To review the literature on microbiota-brain-gut interactions in gut inflammation, psychosocial stress and mental disorders and to discuss the putative mediating role of gut microbiota in the development of psychiatric symptoms or co-morbidities in IBD.

METHODS

A literature search was conducted on Ovid and Pubmed to select relevant animal and human studies reporting an association between IBD, mental disorders and gut microbiota.

RESULTS

Gut microbial alterations are frequently reported in subjects with IBD and with mental disorders. Both have been associated with reduced faecal bacterial diversity, decreased taxa within the phylum Firmicutes and increased Gammaproteobacteria. In animal studies, microbial perturbations induce behavioural changes and modulate inflammation in mice. Anxiety- and depression-like behaviours in animals can be transferred via faecal microbiota. In humans, modulation of the gut microbiota with probiotics is associated with behavioural and mood changes. Recent data show correlations in changes of faecal and mucosal microbiota and psychological distress in patients with IBD independent of disease activity.

CONCLUSION

Both IBD and mental disorders are associated with gut microbial alterations. Preclinical and preliminary human studies have shown a mediating role of the gut microbiota in intestinal inflammation and anxiety, depression and stress. Targeting the gut microbiota may represent a useful therapeutic approach for the treatment of psychiatric co-morbidities in IBD.

Effects of inulin supplementation on intestinal barrier function and immunity in specific pathogen-free chickens with Salmonella infection

We investigated the effects of inulin on intestinal barrier function and mucosal immunity in Salmonella enterica serovar Enteritidis (SE)-infected specific pathogen-free (SPF) chickens. SPF chickens (n = 240, 1-d-old) were divided into 4 groups (6 replicates per group, 10 chickens per replicate): a control group (CON) fed a basal diet without inulin supplementation and 3 SE-infected groups fed a basal diet supplemented with inulin 0% (SE group), 0.5% (0.5% InSE group), and 1% (1% InSE group), respectively. At 28 d of age, the chickens in SE-infected groups were orally infected with SE and in CON group were administrated with phosphated-buffered saline (PBS). Intestinal morphology, mucosal immunity, and intestinal barrier function-related gene expression were analyzed at 1- and 3-d post-infection (dpi). SE challenge significantly increased the mucosal gene expression, such as interleukin-1β (IL-1β), lipopolysaccharide-induced tumor necrosis factor factor (LITAF), interferon-γ (IFN-γ), and interleukin-6 (IL-6), and increased serum IFN-γ, secretory IgA (sIgA), and IgG concentration, and significantly decreased the gene expression levels of mucin 2 (MUC2) and claudin-1 at 3 dpi compared with the CON group (P < 0.05). Inulin supplementation improved the expression levels of these immunity- and intestinal barrier function-related genes, increased villus height (VH), and decreased crypt depth (CD) in the duodenum, jejunum, and ileum at 1 and 3 dpi within the SE-challenged groups (P < 0.05). SE challenge significantly increased ileal Toll-like receptor 4 (TLR4) mRNA at 1 and 3 dpi, suppressor of cytokine signaling 3 (SOCS3) mRNA at 1 dpi, and phospho-signal transducer and activator of transcription 3 (p-STAT3) and Janus kinase1 (JAK1) protein expression at 3 dpi compared with the CON group (P < 0.05). Inulin supplementation suppressed p-STAT3 and JAK1 protein expression and promoted ileal TLR4 and SOCS3 mRNA expression at 3 dpi compared with SE group (P < 0.05). In conclusion, inulin alleviated SE-induced gut injury by decreasing the proinflammatory response and enhancing mucosal immunity in chickens.

Prebiotics: tools to manipulate the gut microbiome and metabolome

The human gut is an ecosystem comprising trillions of microbes interacting with the host. The composition of the microbiota and their interactions play roles in different biological processes and in the development of human diseases. Close relationships between dietary modifications, microbiota composition and health status have been established. This review focuses on prebiotics, or compounds which selectively encourage the growth of beneficial bacteria, their mechanisms of action and benefits to human hosts. We also review advances in synthesis technology for human milk oligosaccharides, part of one of the most well-characterized prebiotic–probiotic relationships. Current and future research in this area points to greater use of prebiotics as tools to manipulate the microbial and metabolic diversity of the gut for the benefit of human health.

Prebiotic, Immunomodulating, and Antifatigue Effects of Konjac Oligosaccharide

Irregular and long time work schedules not only makes people feel fatigue, but also brings great risks of diseases, due to gastrointestinal disorder and immune dysfunction. Therefore, it has positive significance to help challenged people stay energetic and healthy with food supplement. Konjac oligosaccharide has shown various physiological benefits and been recommended in the fortification of functional foods. However, there have been few reports on its application aimed to simultaneously relieve physical fatigue and keep body healthy. In this paper, the potential prebiotic, immunoregulatory, and antifatigue activities of konjac oligosaccharide were evaluated in vitro and in vivo. The results showed that konjac oligosaccharide could promote probiotics growth and short chain fatty acids production in mice cecum. At the concentration of 50 to 200 μg/mL, konjac oligosaccharide could activate murine macrophage RAW 264.7 to secret NO and cytokines of IL-10 and IL-6. Moreover, this oligosaccharide could alleviate physical fatigue by prolonging exhaustive time, improving the level of superoxide dismutases and glutathione peroxidase, increasing the content of blood glucose, and decreasing the content of blood urea nitrogen. The results suggested that konjac oligosaccharide had prebiotic, immunoregulatory, and antifatigue effects, providing its application potential in functional food aimed at people with irregular and long time work.

The effects of inulin on the mucosal morphology and immune status of specific pathogen-free chickens

This study investigated the effects of inulin on mucosal morphology and immune function of specific pathogen-free (SPF) chickens. A total of 200 one-day-old White Leghorns SPF chickens were divided into 5 groups of 4 replicates of 10 chickens each. All SPF chickens were fed a basal diet supplemented with 0, 0.25, 0.5, 1.0, or 2.0% inulin. The mucosal morphology and immune indexes were analyzed on days 7, 14, and 21, respectively. Our results showed that the concentrations of acetate and propionate in the cecum and serum had increased with dietary inulin supplementation on day 21 (P < 0.05). Butyrate could not be detected in the cecal digesta, but was increased in the serum of 1 and 2% groups, as compared with the control group (P < 0.05). The villi height was increased (P < 0.05) and the crypt depth was decreased (P < 0.05) in the duodenum and ileum of SPF chickens fed inulin, as compared with the control group. Also, inulin at a low concentration (0.25 or 0.5%) significantly decreased (P < 0.05) the gene expression of nuclear factor-κB (NF-κB), lipopolysaccharide-induced tumor necrosis factor (LITAF) at 7, 14, and 21 d, and of interleukin-6 (IL-6), and inducible nitric oxide synthase (iNOS) at 7 and 14 d, and increased that of mucin 2 (MUC2) and claudin-1 in the ileum of SPF chickens at 7, 14, and 21 d. High inulin supplementation (2%) significantly increased the gene expression of NF-κB, LITAF, IL-6, iNOS, and Claudin-1 at 14 and 21 d compared to low inulin concentration (0.25 or 0.5%). The results indicated that the effects of inulin on mucosal immune function occurred in a dose-dependent manner. A low concentration (0.25 or 0.5%) of inulin may be beneficial in promoting intestinal immune function.

Inflammasomes and intestinal inflammation

The inflammasome is a cytosolic multi-protein innate immune rheostat, sensing a variety of endogenous and environmental stimuli, and regulating homeostasis or damage control. In the gastrointestinal tract, inflammasomes orchestrate immune tolerance to microbial and potentially food-related signals or drive the initiation of inflammatory responses to invading pathogens. When inadequately regulated, intestinal inflammasome activation leads to a perpetuated inflammatory response leading to immune pathology and tissue damage. In this review, we present the main features of the predominant types of inflammasomes participating in intestinal homeostasis and inflammation. We then discuss current controversies and open questions related to their functions and implications in disease, highlighting how pathological inflammasome over-activation or impaired function impact gut homeostasis, the microbiome ecosystem, and the propensity to develop gut-associated diseases. Collectively, understanding of the molecular basis of intestinal inflammasome signaling may be translated into clinical manipulation of this fundamental pathway as a potential immune modulatory therapeutic intervention.

Uridine Ameliorates Dextran Sulfate Sodium (DSS)-Induced Colitis in Mice

Uridine, one of the four components that comprise RNA, has attracted attention as a novel therapeutic modulator of inflammation. However, very little is known about its effect on intestinal inflammation. The aim of the present study was to investigate the potential protective effect of intracolonic administered uridine against DSS induced colitis in male C57BL/6 mice. Intracolonic instillation of 3 doses of uridine 1 mg/Kg (lower dose), 5 mg/Kg (medium dose), and 10 mg/Kg (higher dose) in saline was performed daily. Uridine at medium and high dose significantly reduced the severity of colitis (DAI score) and alleviated the macroscopic and microscopic signs of the disease. The levels of proinflammatory cytokines IL-6, IL-1β and TNF in serum as well as mRNA expression in colon were significantly reduced in the uridine treated groups. Moreover, colon tissue myloperoxidase activities, protein expression of IL-6, TNF- α, COX-2, P-NFkB and P-Ikk-βα in the colon tissues were significantly reduced in medium and high dose groups. These findings demonstrated that local administration of uridine alleviated experimental colitis in male C57BL/6 mice accompanied by the inhibition of neutrophil infiltration and NF-κB signaling. Thus, Uridine may be a promising candidate for future use in the treatment of inflammatory bowel disease.

Impacts of canine distemper virus infection on the giant panda population from the perspective of gut microbiota

The recent increase in infectious disease outbreaks has been directly linked to the global loss of biodiversity and the decline of some endangered species populations. Between December 2014 and March 2015, five captive giant pandas died due to canine distemper virus (CDV) infection in China. CDV has taken a heavy toll on tigers and lions in recent years. Here, we describe the first gut microbiome diversity study of CDV-infected pandas. By investigating the influence of CDV infection on gut bacterial communities in infected and uninfected individuals and throughout the course of infection, we found that CDV infection distorted the gut microbiota composition by reducing the prevalence of the dominant genera, Escherichia and Clostridium, and increasing microbial diversity. Our results highlight that increases in intestinal inflammation and changes in the relative abundances of pathogen-containing gut communities occur when individuals become infected with CDV. These results may provide new insights into therapeutics that target the microbiota to attenuate the progression of CDV disease and to reduce the risk of gut-linked disease in individuals with CDV. In addition, our findings underscore the need for better information concerning the dynamics of infection and the damage caused by pathogens in panda populations.