Fructooligosaccharide supplementation alleviated the pathological immune response and prevented the impairment of intestinal barrier in DSS-induced acute colitis mice

Fructooligosaccharides slow colonic motility and activate myenteric neurons via calcium sensing and 5-HT3 receptors in the proximal colon

Calcium-sensing receptors (CaSR) regulate a variety of functions in the gastrointestinal tract. Recently, prebiotic-independent effects of fructooligosaccharides (FOS) on epithelial barrier function were found to be mediated by CaSR. Here, we tested the hypothesis that FOS acts via the CaSR to regulate colonic motility and neuronal activity in the enteric nervous system. Using immunohistochemistry, we determined that CaSR were localized on the colonic epithelium of the mouse proximal colon and that a small proportion of enterochromaffin cells coexpress CaSR. We demonstrated that intraluminal administration of FOS slows colonic motility in vivo in male and female mice, an effect that is mediated by both CaSR and 5-HT3 receptors. We assessed neuronal activity in response to luminally perfused FOS in intact segments of the proximal colon from male and female mice expressing a genetically encoded fluorescent calcium reporter in intrinsic primary afferent neurons (Calb1-GCaMP6 mice) or in all enteric neurons (Wnt1-GCaMP6 mice) using live cell confocal imaging. In both Calb1-GCaMP6 mice and Wnt1-GCaMP6 mice, intraluminal FOS perfusion induced a sustained elevation of intracellular Ca2+ in neurons of the myenteric plexus. This effect was sensitive to tetrodotoxin and mediated by CaSR and 5-HT3 receptors. Serosal application of FOS was without effect. Our results demonstrate that FOS acts acutely to slow colonic motility in vivo and activates the enteric nervous system via CaSR and 5-HT3 receptors.NEW & NOTEWORTHY Calcium-sensing receptors regulate a variety of functions in the gastrointestinal tract. Here, we demonstrate a novel action of fructooligosaccharides to regulate colonic motility in vivo and activate the enteric nervous system. These effects are mediated by calcium-sensing and 5-HT3 receptors.

Extracellular Vesicles From Lactobacillus fermentum Enhance Intestinal Barrier Integrity and Restore Gut Microbial Homeostasis in Experimental Murine Colitis

BACKGROUND

Lactobacillus fermentum has been shown to improve intestinal health and treat colitis; however, its precise efficacy and mechanisms in inflammatory bowel disease remain unclear.

OBJECTIVES

This study aimed to evaluate whether L fermentum and its metabolites, extracellular vesicles, and other components could modulate intestinal barrier function and gut microbiota to alleviate dextran sulfate sodium (DSS)-induced colitis in mice.

METHODS

Forty-eight mice were randomly assigned to 6 groups: control, DSS, L fermentum+DSS group (LF+DSS), heat-inactivated L fermentum+DSS group (LHF+DSS), L fermentum supernatant solution+DSS group (LSF+DSS), and L fermentum extracellular vesicles+DSS group (LEV+DSS). After a 1-wk acclimation, mice were gavaged daily for 3 wk. Fresh cultures, including live (LF+DSS), heat-inactivated (LHF+DSS), supernatant (LSF+DSS), and extracellular vesicles (LEV+DSS), were prepared daily. During the final 7 d, the control group received normal water, and the other groups received 3% DSS. Data were collected daily, followed by sample collection from the mice.

RESULTS

In this study, significant reductions (P < 0.05) in body weight changes, disease activity index, intestinal damage, and histology scores were observed in the treatment groups, especially LEV+DSS and LF+DSS. Additionally, compared with the DSS group, colonic mucus secretion, as well as claudin-1 and occludin expression, increased significantly (P < 0.05) in the LEV+DSS and LF+DSS groups, whereas proinflammatory cytokines IL-1β and TNF-α decreased (P < 0.05) and IL-10 increased (P < 0.05) in the LEV+DSS group. L fermentum and its components significantly regulated gut microbiota α-diversity and β-diversity, affecting overall composition. Linear discriminant analysis effect size analysis revealed an enrichment of beneficial bacteria including Prevotellaceae_UCG-001, Romboutsia, and Ruminococcus species in the LF+DSS group and Akkermansia, Odoribacter, and Marvinbryantia species in the LEV+DSS group. Both L fermentum and its extracellular vesicles significantly downregulated the gene expression of TNF-α and IL-1β, whereas the expression of IL-10 was upregulated, thereby contributing to the alleviation of colitis symptoms.

CONCLUSIONS

This study reveals that L fermentum alleviates colitis through modulation of the gut microbiota and reinforcement of the intestinal mucosal barrier, with its extracellular vesicles potentially playing a key role in this regulatory process.

TCP80-1, a new levan-neoseries fructan from Tupistra chinensis Baker rhizomes alleviates ulcerative colitis induced by dextran sulfate sodium in Drosophila melanogaster model

Ulcerative colitis (UC) is a recurrent inflammation of the gastrointestinal tract, for which available treatment drugs are severely limited. Natural polysaccharides show potential for UC prevention. Herein, we extracted TCP80-1, a polysaccharide with significant anti-ulcerative colitis (UC) activity, from Tupistra chinensis Baker for the first time. Structure analysis revealed that TCP80-1 (3190 Da) was a levan-neoseries fructan containing → 6)-α-D-Glcp-(1→, →1)-β-D-Fruf-(2→, →1,6)-β-D-Fruf-(2→, →6)-β-D-Fruf-(2→ and β-D-Fruf-(2→ residues as backbone, with →6)-β-D-Fruf-(2→, and β-D-Fruf-(2→ as side chains substituted at C-6. The protective effect of TCP80-1 on UC was further evaluated using a UC Drosophila melanogaster model. The results demonstrated that TCP80-1 could alleviate the UC symptoms by reducing colonic atrophy, enhancing intestinal barrier, and promoting the proliferation and differentiation of intestinal stem cells (ISCs) into intestinal epithelial cells (IECs). Our findings provide important structural information about TCP80-1 and establish the foundation for the future progression and utilization of T. chinensis polysaccharide within the realm of UC therapy.

Gut microbiome and metabolome characteristics of patients with cholesterol gallstones suggest the preventive potential of prebiotics

Cholesterol gallstones (CGS) still lack effective noninvasive treatment. The etiology of experimentally proven cholesterol stones remains underexplored. This cross-sectional study aims to comprehensively evaluate potential biomarkers in patients with gallstones and assess the effects of microbiome-targeted interventions in mice. Microbiome taxonomic profiling was conducted on 191 samples via V3-V4 16S rRNA sequencing. Next, 60 samples (30 age- and sex-matched CGS patients and 30 controls) were selected for metagenomic sequencing and fecal metabolite profiling via liquid chromatography-mass spectrometry. Microbiome and metabolite characterizations were performed to identify potential biomarkers for CGS. Eight-week-old male C57BL/6J mice were given a lithogenic diet for 8 weeks to promote gallstone development. The causal relationship was examined through monocolonization in antibiotics-treated mice. The effects of short-chain fatty acids such as sodium butyrate, sodium acetate (NaA), sodium propionate, and fructooligosaccharides (FOS) on lithogenic diet-induced gallstones were investigated in mice. Gut microbiota and metabolites exhibited distinct characteristics, and selected biomarkers demonstrated good diagnostic performance in distinguishing CGS patients from healthy controls. Multi-omics data indicated associations between CGS and pathways involving butanoate and propanoate metabolism, fatty acid biosynthesis and degradation pathways, taurine and hypotaurine metabolism, and glyoxylate and dicarboxylate metabolism. The incidence of gallstones was significantly higher in the Clostridium glycyrrhizinilyticum group compared to the control group in mice. The grade of experimental gallstones in control mice was significantly higher than in mice treated with NaA and FOS. FOS could completely inhibit the formation of gallstones in mice. This study characterized gut microbiome and metabolome alterations in CGS. C. glycyrrhizinilyticum contributed to gallstone formation in mice. Supplementing with FOS could serve as a potential approach for managing CGS by altering the composition and functionality of gut microbiota.

Intestinal mucus barrier: A potential therapeutic target for IBD

Intestinal mucus, a viscoelastic medium with mucin2 (MUC2) as its main component, covers the surface of intestinal epithelial cells and protects the intestine from invasion, forming the first barrier of the intestinal tract. Unlike the small intestine, where the mucus layer is a single layer, the colonic mucus layer can be divided into a sterile inner layer and an outer layer with bacterial colonization. Many of the substances in the mucus layer have beneficial effects on the intestinal epithelium, but the mucus layer is often affected by a variety of factors, mainly microbiological, dietary, and immunological. Inflammatory bowel disease (IBD) is a disease of increasing morbidity worldwide, with a complex etiology and a high relapse rate. In recent years, the mucus barrier in IBD has received increasing attention and is considered a key factor in the pathogenesis of IBD. Loss of goblet cells (GCs) and changes in the composition and properties of the mucus layer material are commonly found in the colon of IBD patients. Damage to the mucus layer may make it easier for microorganisms to access the intestinal epithelium and cause inflammation. There are currently a number of herbs and other therapies that can be used to treat IBD and repair the damaged mucus barrier. This review highlights the important role of the mucus layer in IBD and the therapies that target the mucus layer in IBD.

Role of gut microbiota in rheumatoid arthritis: Potential cellular mechanisms regulated by prebiotic, probiotic, and pharmacological interventions

Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects joints and multiple organs and systems, which is long-lasting and challenging to cure and significantly impacting patients' quality of life. Alterations in the composition of intestinal flora in both preclinical and confirmed RA patients indicate that intestinal bacteria play a vital role in RA immune function. However, the mechanism by which the intestinal flora is regulated to improve the condition of RA is not fully understood. This paper reviews the methods of regulating gut microbiota and its metabolites through prebiotics, probiotics, and pharmacological interventions, and discusses their effects on RA. Additionally, it explores the potential predictive role of cellular therapy mechanisms of intestinal flora in treating RA. These findings suggest that restoring the ecological balance of intestinal flora and regulating intestinal barrier function may enhance immune system function, thereby improving rheumatoid arthritis. This offers new insights into its treatment.

Fructo-oligosaccharides Alleviated Ulcerative Colitis via Gut Microbiota-Dependent Tryptophan Metabolism in Association with Aromatic Hydrocarbon Receptor Activation in Mice

Fructo-oligosaccharide (FOS) is a typical prebiotic with intestinal health-promoting effects. Here, we explored the anticolitis activity of FOS and clarified the underlying mechanisms. Dextran sulfate sodium (DSS)-induced mice were gavaged with FOS (400 mg/kg) for 37 days, and administration of FOS alleviated DSS-induced colitis symptoms. Besides, FOS improved gut microbiota dysbiosis and modulated the intestinal microbiota-controlled tryptophan metabolic pathways. Targeted metabolomic results showed that FOS significantly increased the colonic levels of indole-3-acetic acid (IAA) and indole-3-propionic acid (IPA) and subsequently increased the expressions of aromatic hydrocarbon receptors (AhR) in the colon and further promoted the expressions of interleukin-22 (IL-22) and intestinal tight junction proteins in the colitis mice. These findings for the first time highlight a novel anticolitis mechanism of FOS by alleviating intestinal microbiota dysbiosis and modulating microbial tryptophan metabolism to promote IAA and IPA production for triggering AhR/IL-22 axis activation.

The Key Nutrients in the Mediterranean Diet and Their Effects in Inflammatory Bowel Disease: A Narrative Review

The gut microbiome, a collection of gut microorganisms, is crucial in the development and progression of inflammatory bowel diseases (IBD). Therefore, diet and dietary interventions are promising strategies to shape the gut microbiota for IBD management. Of all the diets studied in the IBD field, the Mediterranean diet has the least restrictive nature, promoting long-term adherence. The Mediterranean diet is rich in plants, with a high daily intake of fruits and vegetables (high in fiber, antioxidants, and vitamins), olive oil, whole grains, legumes, and nuts. It includes the moderate consumption of animal products such as oily fish (rich in mono- and polyunsaturated fatty acids), dairy products, and poultry, with a limited intake of red meat and processed foods. This diet is associated with a decreased risk of chronic diseases, including IBD. However, the mechanisms of specific nutrients behind these effects in the Mediterranean diet remain under investigation. Therefore, in this review, we aim to provide an overview of the nutrients that are abundant in the Mediterranean diet and their effects on IBD, with a main focus on preclinical evidence. While several nutrients like fructo-oligosaccharide, chitosan, plant-derived protein, polyphenols, omega-3 polyunsaturated fatty acids, and resveratrol have shown potential beneficial effects in preclinical models, clinical evidence is often limited. However, understanding the complex interactions between specific nutrients and IBD is essential to developing a tailored, multidisciplinary, and personalized approach for disease management; therefore, further research is required.

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

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

Lactobacillus paracasei JY062 and its exopolysaccharide enhance the intestinal barrier through macrophage polarization and Th17/Treg cell balance

Ulcerative colitis (UC) is an immune-mediated intestinal disease without a comprehensive cure, and the alleviation of UC has become an urgent problem. The results showed that JY062 with its EPS group (JEC) alleviated the intestinal barrier damage caused by LPS. After JEC intervention on Caco-2 cells, resulted in upregulation of ZO-1, Claudin-1, Occludin and MUC2 transcript levels and decreased mRNA expression of Claudin-2 (p < 0.05). JEC effectively attenuated the inflammatory response in UC mice and restoration of immunoglobulin levels (IgG, IgM and IgA), which resulted in shortening and swelling of the colon, disappearance of goblet cells, infiltration of inflammatory cells and mucosal damage were alleviated in mice. Similarly, changes in the expression of MUC2 and tight junction proteins after JEC intervention also occurred in UC mice. Administration of JEC significantly inhibited the differentiation of pro-inflammatory Th17 cells in the thymus and peripheral blood, promoted the differentiation of CD4+ T cells to Treg cells, and effectively regulated DSS-induced macrophage imbalance, which was manifested by the polarization of pro-inflammatory M1 macrophages to anti-inflammatory M2 macrophages. This study clearly demonstrates that JEC could significantly prevent intestinal barrier on DSS-induced experimental colitis and could be applied as a potential symbiotic strategy to assist in the alleviation of UC.

Effects of inulin-type oligosaccharides (JSO) from Cichorium intybus L. on behavioral deficits induced by chronic restraint stress in mice and associated molecular alterations

Depression and anxiety are serious psychiatric disorders with significant physical and mental health impacts, necessitating the development of safe and effective treatments. This study aimed to evaluate the efficacy of Jiangshi oligosaccharide (JSO), a type of inulin-based oligosaccharide, in alleviating anxiety and depression and to investigate the underlying molecular mechanisms. Using a mouse model of chronic restraint stress (CRS), JSO was administered orally at doses of 50, 100, and 200 mg/kg for 21 days. Behavioral tests, including the novelty-suppressed feeding test (NSFT), open field test (OFT), elevated plus maze test (EPMT), tail suspension test (TST), and forced swimming test (FST), demonstrated that JSO significantly improved anxiety- and depressive-like behaviors (P< 0.05). Notably, JSO reduced feeding latency in the NSFT, increased time spent in the center in the OFT, enhanced time and entries into open arms in the EPMT, and decreased immobility time in the TST and FST (P< 0.01). Histological and molecular analyses revealed that JSO treatment attenuated neuronal loss in the hippocampus (Hip) and medial prefrontal cortex (mPFC) and reduced the expression of inflammatory markers such as Iba-1 and GFAP in these regions. JSO significantly downregulated the mRNA and protein expression of pro-inflammatory factors (IL-1β, TNF-α, IL-6) while increasing anti-inflammatory markers (IL-10, TGF-β) (P< 0.05). Furthermore, JSO inhibited the c-GAS-STING-NLRP3 axis and apoptosis-related proteins (Bax/Bcl-2, Caspase-3/8/9) while promoting the expression of brain-derived neurotrophic factor (BDNF), PSD-95, and synaptophysin (SYP), indicating improved neuronal survival and synaptic plasticity (P< 0.01). These findings suggest that JSO exerts potent anti-anxiety and antidepressant effects by modulating neuroinflammation, synaptic function, and neuronal apoptosis in the Hip and mPFC of CRS mice. This study highlighted JSO as a potential therapeutic agent for stress-induced anxiety and depression.

Effective Identification and Highly Sensitive Quantification of Fructo-oligosaccharide Isomers with Bi2Se3 Nanosheet-Assisted Laser Desorption Ionization Mass Spectrometry

The growing interest in fructo-oligosaccharides (FOSs) necessitates the effective monitoring of product quality. Identifying and quantifying FOS isomers from the same sources are challenging. Here, we report a new method using Bi2Se3 nanosheets as the matrix for matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), achieving effective differentiation of oligosaccharide isomers through MALDI-MS/MS. Notably, four isomers of pentasaccharides and two isomers of heptasaccharides were successfully identified, with a remarkably low limit of detection of 0.06 pmol. Our approach enabled the specific quantification of 1F-fructofuranosylnystose in commercial FOS products, positioning it as a promising tool for oligosaccharide isomer quantification in nutritional food products. Furthermore, this technique facilitates the rapid and sensitive detection of various saccharides and a wide range of other small molecules with enhanced signal intensities and improved reproducibility. Overall, it facilitates the rapid, selective, and sensitive detection of various saccharides and other small molecules, enhancing analytical chemistry and food science applications.

Immunomodulatory Effects of a Prebiotic Formula with 2'-Fucosyllactose and Galacto- and Fructo-Oligosaccharides on Cyclophosphamide (CTX)-Induced Immunosuppressed BALB/c Mice via the Gut-Immune Axis

Obejectives: This study explored the immunomodulatory effects of a prebiotic formula consisting of 2'-fucosyllactose (2'-FL), galacto-oligosaccharides (GOSs), and fructo-oligosaccharides (FOSs) (hereinafter referred to as 2FGF) in cyclophosphamide (CTX)-induced immunosuppressed BALB/c mice and its underlying mechanisms. Methods: Sixty healthy female BALB/c mice were randomly divided into the following groups: normal control (NC) group; CTX treatment (CTX) group; 2FGF low-dose (2FGF-L) group; 2FGF medium-dose (2FGF-M) group; and 2FGF high-dose (2FGF-H) group. An immunosuppressed model was established in the 2FGF-H group by intraperitoneal injection of 80 mg/kg CTX. After 30 days of 2FGF intervention, peripheral blood, spleen tissue, thymus tissue, and intestinal tissue from the mice were collected and analyzed. The changes in weight and food intake of the mice were recorded weekly. Hematoxylin-eosin (HE) staining was used to observe the histological change of the spleen tissue. Enzyme-linked immunosorbent assay (ELISA) was employed to detect cytokine levels in peripheral blood. Flow cytometry was used to analyze T lymphocyte subgroup ratio of splenic lymphocytes. Western blot analysis was conducted on intestinal tissues to assess the expression of proteins involved in the tight junction, toll-like receptor 4 (TLR4), mitogen-activated protein kinase (MAPK), and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling pathways. Additionally, molecular techniques were used to analyze the intestinal microbiota. Results: The results showed that 2FGF restored CTX-induced splenic injury, increased the number of splenic T lymphocytes, and elevated serum cytokines such as interleukin-4 (IL-4) and IL-10. In the intestine, 2FGF upregulated the expression of intestinal epithelial tight junction proteins such as Claudin-1 and zonula occludens 1 (ZO-1), thereby enhancing intestinal barrier function and activating the MAPK and NF-κB pathways via TLR4. Furthermore, 2FGF elevated the α-diversity (Shannon and Simpson indices) of the gut microbiota in CTX-induced immunosuppressed mice, enriching bacteria species positively correlated with anti-inflammatory cytokines (e.g., IL-4) such as g_Streptomyces and g_Bacillus and negatively correlated with pro-inflammatory cytokines (e.g., IL-1β) such as g_Saccharomyces. The results suggest that 2FGF may enhance immunity via the gut-immune axis. Conclusions: The 2FGF prebiotic formula showed an immunomodulatory effect in CTX-induced immunosuppressed mice, and the mechanism of which might involve optimizing the gut flora, enhancing intestinal homeostasis, strengthening the intestinal barrier, and promoting the expression of immune factors by regulating the TLR-4/MAPK/NF-κB pathway.

Multistrain Probiotics with Fructooligosaccharides Improve Middle Cerebral Artery Occlusion-Driven Neurological Deficits by Revamping Microbiota-Gut-Brain Axis

Recent burgeoning literature unveils the importance of gut microbiota in the neuropathology of post-stroke brain injury and recovery. Indeed, ingestion of prebiotics/probiotics imparts positive effects on post-stroke brain injury, neuroinflammation, gut dysbiosis, and intestinal integrity. However, information on the disease-specific preference of selective prebiotics/probiotics/synbiotics and their underlying mechanism is yet elusive. Herein, we examined the effect of a new synbiotic formulation containing multistrain probiotics (Lactobacillus reuteri UBLRu-87, Lactobacillus plantarum UBLP-40, Lactobacillus rhamnosus UBLR-58, Lactobacillus salivarius UBLS-22, and Bifidobacterium breve UBBr-01), and prebiotic fructooligosaccharides using a middle cerebral artery occlusion (MCAO) model of cerebral ischemia in female and male rats. Three weeks pre-MCAO administration of synbiotic rescinded the MCAO-induced sensorimotor and motor deficits on day 3 post-stroke in rotarod, foot-fault, adhesive removal, and paw whisker test. We also observed a decrease in infarct volume and neuronal death in the ipsilateral hemisphere of synbiotic-treated MCAO rats. The synbiotic treatment also reversed the elevated levels/mRNA expression of the glial fibrillary acidic protein (GFAP), NeuN, IL-1β, TNF-α, IL-6, matrix metalloproteinase-9, and caspase-3 and decreased levels of occludin and zonula occludens-1 in MCAO rats. 16S rRNA gene-sequencing data of intestinal contents indicated an increase in genus/species of Prevotella (Prevotella copri), Lactobacillus (Lactobacillus reuteri), Roseburia, Allobaculum, and Faecalibacterium prausnitzii, and decreased abundance of Helicobacter, Desulfovibrio, and Akkermansia (Akkermansia muciniphila) in synbiotic-treated rats compared to the MCAO surgery group. These findings confer the potential benefits of our novel synbiotic preparation for MCAO-induced neurological dysfunctions by reshaping the gut-brain-axis mediators in rats.

Compound prebiotics as prophylactic and adjunctive treatments ameliorate DSS-induced colitis through gut microbiota modulation effects

The prophylactic and adjunctive impacts of compound prebiotics (CP), comprising galacto-oligosaccharides, fructo-oligosaccharides, and isomalto-oligosaccharides, on colitis remain unclear. This study aimed to elucidate the effects of CP on dextran sodium sulfate (DSS)-induced colitis via modulation of the gut microbiota. Mice received prophylactic CP (PCP) for three weeks and DSS in the second week. In the third week, therapeutic CP, mesalazine, and a combination of CP and mesalazine (CPM) were administered to mice with DSS-induced colitis. The administration of PCP and CPM was found to ameliorate colitis, as evidenced by increases in body weight and colon length, elevation of the anti-inflammatory cytokine IL-10, and reductions in the disease activity index, histological scores, and levels of pro-inflammatory cytokines in mice with DSS-induced colitis on days 14 or 21. Furthermore, an increase in the relative abundance of probiotics (Ligilactobacillus, Bifidobacterium, and Limosilactobacillus), alpha diversity indices, short-chain fatty acids (SCFA) contents, and microbial network complexity was observed following PCP or CPM treatment. Correlation analysis revealed positive associations between these probiotics and both SCFA and IL-10, and negative associations with pro-inflammatory cytokines. This study highlighted the potential of CP as novel prophylactic and adjunctive treatments for alleviating DSS-induced intestinal inflammation and maintaining gut microbiota homeostasis.

Endurance exercise associated with a fructooligosaccharide diet modulates gut microbiota and increases colon absorptive area

BACKGROUND AND AIM

Fructooligosaccharide (FOS) supplementation can stimulate beneficial intestinal bacteria growth, but little is known about its influence on training performance. Therefore, this study analyzed FOS and exercise effects on gut microbiota and intestinal morphology of C57Bl/6 mice.

METHODS

Forty male mice were divided into four groups: standard diet-sedentary (SDS), standard diet-exercised (SDE), FOS supplemented (7.5% FOS)-sedentary (FDS), and FOS supplemented-exercised (FDE), n = 10 each group. Exercise training consisted of 60 min/day, 3 days/week, for 12 weeks.

RESULTS

SDE and FDE groups had an increase in aerobic performance compared to the pretraining period and SDS and FDS groups (P < 0.01), respectively. Groups with FOS increased colonic crypts size (P < 0.05). The FDE group presented rich microbiota (α-diversity) compared to other groups. The FDE group also acquired a greater microbial abundance (β-diversity) than other groups. The FDE group had a decrease in the Ruminococcaceae (P < 0.002) and an increase in Roseburia (P < 0.003), Enterorhabdus (P < 0.004) and Anaerotruncus (P < 0.006).

CONCLUSIONS

These findings suggest that aerobic exercise associated with FOS supplementation modulates gut microbiota and can increase colonic crypt size without improving endurance exercise performance.

Screening of Selenium/Glutathione-Enriched Candida utilis and Its Anti-inflammatory and Antioxidant Activities in Mice

This study aimed to screen a mutant of Candida utilis SE-172 with high selenite tolerance and glutathione (GSH) biosynthesis capability via 60Co γ-radiation mutagenesis to prepare selenium (Se)-enriched yeast. The maximal intracellular contents of GSH and organic Se of 22.94 mg/g and 1308.1 μg/g were obtained, respectively, under a batch culture of SE-172. The physiological mechanism underlying increased GSH and organic Se contents in Se/GSH-enriched C. utilis SE-172 was revealed based on assaying activities of γ-glutamylcysteine synthase (γ-GCS) involved in GSH biosynthesis and selenophosphate synthase (SPS) related to organic Se bioconversion, and by determining intracellular ATP and NADH contents and ATP/ADP and NADH/NAD+ ratios associated with energy supply and regeneration. Moreover, the effect of this selenized yeast on anti-inflammatory and antioxidant activities in mice with colitis was investigated. The supplementation of Se/GSH-enriched yeast decreased the dextran sodium sulfate-induced damage to colon tissues, reduced the expression of pro-inflammatory factors [interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α)] in serum, increased the antioxidant-related enzyme [superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px)] activities, and decreased the malondialdehyde content in colon. The Se/GSH-enriched C. utilis SE-172 showed potent anti-inflammatory and antioxidant activities in mice with colitis.

Orally Administered Lactobacillus rhamnosus CY12 Alleviates DSS-Induced Colitis in Mice by Restoring the Intestinal Barrier and Inhibiting the TLR4-MyD88-NF-κB Pathway via Intestinal Microbiota Modulation

Oral ingestion of probiotics is a promising approach to relieving inflammatory disease through regulating the gut microbiota. A newly discovered strain, Lactobacillus rhamnosus CY12 (LCY12), obtained from cattle-yak milk, displayed numerous probiotic properties. These included enhanced viability in low pH and bile environments, adhesion capabilities, and potent antimicrobial effects. The research aimed to explore the beneficial impacts of the novel LCY12 strain on colitis in mice induced by dextran sulfate sodium (DSS) and to elucidate the underlying molecular mechanisms. The results of the study showed that administration of LCY12 effectively helped to reduce the negative effects of DSS-induced body weight loss, disease activity index score, colon length shortening, loss of goblet cells, and overall histopathological scores in the intestines. Simultaneously, LCY12 administration significantly alleviated intestinal inflammation and safeguarded intestinal barrier integrity by enhancing IL-10 levels, while dampening IL-6, IL-1β, and TNF-α production. Additionally, LCY12 boosted the presence of tight junction proteins. Furthermore, LCY12 hindered the TLR4/MyD88/NF-κB signaling pathway by downregulating TLR4 and MyD88 expression, inactivating phosphorylated IκBα, and preventing translocation of NF-κB p65 from the cytoplasm to the nucleus. The LCY12 also increased specific intestinal microbial communities and short-chain fatty acid (SCFA) production. Altogether, LCY12 oral administration alleviated colitis induced with DSS in mice by improving intestinal barrier function and regulating inflammatory cytokines, SCFA production, and intestinal microbiota.

Gut microbiota modulation and effects of a diet enriched in apple pomace on inflammation in a DSS-induced colitis mouse model

Certain types of soluble dietary fibre, such as pectin and pectic oligosaccharides from different sources, have demonstrated protective effects against inflammation in DSS-induced colitis mouse models. In this work, we have evaluated the impact of a diet enriched in apple pomace (AP-diet), an agricultural by-product with a significant content of pectin and that previously demonstrated prebiotic properties in human fecal batch fermentation models, on the gut microbiota composition, intestinal damage and inflammation markers in a DSS-induced colitis model. We found that the apple pomace enriched diet (AP-diet), providing a significant amount of pectin with demonstrated prebiotic properties, was associated with a slower increase in the disease activity index, translating into better clinical symptomatology of the animals. Histological damage scoring confirmed less severe damage in those animals receiving an AP-diet before and during the DSS administration period. Some serum inflammatory markers, such as TNFα, also demonstrated lower levels in the group receiving the AP-diet, compared to the control diet. AP-diet administration is also associated with the modulation of key taxa in the colonic microbiota of animals, such as some Lachnospiraceae genera and Ruminococcus species, including commensal short chain fatty acid producers that could play a role in attenuating inflammation at the intestinal level.

Disruption of CerS6-mediated sphingolipid metabolism by FTO deficiency aggravates ulcerative colitis

BACKGROUND AND AIMS

Deregulation of RNA N6-methyladenosine (m6A) modification in intestinal epithelial cells (IECs) influences intestinal immune cells and leads to intestinal inflammation. We studied the function of fat mass-and obesity-associated protein (FTO), one of the m6A demethylases, in patients with ulcerative colitis (UC).

METHODS

We analysed colon tissues of Ftoflox/flox; Villin-cre mice and their Ftoflox/flox littermates with dextran sulfate sodium (DSS) using real-time PCR and 16s rRNA sequencing. RNA and methylated RNA immunoprecipitation sequencing were used to analyse immunocytes and IECs. Macrophages were treated with conditioned medium of FTO-knockdown MODE-K cells or sphingosine-1-phosphate (S1P) and analysed for gene expression. Liquid chromatograph mass spectrometry identified C16-ceramide.

RESULTS

FTO downregulation was identified in our in-house cohort and external cohorts of UC patients. Dysbiosis of gut microbiota, increased infiltration of proinflammatory macrophages, and enhanced differentiation of Th17 cells were observed in Ftoflox/flox;Villin-cre mice under DSS treatment. FTO deficiency resulted in an increase in m6A modification and a decrease in mRNA stability of CerS6, the gene encoding ceramide synthetase, leading to the downregulation of CerS6 and the accumulation of S1P in IECs. Subsequentially, the secretion of S1P by IECs triggered proinflammatory macrophages to secrete serum amyloid A protein 1/3, ultimately inducing Th17 cell differentiation. In addition, through bioinformatic analysis and experimental validation, we identified UC patients with lower FTO expression might respond better to vedolizumab treatment.

CONCLUSIONS

FTO downregulation promoted UC by decreasing CerS6 expression, leading to increased S1P accumulation in IECs and aggravating colitis via m6A-dependent mechanisms. Lower FTO expression in UC patients may enhance their response to vedolizumab treatment.

Bioactives and their roles in bone metabolism of osteoarthritis: evidence and mechanisms on gut-bone axis

Bioactives significantly modify and maintain human health. Available data suggest that Bioactives might play a beneficial role in chronic inflammatory diseases. Although promised, defining their mechanisms and opting to weigh their benefits and limitations is imperative. Detailed mechanisms by which critical Bioactives, including probiotics and prebiotics such as dietary lipids (DHA, EPA, alpha LA), vitamin D, polysaccharides (fructooligosaccharide), polyphenols (curcumin, resveratrol, and capsaicin) potentially modulate inflammation and bone metabolism is limited. Certain dietary bioactive significantly impact the gut microbiota, immune system, and pain response via the gut-immune-bone axis. This narrative review highlights a recent update on mechanistic evidence that bioactive is demonstrated demonstrated to reduce osteoarthritis pathophysiology.

Fructo-oligosaccharide-mediated alteration in claudin expression in small intestinal absorptive Caco-2 cells is positively associated with the induction of inflammatory genes and the glucan receptor gene CLEC7A

OBJECTIVES

Indigestible carbohydrates may strengthen tight junctions (TJs) independently of intestinal bacteria. This study investigated whether indigestible carbohydrates (i.e., fructo-oligosaccharides [FOS]) promote TJs directly to intestinal absorptive Caco-2 cells and examined the association between the expression of genes constructing TJs and other genes using mRNA microarray analysis.

METHODS

Caco-2 cells at 1.0 × 105/mL were seeded in a type I collagen plate and cultured in high-glucose Dulbecco's modified Eagle medium (DMEM) supplemented with 10% fetal calf serum (FCS); the cells reached confluence at 7 d after seeding. Ten days after the cells reached confluency, they were cultured for 24 h in 10% FCS-containing DMEM medium supplemented with 0%, 5%, or 10% FOS. We performed mRNA microarray to identify the genes whose expression was altered by FOS. Subsequently, quantitative reverse transcription polymerase chain reaction was performed for these altered genes, including CLEC7A encoding the glucan receptor, and for the claudin (CLDN) family genes. The expression of CLDN2, CLDN4, and CLEC7A proteins was assessed using western blot analysis.

RESULTS

FOS decreased the mRNA and protein expression of CLDN2, which weakens TJs, and increased those of CLDN4, which strengthens TJs, in Caco-2 cells. FOS treatment (10%) reduced the mRNA expression of antioxidative genes and induced the expression of immune response-related genes, including CLEC7A, CCL2, and ITGA2. Furthermore, the expression of CLEC7A protein was enhanced by FOS.

CONCLUSIONS

Induction of TJ-strengthening CLDN4 and reduction of TJ-weakening CLDN2 by FOS treatment in small intestinal absorptive Caco-2 cells is positively associated with the induction of inflammatory genes, including CLEC7A.

Fermentation patterns of prebiotics fructooligosaccharides-SCFA esters inoculated with fecal microbiota from ulcerative colitis patients

Ulcerative colitis (UC) is believed to arise from an imbalance between the intestinal microbiota and mucosal immunity, leading to excessive intestinal inflammation. Modulating the gut microbial community through dietary components presents a valuable strategy in aiding the treatment of UC. In this study, esters formed by binding of well-known prebiotics, fructooligosaccharides (FOS), with short chain fatty acids (SCFAs) via both enzymatic and chemical methods were evaluated for their impact on the gut microbiota of UC patients. An in vitro human colonic fermentation model was employed to monitor changes in total carbohydrates and SCFAs production during the fermentation of these esters by microbiota from patients with active and remission UC. The results showed that pronounced abundance of [Ruminococcus]_gnavus_group, Escherichia_Shigella, Lachnoclostridium, Klebsiella and other potential pathogens were detected in the fecal samples from UC patients, with a milder condition observed during the remission phase. Significant higher levels of corresponding SCFA were observed in the groups with addition of FOS-SCFAs esters during fermentation. Butyrylated fructooligosaccharides (B-FOS) and propionylated fructooligosaccharides (P-FOS) by enzymatic synthesis successfully promoted the proliferation of Bifidobacterium and inhibited Clostridium_sensu_stricto_1 and Klebsiella. Overall, B-FOS and P-FOS exhibit promising potential for restoring intestinal homeostasis and alleviating intestinal inflammation in individuals with UC.

The role of Lactobacillus in inflammatory bowel disease: from actualities to prospects

Inflammatory Bowel Disease (IBD), a chronic nonspecific intestinal inflammatory disease, is comprised of Ulcerative Colitis (UC) and Crohn's Disease (CD). IBD is closely related to a systemic inflammatory reaction and affects the progression of many intestinal and extraintestinal diseases. As one of the representative bacteria for probiotic-assisted therapy in IBD, multiple strains of Lactobacillus have been proven to alleviate intestinal damage and strengthen the intestinal immunological barrier, epithelial cell barrier, and mucus barrier. Lactobacillus also spares no effort in the alleviation of IBD-related diseases such as Colitis-associated Colorectal cancer (CAC), Alzheimer's Disease (AD), Depression, Anxiety, Autoimmune Hepatitis (AIH), and so on via gut-brain axis and gut-liver axis. This article aims to discuss the role of Lactobacillus in IBD and IBD-related diseases, including its underlying mechanisms and related curative strategies from the present to the future.

The function of human milk oligosaccharides and their substitute oligosaccharides as probiotics in gut inflammation

Gut inflammation seriously affects the healthy life of patients, and has a trend of increasing incidence rate. However, the current methods for treating gut inflammation are limited to surgery and drugs, which can cause irreversible damage to patients, especially infants. As natural oligosaccharides in human breast milk, human milk oligosaccharides (HMOs) function as probiotics in treating and preventing gut inflammation: improving the abundance of the gut microbiota, increasing the gut barrier function, and reducing the gut inflammatory reaction. Meanwhile, due to the complexity and high cost of their synthesis, people are searching for functional oligosaccharides that can replace HMOs as a food additive in infants milk powder and adjuvant therapy for chronic inflammation. The purpose of this review is to summarize the therapeutic and preventive effects of HMOs and their substitute functional oligosaccharides as probiotics in gut inflammation, and to summarize the prospect of their application in infant breast milk replacement in the future.

Synergistic synbiotic containing fructooligosaccharides and Lactobacillus delbrueckii CIDCA 133 alleviates chemotherapy-induced intestinal mucositis in mice

Intestinal mucositis is a commonly reported side effect in oncology patients undergoing chemotherapy and radiotherapy. Probiotics, prebiotics, and synbiotics have been investigated as alternative therapeutic approaches against intestinal mucositis due to their well-known anti-inflammatory properties and health benefits to the host. Previous studies showed that the potential probiotic Lactobacillus delbrueckii CIDCA 133 and the prebiotic Fructooligosaccharides (FOS) alleviated the 5-Fluorouracil (5-FU) chemotherapy-induced intestinal mucosa damage. Based on these previous beneficial effects, this work evaluated the anti-inflammatory property of the synbiotic formulation containing L. delbrueckii CIDCA 133 and FOS in mice intestinal mucosa inflammation induced by 5-FU. This work showed that the synbiotic formulation was able to modulate inflammatory parameters, including reduction of cellular inflammatory infiltration, gene expression downregulation of Tlr2, Nfkb1, and Tnf, and upregulation of the immunoregulatory Il10 cytokine, thus protecting the intestinal mucosa from epithelial damage caused by the 5-FU. The synbiotic also improved the epithelial barrier function by upregulating mRNA transcript levels of the short chain fatty acid (SCFA)-associated GPR43 receptor and the occludin tight junction protein, with the subsequent reduction of paracellular intestinal permeability. The data obtained showed that this synbiotic formulation could be a promising adjuvant treatment to be explored against inflammatory damage caused by 5-FU chemotherapy.

Supplementing a specific synbiotic suppressed the incidence of AOM/DSS-induced colorectal cancer in mice

In this study, we evaluated the effect of a specific synbiotic on CAC (AOM/DSS-induced colitis-associated cancer). We confirmed that the synbiotic intervention was able to protect the intestinal barrier and inhibit CAC occurrence via upregulating tight junction proteins and anti-inflammatory cytokines, and downregulating pro-inflammatory cytokines. Moreover, the synbiotic significantly improved the disorder of the colonic microbiota of CAC mice, promoted the formation of SCFAs and the production of secondary bile acids, and alleviated the accumulation of primary bile acids in the CAC mice. Meanwhile, the synbiotic could significantly inhibit the abnormal activation of the intestinal Wnt/β-catenin signaling pathway significantly related to IL-23. In a word, the synbiotic can inhibit the occurrence and development of colorectal tumors and it may be a functional food to prevent inflammation-related colon tumors, and the research also provided a theoretical basis for improving the intestinal microecological environment through diet therapy.

The role of complex interactions between the intestinal flora and host in regulating intestinal homeostasis and inflammatory bowel disease

Pharmacological treatment of inflammatory bowel disease (IBD) is inefficient and difficult to discontinue appropriately, and enterobacterial interactions are expected to provide a new target for the treatment of IBD. We collected recent studies on the enterobacterial interactions among the host, enterobacteria, and their metabolite products and discuss potential therapeutic options. Intestinal flora interactions in IBD are affected in the reduced bacterial diversity, impact the immune system and are influenced by multiple factors such as host genetics and diet. Enterobacterial metabolites such as SCFAs, bile acids, and tryptophan also play important roles in enterobacterial interactions, especially in the progression of IBD. Therapeutically, a wide range of sources of probiotics and prebiotics exhibit potential therapeutic benefit in IBD through enterobacterial interactions, and some have gained wide recognition as adjuvant drugs. Different dietary patterns and foods, especially functional foods, are novel therapeutic modalities that distinguish pro-and prebiotics from traditional medications. Combined studies with food science may significantly improve the therapeutic experience of patients with IBD. In this review, we provide a brief overview of the role of enterobacteria and their metabolites in enterobacterial interactions, discuss the advantages and disadvantages of the potential therapeutic options derived from such metabolites, and postulate directions for further research.

Healthy Diet and Lifestyle Improve the Gut Microbiota and Help Combat Fungal Infection

Western diets are rapidly spreading due to globalization, causing an increase in obesity and diseases of civilization. These Western diets are associated with changes in the gut microbiota related to intestinal inflammation. This review discusses the adverse effects of Western diets, which are high in fat and sugar and low in vegetable fiber, on the gut microbiota. This leads to gut dysbiosis and overgrowth of Candida albicans, which is a major cause of fungal infection worldwide. In addition to an unhealthy Western diet, other factors related to disease development and gut dysbiosis include smoking, excessive alcohol consumption, lack of physical activity, prolonged use of antibiotics, and chronic psychological stress. This review suggests that a diversified diet containing vegetable fiber, omega-3 polyunsaturated fatty acids, vitamins D and E, as well as micronutrients associated with probiotic or prebiotic supplements can improve the biodiversity of the microbiota, lead to short-chain fatty acid production, and reduce the abundance of fungal species in the gut. The review also discusses a variety of foods and plants that are effective against fungal overgrowth and gut dysbiosis in traditional medicine. Overall, healthy diets and lifestyle factors contribute to human well-being and increase the biodiversity of the gut microbiota, which positively modulates the brain and central nervous system.

The Effects of Synbiotics on Dextran-Sodium-Sulfate-Induced Acute Colitis: The Impact of Chitosan Oligosaccharides on Endogenous/Exogenous Lactiplantibacillus plantarum

In this work, Lactiplantibacillus plantarum (L. plantarum) isolated from mice feces (LP-M) and pickles (LP-P) were chosen as the endogenous and exogenous L. plantarum, respectively, which were separately combined with chitosan oligosaccharides (COS) to be synbiotics. The anti-inflammatory activity of LP-M, LP-P, COS, and the synbiotics was explored using dextran-sodium-sulfate (DSS)-induced acute colitis mice, as well as by comparing the synergistic effects of COS with LP-M or LP-P. The results revealed that L. plantarum, COS, and the synbiotics alleviated the symptoms of mice colitis and inhibited the changes in short-chain fatty acids (SCFAs), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, IL-10, and myeloperoxidase (MPO) caused by DSS. In addition, the intervention of L. plantarum, COS, and the synbiotics increased the relative abundance of beneficial bacteria Muribaculaceae and Lactobacillus and suppressed the pathogenic bacteria Turicibacter and Escherichia-Shigella. There was no statistically difference between LP-M and the endogenous synbiotics on intestinal immunity and metabolism. However, the exogenous synbiotics improved SCFAs, inhibited the changes in cytokines and MPO activity, and restored the gut microbiota more effectively than exogenous L. plantarum LP-P. This indicated that the anti-inflammatory activity of exogenous LP-P can be increased by combining it with COS as a synbiotic.

Role of prebiotics, probiotics, and synbiotics in management of inflammatory bowel disease: Current perspectives

Experimental evidence supports the fact that changes in the bowel microflora due to environmental or dietary factors have been investigated as implicating factors in the etiopathogenesis of inflammatory bowel disease (IBD). The amassing knowledge that the inhabited microbiome regulates the gut physiology and immune functions in IBD, has led researchers to explore the effectiveness of prebiotics, probiotics, and synbiotics in treating IBD. This therapeutic approach focuses on restoring the dynamic balance between the microflora and host defense mechanisms in the intestinal mucosa to prevent the onset and persistence of intestinal inflammation. Numerous microbial strains and carbohydrate blends, along with their combinations have been examined in experimental colitis models and clinical trials, and the results indicated that it can be an attractive therapeutic strategy for the suppression of inflammation, remission induction, and relapse prevention in IBD with minimal side effects. Several mechanisms of action of probiotics (for e.g., Lactobacillus species, and Bifidobacterium species) have been reported such as suppression of pathogen growth by releasing certain antimicrobial mediators (lactic and hydrogen peroxide, acetic acid, and bacteriocins), immunomodulation and initiation of an immune response, enhancement of barrier activity, and suppression of human T-cell proliferation. Prebiotics such as lactulose, lactosucrose, oligofructose, and inulin have been found to induce the growth of certain types of host microflora, resulting in an enriched enteric function. These non-digestible food dietary components have been reported to exert anti-inflammatory effects by inhibiting the expression of tumor necrosis factor-α-related cytokines while augmenting interleukin-10 levels. Although pro-and prebiotics has established their efficacy in healthy subjects, a better understanding of the luminal ecosystem is required to determine which specific bacterial strain or combination of probiotics and prebiotics would prove to be the ideal treatment for IBD. Clinical trials, however, have given some conflicting results, requiring the necessity to cite the more profound clinical effect of these treatments on IBD remission and prevention. The purpose of this review article is to provide the most comprehensive and updated review on the utility of prebiotics, probiotics, and synbiotics in the management of active Crohn's disease and ulcerative colitis/pouchitis.

Anti-Inflammatory, Barrier Maintenance, and Gut Microbiome Modulation Effects of Saccharomyces cerevisiae QHNLD8L1 on DSS-Induced Ulcerative Colitis in Mice

The use of probiotics has been considered as a new therapy option for ulcerative colitis (UC), and yeast has recently received widespread recommendation for human health. In this study, the probiotic characteristics of four yeast strains, Saccharomyces boulardii CNCMI-745, Kluyveromyces marxianus QHBYC4L2, Saccharomyces cerevisiae QHNLD8L1, and Debaryomyces hansenii QSCLS6L3, were evaluated in vitro; their ability to ameliorate dextran sulfate sodium (DSS)-induced colitis was investigated. Among these, S. cerevisiae QHNLD8L1 protected against colitis, which was reflected by increased body weight, colon length, histological injury relief, decreased gut inflammation markers, and intestinal barrier restoration. The abundance of the pathogenic bacteria Escherichia–Shigella and Enterococcaceae in mice with colitis decreased after S. cerevisiae QHNLD8L1 treatment. Moreover, S. cerevisiae QHNLD8L1 enriched beneficial bacteria Lactobacillus, Faecalibaculum, and Butyricimonas, enhanced carbon metabolism and fatty acid biosynthesis function, and increased short chain fatty acid (SCFAs) production. Taken together, our results indicate the great potential of S. cerevisiae QHNLD8L1 supplementation for the prevention and alleviation of UC.

Glucose metabolism and glycosylation link the gut microbiota to autoimmune diseases

Carbohydrates serve as important energy sources and structural substances for human body as well as for gut microbes. As evidenced by the advances in immunometabolism, glucose metabolism and adenosine triphosphate (ATP) generation are deeply involved in immune cell activation, proliferation, and signaling transduction as well as trafficking and effector functions, thus contributing to immune response programming and assisting in host adaption to microenvironment changes. Increased glucose uptake, aberrant expression of glucose transporter 1 (e.g., GLU1), and abnormal glycosylation patterns have been identified in autoimmunity and are suggested as partially responsible for the dysregulated immune response and the modification of gut microbiome composition in the autoimmune pathogenesis. The interaction between gut microbiota and host carbohydrate metabolism is complex and bidirectional. Their impact on host immune homeostasis and the development of autoimmune diseases remains to be elucidated. This review summarized the current knowledge on the crosstalk of glucose metabolism and glycosylation in the host with intestinal microbiota and discussed their possible role in the development and progression of autoimmune diseases. Potential therapeutic strategies targeting glucose metabolism and glycosylation in modulating gut ecosystem and treating autoimmune diseases were discussed as well.

Pathological mechanism of intestinal mucosal barrier injury of large intestine dampness-heat syndrome rats and the protective effect of Yujin powder

Large intestine dampness-heat syndrome (LIDHS) is frequently-occurring in the inflammatory intestinal disease of animals and human. Yujin powder (YJP) is a classical prescription for treating LIDHS. To explore the pathological mechanism of intestinal mucosal barrier injury of LIDHS and the protection of YJP, the LIDHS rat model was established through imitating the inducing conditions of LIDHS and treated with YJP. The integrity of ileal and colonic mucosa was detected through histopathological examination. The serum DAO, D-LA and ET levels were detected by ELISA. The mRNA and protein expression levels of Occludin, ZO-1 and MUC2 in ileum and colon were detected using RT-PCR and immunohistochemistry methods, respectively. The results showed that the ileal and colonic epithelium of LIDHS rats were destroyed; the serum DAO, D-LA and ET levels were significantly increased; the mRNA and protein expression levels of Occludin, ZO-1 and MUC2 in ileum and colon were all abnormally expressed. After treatment with YJP, the mucosal integrity was restored; the levels of serum DAO, D-LA and ET, mRNA and protein levels of Occludin and ZO-1 in ileum and colon and MUC2 in ileum were back-regulated; however, MUC2 level in colon was further increased. The results demonstrated that the intestinal mucosal barrier was damaged in LIDHS rats and Occludin, ZO-1 and MUC2 were abnormally expressed, and YJP could repair the intestinal mucosal barrier through up-regulating the expression of Occludin and ZO-1 in ileum and colon as well as MUC2 in colon and down-regulating MUC2 in ileum.

Spheroplexes: Hybrid PLGA-cationic lipid nanoparticles, for in vitro and oral delivery of siRNA

Vectorized small interfering RNAs (siRNAs) are widely used to induce gene silencing. Among the delivery systems used, lipid-based particles are the most effective. Our objective was the development of novel lipid-polymer hybrid nanoparticles, from lipoplexes (complexes of cationic lipid and siRNAs), and poly (lactic-co-glycolic acid) (PLGA), using a simple modified nanoprecipitation method. Due to their morphology, we called these hybrid nanoparticles Spheroplexes. We elucidated their structure using several physico-chemical techniques and showed that they are composed of a hydrophobic PLGA matrix, surrounded by a lipid envelope adopting a lamellar structure, in which the siRNA is complexed, and they retain surface characteristics identical to the starting nanoparticles, i.e. lipoplexes siRNA. We analyzed the composition of the particle population and determined the final percentage of spheroplexes within this population, 80 to 85% depending on the preparation conditions, using fluorescent markers and the ability of flow cytometry to detect nanometric particles (approximately 200 nm). Finally, we showed that spheroplexes are very stable particles and more efficient than siRNA lipoplexes for the delivery of siRNA to cultured cells. We administered spheroplexes contain siRNAs targeting TNF-α to mice with ulcerative colitis induced by dextran sulfate and our results indicate a disease regression effect with a response probably mediated by their uptake by macrophages / monocytes at the level of lamina propria of the colon. The efficacy of decreased level of TNF-α in vivo seemed to be an association of spheroplexes polymer-lipid composition and the specific siRNA. These results demonstrate that spheroplexes are a promising hybrid nanoparticle for the oral delivery of siRNA to the colon.

The Activity of Prebiotics and Probiotics in Hepatogastrointestinal Disorders and Diseases Associated with Metabolic Syndrome

The components of metabolic syndrome (MetS) and hepatogastrointestinal diseases are widespread worldwide, since many factors associated with lifestyle and diet influence their development and correlation. Due to these growing health problems, it is necessary to search for effective alternatives for prevention or adjuvants in treating them. The positive impact of regulated microbiota on health is known; however, states of dysbiosis are closely related to the development of the conditions mentioned above. Therefore, the role of prebiotics, probiotics, or symbiotic complexes has been extensively evaluated; the results are favorable, showing that they play a crucial role in the regulation of the immune system, the metabolism of carbohydrates and lipids, and the biotransformation of bile acids, as well as the modulation of their central receptors FXR and TGR-5, which also have essential immunomodulatory and metabolic activities. It has also been observed that they can benefit the host by displacing pathogenic species, improving the dysbiosis state in MetS. Current studies have reported that paraprobiotics (dead or inactive probiotics) or postbiotics (metabolites generated by active probiotics) also benefit hepatogastrointestinal health.

The role of functional oligosaccharides as prebiotics in ulcerative colitis

The incidence rate of ulcerative colitis (UC) has increased significantly over the past decades and it places an increasing burden on health and social systems. The current studies on UC implicate a strong correlation between host gut microbiota immunity and the pathogenesis of UC. Meanwhile, more and more functional oligosaccharides have been reported as prebiotics to alleviate UC, since many of them can be metabolized by gut microbiota to produce short-chain fatty acids (SCFAs). The present review is focused on the structure, sources and specific applications of various functional oligosaccharides related to the prevention and treatment of UC. The available evidence for the usage of functional oligosaccharides in UC treatment are summarized, including fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), chito-oligosaccharides (COS), alginate-oligosaccharides (AOS), xylooligosaccharides (XOS), stachyose and inulin.

Saccharomyces cerevisiae I4 Showed Alleviating Effects on Dextran Sulfate Sodium-Induced Colitis of Balb/c Mice

Ulcerative colitis (UC) is a chronic inflammatory bowel disease. The purpose of this study was to investigate the ameliorating effects of three yeast strains, Saccharomyces cerevisiae I4, Clavispora lusitaniae 30 and Pichia kudriavzevii 11, isolated from traditional fermented dairy food in Xinjiang, China, on the ulcerative colitis symptoms of Balb/c mice treated by dextran sulfate sodium (DSS). Among which, S. cerevisiae I4 had good tolerance to simulated gastrointestinal juice and strong adhesion to HT–29 cells monolayers. Furthermore, the three yeast strains were oral administered to Balb/c mice with DSS induced colitis. The weight loss, colon shortening and histological injury of colitis mice were ameliorated. Then, oral administration of S. cerevisiae I4 improved the immune state by reducing the contents of TNF–α, IL–6 and IL–1β and increasing immunoglobulin. The relative expression of intestinal barrier proteins Claudin–1, Occludin and Zonula Occludins–1 (ZO–1) of the mice enhanced, and the short chain fatty acids (SCFAs) content such as Propionic acid, Butyric acid, Isobutyric acid and Isovaleric acid in the feces of the mice increased to varying degrees, after S. cerevisiae I4 treatment compared with the model group of drinking 3% DSS water without yeast treatment. Moreover, S. cerevisiae I4 treatment lifted the proportion of beneficial bacteria such as Muribaculaceae, Lactobacillaceae and Rikenellaceae in the intestinal tract of the mice, the abundance of harmful bacteria such as Staphylococcus aureus and Turicibacter was decreased. These results suggested that S. cerevisiae I4 could alleviate DSS induced colitis in mice by enhancing intestinal barrier function and regulating intestinal flora balance.

Functional oligosaccharide fermentation in the gut: Improving intestinal health and its determinant factors-A review

The human intestine is characterized by an abundance of nutrients and a complex microbiota that make crucial contributions to overall health. These nutrients facilitate the adaptation of resident commensals to extreme environments and the development of a robust ecological network in host species. Long-term deprivation of microbiota-accessible carbohydrates (MACs) in the gut results in a loss of bacterial diversity, disruption of intestinal barrier function, and inflammatory diseases. Functional oligosaccharides are excellent MACs possessing important prebiotic properties for intestinal health through their fermentation in the gut. Its mechanism of action is predominantly attributed to acting as carbon sources for specific probiotics, promoting short-chain fatty acids production, and regulating the gut microbiota. In this review, we describe the source and structural characteristics of functional oligosaccharides, provide a framework for strategies to improve intestinal health by oligosaccharide fermentation and discuss structural determinants influencing the functional properties of oligosaccharides.

Butyl-fructooligosaccharides modulate gut microbiota in healthy mice and ameliorate ulcerative colitis in a DSS-induced model

Butyl-fructooligosaccharides (B-FOSs) are newly synthesized prebiotics composed of short-chain FOS (GF2, 1-kestose; GF3, nystose; GF4, fructofuranosyl-nystose; GF5, 1-F-(1-b-D-fructofuranosyl)-2-nystose) bound with one or two butyric groups by ester bonds. Previous in...