Lactobacillus species prevents colitis in interleukin 10 gene-deficient mice

Dietary Porphyra tenera ameliorated dextran sodium sulfate-induced colitis in mice via modulating gut microbiota dysbiosis

Bioactive components from Porphyra tenera (PT) have been reported to confer various health benefits. The role of PT in inflammatory bowel disease (IBD) has not been fully investigated. This study aimed to explore the anti-inflammatory properties of PT on dextran sodium sulfate (DSS)-treated mice. PT supplementation attenuated the severity of colitis in DSS-treated mice, evidenced by the reduction of disease activity index (DAI), restoration of colonic histological damage and suppression of abnormal inflammatory response. Sequencing analysis indicated that intake of PT alleviated DSS-induced gut microbiota dysbiosis, accompanied by reversing the generation of short-chain fatty acids (SCFAs) and bile acids (BAs). Overall, our findings demonstrated that supplementation of PT attenuated the severity of intestinal inflammation and ameliorated gut microbiota dysbiosis in a murine colitis model, which provided a rationale for further application of edible seaweeds for preventing inflammation-related disorders in humans.

Oral enzyme-responsive nanoprobes for targeted theranostics of inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is a progressive and debilitating inflammatory disease of the gastrointestinal tract (GIT). Despite recent advances, precise treatment and noninvasive monitoring remain challenging.

METHODS

Herein, we developed orally-administered, colitis-targeting and hyaluronic acid (HA)-modified, core-shell curcumin (Cur)- and cerium oxide (CeO2)-loaded nanoprobes (Cur@PC-HA/CeO2 NPs) for computed tomography (CT) imaging-guided treatment and monitoring of IBD in living mice.

RESULTS

Following oral administration, high-molecular-weight HA maintains integrity with little absorption in the upper GIT, and then actively accumulates at local colitis sites owing to its colitis-targeting ability, leading to specific CT enhancement lasting for 24 h. The retained NPs are further degraded by hyaluronidase in the colon to release Cur and CeO2, thereby exerting anti-inflammatory and antioxidant effects. Combined with the ability of NPs to regulate intestinal flora, the oral NPs result in substantial relief in symptoms. Following multiple treatments, the gradually decreasing range of the colon with high CT attenuation correlates with the change in the clinical biomarkers, indicating the feasibility of treatment response and remission.

CONCLUSION

This study provides a proof-of-concept for the design of a novel theranostic integration strategy for concomitant IBD treatment and the real-time monitoring of treatment responses.

Engaging natural antibody responses for the treatment of inflammatory bowel disease via phosphorylcholine-presenting nanofibres

Inflammatory bowel disease lacks a long-lasting and broadly effective therapy. Here, by taking advantage of the anti-infection and anti-inflammatory properties of natural antibodies against the small-molecule epitope phosphorylcholine (PC), we show in multiple mouse models of colitis that immunization of the animals with self-assembling supramolecular peptide nanofibres bearing PC epitopes induced sustained levels of anti-PC antibodies that were both protective and therapeutic. The strength and type of immune responses elicited by the nanofibres could be controlled through the relative valency of PC epitopes and exogenous T-cell epitopes on the nanofibres and via the addition of the adjuvant CpG. The nanomaterial-assisted induction of the production of therapeutic antibodies may represent a durable therapy for inflammatory bowel disease.

Challenges and opportunities in inflammatory bowel disease: from current therapeutic strategies to organoid-based models

BACKGROUND

Inflammatory bowel disease (IBD) is an increasingly prevalent global health concern that has garnered substantial attention. However, the underlying mechanisms are still unclear and the current treatments have significant limitations. Intestinal organoids provide an in vitro model to explore the pathogenesis, test the therapeutic effects, and develop regenerative treatments as well as offer the potential to transform drug discovery of IBD.

METHODS

To advance our understanding of the whole story of IBD spanning from the pathogenesis to the current therapeutic strategies and latest advancements, a comprehensive search of major databases including PubMed, Scopus, and Web of Science was conducted to retrieve original articles and reviews related to IBD, organoids, pathogenesis and therapy.

RESULTS

This review deciphers the etiopathogenesis and the current therapeutic approaches in the treatment of IBD. Notably, critical aspects of intestinal organoids in IBD, such as their potential applications, viability, cell renewal ability, and barrier functionality are highlighted. We also discuss the advances, limitations, and prospects of intestinal organoids for precision medicine.

CONCLUSION

The latest strides made in research about intestinal organoids help elucidate intricate aspects of IBD pathogenesis, and pave the prospective avenues for novel therapeutic interventions.

The Anti-Inflammatory Effect of a Probiotic Cocktail in Human Feces Induced-Mouse Model

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract due to altered interaction between the immune system and the gut microbiota. The aim of this study was to investigate the role of a probiotic cocktail in modulating immune dysregulation induced in mice. Mice were divided into 5 groups (n = 5/group), and inflammation was induced in two separate groups by fecal microbiota transplantation (FMT) from the stool of human with IBD and dextran sulfate sodium (DSS). In the other two groups, the cocktail of Lactobacillus spp. and Bifidobacterium spp. (108CFU/kg/day) was administered daily for a total of 28days in addition to inducing inflammation. A group as a contcxsrol group received only water and food. The alteration of the selected genera of gut microbiota and the expression of some genes involved in the regulation of the inflammatory response were studied in the probiotic-treated and untreated groups by quantitative real-time PCR. The selected genera of gut microbiota of the FMT and DSS groups showed similar patterns on day 28 after each treatment. In the probiotic-treated groups, the population of the selected genera of gut microbiota normalized and the abundance of Firmicutes and Actinobacteria increased compared to the DSS and FMT groups. The expression of genes related to immune response and tight junctions was positively affected by the probiotic. Changes in the gut microbiota could influence the inflammatory status in the gut, and probiotics as a preventive or complementary treatment could improve the well-being of patients with inflammatory bowel disease symptoms.

Chromatin Accessibility and Transcriptional Landscape during Inhibition of Salmonella enterica by Lactobacillus reuteri in IPEC-J2 Cells

Lactobacillus reuteri is a probiotic with bacteriostatic effects, which can effectively inhibit the activity of pathogens. However, the molecular mechanism underlying the inhibition of pathogens by L. reuteri in intestinal cells remains unclear. Using the porcine intestinal cell line IPEC-J2 as a model, we combined RNA-seq and ATAC-seq methods to delineate the porcine genome-wide changes in biological processes and chromatin accessibility in IPEC-J2 cells stimulated by Salmonella enterica BNCC186354, as well as L. reuteri ATCC 53608. Overall, we found that many porcine transcripts were altered after S. enterica BNCC186354 treatment, while L. reuteri ATCC 53608 treatment partially restored this alteration, such as salmonella infection and PI3K/AKT and MAPK pathways. Combined analysis of these two datasets revealed that 26 genes with similar trends overlapped between gene expression and chromatin accessibility. In addition, we identified potential host functional transcription factors (TFs), such as GATA1, TAL1, TBP, RUNX1, Gmeb1, Gfi1b, RARA, and RXRG, in IPEC-J2 cells that might play a critical role and are targeted by L. reuteri ATCC 53608. Moreover, we verified that PI3K/AKT, MAPK, and apoptosis pathways are potentially regulated by S. enterica BNCC186354 but restored by L. reuteri ATCC 53608. The PI3K/AKT pathway was activated by L. reuteri ATCC 53608, thereby potentially inhibiting S. enterica BNCC186354 infection. In conclusion, our data provide new insights into the expression pattern of functional genes and the epigenetic alterations in IPEC-J2 cells underlying the bacteriostatic action of L. reuteri ATCC 53608.

Mouse mammary tumor virus is implicated in severity of colitis and dysbiosis in the IL-10-/- mouse model of inflammatory bowel disease

BACKGROUND

Following viral infection, genetically manipulated mice lacking immunoregulatory function may develop colitis and dysbiosis in a strain-specific fashion that serves as a model for inflammatory bowel disease (IBD). We found that one such model of spontaneous colitis, the interleukin (IL)-10 knockout (IL-10-/-) model derived from the SvEv mouse, had evidence of increased Mouse mammary tumor virus (MMTV) viral RNA expression compared to the SvEv wild type. MMTV is endemic in several mouse strains as an endogenously encoded Betaretrovirus that is passaged as an exogenous agent in breast milk. As MMTV requires a viral superantigen to replicate in the gut-associated lymphoid tissue prior to the development of systemic infection, we evaluated whether MMTV may contribute to the development of colitis in the IL-10-/- model.

RESULTS

Viral preparations extracted from IL-10-/- weanling stomachs revealed augmented MMTV load compared to the SvEv wild type. Illumina sequencing of the viral genome revealed that the two largest contigs shared 96.4-97.3% identity with the mtv-1 endogenous loci and the MMTV(HeJ) exogenous virus from the C3H mouse. The MMTV sag gene cloned from IL-10-/- spleen encoded the MTV-9 superantigen that preferentially activates T-cell receptor Vβ-12 subsets, which were expanded in the IL-10-/- versus the SvEv colon. Evidence of MMTV cellular immune responses to MMTV Gag peptides was observed in the IL-10-/- splenocytes with amplified interferon-γ production versus the SvEv wild type. To address the hypothesis that MMTV may contribute to colitis, we used HIV reverse transcriptase inhibitors, tenofovir and emtricitabine, and the HIV protease inhibitor, lopinavir boosted with ritonavir, for 12-week treatment versus placebo. The combination antiretroviral therapy with known activity against MMTV was associated with reduced colonic MMTV RNA and improved histological score in IL-10-/- mice, as well as diminished secretion of pro-inflammatory cytokines and modulation of the microbiome associated with colitis.

CONCLUSIONS

This study suggests that immunogenetically manipulated mice with deletion of IL-10 may have reduced capacity to contain MMTV infection in a mouse-strain-specific manner, and the antiviral inflammatory responses may contribute to the complexity of IBD with the development of colitis and dysbiosis. Video Abstract.

Intestinal Dysbiosis in Rats: Interaction between Amoxicillin and Probiotics, a Histological and Immunohistochemical Evaluation

Gastrointestinal microbiota can be easily altered by common treatments, such as antibiotic therapy. However, the dysmicrobism induced by such a treatment may be counteracted by the administration of different beneficial microbes, such as probiotics. Therefore, this study aimed to establish the interaction between intestinal microbiota, antibiotic therapy, and sporulated bacteria, correlated with the evolution of growth indices. Twenty-five Wistar rats, females, were divided into five groups. Amoxicillin and a probiotic combination of Bacillus subtilis, Bacillus licheniformis, and Pediococcus acidilactici were administered according to each group's purpose. The conventional growth indices were calculated and histological and immunohistochemical assessments were realized from intestinal samples. The results of the conventional growth indices suggested a beneficial effect when the antibiotic therapy was accompanied by probiotics, while for the groups where the dysmicrobism was present, the values for feed conversion ratio were negative. These findings were supported by the microscopic aspects of the intestinal mucosa, which suggested a decreased absorption capacity due to significant morphological changes. Moreover, the immunohistochemical reaction of the inflammatory cells from intestinal lamina propria was intensely positive for the same affected groups. However, for the control group and the group with antibiotic and probiotic treatment, the immunopositivity was significantly decreased. Probiotics based on bacillus spores administered simultaneously with the antibiotic offered the best restoration of the gut microbiota, a fact suggested by the absence of intestinal lesions, a normal food conversion ratio, and low expression of TLR4 and LBP immunomarkers.

Expression Analysis and the Roles of the Sec1 Gene in Regulating the Composition of Mouse Gut Microbiota

The Sec1 gene encodes galactose 2-L-fucosyltransferase, whereas expression during development of the Sec1 gene mouse and its effect on the composition of the gut microbiota have rarely been reported. In this study, we examined Sec1 gene expression during mouse development, constructed Sec1 knockout mice, and sequenced their gut microbial composition. It was found that Sec1 was expressed at different stages of mouse development. Sec1 knockout mice have significantly higher intraperitoneal fat accumulation and body weight than wild-type mice. Analysis of gut microbial composition in Sec1 knockout mice revealed that at the phylum level, Bacteroidetes accounted for 68.8%and 68.3% of gut microbial composition in the Sec1-/- and Sec1+/+ groups, respectively, and Firmicutes accounted for 27.1% and 19.7%, respectively; while Firmicutes/Bacteroidetes were significantly higher in Sec1-/- mice than in Sec1+/+ mice (39.4% vs. 28.8%). In verucomicrobia, it was significantly higher in Sec1-/- mice than in Sec1+/+ group mice. At the family level, the dominant bacteria Prevotellaceae, Akkermansiaceae, Bacteroidaceae, and Lacilltobacaceae were found to be significantly reduced in the gut of Sec1-/- mice among Sec1+/+ gut microbes, while Lachnospiraceae, Ruminococcaceae, Rikenellaceae, Helicobacteraceae, and Tannerellaceae were significantly increased. Indicator prediction also revealed the dominant bacteria Akkermansiaceae and Lactobacillaceae in Sec1+/+ gut microorganisms, while the dominant bacteria Rikenellaceae, Marinifilaceae, ClostridialesvadinBB60aceae, Erysipelotrichaceae, Saccharimonadaceae, Clostridiaceae1, and Christensenellaceae in Sec1-/- group. This study revealed that the Sec1 gene was expressed in different tissues at different time periods in mice, and Sec1 knockout mice had significant weight gain, significant abdominal fat accumulation, and significant changes in gut microbial flora abundance and metabolic function, providing a theoretical basis and data support for the study of Sec1 gene function and effects on gut microbiota-related diseases.

Inflammatory Bowel Disease: A Review of Pre-Clinical Murine Models of Human Disease

Crohn’s disease (CD) and ulcerative colitis (UC) are both highly inflammatory diseases of the gastrointestinal tract, collectively known as inflammatory bowel disease (IBD). Although the cause of IBD is still unclear, several experimental IBD murine models have enabled researchers to make great inroads into understanding human IBD pathology. Here, we discuss the current pre-clinical experimental murine models for human IBD, including the chemical-induced trinitrobenzene sulfonic acid (TNBS) model, oxazolone and dextran sulphate sodium (DSS) models, the gene-deficient I-kappa-B kinase gamma (Iκκ-γ) and interleukin(IL)-10 models, and the CD4⁺ T-cell transfer model. We offer a comprehensive review of how these models have been used to dissect the etiopathogenesis of disease, alongside their limitations. Furthermore, the way in which this knowledge has led to the translation of experimental findings into novel clinical therapeutics is also discussed.

Whole genome sequencing for the risk assessment of probiotic lactic acid bacteria

Probiotic bacteria exhibit beneficial effects on human and/or animal health, and have been widely used in foods and fermented products for decades. Most probiotics consist of lactic acid bacteria (LAB), which are used in the production of various food products but have also been shown to have the ability to prevent certain diseases. With the expansion of applications for probiotic LAB, there is an increasing concern with regard to safety, as cases with adverse effects, i.e., severe infections, transfer of antimicrobial resistance genes, etc., can occur. Currently, in vitro assays remain the primary way to assess the properties of LAB. However, such methodologies are not meeting the needs of strain risk assessment on a high-throughput scale, in the context of the evolving concept of food safety. Analyzing the complete genetic information, including potential virulence genes and other determinants with a negative impact on health, allows for assessing the safe use of the product, for which whole-genome sequencing (WGS) of individual LAB strains can be employed. Genomic data can also be used to understand subtle differences in the strain level important for beneficial effects, or protect patents. Here, we propose that WGS-based bioinformatics analyses are an ideal and cost-effective approach for the initial in silico microbial risk evaluation, while the technique may also increase our understanding of LAB strains for food safety and probiotic property evaluation.

Lactobacillus in Food Animal Production—A Forerunner for Clean Label Prospects in Animal-Derived Products

Lactobacillus, the largest genus within the lactic acid bacteria group, has served diverse roles in improving the quality of foods for centuries. The heterogeneity within this genus has resulted in the industry's continued use of their well-known functions and exploration of novel applications. Moreover, the perceived health benefits in many applications have also made them fond favorites of consumers and researchers alike. Their familiarity lends to their utility in the growing “clean label” movement, of which consumers prefer fewer additions to the food label and opt for recognizable and naturally-derived substances. Our review primarily focuses on the historical use of lactobacilli for their antimicrobial functionality in improving preharvest safety, a critical step to validate their role as biocontrol agents and antibiotic alternatives in food animal production. We also explore their potential as candidates catering to the consumer-driven demand for more authentic, transparent, and socially responsible labeling of animal products.

The antiinflammatory and antifibrotic effect of olive phenols and Lactiplantibacillus plantarum IMC513 in dextran sodium sulfate-induced chronic colitis

OBJECTIVES

After a chronic intestinal injury, several intestinal cells switch their phenotype to activated myofibroblasts, which in turn release an abnormal amount of extracellular matrix proteins, leading to the onset of the fibrotic process. To date, no resolutive pharmacological treatments are available, and the identification of new therapeutic approaches represents a crucial goal to achieve. The onset, maintenance, and progression of inflammatory bowel disease are related to abnormal intestinal immune responses to environmental factors, including diet and intestinal microflora components. This study aimed to evaluate the potential antiinflammatory and antifibrotic effect of a biologically debittered olive cream and its probiotic oral administration in an experimental model of dextran sodium sulfate (DSS)-induced chronic colitis.

METHODS

Chronic colitis was induced in mice by three cycles of oral administration of 2.5% DSS (5 d of DSS followed by 7 d of tap water). Mice were randomly divided into five groups: 10 control mice fed with standard diet (SD), 20 mice receiving SD and DSS (SD+DSS), 20 mice receiving an enriched diet (ED) with olive cream and DSS (ED+DSS), 20 mice receiving SD plus probiotics (PB; Lactiplantibacillus plantarum IMC513) and DSS (SD+PB+DSS), and 20 mice receiving ED plus PB and DSS (ED+ PB+DSS). Clinical features and large bowel macroscopic, histologic, and immunohistochemical findings were evaluated.

RESULTS

The simultaneous administration of ED and PB induced a significant reduction in macroscopic and microscopic colitis scores compared with the other DSS-treated groups. In addition, ED and PB led to a significant decrease in the expression of inflammatory cytokines and profibrotic molecules.

CONCLUSIONS

The concomitant oral administration of a diet enriched with biologically debittered olive cream and a specific probiotic strain (Lactiplantibacillus plantarum IMC513) can exert synergistic antiinflammatory and antifibrotic action in DSS-induced chronic colitis. Further studies are needed to define the cellular and molecular mechanisms modulated by olive cream compounds and by Lactiplantibacillus plantarum IMC513.

Efficacy of probiotics for managing infantile colic due to their anti-inflammatory properties: a meta-analysis and systematic review

BACKGROUND

Infantile colic (IC) is excessive crying in otherwise healthy children. Despite vast research efforts, its etiology remains unknown.

PURPOSE

Most treatments for IC carry various side effects. The collection of evidence may inform researchers of new strategies for the management and treatment of IC as well as new clues for understanding its pathogenesis. This review and meta-analysis aimed to evaluate the efficacy and possible mechanisms of probiotics for mananaging IC.

METHODS

Ten papers met the study inclusion and exclusion criteria, and the meta-analysis was conducted using Review Manager (RevMan) software and a random-effects model.

RESULTS

This meta-analysis revealed that probiotics are effective for treating infantile colic, while the review showed that this efficacy may be due to their anti-inflammatory effects.

CONCLUSION

Probiotics may be an important treatment option for managing infantile colic due to their anti-inflammatory properties.

Akkermansia muciniphila Alleviates Dextran Sulfate Sodium (DSS)-Induced Acute Colitis by NLRP3 Activation

Akkermansia muciniphila has been proved to play a crucial role in the progression of colitis, but its underlying mechanism remains inconclusive. In this study, we aim to investigate the effect of A. muciniphila on the development of acute colitis and explore the underlying mechanism. We found that the fecal level of A. muciniphila was decreased in ulcerative colitis (UC) patients compared to the healthy people in the GMrepo database. Oral administration of A. muciniphila strain BAA-835 significantly ameliorated the symptoms in dextran sulfate sodium (DSS)-induced acute colitis, evidenced by decreased body weight loss, colon length shortening, and colon histological inflammatory score. In addition, the number of goblet cells and the mucin family were enhanced after A. muciniphila treatment. Furthermore, proinflammatory cytokines such as tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and monocyte chemoattractant protein 1 (MCP-1) had a downward trend. Mechanistically, the expression of NLRP3, caspase-1 p20, and IL-1β p17 were upregulated in A. muciniphila-treated mice. Additionally, the colon tissues from high-A. muciniphila UC patients had a higher NLRP3 expression than that from low-A. muciniphila UC patients. Moreover, the upregulation of NLRP3 was observed in mouse macrophage Raw264.7 cells and bone marrow-derived macrophage (BMDM) cells after incubation with A. muciniphila. To clarify whether the protective effect of A. muciniphila in colitis depends on NLRP3, we performed the NLRP3-deficient assay in NLRP3-/- mice in vivo. The evidence showed that NLRP3 deficiency eliminated the protective effects of A. muciniphila in acute colitis. In conclusion, A. muciniphila alleviates DSS-induced acute colitis by NLRP3 activation, which enriches the mechanism and provides a new prospect for the probiotic-based treatment of colitis. IMPORTANCE The gut microbiota and host immune response interaction influences the progression of intestinal inflammatory disease. As a well-recognized next-generation probiotic, Akkermansia muciniphila has been proved to play a crucial role in the progression of colitis, but its underlying mechanism remains inconclusive. We found that oral administration of A. muciniphila strain BAA-835 significantly ameliorated the symptoms of acute colitis. Mechanistically, the expression of NLRP3 was upregulated in the A. muciniphila group, and the protective effect of A. muciniphila in colitis depends on NLRP3 activation. This enriches the mechanism and provides a new prospect for the probiotic-based treatment of colitis, which would promote a deeper understanding of the complex characteristics of A. muciniphila and provide guidance for the treatment of human colitis in the future.

Lactobacillus reuteri Alleviates Gastrointestinal Toxicity of Rituximab by Regulating the Proinflammatory T Cells in vivo

Rituximab (RTX) is a widely used anticancer drug with gastrointestinal side effects, such as nausea, vomiting, and diarrhea. The reason for these side effects is still poorly understood. Previous studies have reported that the intestinal microbiota is associated with the occurrence of disease and the therapeutic effect of drugs. In this study, we observed mucosal damage, inflammatory cell infiltration and increased intestinal inflammatory factor expression in RTX-treated mice. RTX also changed the diversity of the intestinal microbiota in mice, and decreased abundance of Lactobacillus reuteri was observed in RTX-treated mice. Further experiments revealed that intragastric administration of L. reuteri in RTX-treated mice attenuated the intestinal inflammatory response induced by RTX and regulated the proportion of helper T (Th) cells. In conclusion, our data characterize the effect of the intestinal microbiota on RTX-induced intestinal inflammation, suggesting that modifying the gut microbiota may represent a positive strategy for managing adverse reactions.

The impact of the gut microbiome on toxigenic bacteria

Millions of symbiotic and pathogenic microorganisms known as microbiota colonize the host body. The microbiome plays an important role in human health and colonizes hundreds of different species of multicellular organisms so that they are introduced as the metaorganisms. Changes in the microbial population of the gut microbiome may cause resistance to pathogenic bacteria-induced infection. Understanding the principles of Host-Microbiota Interactions (HMIs) is important because it clarifies our insight towards the mechanisms of infections established in the host. Interactions between the host and the microbiota help answer the question of how a microorganism can contribute to the health or disease of the host. Microbiota can increase host resistance to colonization of pathogenic species. Studying the HMIs network can in several ways delineate the pathogenic mechanisms of pathogens and thereby help to increase useful and novel therapeutic pathways. For example, the potentially unique microbial effects that target the distinct host or interfere with the endogenous host interactions can be identified. In addition, the way mutations in essential proteins in the host and/or in the microbes can influence the interactions between them may be determined. Furthermore, HMIs help in identifying host cell regulatory modules.

Gut microbiota and bone metabolism

Osteoporosis is the most common metabolic skeletal disease. It is characterized by the deterioration of the skeletal microarchitecture and bone loss, leading to ostealgia, and even bone fractures. Accumulating evidence has indicated that there is an inextricable relationship between the gut microbiota (GM) and bone homeostasis involving host-microbiota crosstalk. Any perturbation of the GM can play an initiating and reinforcing role in disrupting the bone remodeling balance during the development of osteoporosis. Although the GM is known to influence bone metabolism, the mechanisms associated with these effects remain unclear. Herein, we review the current knowledge of how the GM affects bone metabolism in health and disease, summarize the correlation between pathogen-associated molecular patterns of GM structural components and bone metabolism, and discuss the potential mechanisms underlying how GM metabolites regulate bone turnover. Deciphering the complicated relationship between the GM and bone health will provide new insights into the prevention and treatment of osteoporosis.

Highlighting the Relevance of Gut Microbiota Manipulation in Inflammatory Bowel Disease

Two different conditions are included in inflammatory bowel disease (IBD), Crohn's disease (CD) and ulcerative colitis (UC), being distinguished by chronic recurrence of gut inflammation in persons that are genetically predisposed and subjected to environmental causative factors. The normal structure of the gut microbiome and its alterations in IBD were defined in several microbial studies. An important factor in the prolonged inflammatory process in IBD is the impaired microbiome or "dysbiosis". Thus, gut microbiome management is likely to be an objective in IBD treatment. In this review, we analyzed the existing data regarding the pathophysiological/therapeutic implications of intestinal microflora in the development and evolution of IBD. Furthermore, the main effects generated by the administration of probiotics, prebiotics, fecal transplantation, and phytochemicals supplementation were analyzed regarding their potential roles in improving the clinical and biochemical status of patients suffering from Crohn's disease (CD) and ulcerative colitis (UC), and are depicted in the sections/subsections of the present paper. Data from the literature give evidence in support of probiotic and prebiotic therapy, showing effects such as improving remission rate, improving macroscopic and microscopic aspects of IBD, reducing the pro-inflammatory cytokines and interleukins, and improving the disease activity index. Therefore, the additional benefits of these therapies should not be ignored as adjuvants to medical therapy.

Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is an inflammatory disease affecting premature infants. Intestinal microbial composition may play a key role in determining which infants are predisposed to NEC and when infants are at highest risk of developing NEC. It is unclear how to optimize antibiotic therapy in preterm infants to prevent NEC and how to optimize antibiotic regimens to treat neonates with NEC. This article discusses risk factors for NEC, how dysbiosis in preterm infants plays a role in the pathogenesis of NEC, and how probiotic and antibiotic therapy may be used to prevent and/or treat NEC and its sequelae.

Probiotic and Functional Properties of Limosilactobacillus reuteri INIA P572

Limosilactobacillus reuteri INIA P572 is a strain able to produce the antimicrobial compound reuterin in dairy products, exhibiting a protective effect against some food-borne pathogens. In this study, we investigated some probiotic properties of this strain such as resistance to gastrointestinal passage or to colonic conditions, reuterin production in a colonic environment, and immunomodulatory activity, using different in vitro and in vivo models. The results showed a high resistance of this strain to gastrointestinal conditions, as well as capacity to grow and produce reuterin in a human colonic model. Although the in vitro assays using the RAW 264.7 macrophage cell line did not demonstrate direct immunomodulatory properties, the in vivo assays using a Dextran Sulphate Sodium (DSS)-induced colitic mice model showed clear immunomodulatory and protective effects of this strain.

Efficacy and safety of probiotics and prebiotics in liver transplantation: A systematic review and meta-analysis

Probiotics were used for liver transplantation (LT) patients to reduce postoperative infection, but clinical trials examining the combined use of prebiotics and probiotics are limited. This meta-analysis aimed to compare the safety and efficacy of combined use of prebiotics and probiotics in patients undergoing LT. PubMed, Cochrane, and Embase databases were reviewed for the combined use of prebiotics and probiotics in patients undergoing LT. The weighted mean difference (WMD), risk ratio (RR), and 95% CI were calculated. A total of 6 related studies comprising 345 patients were included. Most prebiotics and probiotics were given for 7.14 days. The overall infection rate (RR = 0.29; 95% CI, 0.14.0.60; P value for heterogeneity [P_H ] = .066; test for heterogeneity [I² ] = 51.7%) and the incidence of urinary tract infection (RR = 0.14; 95% CI, 0.04-0.47, P_H = .724; I² = 0%) were lower in the probiotics group when compared with those in the control group. Furthermore, probiotics significantly reduced the hospital length of stay (WMD = -1.37; 95% CI, -1.92 to 0.82; P_H = .506; I² = 0%) and the duration of antimicrobial therapy (WMD = -4.31; 95% CI, -5.41 to 3.22; P_H = .019; I² = 69.8%) in patients undergoing LT. These findings suggested that the combined use of prebiotics and probiotics (Lactobacillus and Bifidobacterium) was effective in lowering the incidence of bacterial infections and shortening the hospital length of stay and duration of antibiotic therapy in patients undergoing LT, when compared with conventional nutrition.

Glycerol Monocaprylate Modulates Gut Microbiota and Increases Short-Chain Fatty Acids Production without Adverse Effects on Metabolism and Inflammation

Glycerol monocaprylate (GMC) is a glycerol derivative of medium-chain fatty acids (MCFAs) and is widely used as a preservative in food processing. However, GMC and its hydrolytic acid (octylic acid) have antibacterial properties that may affect the physiology and intestinal microecology of the human body. Therefore, in this study, the effects of two different dosages of GMC (150 and 1600 mg kg-1) on glucose, lipid metabolism, inflammation, and intestinal microecology of normal diet-fed C57BL/6 mice were comprehensively investigated. The obtained results showed that the level of triglycerides (TGs) in the low-dose group down-regulated significantly, and the anti-inflammatory cytokine interleukin 10 (IL-10) significantly increased, while the pro-inflammatory cytokines monocyte chemotactic protein 1 (MCP-1) and interleukin 1beta (IL-1β) in the high-dose group were significantly decreased. Importantly, GMC promoted the α-diversity of gut microbiota in normal-diet-fed mice, regardless of dosages. Additionally, it was found that the low-dose treatment of GMC significantly increased the abundance of Lactobacillus, while the high-dose treatment of GMC significantly increased the abundance of SCFA-producers such as Clostridiales, Lachnospiraceae, and Ruminococcus. Moreover, the content of short-chain fatty acids (SCFAs) was significantly increased by GMC supplementation. Thus, our research provides a novel insight into the effects of GMC on gut microbiota and physiological characteristics.

The Association of Gut Microbiota and Treg Dysfunction in Autoimmune Diseases

Autoimmune conditions affect 23 million Americans or 7% of the US population. There are more than 100 autoimmune disorders, affecting every major organ system in humans. This chapter aims to further explain Treg dysfunction autoimmune disorders, including monogenic primary immune deficiency such as immune dysregulation polyendocrinopathy, enteropathy, X-linked inheritance (IPEX) syndrome, and polygenic autoimmune diseases with Treg dysfunction such as multiple sclerosis (MS), inflammatory bowel disease (IBD), and food allergy. These conditions are associated with an abnormal small intestinal and colonic microbiome. Some disorders clearly improve with therapies aimed at microbial modification, including probiotics and fecal microbiota transplantation (FMT). Approaches to prevent and treat these disorders will need to focus on the acquisition and maintenance of a healthy colonic microbiota, in addition to more focused approaches at immune suppression during acute disease exacerbations.

Arjunarishta alleviates experimental colitis via suppressing proinflammatory cytokine expression, modulating gut microbiota and enhancing antioxidant effect

Traditional ayurvedic medicine, Arjunarishta (AA) is used to treat several inflammatory conditions including dysentery associated with blood. The formulation is a decoction of Terminalia arjuna (Roxb.) Wight and Arn. (TA), Madhuca indica J.F.Gmel., Vitis vinifera L., Woodfordia fruticosa (L.) Kurz., and Saccharum officinarum L. Terminalia arjuna, a major constituent of this formulation has been recognized for anti-inflammatory effects. This study aimed at evaluating beneficial effects of AA and probable mechanism of action in Trinitrobenzenesulphonicacid (TNBS) induced colitis model. Response to AA treatment was explored through determination of disease activity index (DAI), histological assessment and damage scores, colonic pro-inflammatory cytokine/chemokine expression and estimation of oxidative stress biomarkers. Improvement in gut microbiome and plasma zinc level was also assessed. Study findings directed therapeutic effects of AA treatment in colitis model by attenuating the colitis symptoms such as weight loss, diarrhoea, blood in stool; histological damage; and downregulated expression of pro-inflammatory cytokines/chemokine (TNF-α, IL-1β, IL-6) and MCP-1). Similarly reduced oxidative stress by decreased level of Nitric Oxide (NO), Myeloperoxidase (MPO), Malondialdehyde (MDA) and enhanced level of Catalase (CAT), Superoxide dismutase (SOD) and Reduced Glutathione (GSH) was also witnessed. In addition, an improved beneficial fecal microbiome profile and restored plasma zinc status was revealed compared to the TNBS control group. The present study directs that downregulated pro-inflammatory cytokines/chemokine expression, enhancement of antioxidant effect, increased plasma zinc status and promising role in modulating fecal microbiome might be potential mechanisms for the therapeutic effect of AA treatment against colitis.

The protective effect of Lactobacillus versus 5-aminosalicylic acid in ulcerative colitis model by modulation of gut microbiota and Nrf2/Ho-1 pathway

AIMS

Ulcerative colitis (UC) has many complications, from colonic damage to colorectal cancer. The mystery of both etiology and effective treatment of UC still challenging process. The role of gut microbiota in UC is still unclear. In the current study we compare the difference in gut microbiota abundance in both UC and normal colon besides the therapeutic effect of Lactobacillus spp. in treating UC versus the standard drug.

MATERIALS AND METHODS

The experimental panel included five group of rats; normal control, UC diseased rats, sterilizing rats, ASA treated and Lactobacillus treated. The change in the microbiota abundance was investigated using conventional and real time PCR. In parallel, clinical evaluation of UC and macroscopic examination scoring was also done. Colonic oxidants/antioxidant stress biomarkers; MDA, GSH, catalase, myeloperoxidase activity, and SOD activity were assessed. Colon Nrf2, HO-1 contents and TNF-α was evaluated.

KEY FINDINGS

The current study revealed a significant difference in the relative abundance of microbiota where, UC is associated with massive increase of E. coli and Fusobacterium spp., while enormous decrease in Bifidobacteria spp. in contrast with negative control. Both 5-ASA and Lactobacillus show a significant amelioration of all antioxidant enzymes and marked decline of inflammatory and oxidative stress markers. Both Lactobacillus and 5-ASA show significant increase of NrF2 and HO-1 and marked decrease of TNF-α.

SIGNIFICANCE

Lactobacillus spp. exerted a beneficial effect on the inflammation, oxidative stress and the symbiosis of gut microbiota that improve structural intestinal defect and promote healing in UC.

Lactobacillus reuteri Ameliorates Intestinal Inflammation and Modulates Gut Microbiota and Metabolic Disorders in Dextran Sulfate Sodium-Induced Colitis in Mice

Lactobacillus reuteri, a commensal intestinal bacteria, has various health benefits including the regulation of immunity and intestinal microbiota. We examined whether L. reuteri I5007 could protect mice against colitis in ameliorating inflammation, modulating microbiota, and metabolic composition. In vitro, HT-29 cells were cultured with L. reuteri I5007 or lipopolysaccharide treatment under three different conditions, i.e., pre-, co- (simultaneous), and posttreatment. Pretreatment with L. reuteri I5007 effectively relieves inflammation in HT-29 cells challenged with lipopolysaccharide. In vivo, mice were given L. reuteri I5007 by gavage throughout the study, starting one week prior to dextran sulfate sodium (DSS) treatment for one week followed by two days without DSS. L. reuteri I5007 improved DSS-induced colitis, which was confirmed by reduced weight loss, colon length shortening, and histopathological damage, restored the mucus layer, as well as reduced pro-inflammatory cytokines levels. Analysis of 16S rDNA sequences and metabolome demonstrates that L. reuteri I5007 significantly alters colonic microbiota and metabolic structural and functional composition. Overall, the results demonstrate that L. reuteri I5007 pretreatment could effectively alleviate intestinal inflammation by regulating immune responses and altering the composition of gut microbiota structure and function, as well as improving metabolic disorders in mice with colitis.

Feeding lactobacilli impacts lupus progression in (NZBxNZW)F1 lupus-prone mice by enhancing immunoregulation

Although the relationship between autoimmunity and microorganisms is complex, there is evidence that microorganisms can prevent the development of various autoimmune diseases. Lactobacilli are beneficial gut bacteria that play an important role in immune system development. The goals of this study were to assess the ability of three different strains of lactobacilli (L. casei B255, L. reuteri DSM 17509 and L. plantarum LP299v) to control lupus development/progression in (NZBxNZW)F1 (BWF1) lupus-prone mice before and after disease onset, and identify the mechanisms mediating protection. BWF1 mice fed with individual L. casei or L. reuteri before disease onset exhibited delayed lupus onset and increased survival, while feeding L. plantarum had little impact. In vitro treatment of BWF1 dendritic cells with individual lactobacilli strains upregulated IL-10 production to various extents, with L. casei being the most effective. The protection mediated by L. casei was associated with upregulation of B7-1 and B7-2 by antigen presenting cells, two costimulatory molecules important for regulatory T cell (Treg) induction. Moreover, feeding L. casei lead to increased percentages of CD4⁺Foxp3⁺ Tregs and IL10-producing T cells in the lymphoid organs of treated mice. More importantly, mice fed L. casei after disease onset remained stable for several months, i.e. exhibited delayed anti-nucleic acid production and kidney disease progression, and increased survival. Therefore, feeding lactobacilli appears to delay lupus progression possibly via mechanisms involving Treg induction and IL-10 production. Altogether, these data support the notion that ingestion of lactobacilli, with immunoregulatory properties, may be a viable strategy for controlling disease development and progression in patients with lupus, i.e. extending remission length and reducing flare frequency.

Human microbiome and homeostasis: insights into the key role of prebiotics, probiotics, and symbiotics

The interest in the study of the gut microbiome has grown exponentially. Indeed, its impact on health and disease has been increasingly reported, and the importance of keeping gut microbiome homeostasis clearly highlighted. However, and despite many advances, there are still some gaps, as well as the real discernment on the contribution of some species falls far short of what is needed. Anyway, it is already more than a solid fact of its importance in maintaining health and preventing disease, as well as in the treatment of some pathologies. In this sense, and given the existence of some ambiguous opinions, the present review aims to discuss the importance of gut microbiome in homeostasis maintenance, and even the role of probiotics, prebiotics, and symbiotics in both health promotion and disease prevention.

Human microbiota-transplanted C57BL/6 mice and offspring display reduced establishment of key bacteria and reduced immune stimulation compared to mouse microbiota-transplantation

Transplantation of germ-free (GF) mice with microbiota from mice or humans stimulates the intestinal immune system in disparate ways. We transplanted a human microbiota into GF C57BL/6 mice and a murine C57BL/6 microbiota into GF C57BL/6 mice and Swiss-Webster (SW) mice. Mice were bred to produce an offspring generation. 56% of the Operational Taxonomic Units (OTUs) present in the human donor microbiota established in the recipient mice, whereas 81% of the C57BL/6 OTUs established in the recipient C57BL/6 and SW mice. Anti-inflammatory bacteria such as Faecalibacterium and Bifidobacterium from humans were not transferred to mice. Expression of immune-related intestinal genes was lower in human microbiota-mice and not different between parent and offspring generation. Expression of intestinal barrier-related genes was slightly higher in human microbiota-mice. Cytokines and chemokines measured in plasma were differentially present in human and mouse microbiota-mice. Minor differences in microbiota and gene expression were found between transplanted mice of different genetics. It is concluded that important immune-regulating bacteria are lost when transplanting microbiota from humans to C57BL/6 mice, and that the established human microbiota is a weak stimulator of the murine immune system. The results are important for study design considerations in microbiota transplantation studies involving immunological parameters.

Disease managing capacities and mechanisms of host effects of lactic acid bacteria

Consumption of lactic acid bacteria (LAB) has been suggested to confer health-promoting effects on the host. However, effects of LABs have been reported to be species- and strain-specific and the mechanisms involved are subjects of discussion. Here, the possible mechanisms by which LABs induce antipathogenic, gut barrier enhancing and immune modulating effects in consumers are reviewed. Specific strains for which it has been proven that health is improved by these mechanisms are discussed. However, most strains probably act via several or combinations of mechanisms depending on which effector molecules they express. Current insight is that these effector molecules are either present on the cell wall of LAB or are excreted. These molecules are reviewed as well as the ligand binding receptors in the host. Also postbiotics are discussed. Finally, we provide an overview of the efficacy of LABs in combating infections caused by Helicobacter pylori, Salmonella, Escherichia coli, Streptococcus pneumoniae, and influenza virus, in controlling gut inflammatory diseases, in managing allergic disorders, and in alleviating cancer.

Fecal IgA Levels and Gut Microbiota Composition Are Regulated by Invariant Natural Killer T Cells

BACKGROUND

The gut microbiota is a key element to support host homeostasis and the development of the immune system. The relationship between the microbiota and immunity is a 2-way road, in which the microbiota contributes to the development/function of immune cells and immunity can affect the composition of microbes. In this context, natural killer T cells (NKT cells) are distinct T lymphocytes that play a role in gut immunity and are influenced by gut microbes. In our work, we investigated the involvement of invariant NKT cells (iNKT) in intestinal homeostasis.

RESULTS

We found that iNKT-deficient mice (iNKT-KO) had reduced levels of fecal IgA and an altered composition of the gut microbiota, with increased Bacteroidetes. The absence of iNKT cells also affected TGF-β1 levels and plasma cells, which were significantly reduced in knockout (KO) mice. In addition, when submitted to dextran sodium sulfate colitis, iNKT-KO mice had worsening of colitis when compared with wild-type (WT) mice. To further address iNKT cell contribution to intestinal homeostasis, we adoptively transferred iNKT cells to KO mice, and they were submitted to colitis. Transfer of iNKT cells improved colitis and restored fecal IgA levels and gut microbiota.

CONCLUSIONS

Our results indicate that intestinal NKT cells are important modulators of intestinal homeostasis and that gut microbiota composition may be a potential target in the management of inflammatory bowel diseases.

Probiotics for maintenance of remission in ulcerative colitis

BACKGROUND

Ulcerative colitis is an inflammatory condition affecting the colon, with an annual incidence of approximately 10 to 20 per 100,000 people. The majority of people with ulcerative colitis can be put into remission, leaving a group who do not respond to first- or second-line therapies. There is a significant proportion of people who experience adverse effects with current therapies. Consequently, new alternatives for the treatment of ulcerative colitis are constantly being sought. Probiotics are live microbial feed supplements that may beneficially affect the host by improving intestinal microbial balance, enhancing gut barrier function and improving local immune response.

OBJECTIVES

The primary objective was to determine the efficacy of probiotics compared to placebo, no treatment, or any other intervention for the maintenance of remission in people with ulcerative colitis. The secondary objective was to assess the occurrence of adverse events associated with the use of probiotics.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and two other databases on 31 October 2019. We contacted authors of relevant studies and manufacturers of probiotics regarding ongoing or unpublished trials that may be relevant to the review, and we searched ClinicalTrials.gov. We also searched references of trials for any additional trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that compared probiotics against placebo or any other intervention, in both adults and children, for the maintenance of remission in ulcerative colitis were eligible for inclusion. Maintenance therapy had to be for a minimum of three months when remission has been established by any clinical, endoscopic,histological or radiological relapse as defined by study authors.

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted data extraction and 'Risk of bias' assessment of included studies. We analysed data using Review Manager 5. We expressed dichotomous and continuous outcomes as risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs). We assessed the certainty of the evidence using the GRADE methodology.

MAIN RESULTS

In this review, we included 12 studies (1473 randomised participants) that met the inclusion criteria. Participants were mostly adults. The studies compared probiotics to placebo, probiotics to 5-aminosalicylic acid (5-ASA) and a combination of probiotics and 5-ASA to 5-ASA. The studies ranged in length from 12 to 52 weeks. The average age of participants was between 32 and 51, with a range between 18 and 88 years. Seven studies investigated a single bacterial strain, and five studies considered mixed preparations of multiple strains. The risk of bias was high in all except three studies due to selective reporting, incomplete outcome data and lack of blinding. This resulted in low- to very low-certainty of evidence. It is uncertain if there is any difference in occurrence of clinical relapse when probiotics are compared with placebo (RR 0.87, 95% CI 0.63 to 1.18; 4 studies, 361 participants; very low-certainty evidence (downgraded for risk of bias, imbalance in baseline characteristics and imprecision)). It is also uncertain whether probiotics lead to a difference in the number of people who maintain clinical remission compared with placebo (RR 1.16, 95% CI 0.98 to 1.37; 2 studies, 141 participants; very low-certainty evidence (downgraded for risk of bias, imbalance in baseline characteristics and imprecision)). When probiotics are compared with 5-ASA, there may be little or no difference in clinical relapse (RR 1.01, 95% CI 0.84 to 1.22; 2 studies, 452 participants; low-certainty evidence) and maintenance of clinical remission (RR 1.06, 95% CI 0.90 to 1.25; 1 study, 125 participants; low-certainty evidence). It is uncertain if there is any difference in clinical relapse when probiotics, combined with 5-ASA are compared with 5-ASA alone (RR 1.11, 95% CI 0.66 to 1.87; 2 studies, 242 participants; very low-certainty evidence (downgraded due to risk of bias and imprecision)). There may be little or no difference in maintenance of remission when probiotics, combined with 5-ASA, are compared with 5-ASA alone (RR 1.05, 95% CI 0.89 to 1.24; 1 study, 122 participants; low-certainty evidence). Where reported, most of the studies which compared probiotics with placebo recorded no serious adverse events or withdrawals due to adverse events. For the comparison of probiotics and 5-ASA, one trial reported 11/110 withdrawals due to adverse events with probiotics and 11/112 with 5-ASA (RR 1.02, 95% CI 0.46 to 2.25; 222 participants; very low-certainty evidence). Discontinuation of therapy was due to gastrointestinal symptoms. One study (24 participants) comparing probiotics combined with 5-ASA with 5-ASA alone, reported no withdrawals due to adverse events; and two studies reported two withdrawals in the probiotic arm, due to avascular necrosis of bilateral femoral head and pulmonary thromboembolism (RR 5.29, 95% CI 0.26 to 107.63; 127 participants; very low-certainty evidence). Health-related quality of life and need for additional therapy were reported infrequently.

AUTHORS' CONCLUSIONS

The effectiveness of probiotics for the maintenance of remission in ulcerative colitis remains unclear. This is due to low- to very low-certainty evidence from poorly conducted studies, which contribute limited amounts of data from a small number of participants. Future trials comparing probiotics with 5-ASA rather than placebo will better reflect conventional care given to people with ulcerative colitis. Appropriately powered studies with a minimum length of 12 months are needed.

Probiotics for induction of remission in ulcerative colitis

BACKGROUND

Ulcerative colitis is an inflammatory condition affecting the colon, with an annual incidence of approximately 10 to 20 per 100,000 people. The majority of people with ulcerative colitis can be put into remission, leaving a group who do not respond to first- or second-line therapies. There is a significant proportion of people who experience adverse effects with current therapies. Consequently, new alternatives for the treatment of ulcerative colitis are constantly being sought. Probiotics are live microbial feed supplements that may beneficially affect the host by improving intestinal microbial balance, enhancing gut barrier function and improving local immune response.

OBJECTIVES

To assess the efficacy of probiotics compared with placebo or standard medical treatment (5-aminosalicylates, sulphasalazine or corticosteroids) for the induction of remission in people with active ulcerative colitis.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and two other databases on 31 October 2019. We contacted authors of relevant studies and manufacturers of probiotics regarding ongoing or unpublished trials that may be relevant to the review, and we searched ClinicalTrials.gov. We also searched references of trials for any additional trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) investigating the effectiveness of probiotics compared to standard treatments or placebo in the induction of remission of active ulcerative colitis. We considered both adults and children, with studies reporting outcomes of clinical, endoscopic, histologic or surgical remission as defined by study authors DATA COLLECTION AND ANALYSIS: Two review authors independently conducted data extraction and 'Risk of bias' assessment of included studies. We analysed data using Review Manager 5. We expressed dichotomous and continuous outcomes as risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs). We assessed the certainty of the evidence using the GRADE methodology.

MAIN RESULTS

In this review, we included 14 studies (865 randomised participants) that met the inclusion criteria. Twelve of the studies looked at adult participants and two studies looked at paediatric participants with mild to moderate ulcerative colitis, the average age was between 12.5 and 47.7 years. The studies compared probiotics to placebo, probiotics to 5-ASA and a combination of probiotics plus 5-ASA compared to 5-ASA alone. Seven studies used a single probiotic strain and seven used a mixture of strains. The studies ranged from two weeks to 52 weeks. The risk of bias was high for all except two studies due to allocation concealment, blinding of participants, incomplete reports of outcome data and selective reporting. This led to GRADE ratings of the evidence ranging from moderate to very low. Probiotics versus placebo Probiotics may induce clinical remission when compared to placebo (RR 1.73, 95% CI 1.19 to 2.54; 9 studies, 594 participants; low-certainty evidence; downgraded due to imprecision and risk of bias, number needed to treat for an additional beneficial outcome (NNTB) 5). Probiotics may lead to an improvement in clinical disease scores (RR 2.29, 95% CI 1.13 to 4.63; 2 studies, 54 participants; downgraded due to risk of bias and imprecision). There may be little or no difference in minor adverse events, but the evidence is of very low certainty (RR 1.04, 95% CI 0.42 to 2.59; 7 studies, 520 participants). Reported adverse events included abdominal bloating and discomfort. Probiotics did not lead to any serious adverse events in any of the seven studies that reported on it, however five adverse events were reported in the placebo arm of one study (RR 0.09, CI 0.01 to 1.66; 1 study, 526 participants; very low-certainty evidence; downgraded due to high risk of bias and imprecision). Probiotics may make little or no difference to withdrawals due to adverse events (RR 0.85, 95% CI 0.42 to 1.72; 4 studies, 401 participants; low-certainty evidence). Probiotics versus 5-ASA There may be little or no difference in the induction of remission with probiotics when compared to 5-ASA (RR 0.92, 95% CI 0.73 to 1.16; 1 study, 116 participants; low-certainty evidence; downgraded due to risk of bias and imprecision). There may be little or no difference in minor adverse events, but the evidence is of very low certainty (RR 1.33, 95% CI 0.53 to 3.33; 1 study, 116 participants). Reported adverse events included abdominal pain, nausea, headache and mouth ulcers. There were no serious adverse events with probiotics, however perforated sigmoid diverticulum and respiratory failure in a patient with severe emphysema were reported in the 5-ASA arm (RR 0.21, 95% CI 0.01 to 4.22; 1 study, 116 participants; very low-certainty evidence). Probiotics combined with 5-ASA versus 5-ASA alone Low-certainty evidence from a single study shows that when combined with 5-ASA, probiotics may slightly improve the induction of remission (based on the Sunderland disease activity index) compared to 5-ASA alone (RR 1.22 CI 1.01 to 1.47; 1 study, 84 participants; low-certainty evidence; downgraded due to unclear risk of bias and imprecision). No information about adverse events was reported. Time to remission, histological and biochemical outcomes were sparsely reported in the studies. None of the other secondary outcomes (progression to surgery, need for additional therapy, quality of life scores, or steroid withdrawal) were reported in any of the studies.

AUTHORS' CONCLUSIONS

Low-certainty evidence suggests that probiotics may induce clinical remission in active ulcerative colitis when compared to placebo. There may be little or no difference in clinical remission with probiotics alone compared to 5-ASA. There is limited evidence from a single study which failed to provide a definition of remission, that probiotics may slightly improve the induction of remission when used in combination with 5-ASA. There was no evidence to assess whether probiotics are effective in people with severe and more extensive disease, or if specific preparations are superior to others. Further targeted and appropriately designed RCTs are needed to address the gaps in the evidence base. In particular, appropriate powering of studies and the use of standardised participant groups and outcome measures in line with the wider field are needed, as well as reporting to minimise risk of bias.

Application of vitamin-producing lactic acid bacteria to treat intestinal inflammatory diseases

Recent studies have shown that inflammatory diseases are becoming more frequent throughout the world. The causes of these disorders are multifactorial and include genetic, immunological, and environmental factors, and intestinal microbiota dysbiosis. The use of beneficial microorganisms has shown to be useful in the prevention and treatment of disorders such as colitis, mucositis, and even colon cancer by their immune-stimulating properties. It has also been shown that certain vitamins, especially riboflavin and folate derivatives, have proven to be helpful in the treatment of these diseases. The application of vitamin-producing lactic acid bacteria, especially strains that produce folate and riboflavin together with immune-stimulating strains, could be used as adjunct treatments in patients suffering from a wide range of inflammatory diseases since they could improve treatment efficiency and prevent undesirable side effects in addition to their nutrition values. In this review, the most up to date information on the current knowledge and uses of vitamin-producing lactic acid bacteria is discussed in order to stimulate further studies in this field.

Hyaluronic acid-bilirubin nanomedicine for targeted modulation of dysregulated intestinal barrier, microbiome and immune responses in colitis

While conventional approaches for inflammatory bowel diseases mainly focus on suppressing hyperactive immune responses, it remains unclear how to address disrupted intestinal barriers, dysbiosis of the gut commensal microbiota and dysregulated mucosal immune responses in inflammatory bowel diseases. Moreover, immunosuppressive agents can cause off-target systemic side effects and complications. Here, we report the development of hyaluronic acid-bilirubin nanomedicine (HABN) that accumulates in inflamed colonic epithelium and restores the epithelium barriers in a murine model of acute colitis. Surprisingly, HABN also modulates the gut microbiota, increasing the overall richness and diversity and markedly augmenting the abundance of Akkermansia muciniphila and Clostridium XIVα, which are microorganisms with crucial roles in gut homeostasis. Importantly, HABN associated with pro-inflammatory macrophages, regulated innate immune responses and exerted potent therapeutic efficacy against colitis. Our work sheds light on the impact of nanotherapeutics on gut homeostasis, microbiome and innate immune responses for the treatment of inflammatory diseases.

Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131 Induce the Expression of the REG3 Family in the Small Intestine of Mice via the Stimulation of Dendritic Cells and Type 3 Innate Lymphoid Cells

Accumulating evidence clarifies that intestinal barrier function, for example, by the mucus layer, antimicrobial peptides, immune systems, and epithelial tight junctions, plays crucial roles in maintaining our health. We reported previously that yogurt fermented with Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131 induced the gene expression of the regenerating family member 3 (REG3) family, which encodes antimicrobial peptides in the small intestine, although it was unclear how the yogurt activated the intestinal cells related to it. Here, we evaluated the cytokine production from the intestinal immune cells stimulated by these strains in vitro and in vivo to elucidate the mechanism for the induction of the REG3 family by the yogurt. The results showed that stimulation by both strains induced interleukin (IL)-23 production from bone marrow-derived dendritic cells (DCs) and IL-22 production from small intestinal lamina propria (LP) cells. In addition, oral administration of these strains to mice increased IL-23p19+ LPDCs and IL-22+ type 3 innate lymphoid cells and induced the expression of Reg3g in small intestinal tissue. Moreover, we showed that the activities for the induction of IL-23 by DCs were strain dependent on L. bulgaricus and S. thermophilus and that S. thermophilus 1131, which is the predominant species in the yogurt, exhibited relatively higher activity compared to the other strains of S. thermophilus. Our findings suggested that these yogurt starter strains, L. bulgaricus 2038 and S. thermophilus 1131, have the potential to maintain and improve intestinal barrier function by stimulating immune cells in the LP.

The role of the gut microbiota in the treatment of inflammatory bowel diseases

The human intestinal microbiota coevolves with its host through a symbiotic relationship and exerts great influence on substantial functions including aspects of physiology, metabolism, nutrition and regulation of immune responses leading to physiological homeostasis. Over the last years, several studies have been conducted toward the assessment of the host-gut microbiota interaction, aiming to elucidate the mechanisms underlying the pathogenesis of several diseases. A defect on the microbiota-host crosstalk and the concomitant dysregulation of immune responses combined with genetic and environmental factors have been implicated in the pathogenesis of inflammatory bowel diseases (IBD). To this end, novel therapeutic options based on the gut microbiota modulation have been an area of extensive research interest. In this review we present the recent findings on the association of dysbiosis with IBD pathogenesis, we focus on the role of gut microbiota on the treatment of IBD and discuss the novel and currently available therapeutic strategies in manipulating the composition and function of gut microbiota in IBD patients. Applicable and emerging microbiota treatment modalities, such as the use of antibiotics, prebiotics, probiotics, postbiotics, synbiotics and fecal microbiota transplantation (FMT) constitute promising therapeutic options. However, the therapeutic potential of the aforementioned approaches is a topic of investigation and further studies are needed to elucidate their position in the present treatment algorithms of IBD.

Effect of dietary probiotics on colon length in an inflammatory bowel disease-induced murine model: A meta-analysis

We investigated the effect of probiotic supplementation on inflammatory bowel disease (IBD) by meta-analysis. We included 30 studies to assess the effect of probiotic administration. We estimated the effect size using standardized mean difference, and we evaluated the statistical heterogeneity of the effect size using Cochran's Q test, followed by meta-ANOVA and meta-regression analysis to explain the heterogeneity of the effect size using a mixed-effects model. We conducted Egger's linear regression test to evaluate publication bias. Among the factors evaluated, colon length and myeloperoxidase showed the greatest Q statistic and I² index, respectively. Colon length, transforming growth factor-β, IL-10, superoxide dismutase, and glutathione showed positive effect sizes in the fixed- and random-effects models. The others (spleen weight, tumor necrosis factor α, IL-1β, IL-6, IL-12, IL-17, IFN-γ, disease activity index, thiobarbituric acid reactive substances, nitric oxide, myeloperoxidase, malondialdehyde, histological score, and macroscopic inflammatory score) showed negative effect sizes in the fixed- and random-effects models. Probiotics showed a significant effect on all investigated factors, except IL-10. In meta-ANOVA and meta-regression analysis, Lactobacillus paracasei was the most effective probiotic for colon length. Lactobacillus paracasei, Lactobacillus reuteri, Lactobacillus fermentum, and a mixture of Lactobacillus bulgaricus and Saccharomyces boulardii (LC + SB) were effective for colon length, tumor necrosis factor α, IL-6, IL-10, IFN-γ, and disease activity index. Lactobacillus rhamnosus was most effective for IL-10 and IFN-γ. Dietary probiotics are effective in improving the symptoms of IBD. Although the results of this meta-analysis had some limitations due to a lack of animal experiments, they will be meaningful to people with IBD.

Probiotic mixtures with aerobic constituent promoted the recovery of multi-barriers in DSS-induced chronic colitis

AIMS

Gut microbiota has been closely linked to the mucosal immune and been regarded as a reliable target for intestinal inflammation. This study aimed to explore the therapeutic roles of probiotic mixtures of Bifidobacterium infantis, Lactobacillus acidophilus, Enterococcus faecalis with (quadruple probiotics, P-qua) or without (triple probiotics, P-tri) aerobic Bacillus cereus in colitis, focusing on the multiple barrier functions.

MATERIALS AND METHODS

Chronic colitis was induced by dextran sulfate sodium (DSS) in C57BL/6 mice. The probiotic mixtures P-qua or P-tri was gavage administrated respectively, while fecal microbiota transplantation (FMT) as a positive control. The intestinal inflammation and functions of multiple barriers were assessed, including the mucus barrier, epithelial barrier and endothelial barrier known as gut-vascular barrier (GVB). Altered composition and diversity in gut microbiota were observed via sequencing analysis.

KEY FINDINGS

Both P-qua and P-tri relieved the intestinal inflammation and improved the functions of multiple barriers with increased integrity of mucous layer, enhanced transepithelial electrical resistance, declined epithelial and endothelial permeability to macromolecules in DSS-colitis. Aerobe-contained P-qua revealed a more active role in barrier recovering relative to P-tri, while FMT as a positive control seemed to get better results than pure probiotics. Indeed, P-qua was effective in rebuilding the structure and diversity of gut flora in DSS-colitis, especially increased abundance of Bifidobacterium, Akkermansia, Lactobacillus and Bacteroides.

SIGNIFICANCE

Aerobe-contained P-qua was a powerful adjuvant therapy for chronic colitis, via restoring the intestinal microflora and recovering the multi-barriers in the inflamed gut.

Exacerbation of Type 1 Diabetes in Perinatally Genistein Exposed Female Non-Obese Diabetic (NOD) Mouse Is Associated With Alterations of Gut Microbiota and Immune Homeostasis

Despite various hypothesized benefits of dietary isoflavone genistein (GEN) from soy-based products, many questions surrounding GEN's immunotoxic effects, especially during perinatal exposure, have yet to be answered. The objective of the study was to determine if there existed a sex-specific effect of GEN on type 1 diabetes (T1D) following perinatal exposure. We exposed offspring of non-obese diabetic (NOD) mice to GEN per oral at a physiological dose (20 mg/kg body weight) from embryonic day 7 to postnatal day (PND) 21. In female offspring, perinatal GEN dosing significantly increased the incidence of T1D at early time points, and the exacerbation was associated with decreased serum levels of interleukin (IL)-10, IgG2a, and IgM. In male offspring dosed with GEN, a decrease in serum IgG1 was also observed. Flow cytometric analysis in females suggested an increased pro-inflammatory splenic CD5+CD24- and CD4-CD8+ cell counts, while both %T cells and %CD4+ T cells were significantly decreased in males, suggesting an anti-inflammatory effect. Gut microbiota (GMB) analysis indicated that fecal microbiota from PND 90 female offspring exhibited an increased level of Enterobacteriales (suggesting a pro-inflammatory response), while the similar changes were not found in PND 30 females. Moreover, RNA sequencing showed that intestinal α-defensin expression was down-regulated in GEN-treated females, supporting a pro-inflammatory response. However, perinatal GEN administration perturbed GMB toward an anti-inflammatory response in PND 90 males. Taken together, a strong sex-specific effect was found in the perinatal GEN exposure window, and the T1D exacerbation in NOD females was associated with GMB-related immunomodulatory mechanisms.

Phosphoinositide 3-Kinase P110δ-Signaling Is Critical for Microbiota-Activated IL-10 Production by B Cells that Regulate Intestinal Inflammation

The phosphoinositide 3-kinase catalytic subunit p110δ (PI3Kδ) gene maps to a human inflammatory bowel diseases (IBD) susceptibility locus, and genetic deletion of PI3Kδ signaling causes spontaneous colitis in mice. However, little is known regarding the role of PI3Kδ on IL-10-producing B cells that help regulate mucosal inflammation in IBD. We investigated the role of PI3Kδ signaling in B cell production of IL-10, following stimulation by resident bacteria and B cell regulatory function against colitis. In vitro, B cells from PI3KδD910A/D910A mice or wild-type B cells treated with PI3K specific inhibitors secreted significantly less IL-10 with greater IL-12p40 following bacterial stimulation. These B cells failed to suppress inflammatory cytokines by co-cultured microbiota-activated macrophages or CD4+ T cells. In vivo, co-transferred wild-type B cells ameliorated T cell-mediated colitis, while PI3KδD910A/D910A B cells did not confer protection from mucosal inflammation. These results indicate that PI3Kδ-signaling mediates regulatory B cell immune differentiation when stimulated with resident microbiota or their components, and is critical for induction and regulatory function of IL-10-producing B cells in intestinal homeostasis and inflammation.

Compound polysaccharides ameliorate experimental colitis by modulating gut microbiota composition and function

BACKGROUND AND AIM

Inflammatory bowel disease results from a dysregulated immune response to intestinal microbial flora in individuals with genetic predisposition(s). This study aimed to determine the effects of compound polysaccharides (CP) containing yam polysaccharide and inulin on the rat model of colitis induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) and to explain the mechanism in terms of gut microbiota composition and function.

METHODS

Male SD rats were divided into three groups: the control group, the model group, and the CP group. Disease activity index, serum myeloperoxidase level, and the composition and function of gut microbiota were analyzed.

RESULTS

The data in the study showed CP reduced inflammation in the rat model of colitis induced by TNBS and ameliorated the experimental colitis. The results also indicated that CP not only reversed TNBS-induced gut dysbiosis-indexed by increased short-chain fatty acids (SCFAs)-producing bacteria, lactic acid-producing bacteria, and decreased Bacteroides, Proteobacteria as well as sulfate-reducing bacteria, but also restored the dysregulated microbiota function of colitic rats into a normal condition, including an improvement on basic metabolism and a reduction on oxidative stress, cell motility, signal transduction, xenobiotics biodegradation, and metabolism as well as pathogenesis processes.

CONCLUSIONS

Compound polysaccharides ameliorated the experimental colitis of rats induced by TNBS by modulating the gut microbiota composition and function profiles, which makes it possible to be used as prebiotic agents to treat gut dysbiosis in colitis individuals.

Role of inulin as prebiotics on inflammatory bowel disease

The present review is focused on the prebiotic impact of inulin on the management of the gastrointestinal disorder. Prebiotics can be described as "non-digestible food ingredient stimulating the growth of a certain number of bacteria in the colon, which can improve the host health". In 2004 this definition was modernized to include other areas that may benefit from selective targeting of particular microorganisms: "selectively fermented ingredients that alter the configuration and activity in the gastrointestinal microbiota that confer positive effect". The positive impact of prebiotics in experimental colitis and human inflammatory bowel disease (IBD) has already been established. Prebiotics shows a positive effect in the prevention of IBD by modulating the trophic functions of the flora. Inulin enhances the growth of indigenous lactobacilli and/or bifidobacteria by inducing colonic production of short chain fatty acids (SCFA's) and these properties are related to decreased mucosal lesion scores and diminished mucosal inflammation. Inulin shows a positive approach to retain microbial populations and to support epithelial barrier function by their prebiotic effect which helps in the host defense against invasion and pathogens translocation (endogenous and/or exogenous) and in the inhibition of gastrointestinal diseases and this impact should be verified in further clinical studies. In the present review, we discussed the positive effect of prebiotics in rat IBD models and in human subjects along with their potential protective mechanisms. Preclinical and clinical data revealed that the gut mucosal barrier would be improved by the use of prebiotics in IBD.

Gnotobiotics: Past, present and future

Gnotobiotics or gnotobiology is a research field exploring organisms with a known microbiological state. In animal research, the development of gnotobiotics started in the late 19th century with the rederivation of germ-free guinea pigs. Cutting-edge achievements were accomplished by scientists in the Laboratories of Bacteriology at the University of Notre Dame (LOBUND). The primary goals of gnotobiotics were not only the development of the equipment required for long-term husbandry but also phenotypic characterization of germ-free animals. The first isolators were designed by Reynolds and Gustafsson as rigid-wall stainless steel autoclave-like chambers, which were subsequently replaced by Trexler’s flexible-film polyvinyl plastic isolators. Flexible-film or semi-rigid isolators are commonly used today. The long-term maintenance of gnotobiotic rodents is performed in positive-pressure isolators. However, to facilitate gnotobiotic experimental procedures, short-term husbandry systems have been developed. Gnotobiotic animal husbandry is laborious and requires experienced staff. Germ-free animals can be rederived from existing rodent colonies by hysterectomy or embryo transfer. The physiology and anatomy of germ-free rodents are different from those of specified pathogen-free (SPF) rodents. Furthermore, to guarantee gnotobiotic status, the colonies need to be regularly microbiologically monitored. Today, gnotobiotics provides a powerful tool to analyse functional effects of host-microbe interactions, especially in complex disease models. Gnotobiotic models combined with ‘omics’ approaches will be indispensable for future advances in microbiome research. Furthermore, these approaches will contribute to the development of novel therapeutic targets. In addition, regional or national gnotobiotic core facilities should be established in the future to support further applications of gnotobiotic models.

Mulberry juice freeze-dried powder attenuates the disease severity by the maintaining of colon mucosa in mice with DSS-induced acute colitis

This study aimed to evaluate the microbial compositions and gene expression related to inflammation in dextran sodium sulfate (DSS)-induced acute colitis and the effect of mulberry supplementation. Male BALB/c mice received a diet supplemented with mulberry juice freeze-dried powder (MFP) or not for 3 weeks. After 3 weeks, the mice received water containing 5% (w/v) DSS or not for 1 week. The disease activity index score in mice fed MFP was significantly decreased. A significant decrease in Bifidobacterium spp. and the Clostridium perfringens subgroup was observed in mice not fed MFP. The number of goblet cell and NLRP6 expression were observed in mice fed a diet supplemented with MFP compared with mice not fed MFP. These results may indicate that mulberry mitigates DSS-induced acute colitis by a changing the gut microbial flora and by improving mucosal conditions.

Analysis of Cdcs1 colitogenic effects in the hematopoietic compartment reveals distinct microbiome interaction and a new subcongenic interval active in T cells

Disease activity in Interleukin-10-deficient (Il10^-/-) mice, a model for IBD, depends on genetic background and microbiome composition. B6.129P2/JZtm-Il10^tm1Cgn (B6-Il10^-/-) mice are partially resistant to colitis, whereas mice carrying the Cdcs1^C3Bir haplotype on chromosome 3, B6.Cg-Il10^tm1CgnMMU3(D3Mit11-D3Mit348)/JZtm (BC-R3-Il10^-/-), are susceptible. This study was performed to clarify Cdcs1 and candidate gene effects on the colitogenic potential of hematopoietic cells using bone marrow (BM) and T-cell transfer models. Acute and chronic graft versus host reaction was excluded by high-density genotyping, in vitro and in vivo approaches. BM-chimeras were created with animals housed in two barriers (I and II) with distinct microbiota composition as identified by sequencing. BM-chimeras of all groups developed comparable moderate-to-severe colitis in Barrier I, however, in Barrier II only recipients of BC-R3-Il10^-/- BM. Subsequent adoptive T cell transfers pointed to a new subcongenic interval within Cdcs1 affecting their colitogenic potential. Transfers excluded Larp7 and Alpk1 but highlighted Ifi44 as potential candidate genes. In this model-system, colitis development after cell transfer heavily depends on microbiome, though Cdcs1 acts mainly independently in hematopoietic cells. A new subcongenic interval, provisionally named Cdcs1.4, modifies colitogenic T cell function. Within this locus, Ifi44 represents an important candidate gene for colitis expression.

Contribution of Non-immune Cells to Activation and Modulation of the Intestinal Inflammation

The mucosal immune system constitutes a physical and dynamic barrier against foreign antigens and pathogens and exerts control mechanisms to maintain intestinal tolerance to the microbiota and food antigens. Chronic alterations of the intestinal homeostasis predispose to inflammatory diseases of the gastrointestinal tract, such as Inflammatory Bowel Diseases (IBD). There is growing evidence that the frequency and severity of these diseases are increasing worldwide, which may be probably due to changes in environmental factors. Several stromal and immune cells are involved in this delicate equilibrium that dictates homeostasis. In this review we aimed to summarize the role of epithelial cells and fibroblasts in the induction of mucosal inflammation in the context of IBD. It has been extensively described that environmental factors are key players in this process, and the microbiome of the gastrointestinal tract is currently being intensively investigated due to its profound impact the immune response. Recent findings have demonstrated the interplay between dietary and environmental components, the gut microbiome, and immune cells. "Western" dietary patterns, such as high caloric diets, and pollution can induce alterations in the gut microbiome that in turn affect the intestinal and systemic homeostasis. Here we summarize current knowledge on the influence of dietary components and air particulate matters on gut microbiome composition, and the impact on stromal and immune cells, with a particular focus on promoting local inflammation.

Oral Lactobacillus reuteri LR06 or Bifidobacterium BL5b supplement do not produce analgesic effects on neuropathic and inflammatory pain in rats

BACKGROUND

Previous studies have reported that certain bacteria exert visceral antinociceptive activity in visceral pain and may also help to relieve neuropathic and inflammatory pain.

OBJECTIVE

The aim of this study was to explore the analgesic effect of Lactobacillus reuteri LR06 (LR06) or Bifidobacterium BL5b (BL5b) in chronic pain in vivo.

DESIGN

Rats were randomly assigned into four groups: sham, Chronic Constriction Injury (CCI)/Complete Freund's Adjuvant (CFA) + control, CCI/CFA + LR06, and CCI/CFA + BL5b. Rats from the probiotic groups were treated with 1 x 10⁹ cfu (LR06 or BL5b) daily through gavage for 14 days after a pain model was successfully established. Mechanical and thermal hyperalgesia were used to assess the analgesic effect of the probiotics. Iba1 was used to verify the microglial inflammatory reaction in the different groups.

RESULTS

The results showed that probiotics L. reuteri LR06 or Bifidobacterium BL5b had no significant antinociception effects in chronic pain rats. The chronic pain-induced activation of microglia (Iba1) was not relieved by probiotics in CCI/CFA-induced neuropathic or inflammatory pain rats.

CONCLUSION

Our results suggested that L. reuteri LR06 or Bifidobacterium BL5b had no antinociceptive effects on CCI-induced neuropathic pain and CFA-induced inflammatory pain in rats.