Antibiotics and probiotics in inflammatory bowel disease: when to use them?

The gut microbiota predicts and time-restricted feeding delays experimental colitis

The etiology of inflammatory bowel disease (IBD) remains unclear, treatment options unsatisfactory and disease development difficult to predict for individual patients. Dysbiosis of the gastrointestinal microbiota and disruption of the biological clock have been implicated and studied as diagnostic and therapeutic targets. Here, we examine the relationship of IBD to biological clock and gut microbiota by using the IL-10 deficient (IL-10-/-) mouse model for microbiota-dependent spontaneous colitis in combination with altered (4 h/4 h) light/dark cycles to disrupt and time-restricted feeding (TRF) to restore circadian rhythmicity. We show that while altered light/dark cycles disrupted the intestinal clock in wild type (WT) mice, IL-10-/- mice were characterized by altered microbiota composition, impaired intestinal clock, and microbiota rhythmicity irrespective of external clock disruption, which had no consistent colitis-promoting effect on IL-10-/- mice. TRF delayed colitis onset reduced the expression of inflammatory markers and increased the expression of clock genes in the intestine, and increased gut microbiota rhythmicity in IL-10-/- mice. Compositional changes and reduced rhythmicity of the fecal microbiota preceded colitis and could predict colitis symptoms for individual IL-10-/- mice across different experiments. Our findings provide perspectives for new diagnostic and TRF-based, therapeutic applications in IBD that should be further explored.

Prevalence of Plasmid-Mediated Quinolone Resistance Genes in Escherichia coli Isolates From Colonic Biopsies of Iranian Patients With Inflammatory Bowel Diseases: A Cross-Sectional Study

Background and Aims

Emerging evidence suggests that ciprofloxacin and other quinolones can be effectively used as adjuncts to immunosuppressive therapy in managing inflammatory bowel disease (IBD). Clinical isolates of Enterobacterales frequently exhibit quinolone resistance. Additionally, increased IBD severity has been linked to the proliferation of Enterobacterales in the gut. This study aimed to explore the frequency of fluoroquinolone resistance and the presence of associated resistance genes in Escherichia coli isolates obtained from intestinal biopsies of patients with IBD in Iran.

Methods

In this research, we conducted a study that involved the isolation and examination of E. coli bacteria from inflamed ileal and/or colonic tissues of patients diagnosed with IBD, specifically ulcerative colitis (UC) and Crohn's disease (CD), during colonoscopy procedures. We collected demographic and clinical information from the patients. To identify E. coli strains that were resistant to quinolone antibiotics, we performed both phenotypic and molecular analyses.

Results

From the colonic and ileal biopsies of 121 patients with IBD, we isolated 107 unique strains of E. coli. Among these strains, 18 (16.8%) were derived from patients with CD, and 89 (83.2%) came from those with UC. Antimicrobial susceptibility tests revealed that 61 out of 107 isolates (57%) of the isolates showed phenotypic resistance to at least one type of quinolone. Additionally, plasmid-mediated quinolone resistance (PMQR) genes, specifically oqxA, oqxB, and qnrS were detected in the E. coli strains linked to both UC and CD. Notably, there was a significant positive correlation observed between intestinal colonization by ciprofloxacin-resistant E. coli and the patients' history of extended ciprofloxacin antibiotic therapy.

Conclusion

Our results reveal that a significant number of patients with IBD carry quinolone-resistant E. coli. This colonization may pose a risk factor that could affect disease progression and contribute to potential complications.

Targeting inflammation and gut microbiota with antibacterial therapy: Implications for central nervous system health

The complex symbiotic relationship between inflammation, the gut microbiota, and the central nervous system (CNS) has become a pivotal focus of contemporary biomedical research. Inflammation, as a physiological defense mechanism, plays a dual role as both a protective and pathological factor, and is intricately associated with gut microbiota homeostasis, often termed the "second brain." The gutbrain axis (GBA) exemplifies this multifaceted interaction, where gut health exerts significantly regulatory effects on CNS functions. Antibacterial therapies represent both promising and challenging strategies for modulating inflammation and gut microbiota composition to confer CNS benefits. However, while such therapies may exert positive modulatory effects on the gut microbiota, they also carry the potential to disrupt microbial equilibrium, potentially exacerbating neurological dysfunction. Recent advances have provided critical insights into the therapeutic implications of antibacterial interventions; nevertheless, the application of these therapies in the context of CNS health warrants a judicious and evidence-based approach. As research progresses, deeper investigation into the microbial-neural interface is essential to fully realize the potential of therapies targeting inflammation and the gut microbiota for CNS health. Future efforts should focus on refining antibacterial interventions to modulate the gut microbiota while minimizing disruption to microbial balance, thereby reducing risks and enhancing efficacy in CNS-related conditions. In conclusion, despite challenges, a more comprehensive understanding of the GBA, along with precise modulation through targeted antibacterial therapies, offers significant promise for advancing CNS disorder treatment. Continued research in this area will lead to innovative interventions and improved patient outcomes.

Drug Interaction-Informed Approaches to Inflammatory Bowel Disease Management

Inflammatory bowel disease (IBD) is a complex and chronic condition that requires the use of various pharmacological agents for its management. Despite advancements in IBD research, the multifaceted mechanisms involved continue to pose significant challenges for strategic prevention. Therefore, it is crucial to prioritize safe and effective treatment strategies using the currently available pharmacological agents. Given that patients with IBD often require multiple medications due to combination therapy or other underlying conditions, a comprehensive understanding of drug interactions is essential for optimizing treatment regimens. In this review, we examined the pharmacological treatment options recommended in the current IBD management guidelines and provided a comprehensive analysis of the known pharmacokinetic interactions associated with these medications. In particular, this review includes recent research results for the impact of anti-drug antibodies (ADAs) on the concentrations of biological agents used in IBD treatment. By leveraging detailed interaction data and employing personalized dosing strategies, healthcare providers can improve therapeutic outcomes and minimize adverse effects, ultimately improving the quality of care for patients with IBD.

Targeting the Intestinal Microbiota: A Novel Direction in the Treatment of Inflammatory Bowel Disease

Over the past decade, there has been a rapid increase in the incidence of inflammatory bowel disease. It has been suggested that multifactorial interactions of environmental factors, genetic factors, immune response and intestinal microbiota are involved in the pathogenesis of inflammatory bowel disease. It is widely recognized that the intestinal microbiota are essential for human metabolism, the immune system and pathogen resistance, and are integral to human health. Therefore, the dysbiosis of the microbiota is a critical step leading to intestinal mucosal damage and a key factor in the pathogenesis of inflammatory bowel disease. Regulating the microbiota through interventions such as enteral nutrition, fecal microbiota transplantation, and probiotic supplementation has the potential to prevent or even reverse intestinal dysbiosis, opening up new perspectives for the treatment of inflammatory bowel disease.

Dubosiella newyorkensis modulates immune tolerance in colitis via the L-lysine-activated AhR-IDO1-Kyn pathway

Commensal bacteria generate immensely diverse active metabolites to maintain gut homeostasis, however their fundamental role in establishing an immunotolerogenic microenvironment in the intestinal tract remains obscure. Here, we demonstrate that an understudied murine commensal bacterium, Dubosiella newyorkensis, and its human homologue Clostridium innocuum, have a probiotic immunomodulatory effect on dextran sulfate sodium-induced colitis using conventional, antibiotic-treated and germ-free mouse models. We identify an important role for the D. newyorkensis in rebalancing Treg/Th17 responses and ameliorating mucosal barrier injury by producing short-chain fatty acids, especially propionate and L-Lysine (Lys). We further show that Lys induces the immune tolerance ability of dendritic cells (DCs) by enhancing Trp catabolism towards the kynurenine (Kyn) pathway through activation of the metabolic enzyme indoleamine-2,3-dioxygenase 1 (IDO1) in an aryl hydrocarbon receptor (AhR)-dependent manner. This study identifies a previously unrecognized metabolic communication by which Lys-producing commensal bacteria exert their immunoregulatory capacity to establish a Treg-mediated immunosuppressive microenvironment by activating AhR-IDO1-Kyn metabolic circuitry in DCs. This metabolic circuit represents a potential therapeutic target for the treatment of inflammatory bowel diseases.

Lactobacillus paracasei JY062 Alleviates Glucolipid Metabolism Disorders via the Adipoinsular Axis and Gut Microbiota

Glycolipid metabolic disorders (GLMD) refer to a series of metabolic disorders caused by abnormal processes of glucose and lipid synthesis, decomposition, and absorption in the body, leading to glucose and lipid excess, insulin resistance, and obesity. Probiotic intervention is a new strategy to alleviate metabolic syndrome. Lactobacillus paracasei JY062 (L. paracasei JY062) was separated from the Tibet-fermented dairy products. The results demonstrated a strong ability to relieve blood glucose disorders, blood lipid disorders, and tissue damage. The LPH group had the best effect, significantly decreasing the total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), leptin, insulin, and free fatty acid (FFA) concentrations and increasing the high-density lipoprotein cholesterol, adiponectin, and GLP-1 level compared to HFD-group mice. L. paracasei JY062 could activate the APN-AMPK pathway, increased AdipoQ, AMPK GLUT-4, and PGC-1α mRNA expression and decreased SREBP-1c, ACC, and FAS mRNA expression. L. paracasei JY062 intervention decreased the relative abundance of harmful bacteria, increased the relative abundance of beneficial bacteria, and restored the imbalance of gut microbiota homeostasis caused by a high-glucose-fat diet. L. paracasei JY062 alleviated glucolipid metabolism disorders via the adipoinsular axis and gut microbiota. This study provided a theoretical basis for probiotics to ameliorate glucolipid metabolism disorders by regulating the adipoinsular axis.

Amelioration of acetic acid-induced ulcerative colitis in rats by cetirizine and loratadine via regulation of the PI3K/Akt/Nrf2 signalling pathway and pro-inflammatory cytokine release

Objectives

Ulcerative colitis is a chronic inflammatory bowel disease (IBD) that causes inflammation and ulcers in the rectum and the innermost layer of the large intestine. Our study aimed to elucidate the ameliorative effect of cetirizine (CTZ) and loratadine (LOR) against acetic acid-induced ulcerative colitis in rats via assessment of the PI3K/p-Akt/Nrf2 signaling pathway and proinflammatory cytokine release.

Materials and Methods

Thirty-two rats were allocated into four groups (n=8). Group (I) was considered normal control. Acetic acid (AA) was injected intrarectally in groups (2-4). Group (2) was kept untreated. Group (3) was administered CTZ (20 mg/kg/day) for 7 days. Group (4) was administered LOR (10 mg/kg/day) for 7 days.

Results

AA showed severe macroscopic colonic lesions associated with increased ulcer number, area, and severity with significantly elevated PI3K, p-Akt, Nrf2, TNF-α, and IL-6 in colorectal tissue as compared to the normal control group. All the aforementioned indicators were greatly improved by CTZ and LOR therapy.

Conclusion

This is the first study to elucidate the ameliorative effect of CTZ and LOR against AA-induced UC in rats. CTZ and LOR treatment mitigates UC via amelioration of the PI3K/p-Akt/Nrf2 pathway and proinflammatory cytokine release.

Microbiota as key factors in inflammatory bowel disease

Inflammatory Bowel Disease (IBD) is characterized by prolonged inflammation of the gastrointestinal tract, which is thought to occur due to dysregulation of the immune system allowing the host's cells to attack the GI tract and cause chronic inflammation. IBD can be caused by numerous factors such as genetics, gut microbiota, and environmental influences. In recent years, emphasis on commensal bacteria as a critical player in IBD has been at the forefront of new research. Each individual harbors a unique bacterial community that is influenced by diet, environment, and sanitary conditions. Importantly, it has been shown that there is a complex relationship among the microbiome, activation of the immune system, and autoimmune disorders. Studies have shown that not only does the microbiome possess pathogenic roles in the progression of IBD, but it can also play a protective role in mediating tissue damage. Therefore, to improve current IBD treatments, understanding not only the role of harmful bacteria but also the beneficial bacteria could lead to attractive new drug targets. Due to the considerable diversity of the microbiome, it has been challenging to characterize how particular microorganisms interact with the host and other microbiota. Fortunately, with the emergence of next-generation sequencing and the increased prevalence of germ-free animal models there has been significant advancement in microbiome studies. By utilizing human IBD studies and IBD mouse models focused on intraepithelial lymphocytes and innate lymphoid cells, this review will explore the multifaceted roles the microbiota plays in influencing the immune system in IBD.

Consenso colombiano de la enfermedad inflamatoria intestinal pediátrica

Introducción: la colitis ulcerativa pediátrica (CUP), la enfermedad de Crohn pediátrica (ECP) y la enfermedad inflamatoria intestinal pediátrica no clasificable (EIIPNC) tienen particularidades clínicas y psicosociales que las diferencian de las del adulto y pueden condicionar enfoques terapéuticos distintos por las posibles repercusiones nutricionales, crecimiento y desarrollo, lo que representa un desafío para el pediatra y el gastroenterólogo. Objetivo: desarrollar recomendaciones basadas en la evidencia por consenso de expertos para el diagnóstico y el tratamiento oportunos y seguros de la enfermedad inflamatoria intestinal pediátrica (EIIP) en menores de 18 años, para los profesionales que atienden estos pacientes y los pagadores en salud. Metodología: a través de un panel de expertos del Colegio Colombiano de Gastroenterología, Hepatología y Nutrición Pediátrica (COLGAHNP) y un grupo multidisciplinario se formularon 35 preguntas en relación con el cuadro clínico, el diagnóstico y el tratamiento de la EIIP. A través de una revisión y un análisis crítico de la literatura, con especial énfasis en las principales guías de práctica clínica (GPC), estudios clínicos aleatorizados (ECA) y metaanálisis de los últimos 10 años, los expertos plantearon 77 recomendaciones que respondían a cada una de las preguntas de investigación con sus respectivos puntos prácticos. Posteriormente, cada una de las afirmaciones se sometieron a votación dentro del grupo desarrollador, incluyendo las afirmaciones que alcanzaron > 80 %. Resultados: todas las afirmaciones alcanzaron una votación > 80 %. La EIIP tiene mayor extensión, severidad y evolución hacia la estenosis, enfermedad perianal, manifestaciones extraintestinales y retraso en el crecimiento en comparación con los pacientes adultos, por lo que su manejo debe ser realizado por grupos multidisciplinarios liderados por gastroenterólogos pediatras y prepararlos para una transición a la edad adulta. Los criterios de Porto permiten una clasificación práctica de la EIIP. En la ECP, debemos usar la clasificación de París y debemos realizar ileocolonoscopia y esofagogastroduodenoscopia, ya que el 50 % tienen un compromiso superior, usando el SES-CD (UCEIS/Mayo en CUP) y tomando múltiples biopsias. Los laboratorios iniciales deben incluir marcadores de inflamación, calprotectina fecal y descartar infecciones intestinales. El tratamiento, la inducción y el mantenimiento de la EIIP deben ser individualizados y decididos según la estratificación de riesgo. En el seguimiento se debe usar el Pediatric Crohn Disease Activity Index (PCDAI) y Pediatric Ulcerative Colitis Activity Index (PUCAI) de las últimas 48 horas. Los pacientes con EIIP temprana e infantil, deben ser valorados por inmunólogos y genetistas. Conclusión: se proporciona una guía de consenso con recomendaciones basadas en la evidencia sobre el diagnóstico y los tratamientos oportunos y seguros en los pacientes con EIIP.

Evaluation of microbial and vancomycin treatments in ulcerative colitis in murine models

BACKGROUND

Despite the number of available therapies for ulcerative colitis (UC), severe side effects and high cost has limited their clinical application. Thus, finding new alternative strategies with minimal side effects is inevitable. Therefore, this study aimed to compare the effectiveness of different therapeutic approaches in DSS-induced colitis.

METHODS

Firstly, we designed oral bio-therapeutic products, Live Bacterial Products (LBP), which include a mixture of fecal bacteria strains isolated from healthy mice and prepared by microencapsulation and freeze-dried techniques. Then we investigated the efficiency of 7 days of freeze-dried FMT, LBP, and vancomycin treatments in DSS-induced colitis. Secondly, we compared the effect of 15 days of microbial therapies (freeze-dried powder of FMT and LBP microcapsules) and seven days of oral vancomycin on the severity of colitis in mice. Furthermore, the levels of IL-1β and TNF-α were measured in serum by ELISA, and the fecal microbiota diversity was analyzed by high-throughput sequencing for all mice groups.

RESULTS

After seven days of treatments, our results indicated that oral vancomycin reduced the severity of DSS-induced colitis in mice, where weight gain and a decrease in IL-1 β and TNF-α levels were observed in the vancomycin group compared with other treatment groups. While after two weeks of treatment, the LBP microcapsules were able to reduce the severity of colitis. And at the end of the treatment period, weight gain and a decrease in the DAI scores and the levels of IL-1β and TNF-α were noted in the LBP treatment group compared to other treatment groups. By high-throughput sequencing of the 16S rRNA gene, our results showed that while the microcapsules LBP treatment increased the fecal microbial diversity, after vancomycin therapy, most of the fecal microbiota genera and operational taxonomic units (OTUs) were depleted.

CONCLUSION

Our results concluded that treatment duration and preparation methods affect the microbial therapies' efficiency in UC. Furthermore, this study highlighted the negative consequences of oral vancomycin administration on gut health that should be known before using this medication.

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.

Manifestations of the gastrointestinal tract in systemic rheumatic diseases: A narrative review

Gastrointestinal disorders are important place among the visceral manifestations of systemic autoimmune and immunoinflammatory rheumatic diseases (RD). Pathology of the esophagus, stomach, small and large intestine can vary from moderate functional disorders to the development of severe chronic inflammation with metaplasia and dysplasia of the mucous membrane, the formation of multiple erosions, hemorrhages and deep ulcers. Complications of gastrointestinal pathology in RD, such as bleeding, perforations and strictures, can cause death. This review examines the main clinical manifestations, possibilities of diagnosis and treatment of gastrointestinal lesions in systemic scleroderma, idiopathic inflammatory myopathies, systemic vasculitis, Sjogren’s syndrome and disease, as well as systemic lupus erythematosus.

Enterobacter ludwigii protects DSS-induced colitis through choline-mediated immune tolerance

Commensal intestinal bacteria play key roles in regulating host immune tolerance; however, bacterial strains and related metabolites directly involved in this regulation are largely unknown. Here, using a mouse model of dextran sulfate sodium (DSS)-induced colitis combined with different antibiotic treatment, Enterobacter ludwigii, abundant in microbiota of mice treated with metronidazole, is screened out to have prophylactic and therapeutic effects on DSS-induced colitis with or without the presence of complex intestinal bacteria. E. ludwigii is found to induce CD103⁺DC and regulatory T (Treg)-mediated immune tolerance for colitis remission using in vitro and in vivo experiments. Moreover, choline, one metabolite of E. ludwigii, is identified to increase dendritic cells' (DCs) immune tolerance to promote Treg differentiation. E. ludwigii is found to induce DCs' immune tolerance ability for Treg differentiation through choline and α7nAChR-mediated retinoic acid (RA) and transforming growth factor beta (TGF-β) upregulation, resulting in protecting mice against DSS-induced colitis. This study suggests potential therapeutic approaches for inflammatory bowel diseases (IBDs).

Mechanisms of mucosal healing: treating inflammatory bowel disease without immunosuppression?

Almost all currently available treatments for inflammatory bowel disease (IBD) act by inhibiting inflammation, often blocking specific inflammatory molecules. However, given the infectious and neoplastic disease burden associated with chronic immunosuppressive therapy, the goal of attaining mucosal healing without immunosuppression is attractive. The absence of treatments that directly promote mucosal healing and regeneration in IBD could be linked to the lack of understanding of the underlying pathways. The range of potential strategies to achieve mucosal healing is diverse. However, the targeting of regenerative mechanisms has not yet been achieved for IBD. Stem cells provide hope as a regenerative treatment and are used in limited clinical situations. Growth factors are available for the treatment of short bowel syndrome but have not yet been applied in IBD. The therapeutic application of organoid culture and stem cell therapy to generate new intestinal tissue could provide a novel mechanism to restore barrier function in IBD. Furthermore, blocking key effectors of barrier dysfunction (such as MLCK or damage-associated molecular pattern molecules) has shown promise in experimental IBD. Here, we review the diversity of molecular targets available to directly promote mucosal healing, experimental models to identify new potential pathways and some of the anticipated potential therapies for IBD.

Mechanisms of mucosal healing: treating inflammatory bowel disease without immunosuppression?

Almost all currently available treatments for inflammatory bowel disease (IBD) act by inhibiting inflammation, often blocking specific inflammatory molecules. However, given the infectious and neoplastic disease burden associated with chronic immunosuppressive therapy, the goal of attaining mucosal healing without immunosuppression is attractive. The absence of treatments that directly promote mucosal healing and regeneration in IBD could be linked to the lack of understanding of the underlying pathways. The range of potential strategies to achieve mucosal healing is diverse. However, the targeting of regenerative mechanisms has not yet been achieved for IBD. Stem cells provide hope as a regenerative treatment and are used in limited clinical situations. Growth factors are available for the treatment of short bowel syndrome but have not yet been applied in IBD. The therapeutic application of organoid culture and stem cell therapy to generate new intestinal tissue could provide a novel mechanism to restore barrier function in IBD. Furthermore, blocking key effectors of barrier dysfunction (such as MLCK or damage-associated molecular pattern molecules) has shown promise in experimental IBD. Here, we review the diversity of molecular targets available to directly promote mucosal healing, experimental models to identify new potential pathways and some of the anticipated potential therapies for IBD.

An Update on Current Pharmacotherapeutic Options for the Treatment of Ulcerative Colitis

The main goals of Ulcerative Colitis (UC) treatment are to both induce and maintain the clinical and endoscopic remission of disease, reduce the incidence of complications such as dysplasia and colorectal carcinoma and improve quality of life. Although a curative medical treatment for UC has not yet been found, new therapeutic strategies addressing specific pathogenetic mechanisms of disease are emerging. Notwithstanding these novel therapies, non-biological conventional drugs remain a mainstay of treatment. The aim of this review is to summarize current therapeutic strategies used as treatment for ulcerative colitis and to briefly focus on emerging therapeutic strategies, including novel biologic therapies and small molecules. To date, multiple therapeutic approaches can be adopted in UC and the range of available compounds is constantly increasing. In this era, the realization of well-designed comparative clinical trials, as well as the definition of specific therapeutic models, would be strongly suggested in order to achieve personalized management for UC patients.

Successful Manipulation of the Gut Microbiome to Treat Spontaneous and Induced Murine Models of Colitis

Background and Aims

There is clinical interest in the sustainability or otherwise of prebiotic, microbial, and antibiotic treatments to both prevent and treat inflammatory bowel diseases. This study examined the role of antibiotic manipulation of the gut microbiome to treat spontaneous and induced murine models of colitis.

Methods

Symptomatic, histological, molecular, and microbial ecology and bioinformatic readouts were used to study the effect of a 10-day antibiotic cocktail and then follow-up over 2 months in the spontaneous Winnie colitis mouse preclinical model of ulcerative colitis and also the indirect antibiotic and Winnie microbiotic gavage effects in an acute dextran sodium sulfate-induced colitis model in wild-type mice.

Results

The antibiotics elicited a striking reduction in both colitis symptoms and blinded histological colitis scores, together with a convergence of the microbial taxonomy of the spontaneous colitis and wild-type control mice, toward a taxonomic phenotype usually considered to be dysbiotic. The improvement in colitis was sustained over the following 8 weeks although the microbial taxonomy changed. In vitro, fecal waters from the antibiotic-treated colitis and wild-type mice suppressed the inflammatory tenor of colonic epithelial cells, and gavaged cecal slurries from these mice moderated the acute induced colitis.

Conclusion

The results clearly show the possibility of a sustained remission of colitis by microbial manipulation, which is relevant to clinical management of inflammatory bowel diseases. The beneficial effects appeared to depend on the microbial metabolome rather than its taxonomy.

Clinical trials of probiotics in patients with IBS - some points to consider

Probiotic products in various formulations are widely used world-wide for a seemingly limitless range of indications--from health maintenance to the alleviation of common intestinal ailments and on to the prevention and treatment of a variety of gastrointestinal diseases and disorders. The profusion of probiotic preparations, together with a very different regulatory climate compared to that which surrounds drugs and devices, leaves the consumer and the health care professional alike bewildered. How can they tell which products truly are what they claim to be? Which probiotics should be chosen for a particular clinical situation? These questions are thrown into stark relief when one evaluates the literature on probiotics in irritable bowel syndrome. To provide some guidance the current probiotic landscape is reviewed and some achievable steps to help bring light to a murky environment are proposed. The goal is to promote verifiable quality control and generate actionable evidence from well-conducted clinical trials of probiotic products in irritable bowel syndrome.

Microbial pathogenesis in inflammatory bowel diseases

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal system. Previously, it is considered the disease of the western world but now the incidence and prevalence of IBD are increasing globally with urbanization and modernization. Additionally, the major problem is the highest incidence of IBD among children and adolescents. The precise etiology of IBD is unknown and there is no cure for IBD, which is also the reason for increasing the number of cases worldwide. The IBD is a complex interplay of environment, immune system, and microbiota in a genetically susceptible host. Among these factors, the alteration in intestinal microbiota has been detected in IBD patients. The bacterial species associated with IBD include Mycobacterium paratuberculosis, adherent-invasive E. coli (AIEC), Helicobacter pylori, and Campylobacter concisus. Moreover, the efficacy of antibiotics and probiotics further suggests the role of microbes in IBD. However, no study confirmed the bacterial species as a cause of IBD as per Koch's postulates. Thus, still controversies exist regarding the role of microbes in IBD. Therefore, this paper aims to review the current literature to evaluate the role of microbes in IBD that would be a useful inventory of researchers working in this area.

Gut microbiota: sculptors of the intestinal stem cell niche in health and inflammatory bowel disease

Intestinal epithelium represents a dynamic and diverse cellular system that continuously interacts with gut commensals and external cues. Intestinal stem cells, which lie at the heart of epithelial renewal and turnover, proliferate to maintain a steady stem cell population and differentiate to form functional epithelial cell types. This rather sophisticated assembly-line is maintained by an elaborate micro-environment, sculpted by a myriad of host and gut microbiota-derived signals, forming an intestinal stem cell niche. This complex, yet crucial signaling niche undergoes dynamic changes during homeostasis and chronic intestinal inflammation. Inflammatory bowel disease refers to a chronic inflammatory response toward pathogenic or commensal microbiota, in a genetically susceptible host. Compositional and functional alterations in gut microbiota are pathognomonic of IBD.The present review highlights the modulatory role of gut microbiota on the intestinal stem cell niche during homeostasis and inflammatory bowel disease. We discuss the mechanisms of direct action of gut commensals (through microbiota-derived or microbiota-influenced metabolites) on ISCs, followed by their effects via other epithelial and immune cell types.

Evaluation of Microbiome Alterations Following Consumption of BIOHM, a Novel Probiotic

Gastrointestinal microbiome dysbiosis may result in harmful effects on the host, including those caused by inflammatory bowel diseases (IBD). The novel probiotic BIOHM, consisting of Bifidobacterium breve, Saccharomyces boulardii, Lactobacillus acidophilus, L. rhamnosus, and amylase, was developed to rebalance the bacterial–fungal gut microbiome, with the goal of reducing inflammation and maintaining a healthy gut population. To test the effect of BIOHM on human subjects, we enrolled a cohort of 49 volunteers in collaboration with the Fermentation Festival group (Santa Barbara, CA, USA). The profiles of gut bacterial and fungal communities were assessed via stool samples collected at baseline and following 4 weeks of once-a-day BIOHM consumption. Mycobiome analysis following probiotic consumption revealed an increase in Ascomycota levels in enrolled individuals and a reduction in Zygomycota levels (p value < 0.01). No statistically significant difference in Basidiomycota was detected between pre- and post-BIOHM samples and control abundance profiles (p > 0.05). BIOHM consumption led to a significant reduction in the abundance of Candida genus in tested subjects (p value < 0.013), while the abundance of C. albicans also trended lower than before BIOHM use, albeit not reaching statistical significance. A reduction in the abundance of Firmicutes at the phylum level was observed following BIOHM use, which approached levels reported for control individuals reported in the Human Microbiome Project data. The preliminary results from this clinical study suggest that BIOHM is capable of significantly rebalancing the bacteriome and mycobiome in the gut of healthy individuals, suggesting that further trials examining the utility of the BIOHM probiotic in individuals with gastrointestinal symptoms, where dysbiosis is considered a source driving pathogenesis, are warranted.

Microbiota-Immune Interactions in Ulcerative Colitis and Colitis Associated Cancer and Emerging Microbiota-Based Therapies

Ulcerative colitis (UC) is a chronic autoimmune disorder affecting the colonic mucosa. UC is a subtype of inflammatory bowel disease along with Crohn's disease and presents with varying extraintestinal manifestations. No single etiology for UC has been found, but a combination of genetic and environmental factors is suspected. Research has focused on the role of intestinal dysbiosis in the pathogenesis of UC, including the effects of dysbiosis on the integrity of the colonic mucosal barrier, priming and regulation of the host immune system, chronic inflammation, and progression to tumorigenesis. Characterization of key microbial taxa and their implications in the pathogenesis of UC and colitis-associated cancer (CAC) may present opportunities for modulating intestinal inflammation through microbial-targeted therapies. In this review, we discuss the microbiota-immune crosstalk in UC and CAC, as well as the evolution of microbiota-based therapies.

Antibiotics for induction and maintenance of remission in ulcerative colitis: systematic review and meta-analysis

Objectives: To ascertain the role of antibiotics in induction and maintenance of remission in ulcerative colitis (UC)Methods: We searched electronic databases for keywords ulcerative colitis or inflammatory bowel disease and antibiotics or antimicrobials. We performed a meta-analysis of randomized trials comparing antibiotics with control/placebo for clinical response, need for second line therapy, colectomy, and adverse effects. Subgroup analysis to clarify the mode of administration, number of antibiotics or the setting of use (acute severe UC or active non-severe UC) were also performed.Results: Thirteen trials with 785 patients were included. The pooled odds ratio of achieving clinical response with antibiotics was 1.74 (95% CI, 1.17-2.58). No differences were noted in relapse rates, need for second line therapy, colectomy or, adverse effects with the use of antibiotics. Subgroup analysis showed no differences with use of single or combination of antibiotics. Analysis of trials only in the setting of acute severe colitis did not demonstrate any benefit.Conclusion: The use of oral antibiotics in the setting of non-severe active UC could have some benefit in clinical response. The use of antibiotics is not of benefit in acute severe colitis, but oral antibiotics need to be evaluated in adult patients.

Rules of Engagement: Epithelial-Microbe Interactions and Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are complex, multifactorial disorders that lead to chronic and relapsing intestinal inflammation. The exact etiology remains unknown, however multiple factors including the environment, genetic, dietary, mucosal immunity, and altered microbiome structure and function play important roles in disease onset and progression. Supporting this notion that the gut microbiota plays a pivotal role in IBD pathogenesis, studies in gnotobiotic mice have shown that mouse models of intestinal inflammation require a microbial community to develop colitis. Additionally, antimicrobial therapy in some IBD patients will temporarily induce remission further demonstrating an association between gut microbes and intestinal inflammation. Finally, a dysfunctional intestinal epithelial barrier is also recognized as a key pathogenic factor in IBD. The intestinal epithelium serves as a barrier between the luminal environment and the mucosal immune system and guards against harmful molecules and microorganisms while being permeable to essential nutrients and solutes. Beneficial (i.e., mutualists) bacteria promote mucosal health by strengthening barrier integrity, increasing local defenses (mucin and IgA production) and inhibiting pro-inflammatory immune responses and apoptosis to promote mucosal homeostasis. In contrast, pathogenic bacteria and pathobionts suppress expression and localization of tight junction proteins, cause dysregulation of apoptosis/proliferation and increase pro-inflammatory signaling that directly damages the intestinal mucosa. This review article will focus on the role of intestinal epithelial cells (IECs) and the luminal environment acting as mediators of barrier function in IBD. We will also share some of our translational observations of interactions between IECs, immune cells, and environmental factors contributing to maintenance of mucosal homeostasis, as it relates to GI inflammation and IBD in different animal models.

Silk fibroin nanoparticles enhance quercetin immunomodulatory properties in DSS-induced mouse colitis

Inflammatory bowel disease (IBD) is a chronic and idiopathic inflammatory disorder affecting the gastrointestinal tract. The pharmacological treatments used currently for its treatment lack efficacy, so new therapeutic strategies should be developed. In this context, flavonoids loaded in biopolymeric nanoparticles can be considered as novel promising candidates. The aim of the present study was to evaluate the intestinal anti-inflammatory effects of quercetin when is administered loaded in silk fibroin nanoparticles (QSFN) in the dextran sulphate sodium experimental model of mouse colitis, which displays some similarities to human IBD. Previously characterized quercetin-loaded silk fibroin nanoparticles (QSFN). QSFN showed a reversible aggregation profile induced by the acidification of the solution but did not affect the loaded quercetin. Daily administration of QSFN significantly reduced disease activity index values compared to the control colitic group. This beneficial effect was not only corroborated by the histological examination of the colonic specimens but also the improvement of the colonic expression of the different proinflammatory cytokines (Tnf-α, Il-1β, Il-6, Mcp-1, Icam-1, Nlrp3 and iNOS). Therefore, these data suggest that QSFN could be a promising alternative to current treatments as a drug delivery system for IBD treatment.

Psychological comorbidity in gastrointestinal diseases: Update on the brain-gut-microbiome axis

The high comorbidity of psychological disorders in both functional and organic gastrointestinal diseases suggests the intimate and complex link between the brain and the gut. Termed the brain-gut axis, this bidirectional communication between the central nervous system and enteric nervous system relies on immune, endocrine, neural, and metabolic pathways. There is increasing evidence that the gut microbiome is a key part of this system, and dysregulation of the brain-gut-microbiome axis (BGMA) has been implicated in disorders of brain-gut interaction, including irritable bowel syndrome, and in neuropsychiatric disorders, including depression, Alzheimer's disease, and autism spectrum disorder. Further, alterations in the gut microbiome have been implicated in the pathogenesis of organic gastrointestinal diseases, including inflammatory bowel disease. The BGMA is an attractive therapeutic target, as using prebiotics, probiotics, or postbiotics to modify the gut microbiome or mimic gut microbial signals could provide novel treatment options to address these debilitating diseases. However, despite significant advancements in our understanding of the BGMA, clinical data is lacking. In this article, we will review current understanding of the comorbidity of gastrointestinal diseases and psychological disorders. We will also review the current evidence supporting the key role of the BGMA in this pathology. Finally, we will discuss the clinical implications of the BGMA in the evaluation and management of psychological and gastrointestinal disorders.

Polyphenols from food by-products: An alternative or complementary therapy to IBD conventional treatments

Inflammatory bowel diseases (IBD) are illnesses characterized by chronic intestinal inflammation and microbial dysbiosis that have emerged as a public health challenge worldwide. It comprises two main conditions: Crohn's disease and ulcerative colitis. Currently, conventional therapy to treat IBD are not free from side effects, such as liver and kidney toxicity, drug resistance, and allergic reactions. In view of this, there is growing research for alternative and complementary therapies that, in addition to acting in the prevention or the control of the disease, do not compromise the quality of life and health of individuals. In this sense, a growing body of evidence has confirmed the benefits of natural phenolic compounds in intestinal health. Phenolic compounds or polyphenols are molecules widely distributed throughout the plant kingdom (flowers, vegetables, leaves, and fruits), including plant materials remaining of the handling and food industrial processing, referred to in the scientific literature as by-products, food waste, or bagasse. Since by-products are low-cost, abundant, easily accessible, safe, and rich in bioactive compounds, it becomes an exciting option to extract, concentrate or isolate phenolic compounds to be posteriorly applied in the therapeutic approach of IBD. In this article, we have reviewed the main phenolic compounds present in various plants and by-products that have shown beneficial and/or promising effects in experimental pre-clinical, clinical, and in vitro research with IBD. In addition, we have mentioned and suggested several plants and by-products originated and produced in Latin America that could be part of future research as good sources of specific phenolic compounds to be applied in the prevention and development of alternative treatments for IBD. This review may offer a valuable reference for studies related to IBD administering phenolic compounds from natural, cheap, and easily accessible raw and undervalued materials.

[Yoghurt-induced Lactobacillus bacteremia in a patient with Crohn's disease on therapy with ustekinumab and concomitant HIV-Infection]

Probiotics are live microorganisms that are often used as adjunctive therapy in patients with inflammatory bowel disease. Although there is a lack of evidence for their benefit, the use of probiotics is encouraged by the perceived lack of adverse events. However, in rare instances, probiotics can cause systemic infections through bacteremia. We report about a patient with Crohn's disease and HIV-infection, who developed a septicemia. A Lactobacillus-bacteremia was diagnosed, the causative agents could be traced back to the consumption of self-made yoghurt. The utility of probiotics in IBD patients with underlying immune-compromising diseases is a risk which is difficult to predict, therefore their use in these patients should be discouraged.

Enteral Nutrition Supplemented with Transforming Growth Factor-β, Colostrum, Probiotics, and Other Nutritional Compounds in the Treatment of Patients with Inflammatory Bowel Disease

Enteral nutrition seems to play a significant role in the treatment of both adults and children with active Crohn's disease, and to a lesser degree in the treatment of patients with active ulcerative colitis. The inclusion of some special factors in the enteral nutrition formulas might increase the rate of the efficacy. Actually, enteral nutrition enriched in Transforming Growth Factor-β reduced the activity index and maintained remission in patients with Crohn's disease. In addition, a number of experimental animal studies have shown that colostrum exerts a significantly positive result. Probiotics of a special type and a certain dosage could also reduce the inflammatory process in patients with active ulcerative colitis. Therefore, the addition of these factors in an enteral nutrition formula might increase its effectiveness. Although the use of these formulas is not supported by large clinical trials, it could be argued that their administration in selected cases as an exclusive diet or in combination with the drugs used in patients with inflammatory bowel disease could benefit the patient. In this review, the authors provide an update on the role of enteral nutrition, supplemented with Transforming Growth Factor-β, colostrum, and probiotics in patients with inflammatory bowel disease.