Immunomodulating Activity and Therapeutic Effects of Short Chain Fatty Acids and Tryptophan Post-biotics in Inflammatory Bowel Disease

Impact of Simulated Human Gastrointestinal Digestion on the Functional Properties of Dietary Fibres Obtained from Broccoli Leaves, Grape Stems, Pomegranate and Tomato Peels

This study aimed to analyse the impact of a simulated human digestion process on the composition and functional properties of dietary fibres derived from pomegranate-peel, tomato-peel, broccoli-stem and grape-stem by-products. For this purpose, a computer-controlled simulated digestion system consisting of three bioreactors (simulating the stomach, small intestine and colon) was utilised. Non-extractable phenols associated with dietary fibre and their influence on antioxidant capacity and antiproliferative activity were investigated throughout the simulated digestive phases. Additionally, the modifications in oligosaccharide composition, the microbiological population and short-chain fatty acids produced within the digestion media were examined. The type and composition of each dietary fibre significantly influenced its functional properties and behaviour during intestinal transit. Notably, the dietary fibre from the pomegranate peel retained its high phenol content throughout colon digestion, potentially enhancing intestinal health due to its strong antioxidant activity. Similarly, the dietary fibre from broccoli stems and pomegranate peel demonstrated anti-proliferative effects in both the small and the large intestines, prompting significant modifications in colonic microbiology. Moreover, these fibre types promoted the growth of bifidobacteria over lactic acid bacteria. Thus, these results suggest that the dietary fibre from pomegranate peel seems to be a promising functional food ingredient for improving human health.

The Role of the Gut Microbiome in Inflammatory Bowel Disease: The Middle East Perspective

The gut microbiome is of paramount importance in preserving internal balance in the gastrointestinal tract; therefore, disruptions in its regulation have been linked to the development of inflammatory bowel disease (IBD). This article explores the intricate details of the gastrointestinal microbiome as it pertains to inflammatory bowel disease (IBD), with an emphasis on the Middle East. The study reviews the typical gut microbiome, modifications in inflammatory bowel disease (IBD), determinants impacting the gut microbiome of the Middle East, and prospective therapeutic interventions.

The Gut Microbiome and Symptom Burden After Kidney Transplantation: An Overview and Research Opportunities

Many kidney transplant recipients continue to experience high symptom burden despite restoration of kidney function. High symptom burden is a significant driver of quality of life. In the post-transplant setting, high symptom burden has been linked to negative outcomes including medication non-adherence, allograft rejection, graft loss, and even mortality. Symbiotic bacteria (microbiota) in the human gastrointestinal tract critically interact with the immune, endocrine, and neurological systems to maintain homeostasis of the host. The gut microbiome has been proposed as an underlying mechanism mediating symptoms in several chronic medical conditions including irritable bowel syndrome, chronic fatigue syndrome, fibromyalgia, and psychoneurological disorders via the gut-brain-microbiota axis, a bidirectional signaling pathway between the enteric and central nervous system. Post-transplant exposure to antibiotics, antivirals, and immunosuppressant medications results in significant alterations in gut microbiota community composition and function, which in turn alter these commensal microorganisms' protective effects. This overview will discuss the current state of the science on the effects of the gut microbiome on symptom burden in kidney transplantation and future directions to guide this field of study.

Gut health benefits and associated systemic effects provided by functional components from the fermentation of natural matrices

Recently, the role of the gut microbiota in metabolic health, immunity, behavioral balance, longevity, and intestine comfort has been the object of several studies from scientific communities. They were encouraged by a growing interest from food industries and consumers toward novel fermented ingredients and formulations with powerful biological effects, such as pre, pro, and postbiotic products. Depending on the selected strains, the operating conditions, the addition of suitable reagents or enzymes, the equipment, and the reactor configurations, functional compounds with high bioactivity, such as short-chain fatty acids, gamma-aminobutyric acid, bioactive peptides, and serotonin, can be enhanced and/or produced through fermentation of several vegetable matrices. Otherwise, their formation can also be promoted directly in the gut after the dietary intake of fermented foods: In this case, fermentation will aim to increase the content of precursor substances, such as indigestible fibers, polyphenols, some amino acids, and resistant starch, which can be potentially metabolized by endogenous gut microorganisms and converted in healthy molecules. This review provides an overview of the main functional components currently investigated in literature and the associated gut health benefits. The current state of the art about fermentation technology as a promising functionalization tool to promote the direct or indirect formation of gut-health-enhancing components was deepened, highlighting the importance of optimizing microorganism selection, system setups, and process conditions according to the target compound of interest. The collected data suggested the possibility of gaining novel functional food ingredients or products rich in functional molecules through fermentation without performing additional extraction and purification stages, which are needed when conventional culture broths are used.

Effects of Dietary Fiber on Short Chain Fatty Acid Receptor mRNA in Microglia and Serotonergic Neurons in the Mouse Brain

Short-chain fatty acids (SCFAs) are bioactive lipids that are released into the colon as a metabolite of bacterial fermentation of dietary fibers. Beyond their function in the gastrointestinal tract, SCFAs can also have effects inthe brain, as a part of the gut-brain axis. Recent investigations into potential therapeutic interventions via the manipulation of the gut microbiome-and thus their SCFA metabolites-has been emerging as a new branch of personalized medicine,especially for mental health conditions. The current study sought to measure and localize SCFA receptors in the mouse brain. Two cell types have been implicated in the gut-brain axis: microglia and serotonergic neurons. We used fluorescentin situhybridization in brain sections from mice fed diets with different compositions of fat and fiber to quantify the mRNA levels of known gene markers of these two cell types and colocalize each with mRNA for free fatty acid receptors that bind SCFAs. We focused onmicroglia in the hippocampus and the serotonergic neurons of the dorsal raphe. We found high colocalization of SCFA receptors in both microglia and serotonergic neurons and discovered that SCFA receptor expression in the dorsal raphe is driven by fiber solubility, while SCFA receptor expression in the hippocampus is driven by fiber amount. Higher dietary fiber was associated with decreased tyrosine hydroxylase expression. Thus, our results indicate that the amount and solubility of dietary fiber can change gene expression in the brain's microglia and serotonin neurons, potentially via sensitivity to circulating levels of SCFAs produced in the gut.

Butyrate as a promising therapeutic target in cancer: From pathogenesis to clinic (Review)

Cancer is one of the leading causes of mortality worldwide. The etiology of cancer has not been fully elucidated yet, and further enhancements are necessary to optimize therapeutic efficacy. Butyrate, a short‑chain fatty acid, is generated through gut microbial fermentation of dietary fiber. Studies have unveiled the relevance of butyrate in malignant neoplasms, and a comprehensive understanding of its role in cancer is imperative for realizing its full potential in oncological treatment. Its full antineoplastic effects via the activation of G protein‑coupled receptors and the inhibition of histone deacetylases have been also confirmed. However, the underlying mechanistic details remain unclear. The present study aimed to review the involvement of butyrate in carcinogenesis and its molecular mechanisms, with a particular emphasis on its association with the efficacy of tumor immunotherapy, as well as discussing relevant clinical studies on butyrate as a therapeutic target for neoplastic diseases to provide new insights into cancer treatment.

Biomolecular Actions by Intestinal Endotoxemia in Metabolic Syndrome

Metabolic syndrome (MetS) is a combination of metabolic disorders that concurrently act as factors promoting systemic pathologies such as atherosclerosis or diabetes mellitus. It is now believed to encompass six main interacting conditions: visceral fat, imbalance of lipids (dyslipidemia), hypertension, insulin resistance (with or without impairing both glucose tolerance and fasting blood sugar), and inflammation. In the last 10 years, there has been a progressive interest through scientific research investigations conducted in the field of metabolomics, confirming a trend to evaluate the role of the metabolome, particularly the intestinal one. The intestinal microbiota (IM) is crucial due to the diversity of microorganisms and their abundance. Consequently, IM dysbiosis and its derivate toxic metabolites have been correlated with MetS. By intervening in these two factors (dysbiosis and consequently the metabolome), we can potentially prevent or slow down the clinical effects of the MetS process. This, in turn, may mitigate dysregulations of intestinal microbiota axes, such as the lung axis, thereby potentially alleviating the negative impact on respiratory pathology, such as the chronic obstructive pulmonary disease. However, the biomolecular mechanisms through which the IM influences the host's metabolism via a dysbiosis metabolome in both normal and pathological conditions are still unclear. In this study, we seek to provide a description of the knowledge to date of the IM and its metabolome and the factors that influence it. Furthermore, we analyze the interactions between the functions of the IM and the pathophysiology of major metabolic diseases via local and systemic metabolome's relate endotoxemia.

ExpLOring the role of the intestinal MiCrobiome in InflammATory bowel disease-AssocIated SpONdylarthritis (LOCATION-IBD)

Background

Inflammatory Bowel Disease (IBD)-associated arthritis is a frequent and potentially debilitating complication of IBD, that can affect those with or without active intestinal disease, and is often difficult to treat. The microbiome is known to play a role in IBD development and has been shown to be associated with inflammatory arthritis without concomitant IBD, but its role in IBD-associated arthritis is still unexplored. Further, disease localization is associated with development of IBD-associated arthritis, and stool compositional profiles are predictive of disease localization, yet mucosal location-specific microbiomes have not been well characterized. To address this gap in understanding, we designed a study (LOCATION-IBD) to characterize the mucosa-associated intestinal microbiome and metabolome in IBD-associated arthritis.

Methods

Adults with an established diagnosis of IBD undergoing clinical colonoscopy between May of 2021 and February of 2023 were invited to participate in this study; those interested in participation who met inclusion criteria were enrolled. Prior to enrollment, participants were stratified into those with or without IBD-associated arthritis. All participants were interviewed and had clinical and demographic data collected, and 97.8% completed clinical colonoscopy with biopsy collection.

Results and conclusion

A total of 182 participants, 53 with confirmed IBD-associated arthritis, were enrolled in this study, resulting in 1151 biopsies obtained for microbiome and metabolome analysis (median 6, mean 6.3 per participant). Clinical and demographic data obtained from the study population will be analyzed with microbiome and metabolome data obtained from biopsies, with the goal of better understanding the mechanisms underpinning the host-microbiome relationship associated the development of IBD-associated arthritis.

Hydrogen Regulates Ulcerative Colitis by Affecting the Intestinal Redox Environment

The redox balance in the intestine plays an important role in maintaining intestinal homeostasis, and it is closely related to the intestinal mucosal barrier, intestinal inflammation, and the gut microbiota. Current research on the treatment of ulcerative colitis has focused on immune disorders, excessive inflammation, and oxidative stress. However, an imbalance in intestinal redox reaction plays a particularly critical role. Hydrogen is produced by some anaerobic bacteria via hydrogenases in the intestine. Increasing evidence suggests that hydrogen, as an inert gas, is crucial for immunity, inflammation, and oxidative stress and plays a protective role in ulcerative colitis. Hydrogen maintains the redox state balance in the intestine in ulcerative colitis and reduces damage to intestinal epithelial cells by exerting its selective antioxidant ability. Hydrogen also regulates the intestinal flora, reduces the harmful effects of bacteria on the intestinal epithelial barrier, promotes the restoration of normal anaerobic bacteria in the intestines, and ultimately improves the integrity of the intestinal epithelial barrier. The present review focuses on the therapeutic mechanisms of hydrogen-targeting ulcerative colitis.

Postbiotics: An alternative and innovative intervention for the therapy of inflammatory bowel disease

Inflammatory Bowel Disease (IBD) is a persistent gastrointestinal (GI) tract inflammatory disease characterized by downregulated mucosal immune activities and a disrupted microbiota environment in the intestinal lumen. The involvement of bacterium postbiotics as mediators between the immune system and gut microbiome could be critical in determining why host-microbial relationships are disrupted in IBD. Postbiotics including Short-chain fatty acids (SCFAs), Organic acids, Proteins, Vitamins, Bacteriocins, and Tryptophan (Trp) are beneficial bioactive compounds formed via commensal microbiota in the gut environment during the fermentation process that can be used to improve consumer health. The use of metabolites or fragments from microorganisms can be a very attractive treatment and prevention technique in modern medicine. Postbiotics are essential in the immune system's development since they alter the barrier tightness, and the gut ecology and indirectly shape the microbiota's structure. As a result, postbiotics may be beneficial in treating or preventing various diseases, even some for which there is no effective causative medication. Postbiotics may be a promising tool for the treatment of IBD in individuals of all ages, genders, and even geographical locations. Direct distribution of postbiotics may provide a new frontier in microbiome-based therapy for IBD since it allows both the management of host homeostasis and the correction of the negative implications of dysbiosis. Further studies of the biological effects of these metabolites are expected to reveal innovative applications in medicine and beyond. This review attempts to explore the possible postbiotic-based interventions for the treatment of IBD.

The History and Prediction of Prebiotics and Postbiotics: A Patent Analysis

Prebiotics and postbiotics have gained attention as functional food additives due to their substantial influence on the gut microbiome and potential implications for human health on a broader scale. In addition, the number of patents for these additives has also increased, yet their functional classification has been problematic. In this study, we classified 2215 patents granted from 2001 to 2020 by functionality to enable predictions of future development directions. These patents encompassed subjects as diverse as feed supplementation, regulation of intestinal homeostasis, prevention of gastrointestinal ailments, targeted drug administration and augmentation of drug potency. The progression of patents issued during this time frame could be divided into three phases: occasional accounts prior to 2001, a period from 2001 to 2013 during which an average of 42 patents were issued annually, followed by a surge exceeding 140 patents annually after 2013. The latter increase has indicated that pre- and post-biotics have been recognized as biologically relevant. Patent mining therefore can enable forecasts of the future trajectory of these biologics and provide insights to evaluate their advancement. Moreover, this research is the first attempt to generalize and predict the directions of prebiotics and postbiotics using patent information and offers a comprehensive perspective for the potential utilization of prebiotics and postbiotics across a wide variety of fields.

Short Chain Fatty Acids: Essential Weapons of Traditional Medicine in Treating Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic and recurrent intestinal inflammatory disease, mainly including Crohn's disease (CD) and ulcerative colitis (UC). In recent years, the incidence and prevalence of IBD have been on the rise worldwide and have become a significant concern of health and a huge economic burden on patients. The occurrence and development of IBD involve a variety of pathogenic factors. The changes in short-chain fatty acids (SCFAs) are considered to be an important pathogenic mechanism of this disease. SCFAs are important metabolites in the intestinal microbial environment, which are closely involved in regulating immune, anti-tumor, and anti-inflammatory activities. Changes in metabolite levels can reflect the homeostasis of the intestinal microflora. Recent studies have shown that SCFAs provide energy for host cells and intestinal microflora, shape the intestinal environment, and regulate the immune system, thereby regulating intestinal physiology. SCFAs can effectively reduce the incidence of enteritis, cardiovascular disease, colon cancer, obesity, and diabetes, and also play an important role in maintaining the balance of energy metabolism (mainly glucose metabolism) and improving insulin tolerance. In recent years, many studies have shown that numerous decoctions and natural compounds of traditional Chinese medicine have shown promising therapeutic activities in multiple animal models of colitis and thus attracted increasing attention from scientists in the study of IBD treatment. Some of these traditional Chinese medicines or compounds can effectively alleviate colonic inflammation and clinical symptoms by regulating the generation of SCFAs. This study reviews the effects of various traditional Chinese medicines or bioactive substances on the production of SCFAs and their potential impacts on the severity of colonic inflammation. On this basis, we discussed the mechanism of SCFAs in regulating IBD-associated inflammation, as well as the related regulatory factors and signaling pathways. In addition, we provide our understanding of the limitations of current research and the prospects for future studies on the development of new IBD therapies by targeting SCFAs. This review may widen our understanding of the effect of traditional medicine from the view of SCFAs and their role in alleviating IBD animal models, thus contributing to the studies of IBD researchers.

Indole-3-acetic acid alleviates DSS-induced colitis by promoting the production of R-equol from Bifidobacterium pseudolongum

BACKGROUND

Inflammatory bowel disease (IBD) is characterized by immune-mediated, chronic inflammation of the intestinal tract. The occurrence of IBD is driven by the complex interactions of multiple factors. The objective of this study was to evaluate the therapeutic effects of IAA in colitis.

METHOD

C57/BL6 mice were administered 2.5% DSS in drinking water to induce colitis. IAA, Bifidobacterium pseudolongum, and R-equol were administered by oral gavage and fed a regular diet. The Disease Activity Index was used to evaluate disease activity. The degree of colitis was evaluated using histological morphology, RNA, and inflammation marker proteins. CD45+ CD4+ FOXP3+ Treg and CD45+ CD4+ IL17A+ Th17 cells were detected by flow cytometry. Analysis of the gut microbiome in fecal content was performed using 16S rRNA gene sequencing. Gut microbiome metabolites were analyzed using Untargeted Metabolomics.

RESULT

In our study, we found IAA alleviates DSS-induced colitis in mice by altering the gut microbiome. The abundance of Bifidobacterium pseudolongum significantly increased in the IAA treatment group. Bifidobacterium pseudolongum ATCC25526 alleviates DSS-induced colitis by increasing the ratio of Foxp3+T cells in colon tissue. R-equol alleviates DSS-induced colitis by increasing Foxp3+T cells, which may be the mechanism by which ATCC25526 alleviates DSS-induced colitis in mice.

CONCLUSION

Our study demonstrates that IAA, an indole derivative, alleviates DSS-induced colitis by promoting the production of Equol from Bifidobacterium pseudolongum, which provides new insights into gut homeostasis regulated by indole metabolites other than the classic AHR pathway.

Lactobacillus rhamnosus (LR) ameliorates pulmonary and extrapulmonary acute respiratory distress syndrome (ARDS) via targeting neutrophils

Pulmonary and extrapulmonary acute respiratory distress syndrome (ARDS) is a life-threatening respiratory failure associated with high mortality. Despite progress in our understanding of the pathological mechanism causing the crippling illness, there are currently no targeted pharmaceutical treatments available for it. Recent discoveries have emphasized the existence of a potential nexus between gut and lung health fueling novel approaches including probiotics for the treatment of ARDS. We thus investigated the prophylactic-potential of Lactobacillus rhamnosus-(LR) in lipopolysaccharide (LPS)-induced pulmonary and cecal ligation puncture (CLP) induced extrapulmonary ARDS mice. Our in-vivo findings revealed that pretreatment with LR significantly ameliorated vascular-permeability (edema) of the lungs via modulating the neutrophils along with significantly reducing the expression of inflammatory-cytokines in the BALF, lungs and serum in both pulmonary and extrapulmonary mice-models. Interestingly, our ex-vivo immunofluorescence and flow cytometric data suggested that mechanistically LR via short chain fatty acids (butyrate being the most potent and efficient in ameliorating the pathophysiology of both pulmonary and extra-pulmonary ARDS) targets the phagocytic and neutrophils extracellular traps (NETs) releasing potential of neutrophils. Moreover, our in-vivo data further corroborated our ex-vivo findings and suggested that butyrate exhibits enhanced potential in ameliorating the pathophysiology of ARDS via reducing the infiltration of neutrophils into the lungs. Altogether, our study establishes the prophylactic role of LR and its associated metabolites in the prevention and management of both pulmonary and extrapulmonary ARDS via targeting neutrophils.

The gut ecosystem and immune tolerance

The gastrointestinal tract is home to the largest microbial population in the human body. The gut microbiota plays significant roles in the development of the gut immune system and has a substantial impact on the maintenance of immune tolerance beginning in early life. These microbes interact with the immune system in a dynamic and interdependent manner. They generate immune signals by presenting a vast repertoire of antigenic determinants and microbial metabolites that influence the development, maturation and maintenance of immunological function and homeostasis. At the same time, both the innate and adaptive immune systems are involved in modulating a stable microbial ecosystem between the commensal and pathogenic microorganisms. Hence, the gut microbial population and the host immune system work together to maintain immune homeostasis synergistically. In susceptible hosts, disruption of such a harmonious state can greatly affect human health and lead to various auto-inflammatory and autoimmune disorders. In this review, we discuss our current understanding of the interactions between the gut microbiota and immunity with an emphasis on: a) important players of gut innate and adaptive immunity; b) the contribution of gut microbial metabolites; and c) the effect of disruption of innate and adaptive immunity as well as alteration of gut microbiome on the molecular mechanisms driving autoimmunity in various autoimmune diseases.

The Promise of Precision Nutrition for Modulation of the Gut Microbiota as a Novel Therapeutic Approach to Acute Graft-versus-host Disease

Acute graft-versus-host disease (aGVHD) is a severe side effect of allogeneic hematopoietic stem cell transplantation (aHSCT) that has complex phenotypes and often unpredictable outcomes. The current management is not always able to prevent aGVHD. A neglected actor in the management of aGVHD is the gut microbiota. Gut microbiota dysbiosis after aHSCT is caused by many factors and may contribute to the development of aGVHD. Diet and nutritional status modify the gut microbiota and a wide range of products are now available to manipulate the gut microbiota (pro-, pre-, and postbiotics). New investigations are testing the effect of probiotics and nutritional supplements in both animal models and human studies, with encouraging results. In this review, we summarize the most recent literature about the probiotics and nutritional factors able to modulate the gut microbiota and we discuss the future perspective in developing new integrative therapeutic approaches to reducing the risk of graft-versus-host disease in patients undergoing aHSCT.

Microbial-Related Metabolites May Be Involved in Eight Major Biological Processes and Represent Potential Diagnostic Markers in Gastric Cancer

Metabolites associated with microbes regulate human immunity, inhibit bacterial colonization, and promote pathogenicity. Integrating microbe and metabolome research in GC provides a direction for understanding the microbe-associated pathophysiological process of metabolic changes and disease occurrence. The present study included 30 GC patients with 30 cancerous tissues and paired non-cancerous tissues (NCs) as controls. LC-MS/MS metabolomics and 16S rRNA sequencing were performed to obtain the metabolic and microbial characteristics. Integrated analysis of the microbes and metabolomes was conducted to explore the coexistence relationship between the microbial and metabolic characteristics of GC and to identify microbial-related metabolite diagnostic markers. The metabolic analysis showed that the overall metabolite distribution differed between the GC tissues and the NC tissues: 25 metabolites were enriched in the NC tissues and 42 metabolites were enriched in the GC tissues. The α and β microbial diversities were higher in the GC tissues than in the NC tissues, with 11 differential phyla and 52 differential genera. In the correlation and coexistence integrated analysis, 66 differential metabolites were correlated and coexisted, with specific differential microbes. The microbes in the GC tissue likely regulated eight metabolic pathways. In the efficacy evaluation of the microbial-related differential metabolites in the diagnosis of GC, 12 differential metabolites (area under the curve [AUC] >0.9) exerted relatively high diagnostic efficiency, and the combined diagnostic efficacy of 5 to 6 microbial-related differential metabolites was higher than the diagnostic efficacy of a single feature. Therefore, microbial diversity and metabolite distribution differed between the GC tissues and the NC tissues. Microbial-related metabolites may be involved in eight major metabolism-based biological processes in GC and represent potential diagnostic markers.

Dietary cultured supernatant mixture of Cetobacterium somerae and Lactococcus lactis improved liver and gut health, and gut microbiota homeostasis of zebrafish fed with high-fat diet

Postbiotics have the ability to improve host metabolic disorders and immunity. In order to explore whether the postbiotics SWFC (cultured supernatant mixture of Cetobacterium somerae and Lactococcus lactis) repaired the adverse effects caused by feeding of high-fat diet (HFD), zebrafish were selected as the experimental animal and fed for 6 weeks, with dietary HFD as the control group, and HFD containing 0.3 g/kg and 0.4 g/kg SWFC as the treatment groups. The results indicated that addition of SWFC in the diet at a level of 0.3 and 0.4 g/kg didn't affect the growth performance of zebrafish (P > 0.05). Supplementation of dietary SWFC0.3 relieved lipid metabolism disorders through significant increasing in the expression of pparα and cpt1, and decreasing the expression of cebpα, pparγ, acc1 and dgat-2 genes (P < 0.05). Moreover, the content of triacylglycerol was markedly lower in the liver of zebrafish grouped under SWFC0.3 (P < 0.05). Dietary SWFC0.3 also improved the antioxidant capacity via increasing the expression level of ho-1, sod and gstr genes, and significant inducing malondialdehyde content in the liver of zebrafish (P < 0.05). Besides, dietary SWFC0.3 also notably improved the expression level of lysozyme, c3a, defbl1 and defbl2 (P < 0.05). The expression level of pro-inflammatory factors (nf-κb, tnf-α, and il-1β) were significantly decreased and the expression level of anti-inflammatory factor (il-10) was markedly increased in the postbiotics 0.3 g/kg group (P < 0.05). Feeding with SWFC0.3 supplemented diet for 6 weeks improved the homeostasis of gut microbiota and increased the survival rate of zebrafish after challenged with Aeromonus veronii Hm091 (P < 0.01). It was worth noting that the positive effect of dietary SWFC at a level of 0.3 g/kg was considerably better than that of 0.4 g/kg. This may imply that the effectiveness and use of postbiotics is limited by dosage.

Short-chain fatty acids in diseases

Short-chain fatty acids (SCFAs) are the main metabolites produced by bacterial fermentation of dietary fibre in the gastrointestinal tract. The absorption of SCFAs is mediated by substrate transporters, such as monocarboxylate transporter 1 and sodium-coupled monocarboxylate transporter 1, which promote cellular metabolism. An increasing number of studies have implicated metabolites produced by microorganisms as crucial executors of diet-based microbial influence on the host. SCFAs are important fuels for intestinal epithelial cells (IECs) and represent a major carbon flux from the diet, that is decomposed by the gut microbiota. SCFAs play a vital role in multiple molecular biological processes, such as promoting the secretion of glucagon-like peptide-1 by IECs to inhibit the elevation of blood glucose, increasing the expression of G protein-coupled receptors such as GPR41 and GPR43, and inhibiting histone deacetylases, which participate in the regulation of the proliferation, differentiation, and function of IECs. SCFAs affect intestinal motility, barrier function, and host metabolism. Furthermore, SCFAs play important regulatory roles in local, intermediate, and peripheral metabolisms. Acetate, propionate, and butyrate are the major SCFAs, they are involved in the regulation of immunity, apoptosis, inflammation, and lipid metabolism. Herein, we review the diverse functional roles of this major class of bacterial metabolites and reflect on their ability to affect intestine, metabolic, and other diseases. Video Abstract.

Polysaccharides from Armillariella tabescens mycelia mitigate DSS-induced ulcerative colitis via modulating intestinal microbiota in mice

Polysaccharides from Armillariella tabescens mycelia (AT) have a potent anti-inflammatory effect. Nevertheless, the impact of AT on dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) has not yet been illustrated. This study aimed to explore AT's impact on experimental UC mice and investigate its underlying mechanisms. Mice were given DSS, 0.2 g/kg AT or 0.4 g/kg AT for seven days, and the symptoms of UC were observed. The serum and colon samples were harvested to analyze the biochemical indices and inflammasome-related proteins. The feces were collected to analyze short-chain fatty acids (SCFAs) and gut microbiota. The present study found that AT improved the symptoms of UC, colonic oxidative stress, and inflammation. AT treatment elevated SCFAs contents and colonic barrier function. Furthermore, AT improved microbial community structure through the selective enrichment of beneficial bacterial species. In conclusion, these results underlined that AT improved DSS-induced colitis and inhibited colonic inflammation via regulating the intestinal microbial community and enhancing the colonic mucosal barrier.

Intestinal Immune Imbalance is an Alarm in the Development of IBD

Immune regulation plays a crucial role in human health and disease. Inflammatory bowel disease (IBD) is a chronic relapse bowel disease with an increasing incidence worldwide. Clinical treatments for IBD are limited and inefficient. However, the pathogenesis of immune-mediated IBD remains unclear. This review describes the activation of innate and adaptive immune functions by intestinal immune cells to regulate intestinal immune balance and maintain intestinal mucosal integrity. Changes in susceptible genes, autophagy, energy metabolism, and other factors interact in a complex manner with the immune system, eventually leading to intestinal immune imbalance and the onset of IBD. These events indicate that intestinal immune imbalance is an alarm for IBD development, further opening new possibilities for the unprecedented development of immunotherapy for IBD.

Plant-Based Nutrition: Exploring Health Benefits for Atherosclerosis, Chronic Diseases, and Metabolic Syndrome-A Comprehensive Review

Atherosclerosis, chronic non-communicable diseases, and metabolic syndrome are highly interconnected and collectively contribute to global health concerns that reduce life expectancy and quality of life. These conditions arise from multiple risk factors, including inflammation, insulin resistance, impaired blood lipid profile, endothelial dysfunction, and increased cardiovascular risk. Adopting a plant-based diet has gained popularity as a viable alternative to promote health and mitigate the incidence of, and risk factors associated with, these three health conditions. Understanding the potential benefits of a plant-based diet for human health is crucial, particularly in the face of the rising prevalence of chronic diseases like diabetes, hypertension, dyslipidemia, atherosclerosis, and cancer. Thus, this review focused on the plausible advantages of consuming a type of food pattern for the prevention and/or treatment of chronic diseases, emphasizing the dietary aspects that contribute to these conditions and the evidence supporting the benefits of a plant-based diet for human health. To facilitate a more in-depth analysis, we present separate evidence for each of these three concepts, acknowledging their intrinsic connection while providing a specific focus on each one. This review underscores the potential of a plant-based diet to target the underlying causes of these chronic diseases and enhance health outcomes for individuals and populations.

High-Fiber Diet and Crohn's Disease: Systematic Review and Meta-Analysis

Crohn's disease (CD) is a subtype of inflammatory bowel disease (IBD). CD is a health problem in Western countries such as the US and European nations and is an idiopathic disease; however, certain cases of CD have been associated with intestinal dysbiosis. A systematic review with a meta-analysis was carried out to determine the efficacy of a diet rich in fiber with or without cointervention to improve remission rates for CD. The literature in the PubMed, Scopus, Web of Science, and ClinicalTrials databases was reviewed. The quality of the studies was evaluated using the Johanna Briggs Institute (JBI) scale. This review was conducted in accordance with the structure outlined in the PRISMA statement. In addition, a meta-analysis was performed with a 95% confidence interval (CI) and a random effects model. Eleven studies were included, totaling 2389 patients with CD. Applying a diet rich in fiber with or without the administration of routine therapies improved CD remission rates. Data regarding CD activity, remission time, and adverse effects derived from fiber consumption were analyzed. Consumption of fiber in the diet could improve remission rates for CD patients who receive or do not receive other treatment to maintain remission.

Protective Effects of Different Molecular Weights of Purslane (Portulaca oleracea L.) Aqueous Extract on DSS-Induced Ulcerative Colitis in Mice

Purslane, a common wild vegetable, contains active substances with various biological functions. However, its effects have been under-investigated in ulcerative colitis (UC). Therefore, this study investigated the therapeutic effects of purslane macromolecular (POEM) and small molecular extracts (POES) on dextran sulfate sodium (DSS)-induced UC in mice. Membrane separation was used to obtain extracts of different molecular weights, and their compositional differences were compared using liquid chromatography-mass spectrometry (LC/MS). POEM contained more proteins and polysaccharides, whereas POES contained more organic acids and alkaloids. These differences in composition were directly responsible for the different degrees of remission of the alleviated UC in model mice. POEM may alleviate UC by regulating the antioxidant capacity and the gut microbiota, whereas the major alleviatory effect of POES was primarily related to the regulation of antioxidant capacity. The POEM and POES effects identified in this study provide a theoretical basis for the development of purslane as a functional food.

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

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

Galactooligosaccharide or 2'-Fucosyllactose Modulates Gut Microbiota and Inhibits LPS/TLR4/NF-κB Signaling Pathway to Prevent DSS-Induced Colitis Aggravated by a High-Fructose Diet in Mice

A high-fructose diet (HFrD) has been reported to exacerbate dextran sulfate sodium (DSS)-induced colitis. 2'-Fucosyllactose (FL) and galactooligosaccharide (GOS) have been shown, respectively, to have preventive and ameliorative effects on colitis, while limited research has explored whether GOS and FL may be equally protective or preventive in mice with HFrD. Here, we evaluated the protective effects of FL and GOS on colitis exacerbated by feeding HFrD and explored the underlying mechanisms. DSS-induced colitis was studied in four randomized C57BL/6J male mice (n = 8 mice/group). Among them, three groups were fed with HFrD, and two received either GOS or FL treatment, respectively. Gut microbial composition was analyzed by 16S rDNA gene sequencing. Intestinal barrier integrity and inflammatory pathway expression were measured using qPCR, immunofluorescence, and Western blot methods. Compared to the HFrD group, GOS or FL treatment increased the α-diversity of the gut microbiota, reduced the relative abundance of Akkermansia, and increased the content of short-chain fatty acids (SCFAs), respectively. Compared with the HFrD group, GOS or FL treatment improved the loss of goblet cells and the reduction of tight junction protein expression, thereby improving intestinal barrier integrity. Also, GOS or FL inhibited the LPS/TLR4/NF-κB signaling pathway and oxidative stress to suppress the inflammatory cascade compared with the HFrD group. These findings suggest that GOS or FL intake can alleviate HFrD-exacerbated colitis, with no significant difference observed between GOS and FL treatments.

Role of microbiota short-chain fatty acid chains in the pathogenesis of autoimmune diseases

There is emerging evidence that microbiota and its metabolites play an important role in helath and diseases. In this regard, gut microbiota has been found as a crucial component that influences immune responses as well as immune-related disorders such as autoimmune diseases. Gut bacterial dysbiosis has been shown to cause disease and altered microbiota metabolite synthesis, leading to immunological and metabolic dysregulation. Of note, microbiota in the gut produce short-chain fatty acids (SCFAs) such as acetate, butyrate, and propionate, and remodeling in these microbiota metabolites has been linked to the pathophysiology of a number of autoimmune disorders such as type 1 diabetes, multiple sclerosis, inflammatory bowel disease, rheumatoid arthritis, celiac disease, and systemic lupus erythematosus. In this review, we will address the most recent findings from the most noteworthy studies investigating the impact of microbiota SCFAs on various autoimmune diseases.

Acetate and propionate effects in response to LPS in a porcine intestinal co-culture model

BACKGROUND

The interest in acetate and propionate as short chain fatty acids (SCFA) derives from research on alternative strategies to the utilization of antibiotics in pig farms. SCFA have a protective role on the intestinal epithelial barrier and improve intestinal immunity by regulating the inflammatory and immune response. This regulation is associated with an increase in intestinal barrier integrity, mediated by the enhancement of tight junction protein (TJp) functions, which prevent the passage of pathogens through the paracellular space. The purpose of this study was to evaluate the effect of in vitro supplementation with SCFA (5 mM acetate and 1 mM propionate) on viability, nitric oxide (NO) release (oxidative stress), NF-κB gene expression, and gene and protein expression of major TJp (occludin [OCLN], zonula occludens-1 [ZO-1], and claudin-4 [CLDN4]) in a porcine intestinal epithelial cell (IPEC-J2) and peripheral blood mononuclear cell (PBMC) co-culture model upon LPS stimulation, through which an acute inflammatory state was simulated.

RESULTS

Firstly, the inflammatory stimulus induced by LPS evaluated in the IPEC-J2 monoculture was characterized by a reduction of viability, gene expression of TJp and OCLN protein synthesis, and an increase of NO release. The response evaluated in the co-culture showed that acetate positively stimulated the viability of both untreated and LPS-stimulated IPEC-J2 and reduced the release of NO in LPS-stimulated cells. Acetate also promoted an increase of gene expression of CLDN4, ZO-1, and OCLN, and protein synthesis of CLDN4, OCLN and ZO-1 in untreated and LPS-stimulated cells. Propionate induced a reduction of NO release in both untreated and LPS-stimulated IPEC-J2. In untreated cells, propionate induced an increase of TJp gene expression and of CLDN4 and OCLN protein synthesis. Contrarily, propionate in LPS-stimulated cells induced an increase of CLDN4 and OCLN gene expression and protein synthesis. PBMC were influenced by acetate and propionate supplementation, in that NF-κB expression was strongly downregulated in LPS-stimulated cells.

CONCLUSIONS

The present study demonstrates the protective effect of acetate and propionate upon acute inflammation by regulating epithelial tight junction expression and protein synthesis in a co-culture model, which simulates the in vivo interaction between epithelial intestinal cells and local immune cells.

Multi-omics in Crohn's disease: New insights from inside

Crohn's disease (CD) is an inflammatory bowel disease (IBD) with complex clinical manifestations such as chronic diarrhea, weight loss and hematochezia. Despite the increasing incidence worldwide, cure of CD remains extremely difficult. The rapid development of high-throughput sequencing technology with integrated-omics analyses in recent years has provided a new means for exploring the pathogenesis, mining the biomarkers and designing targeted personalized therapeutics of CD. Host genomics and epigenomics unveil heredity-related mechanisms of susceptible individuals, while microbiome and metabolomics map host-microbe interactions in CD patients. Proteomics shows great potential in searching for promising biomarkers. Nonetheless, single omics technology cannot holistically connect the mechanisms with heterogeneity of pathological behavior in CD. The rise of multi-omics analysis integrates genetic/epigenetic profiles with protein/microbial metabolite functionality, providing new hope for comprehensive and in-depth exploration of CD. Herein, we emphasized the different omics features and applications of CD and discussed the current research and limitations of multi-omics in CD. This review will update and deepen our understanding of CD from integration of broad omics spectra and will provide new evidence for targeted individualized therapeutics.

Effects of compound prebiotics as prophylactic and therapeutic supplementation in a mouse model of acute colitis

Compound prebiotics (CP) have been explored in modulation of intestinal microbiota and remission of inflammatory responses in the acute colitis (AC). Yet, research on the roles of simultaneous prophylactic and therapeutic CP intervention in relation to AC remains lacking. Here, CP were pre-fed to examine preventive effects. CP, CP combined with mesalazine (5-aminosalicylic acid) (CPM), and mesalazine were used to evaluate therapeutic effects on the dextran sulfate sodium (DSS)-induced AC. Results showed that prophylactic CP and therapeutic CPM alleviated AC, evidenced by variations of body weight, colon length, spleen index, disease activity index score, histological score, and intestinal mucosa. Ruminococcus and Bifidobacterium were detected in significant abundance in the prophylactic CP and therapeutic CPM groups, respectively. Phylogenetic ecological network analysis revealed that therapeutic CPM probably had the strongest coupling between microbes in changing intestinal microbiota to influence treatment. However, changes in short-chain fatty acids (SCFAs) seemed to have no persuasive results, probably due to reduced SCFA level in feces and variability in transit, absorption, and utilization. Furthermore, therapeutic CP exerted higher value in terms of observed species and Shannon diversity, as well as a more concentrated distribution by principal coordinates analysis. Together, the favorable roles of CP in colitis provide directions for prebiotics in designing effective prophylactic functional diets and treatment strategies. KEY POINTS: • Prebiotics as prophylactic intervention effectively inhibited acute colitis. • Prebiotics as prophylactic and therapeutic interventions had distinct effects on gut microbiota. • Prebiotics combined with drug intervention had higher efficacy in treating acute colitis.

Bile salt hydrolase of Lactiplantibacillus plantarum plays important roles in amelioration of DSS-induced colitis

Bile salt hydrolases are thought to be the gatekeepers of bile acid metabolism. To study the role of BSH in colitis, we investigated the ameliorative effects of different BSH-knockout strains of Lactiplantibacillus plantarum AR113. The results showed that L. plantarum Δbsh 1 and Δbsh 3 treatments did not improve body weight and alleviate the hyperactivated myeloperoxidase activity to the DSS group. However, the findings for L. plantarum AR113, L. plantarum Δbsh 2 and Δbsh 4 treatments were completely opposite. The double and triple bsh knockout strains further confirmed that BSH 1 and BSH 3 are critical for the ameliorative effects of L. plantarum AR113. In addition, L. plantarum Δbsh 1 and Δbsh 3 did not significantly inhibit the increase in pro-inflammatory cytokines or the decrease in an anti-inflammatory cytokine. These results suggest that BSH 1 and BSH 3 in L. plantarum play important roles in alleviating enteritis symptoms.

Bacillus subtilis DSM29784 attenuates Clostridium perfringens-induced intestinal damage of broilers by modulating intestinal microbiota and the metabolome

Necrotic enteritis (NE), especially subclinical NE (SNE), without clinical symptoms, in chicks has become one of the most threatening problems to the poultry industry. Therefore, increasing attention has been focused on the research and application of effective probiotic strains as an alternative to antibiotics to prevent SNE in broilers. In the present study, we evaluated the effects of Bacillus subtilis DSM29784 (BS) on the prevention of subclinical necrotic enteritis (SNE) in broilers. A total of 480 1-day-old broiler chickens were randomly assigned to four dietary treatments, each with six replicates pens of twenty birds for 63 d. The negative (Ctr group) and positive (SNE group) groups were only fed a basal diet, while the two treatment groups received basal diets supplemented with BS (1 × 109 colony-forming units BS/kg) (BS group) and 10mg/kg enramycin (ER group), respectively. On days 15, birds except those in the Ctr group were challenged with 20-fold dose coccidiosis vaccine, and then with 1 ml of C. perfringens (2 × 108) at days 18 to 21 for SNE induction. BS, similar to ER, effectively attenuated CP-induced poor growth performance. Moreover, BS pretreatment increased villi height, claudin-1 expression, maltase activity, and immunoglobulin abundance, while decreasing lesional scores, as well as mucosal IFN-γ and TNF-α concentrations. In addition, BS pretreatment increased the relative abundance of beneficial bacteria and decreased that of pathogenic species; many lipid metabolites were enriched in the cecum of treated chickens. These results suggest that BS potentially provides active ingredients that may serve as an antibiotic substitute, effectively preventing SNE-induced growth decline by enhancing intestinal health in broilers.

The role of endoplasmic reticulum stress in regulation of intestinal barrier and inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disease involving the digestive tract, characterized by abdominal pain, diarrhea, rectal bleeding, and so on, which can make patients physically weakened and live difficultly. Although IBD has been recognized for many years, the pathogenesis of IBD has not yet been established and damage to intestinal barrier is thought to be closely associated with IBD. Intestinal barrier is an innate barrier that maintains the homeostasis of the intestinal environment and impedes pathogenic bacteria and toxins, and the endoplasmic reticulum (ER) has recently been found to be involved in maintaining the integrity of intestinal barrier. Endoplasmic reticulum stress (ERS) is a status of endoplasmic reticulum damaged when unfolded or misfolded proteins accumulate in excess of the degradation systematic clearance limit of the misfolded proteins. The regulation of ERS on protein folding synthesis and maintenance of cellular homeostasis is an important factor in influencing the integrity of the intestinal barrier. This paper mainly discusses the relationship between ERS and the intestinal barrier, aiming to understand the regulatory role of ERS on the intestinal barrier and the mechanism and to improve new solutions and notions for the treatment or prevention of IBD.

Herba Origani alleviated DSS-induced ulcerative colitis in mice through remolding gut microbiota to regulate bile acid and short-chain fatty acid metabolisms

This study aimed to investigate the protective effect of Herba Origani, the dried whole herb of Origanum vulgare L., on dextran sodium sulfate (DSS)-induced ulcerative colitis in mice and explore its mechanisms of action through analyzing the intestinal microbiota in cecum contents and metabolites in colonic tissues. HOEP alleviated colitis symptoms, colonic inflammation and pathological injury as well as repaired intestinal barrier function in DSS-induced UC mice. The intestinal microbiota analysis showed that HOEP restored the gut microbiota dysbiosis in DSS-treated mice by increasing the alpha diversity of the intestinal microbiota, increasing the abundance of the Bacteroidota community and adjusting short-chain fatty acids (SCFAs), which maintain mucosal immunity and intestinal barrier. Metabolomic analysis revealed that HOEP promoted bile acids absorption and regulated bile acids metabolism in the intestine, thereby maintaining intestinal mucosal immune homeostasis. In addition, HOEP might also regulate the intestinal immune system through the phosphatidylinositol signaling system. These findings suggested that HOEP exerted promising protection against DSS-induced ulcerative mice through remolding gut microbiota to regulate bile acid and SCFA metabolism, and that HOEP have a potential to be utilized for the treatment of inflammatory intestinal diseases.

The gut microbiome and allergic rhinitis; refocusing on the role of probiotics as a treatment option

INTRODUCTION

In the industrialized world, the incidence of Allergic rhinitis (AR), often known as hay fever, and other allergic disorders continues to grow. Recent studies have suggested environmental variables such as bacterial exposures as a potential reason for the rising prevalence of AR. With breakthroughs in our abilities to research the complex crosstalk of bacteria, the gut microbiomes' effect on human development, nutritional requirements, and immunologic disorders has become apparent METHODS: Three search engines, including Scopus, Medline, and PubMed, were searched for related published articles up to and including 1st July 2022.

RESULTS

Several studies have investigated links between commensal microbiome alterations and the development of atopic diseases such as asthma and AR. Besides, studies using probiotics for treating AR suggest that they may alleviate symptoms and improve patient's quality of life.

CONCLUSION

Research on probiotics and synbiotics for AR suggests they may improve symptoms, quality of life, and laboratory indicators. A better treatment strategy with advantages for patients may be achieved using probiotics, but only if more detailed in vitro and in vivo investigations are conducted with more participants.

Endotoxemia and Gastrointestinal Cancers: Insight into the Mechanisms Underlying a Dangerous Relationship

Lipopolysaccharide (LPS), also known as endotoxin, is a component of the membrane of gram-negative bacteria and a well-recognized marker of sepsis. In case of disruption of the intestinal barrier, as occurs with unhealthy diets, alcohol consumption, or during chronic diseases, the microbiota residing in the gastrointestinal tract becomes a crucial factor in amplifying the systemic inflammatory response. Indeed, the translocation of LPS into the bloodstream and its interaction with toll-like receptors (TLRs) triggers molecular pathways involved in cytokine release and immune dysregulation. This is a critical step in the exacerbation of many diseases, including metabolic disorders and cancer. Indeed, the role of LPS in cancer development is widely recognized, and examples include gastric tumor related to Helicobacter pylori infection and hepatocellular carcinoma, both of which are preceded by a prolonged inflammatory injury; in addition, the risk of recurrence and development of metastasis appears to be associated with endotoxemia. Here, we review the mechanisms that link the promotion and progression of tumorigenesis with endotoxemia, and the possible therapeutic interventions that can be deployed to counteract these events.

Ongoing Treatment with a Spore-Based Probiotic Containing Five Strains of Bacillus Improves Outcomes of Mild COVID-19

Spore-based Bacillus probiotic treatment improves intestinal health. The intestinal microbiota influences both the innate and adaptive immune responses. As such, the influence of ongoing spore-based probiotic treatment (five probiotic strains of Bacillus) on the clinical outcomes of mild COVID-19 was evaluated in this retrospective, observational study. Demographics, medical history, probiotic use, and COVID-19 symptom information were collected. The study included 120 patients with a PCR-confirmed SARS-CoV-2 infection and mild COVID-19 symptoms. The probiotic group (n = 60) comprised patients with ongoing probiotic treatment (≥1 month); the control group comprised patients not taking probiotics (n = 60). The primary outcome was time to symptom resolution; secondary outcomes included time to fever resolution and presence of digestive symptoms. The probiotic group had a significantly shorter time to symptom resolution (mean (95% confidence interval) days: control group, 8.48 (6.56, 10.05); probiotic group, 6.63 (5.56; 6.63); p = 0.003) and resolution of fever (control group, 2.67 (1.58, 3.61); probiotic group, 1.48 (1.21, 2.03); p < 0.001). More patients in the probiotic group (n = 53) than in the control group (n = 34) did not have digestive symptoms (p < 0.001). Among adults with mild COVID-19, participants receiving ongoing probiotic treatment had a shorter clinical course, and fewer had digestive symptoms compared with those not taking probiotics.

Immunological consequences of microbiome-based therapeutics

The complex network of microscopic organisms living on and within humans, collectively referred to as the microbiome, produce wide array of biologically active molecules that shape our health. Disruption of the microbiome is associated with susceptibility to a range of diseases such as cancer, diabetes, allergy, obesity, and infection. A new series of next-generation microbiome-based therapies are being developed to treat these diseases by transplanting bacteria or bacterial-derived byproducts into a diseased individual to reset the recipient's microbiome and restore health. Microbiome transplantation therapy is still in its early stages of being a routine treatment option and, with a few notable exceptions, has had limited success in clinical trials. In this review, we highlight the successes and challenges of implementing these therapies to treat disease with a focus on interactions between the immune system and microbiome-based therapeutics. The immune activation status of the microbiome transplant recipient prior to transplantation has an important role in supporting bacterial engraftment. Following engraftment, microbiome transplant derived signals can modulate immune function to ameliorate disease. As novel microbiome-based therapeutics are developed, consideration of how the transplants will interact with the immune system will be a key factor in determining whether the microbiome-based transplant elicits its intended therapeutic effect.

Colonization with two different Blastocystis subtypes in DSS-induced colitis mice is associated with strikingly different microbiome and pathological features

Rationale: The gut microbiota plays a significant role in the pathogenesis of inflammatory bowel disease (IBD). However, the role of Blastocystis infection and Blastocystis-altered gut microbiota in the development of inflammatory diseases and their underlying mechanisms are not well understood. Methods: We investigated the effect of Blastocystis ST4 and ST7 infection on the intestinal microbiota, metabolism, and host immune responses, and then explored the role of Blastocystis-altered gut microbiome in the development of dextran sulfate sodium (DSS)-induced colitis in mice. Results: This study showed that prior colonization with ST4 conferred protection from DSS-induced colitis through elevating the abundance of beneficial bacteria, short-chain fatty acid (SCFA) production and the proportion of Foxp3⁺ and IL-10-producing CD4⁺ T cells. Conversely, prior ST7 infection exacerbated the severity of colitis by increasing the proportion of pathogenic bacteria and inducing pro-inflammatory IL-17A and TNF-α-producing CD4⁺ T cells. Furthermore, transplantation of ST4- and ST7-altered microbiota resulted in similar phenotypes. Conclusions: Our data showed that ST4 and ST7 infection exert strikingly differential effects on the gut microbiota, and these could influence the susceptibility to colitis. ST4 colonization prevented DSS-induced colitis in mice and may be considered as a novel therapeutic strategy against immunological diseases in the future, while ST7 infection is a potential risk factor for the development of experimentally induced colitis that warrants attention.

Protective Effect of Clostridium butyricum on Escherichia coli-Induced Endometritis in Mice via Ameliorating Endometrial Barrier and Inhibiting Inflammatory Response

Endometritis is a common reproductive disease occurs both in human and animals. Clostridium butyricum is a Gram-positive anaerobic bacterium that can ferment various carbohydrates into butyric acid. In this study, we investigated the effects of C. butyricum on Escherichia coli-induced endometritis and clarified the underlying mechanism. We first verified the protective effect of C. butyricum in vivo by establishing a mouse model of E. coli-induced endometritis. It was determined that C. butyricum pretreatment significantly reversed E. coli-induced uterine histopathological changes. Meanwhile, C. butyricum pretreatment significantly decreased the production of pro-inflammatory mediators and the levels of myeloperoxidase (MPO) and malondialdehyde (MDA). We found that C. butyricum could inhibit TLR4-mediated phosphorylation of NF-κB and the activity of histone deacetylase (HDAC). Furthermore, C. butyricum significantly increased the expression of the tight junction proteins (TJPs) ZO-1, claudin-3, and occludin. Additionally, treatment with C. butyricum culture supernatant dramatically suppressed the degree of inflammation in the uterus, and inactivated C. butyricum did not exert a protective effect. We subsequently investigated butyrate levels in both the uterus and blood and observed a marked augment in the C. butyricum treatment group. Collectively, our data suggest that C. butyricum maintains epithelial barrier function and suppresses inflammatory response during E. coli-induced endometritis and that the protective effect of C. butyricum may be related to the production of butyrate. IMPORTANCE Endometritis is a common reproductive disease both in human and animals. It impairs female fertility by disrupting endometrial function. Antibiotics are widely used to treat endometritis in clinical practice, but the misuse of antibiotics often leads to antibiotic resistance. Therefore, there is an urgent need for new therapeutic agents to treat bacterial endometritis and overcome bacterial resistance. In this study, we found that C. butyricum could protect from E. coli-induced endometritis.

Microbial Modulation in Inflammatory Bowel Diseases

Gut dysbiosis is one of prominent features in inflammatory bowel diseases (IBDs) which are of an unknown etiology. Although the cause-and-effect relationship between IBD and gut dysbiosis remains to be elucidated, one area of research has focused on the management of IBD by modulating and correcting gut dysbiosis. The use of antibiotics, probiotics either with or without prebiotics, and fecal microbiota transplantation from healthy donors are representative methods for modulating the intestinal microbiota ecosystem. The gut microbiota is not a simple assembly of bacteria, fungi, and viruses, but a complex organ-like community system composed of numerous kinds of microorganisms. Thus, studies on specific changes in the gut microbiota depending on which treatment option is applied are very limited. Here, we review previous studies on microbial modulation as a therapeutic option for IBD and its significance in the pathogenesis of IBD.

Bermúdez M, Campoy C. Impact of Total Parenteral Nutrition on Gut Microbiota in Pediatric Population Suffering Intestinal Disorders

Parenteral nutrition (PN) is a life-saving therapy providing nutritional support in patients with digestive tract complications, particularly in preterm neonates due to their gut immaturity during the first postnatal weeks. Despite this, PN can also result in several gastrointestinal complications that are the cause or consequence of gut mucosal atrophy and gut microbiota dysbiosis, which may further aggravate gastrointestinal disorders. Consequently, the use of PN presents many unique challenges, notably in terms of the potential role of the gut microbiota on the functional and clinical outcomes associated with the long-term use of PN. In this review, we synthesize the current evidence on the effects of PN on gut microbiome in infants and children suffering from diverse gastrointestinal diseases, including necrotizing enterocolitis (NEC), short bowel syndrome (SBS) and subsequent intestinal failure, liver disease and inflammatory bowel disease (IBD). Moreover, we discuss the potential use of pre-, pro- and/or synbiotics as promising therapeutic strategies to reduce the risk of severe gastrointestinal disorders and mortality. The findings discussed here highlight the need for more well-designed studies, and harmonize the methods and its interpretation, which are critical to better understand the role of the gut microbiota in PN-related diseases and the development of efficient and personalized approaches based on pro- and/or prebiotics.

Polyphenols and Ulcerative Colitis: An Exploratory Study of the Effects of Red Wine Consumption on Gut and Oral Microbiome in Active-Phase Patients

SCOPE

This paper explores the effects of moderate red wine consumption on the clinical status and symptomatology of patients with ulcerative colitis (UC), including the study of the oral and intestinal microbiome.

METHODS AND RESULTS

A case control intervention study in UC patients is designed. Intervention patients (n = 5) consume red wine (250 mL day^-1 ) for 4 weeks whereas control patients (n = 5) do not. Moderate wine consumption significantly (p < 0.05) improves some clinical parameters related to serum iron, and alleviates intestinal symptoms as evaluated by the IBDQ-32 questionnaire. 16S rRNA gene sequencing indicate a non-significant (p > 0.05) increase in bacterial alpha diversity after wine intervention in both saliva and fecal microbiota. Additional comparison of taxonomic data between UC patients (n = 10) and healthy subjects (n = 8) confirm intestinal dysbiosis for the UC patients. Finally, analysis of fecal metabolites (i.e., phenolic acids and SCFAs) indicates a non-significant increase (p > 0.05) for the UC patients that consumed wine.

CONCLUSIONS

Moderate and regular red wine intake seems to improve the clinical status and symptoms of UC patients in the active phase of the disease. However, studies with a greater sample size are required to achieve conclusive results.

Butyrate: Connecting the gut-lung axis to the management of pulmonary disorders

Short-chain fatty acids (SCFAs) are metabolites released by bacterial components of the microbiota. These molecules have a wide range of effects in the microbiota itself, but also in host cells in which they are known for contributing to the regulation of cell metabolism, barrier function, and immunological responses. Recent studies indicate that these molecules are important players in the gut-lung axis and highlight the possibility of using strategies that alter their intestinal production to prevent or treat distinct lung inflammatory diseases. Here, we review the effects of the SCFA butyrate and its derivatives in vitro and in vivo on murine models of respiratory disorders, besides discussing the potential therapeutic use of butyrate and the other SCFAs in lung diseases.

The Impact of Low-Viscosity Soluble Dietary Fibers on Intestinal Microenvironment and Experimental Colitis: A Possible Preventive Application of Alpha-Cyclodextrin in Intestinal Inflammation

SCOPE

The purpose of this study is to compare the impact of four low-viscosity soluble dietary fibers (DFs) on the intestinal microenvironment, in terms of microbiota composition, short-chain fatty acid (SCFA) production, proportion of colonic peripherally induced regulatory T cells (pTregs), and experimental colitis in mice.

METHODS AND RESULTS

Mice are administered 5% w/v low-viscosity soluble DFs in drinking water for 2 weeks. The gut microbiota composition is determined using 16S rRNA sequencing. Luminal SCFAs are quantified by gas chromatography, and colonic pTregs are analyzed using flow cytometry. All low-viscosity soluble DFs promote the growth of beneficial bacteria such as Akkermansia muciniphila and Bacteroides acidifaciens, while eliminating pathogenic bacteria such as Clostridium perfringens. Moreover, two low-viscosity soluble DFs significantly increase the abundance of commensal bacteria and promote the accumulation of propionate and butyrate, leading to marked induction of colonic pTregs. Consistently, these two fibers, in particular α-cyclodextrin, show remarkable anti-inflammatory properties in a colitis mouse model.

CONCLUSION

Mice administered any low-viscosity soluble DF show comparable gut microbiota compositions, but differ in terms of bacterial abundance, SCFA concentration, pTreg population, and colitis development. This exploratory study suggests that administration of α-cyclodextrin may be a possible strategy for the prevention of colitis.

Postbiotics: From emerging concept to application

The microbiome innovation has resulted in an umbrella term, postbiotics, which refers to non-viable microbial cells, metabolic byproducts and their microbial components released after lysis. Postbiotics, modulate immune response, gene expression, inhibit pathogen binding, maintain intestinal barriers, help in controlling carcinogenesis and pathogen infections. Postbiotics have antimicrobial, antioxidant, and immunomodulatory properties with favorable physiological, immunological, neuro-hormonal, regulatory and metabolic reactions. Consumption of postbiotics relieves symptoms of various diseases and viral infections such as SARS-CoV-2. Postbiotics can act as alternatives for pre-probiotic specially in immunosuppressed patients, children and premature neonates. Postbiotics are used to preserve and enhance nutritional properties of food, elimination of biofilms and skin conditioning in cosmetics. Postbiotics have numerous advantages over live bacteria with no risk of bacterial translocation from the gut to blood, acquisition of antibiotic resistance genes. The process of extraction, standardization, transport, and storage of postbiotic is more natural. Bioengineering techniques such as fermentation technology, high pressure etc., may be used for the synthesis of different postbiotics. Safety assessment and quality assurance of postbiotic is important as they may induce stomach discomfort, sepsis and/or toxic shock. Postbiotics are still in their infancy compared to pre- and pro- biotics but future research in this field may contribute to improved physiological functions and host health. The current review comprehensively summarizes new frontiers of research in postbiotics.

Short-chain fatty acids affect the development of inflammatory bowel disease through intestinal barrier, immunology, and microbiota: A promising therapy?

Intestinal metabolites are attracting increasing interest, especially more and more studies have found they are closely related to diseases. Microbial fermentation of indigestible dietary fibers in the gut produces short chain fatty acids (SCFAs) as the main product. SCFAs can exert influences on the integrity of the intestinal epithelial and mucosal barrier, immune reactions, and the diversity of microbiota in humans. Thus, alteration in SCFAs may affect inflammatory bowel disease (IBD). In IBD, SCFAs are involved in the main pathogenic process and play an important role in the development of intestinal inflammation. Although many studies have proved that pretreatment with SCFAs can effectively ameliorate inflammation in the gut, the mechanisms are not fully understood. In this review, we describe the relationship between SCFAs and IBD from the aspects of defense barrier, immune effects, and microbial alterations. We also summarize the effects of SCFAs on comorbidities in IBD via the gut-brain, gut-liver, and gut-lung axis, and we give an overview of the prospects of their clinical application. A better understanding of the relevance of SCFAs in IBD may reveal novel targets for future study.