Early administration of probiotic Lactobacillus acidophilus and/or prebiotic inulin attenuates pathogen-mediated intestinal inflammation and Smad 7 cell signaling

Inulin alleviates GenX-induced intestinal injury in mice by modulating the MAPK pathway, cell cycle, and cell adhesion proteins

GenX, a substitute for perfluorooctanoic acid, has demonstrated potential enterotoxicity. The enterotoxic effects of GenX and effective interventions need further investigation. In the present study, the mice were administered GenX (2 mg/kg/day) with or without inulin supplementation (5 g/kg/day) for 12 weeks. Histopathological assessments revealed that GenX induced colonic gland atrophy, inflammatory cell infiltration, a reduction in goblet cell numbers, and decreased mucus secretion. Furthermore, a significant decrease in the protein levels of ZO-1, occludin, and claudin-5 indicated compromised barrier integrity. Transcriptomic analysis identified 2645 DEGs, which were mapped to 39 significant pathways. The TGF-β, BMP6, and β-catenin proteins were upregulated in the intestinal mucosa following GenX exposure, indicating activation of the TGF-β pathway. Conversely, the protein expression of PAK3, CyclinD2, contactin1, and Jam2 decreased, indicating disruptions in cell cycle progression and cell adhesion. Inulin cotreatment ameliorated these GenX-induced alterations, partially through modulating the MAPK pathway, as evidenced by the upregulation of the cell cycle and cell adhesion proteins. Collectively, these findings suggested that GenX exposure triggered intestinal injury in mice by activating the TGF-β pathway and disrupting proteins crucial for the cell cycle and cell adhesion, whereas inulin supplementation mitigated this injury by modulating the MAPK pathway.

Integrative approaches to atrial fibrillation prevention and management: Leveraging gut health for improved cardiovascular outcomes in the aging population

Atrial fibrillation (AF) is a prevalent clinical arrhythmia associated with a high incidence and severe complications such as cerebral embolism and heart failure. While the etiology and pathogenesis of AF involve numerous factors, recent research emphasizes the significant role of intestinal microbiota imbalance in the emergence and progression of AF, particularly among older adults. This review investigates the mechanisms by which intestinal flora and their metabolites contribute to the onset of AF in the elderly, highlighting novel interactions between gut health and cardiac function. Current literature often overlooks these critical connections, indicating a substantial research gap in understanding how dysbiosis may exacerbate AF and hinder recovery. Furthermore, exploring the bidirectional relationship between the gut microbiome and systemic inflammation in the context of AF provides a unique perspective that has yet to be thoroughly investigated. Future research should focus on longitudinal studies assessing gut microbiota composition and function in AF patients and consider probiotics or prebiotics as potential adjunctive therapies for mitigating AF. This comprehensive approach may pave the way for innovative treatments integrating cardiology with gastroenterology, enhancing patient outcomes through a holistic understanding of health.

Inulin alleviates perfluorooctanoic acid-induced intestinal injury in mice by modulating the PI3K/AKT/mTOR signaling pathway

Perfluorooctanoic acid (PFOA) is a widely used industrial compound that has been found to induce intestinal toxicity. However, the underlying mechanisms have not been fully clarified and effective interventions are rarely developed. Inulin, a prebiotic, has been used as a supplement in human daily life as well as in gastrointestinal diseases and metabolic disorders. In this study, male mice were exposed to PFOA with or without inulin supplementation to investigate the enterotoxicity and potential intervention effects of inulin. Mice were administered PFOA at 1 mg/kg/day, PFOA with inulin at 5 g/kg/day, or Milli-Q water for 12 weeks. Histopathological analysis showed that PFOA caused colon shortening, goblet cell reduction, and inflammatory cell infiltration. The expression of the tight junction proteins ZO-1, occludin and claudin5 significantly decreased, indicating impaired barrier function. According to the RNA-sequencing analysis, PFOA exposure resulted in 917 differentially expressed genes, involving 39 significant pathways, such as TNF signaling and cell cycle pathways. In addition, the protein expression of TNF-α, IRG-47, cyclinB1, and cyclinB2 increased, while Gadd45γ, Lzip, and Jam2 decreased, suggesting the involvement of the TNF signaling pathway, cell cycle, and cell adhesion molecules in PFOA-associated intestinal injury. Inulin intervention alleviated PFOA-induced enterotoxicity by activating the PI3K/AKT/mTOR signaling pathway and increasing the protein expression of Wnt1, β-catenin, PI3K, Akt3, and p62, while suppressing MAP LC3β, TNF-α, and CyclinE expression. These findings suggested that PFOA-induced intestinal injury, including inflammation and tight junction disruption, was mitigated by inulin through modifying the PI3K/AKT/mTOR signaling pathways. Our study provides valuable insights into the enterotoxic effects of PFOA and highlights the potential therapeutic role of inulin.

Role of the intestinal microbiome and its therapeutic intervention in cardiovascular disorder

The gut microbiome is a heterogeneous population of microbes comprising viruses, bacteria, fungi, and protozoa. Such a microbiome is essential for sustaining host equilibrium, and its impact on human health can be altered by a variety of factors such as external variables, social behavior, age, nutrition, and genetics. Gut microbes' imbalances are related to a variety of chronic diseases including cancer, obesity, and digestive disorders. Globally, recent findings show that intestinal microbes have a significant role in the formation of cardiovascular disease (CVD), which is still the primary cause of fatalities. Atherosclerosis, hypertension, diabetes, inflammation, and some inherited variables are all cardiovascular risk variables. However, studies found correlations between metabolism, intestinal flora, and dietary intake. Variations in the diversity of gut microbes and changes in their activity are thought to influence CVD etiology. Furthermore, the gut microbiota acts as an endocrine organ, producing bioactive metabolites such as TMA (trimethylamine)/TMAO (trimethylamine N-oxide), SCFA (short-chain fatty acids), and bile acids, which have a substantial impact on host wellness and disease by multiple mechanisms. The purpose of this overview is to compile current evidence highlighting the intricate links between gut microbiota, metabolites, and the development of CVD. It focuses on how intestinal dysbiosis promotes CVD risk factors such as heart failure, hypertension, and atherosclerosis. This review explores the normal physiology of intestinal microbes and potential techniques for targeting gut bacteria for CVD treatment using various microbial metabolites. It also examines the significance of gut bacteria in disease treatment, including supplements, prebiotics, probiotics, antibiotic therapies, and fecal transplantation, which is an innovative approach to the management of CVD. As a result, gut bacteria and metabolic pathways become increasingly attractive as potential targets for CVD intervention.

The interplay between microbial metabolites and macrophages in cardiovascular diseases: A comprehensive review

The gut microbiome has emerged as a crucial player in developing and progressing cardiovascular diseases (CVDs). Recent studies have highlighted the role of microbial metabolites in modulating immune cell function and their impact on CVD. Macrophages, which have a significant function in the pathogenesis of CVD, are very vulnerable to the effects of microbial metabolites. Microbial metabolites, such as short-chain fatty acids (SCFAs) and trimethylamine-N-oxide (TMAO), have been linked to atherosclerosis and the regulation of immune functions. Butyrate has been demonstrated to reduce monocyte migration and inhibit monocyte attachment to injured endothelial cells, potentially contributing to the attenuation of the inflammatory response and the progression of atherosclerosis. On the other hand, TMAO, another compound generated by gut bacteria, has been linked to atherosclerosis due to its impact on lipid metabolism and the accumulation of cholesterol in macrophages. Indole-3-propionic acid, a tryptophan metabolite produced solely by microbes, has been found to promote the development of atherosclerosis by stimulating macrophage reverse cholesterol transport (RCT) and raising the expression of ABCA1. This review comprehensively discusses how various microbiota-produced metabolites affect macrophage polarization, inflammation, and foam cell formation in CVD. We also highlight the mechanisms underlying these effects and the potential therapeutic applications of targeting microbial metabolites in treating CVD.

Therapeutic interventions target the NLRP3 inflammasome in ulcerative colitis: Comprehensive study

One of the significant health issues in the world is the prevalence of ulcerative colitis (UC). UC is a chronic disorder that mainly affects the colon, beginning with the rectum, and can progress from asymptomatic mild inflammation to extensive inflammation of the entire colon. Understanding the underlying molecular mechanisms of UC pathogenesis emphasizes the need for innovative therapeutic approaches based on identifying molecular targets. Interestingly, in response to cellular injury, the NLR family pyrin domain containing 3 (NLRP3) inflammasome is a crucial part of the inflammation and immunological reaction by promoting caspase-1 activation and the release of interleukin-1β. This review discusses the mechanisms of NLRP3 inflammasome activation by various signals and its regulation and impact on UC.

Inflammatory Response: A Crucial Way for Gut Microbes to Regulate Cardiovascular Diseases

Gut microbiota is the largest and most complex microflora in the human body, which plays a crucial role in human health and disease. Over the past 20 years, the bidirectional communication between gut microbiota and extra-intestinal organs has been extensively studied. A better comprehension of the alternative mechanisms for physiological and pathophysiological processes could pave the way for health. Cardiovascular disease (CVD) is one of the most common diseases that seriously threatens human health. Although previous studies have shown that cardiovascular diseases, such as heart failure, hypertension, and coronary atherosclerosis, are closely related to gut microbiota, limited understanding of the complex pathogenesis leads to poor effectiveness of clinical treatment. Dysregulation of inflammation always accounts for the damaged gastrointestinal function and deranged interaction with the cardiovascular system. This review focuses on the characteristics of gut microbiota in CVD and the significance of inflammation regulation during the whole process. In addition, strategies to prevent and treat CVD through proper regulation of gut microbiota and its metabolites are also discussed.

Gut Microbiota and Cardiovascular System: An Intricate Balance of Health and the Diseased State

Gut microbiota encompasses the resident microflora of the gut. Having an intricate relationship with the host, it plays an important role in regulating physiology and in the maintenance of balance between health and disease. Though dietary habits and the environment play a critical role in shaping the gut, an imbalance (referred to as dysbiosis) serves as a driving factor in the occurrence of different diseases, including cardiovascular disease (CVD). With risk factors of hypertension, diabetes, dyslipidemia, etc., CVD accounts for a large number of deaths among men (32%) and women (35%) worldwide. As gut microbiota is reported to have a direct influence on the risk factors associated with CVDs, this opens up new avenues in exploring the possible role of gut microbiota in regulating the gross physiological aspects along the gut-heart axis. The present study elaborates on different aspects of the gut microbiota and possible interaction with the host towards maintaining a balance between health and the occurrence of CVDs. As the gut microbiota makes regulatory checks for these risk factors, it has a possible role in shaping the gut and, as such, in decreasing the chances of the occurrence of CVDs. With special emphasis on the risk factors for CVDs, this paper includes information on the prominent bacterial species (Firmicutes, Bacteriodetes and others) towards an advance in our understanding of the etiology of CVDs and an exploration of the best possible therapeutic modules for implementation in the treatment of different CVDs along the gut-heart axis.

Update on gut microbiota in cardiovascular diseases

In recent years, due to the development and widespread utilization of metagenomic sequencing and metabolomics, the relationship between gut microbiota and human cardiovascular diseases (CVDs) has received extensive attention. A growing number of studies have shown a strong relationship between gut microbiota and CVDs, such as coronary atherosclerosis, hypertension (HTN) and heart failure (HF). It has also been revealed that intestinal flora-related metabolites, such as trimethylamine-N-oxide (TMAO), short-chain fatty acids (SCFA) and bile acids (BAs), are also related to the development, prevention, treatment and prognosis of CVDs. In this review, we presented and summarized the recent findings on the relationship between gut microbiota and CVDs, and concluded several currently known gut microbiota-related metabolites and the occurrence and development of CVDs.

Oral supplementation with selected Lactobacillus acidophilus triggers IL-17-dependent innate defense response, activation of innate lymphoid cells type 3 and improves colitis

Live biotherapeutic products constitute an emerging therapeutic approach to prevent or treat inflammatory bowel diseases. Lactobacillus acidophilus is a constituent of the human microbiota with probiotic potential, that is illustrated by improvement of intestinal inflammation and antimicrobial activity against several pathogens. In this study, we evaluated the immunomodulatory properties of the L. acidophilus strain BIO5768 at steady state and upon acute inflammation. Supplementation of naïve mice with BIO5768 heightened the transcript level of some IL-17 target genes encoding for protein with microbicidal activity independently of NOD2 signaling. Of these, the BIO5768-induced expression of Angiogenin-4 was blunted in monocolonized mice that are deficient for the receptor of IL-17 (but not for NOD2). Interestingly, priming of bone marrow derived dendritic cells by BIO5768 enhanced their ability to support the secretion of IL-17 by CD4⁺ T cells. Equally of importance, the production of IL-22 by type 3 innate lymphoid cells is concomitantly heightened in response to BIO5768. When administered alone or in combination with Bifidobacterium animalis spp. lactis BIO5764 and Limosilactobacillus reuteri, BIO5768 was able to alleviate at least partially intestinal inflammation induced by Citrobacter rodentium infection. Furthermore, BIO5768 was also able to improve colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). In conclusion, we identify a new potential probiotic strain for the management of inflammatory bowel diseases, and provide some insights into its IL-17-dependent and independent mode of action.

Probiotic supplementation and systemic inflammation in relapsing-remitting multiple sclerosis: A randomized, double-blind, placebo-controlled trial

Background

Multiple sclerosis (MS) is a complex inflammatory disease in which demyelination occurs in the central nervous system affecting approximately 2.5 million people worldwide. Intestinal microbiome changes play an important role in the etiology of chronic diseases.

Objective

This study aimed to investigate the effect of probiotic supplementation on systemic inflammation in patients with MS.

Methods

A 12-week double-blind clinical trial study was designed and seventy patients with MS were randomly divided into two groups receiving probiotics and placebo. Patients in the intervention group received two capsules containing multi-strain probiotics daily and patients in the control group received the same amount of placebo. Factors associated with systemic inflammation were assessed at the beginning and end of the study.

Results

Sixty-five patients were included in the final analysis. There was no significant difference between the two groups in terms of baseline variables except for the duration of the disease (P > 0.05). At the end of the study, probiotic supplementation compared to the placebo caused a significant reduction in the serum levels of CRP (-0.93 ± 1.62 vs. 0.05 ± 1.74, P = 0.03), TNF-α (-2.09 ± 1.88 vs. 0.48 ± 2.53, P = 0.015) and IFN-γ (-13.18 ± 7.33 vs. -1.93 ± 5.99, P < 0.001). Also, we found a significant increase in the FOXP3 and TGF-β levels in the intervention group (P < 0.05).

Conclusion

The results of our study showed that supplementation with probiotics can have beneficial effects on serum levels of some factors associated with systemic inflammation.

Clinical trial registration

[http://www.irct.ir], identifier [IRCT20181210041 918N1].

Modulatory Impacts of Multi-Strain Probiotics on Rabbits’ Growth, Nutrient Transporters, Tight Junctions and Immune System to Fight against Listeria monocytogenes Infection

Simple Summary

Weaning is a crucial period associated with great stress and susceptibility to infection, implying adverse impacts on farmed rabbits’ production. Recently, probiotics have been provided as direct microbial feed supplements, which are considered the ideal antibiotic substitutes during pathogenic infections with an emphasis on promoting rabbits’ growth and modulating their immune functions. Therefore, our experiment was carried out to explore the efficacy of multi-strain probiotics (MSP) on rabbits’ growth, molecular aspects, such as nutrients transporters, cytokines, and intestinal integrity, and effectiveness against Listeria monocytogenes (L. monocytogenes) infection. Altogether, our findings proposed the beneficial consequences of MSP on rabbits’ growth, gut health, and immunity. After post-experimental infection of rabbits with L. monocytogenes, administration of MSP during the whole rearing period greatly reduced the detrimental impact of infection and consequently renovated efficient rabbits’ production.

Abstract

Multi-strain probiotics (MSP) are considered innovative antibiotics’ substitutes supporting superior gut health and immunity of farmed rabbits. The promising roles of MSP on performance, intestinal immunity, integrity and transporters, and resistance against Listeria monocytogenes (L. monocytogenes) were evaluated. In the feeding trial, 220 rabbits were fed a control diet or diet supplemented with three MSP graded levels. At 60 days of age, rabbits were experimentally infected with L. monocytogenes and the positive control, enrofloxacin, prophylactic MSP (MSPP), and prophylactic and therapeutic MSP (MSPTT) groups were included. During the growing period, MSP at the level of 1 × 10⁸ CFU/kg diet (MSPIII) promoted the rabbits’ growth, upregulated the nutrient transporters and tight-junction-related genes, and modified cytokines expression. Supplementing MSPTT for L. monocytogenes experimentally-infected rabbits restored the impaired growth and intestinal barriers, reduced clinical signs of severity and mortalities, and attenuated the excessive inflammatory reactions. Notably, enrofloxacin decreased L. monocytogenes and beneficial microbial loads; unlike MSPTT, which decreased pathogenic bacterial loads and sustained the beneficial ones. Histopathological changes were greatly reduced in MSPTT, confirming its promising role in restricting L. monocytogenes translocation to different organs. Therefore, our results suggest the use of MSPTT as an alternative to antibiotics, thereby conferring protection for rabbits against L. monocytogenes infection.

Effect of the Microbiome on Intestinal Innate Immune Development in Early Life and the Potential Strategy of Early Intervention

Early life is a vital period for mammals to be colonized with the microbiome, which profoundly influences the development of the intestinal immune function. For neonates to resist pathogen infection and avoid gastrointestinal illness, the intestinal innate immune system is critical. Thus, this review summarizes the development of the intestinal microbiome and the intestinal innate immune barrier, including the intestinal epithelium and immune cells from the fetal to the weaning period. Moreover, the impact of the intestinal microbiome on innate immune development and the two main way of early-life intervention including probiotics and fecal microbiota transplantation (FMT) also are discussed in this review. We hope to highlight the crosstalk between early microbial colonization and intestinal innate immunity development and offer some information for early intervention.

The Gut Microbiota (Microbiome) in Cardiovascular Disease and Its Therapeutic Regulation

In the last two decades, considerable interest has been shown in understanding the development of the gut microbiota and its internal and external effects on the intestine, as well as the risk factors for cardiovascular diseases (CVDs) such as metabolic syndrome. The intestinal microbiota plays a pivotal role in human health and disease. Recent studies revealed that the gut microbiota can affect the host body. CVDs are a leading cause of morbidity and mortality, and patients favor death over chronic kidney disease. For the function of gut microbiota in the host, molecules have to penetrate the intestinal epithelium or the surface cells of the host. Gut microbiota can utilize trimethylamine, N-oxide, short-chain fatty acids, and primary and secondary bile acid pathways. By affecting these living cells, the gut microbiota can cause heart failure, atherosclerosis, hypertension, myocardial fibrosis, myocardial infarction, and coronary artery disease. Previous studies of the gut microbiota and its relation to stroke pathogenesis and its consequences can provide new therapeutic prospects. This review highlights the interplay between the microbiota and its metabolites and addresses related interventions for the treatment of CVDs.

Inulin fructans in diet: Role in gut homeostasis, immunity, health outcomes and potential therapeutics

Inulin consumption in both humans and animal models is recognized for its prebiotic action with the most consistent change that lies in enhancing the growth and functionality of Bifidobacterium bacteria, as well as its effect on host gene expression and metabolism. Further, inulin-type fructans are utilized in the colon by bacterial fermentation to yield short-chain fatty acids (SCFAs), which play important role in its biological effects both locally inside the gut and in systemic actions. The gut symbiosis sustained by inulin supplementation among other dietary fibers exerts preventive and/or therapeutic options for many metabolic disorders including obesity, type 2 diabetes mellitus, cardiometabolic diseases, kidney diseases and hyperuricemia. Although, gastrointestinal negative effects due to inulin consumption were reported, such as gastrointestinal symptoms in humans and exacerbated inflammatory bowel disease (IBD) in mice. This comprehensive review aims to present the whole story of how inulin functions as a prebiotic at cellular levels and the interplay between physiological, functional and immunological responses inside the animal or human gut as influenced by inulin in diets, in context to its structural composition. Such review is of importance to identify management and feed strategies to optimize gut health, for instance, consumption of the tolerated doses to healthy adults of 10 g/day of native inulin or 5 g/day of naturally inulin-rich chicory extract. In addition, inulin-drug interactions should be further clarified particularly if used as a supplement for the treatment of degenerative diseases (e.g., diabetes) over a long period. The combined effect of probiotics and inulin appears more effective, and more research on this synergy is still needed.

Probiotics and gut microbiota: mechanistic insights into gut immune homeostasis through TLR pathway regulation

Consumption of probiotics as a useful functional food improves the host's wellbeing, and, when paired with prebiotics (indigestible dietary fibre/carbohydrate), often benefits the host through anaerobic fermentation.

Maternal microbiome in preeclampsia pathophysiology and implications on offspring health

Preeclampsia is a devastating hypertensive pregnancy disorder that currently affects 2%–8% of pregnancies worldwide. It is associated with maternal and fetal mortality and morbidity and adverse health outcomes both in mom and offspring beyond pregnancy. The pathophysiology is not completely understood, and there are no approved therapies to specifically treat for the disease, with only few therapies approved to manage symptoms. Recent advances suggest that aberrations in the composition of the microbiome may play a role in the pathogenesis of various diseases including preeclampsia. The maternal and uteroplacental environments greatly influence the long‐term health outcomes of the offspring through developmental programming mechanisms. The current review summarizes recent developments on the role of the microbiome in adverse pregnancy outcomes with a focus on preeclampsia. It also discusses the potential role of the maternal microbiome in fetal programming; explores gut‐targeted therapeutics advancement and their implications in the treatment of preeclampsia.

Role of p40phox in host defense against Citrobacter rodentium infection

NADPH oxidase (NOX) is a membrane-bound enzyme complex that generates reactive oxygen species (ROS). Mutations in NOX subunit genes have been implicated in the pathogenesis of inflammatory bowel disease (IBD), indicating a crucial role for ROS in regulating host immune responses. In this study, we utilize genetically deficient mice to investigate whether defects in p40phox , one subunit of NOX, impair host immune response in the intestine and aggravate disease in an infection-based (Citrobacter rodentium) model of colitis. We show that p40phox deficiency does not increase susceptibility of mice to C. rodentium infection, as no differences in body weight loss, bacterial clearance, colonic pathology, cytokine production, or immune cell recruitment were observed between p40phox-/- and wild-type mice. Interestingly, higher IL-10 levels were observed in the supernatants of MLN cells and splenocytes isolated from infected p40phox -deficient mice. Further, a higher expression level of inducible nitric oxide synthase (iNOS) was also noted in mice lacking p40phox . In contrast to wild-type mice, p40phox-/- mice exhibited greater NO production after LPS or bacterial antigen re-stimulation. These results suggest that p40phox-/- mice do not develop worsened colitis. While the precise mechanisms are unclear, it may involve the observed alteration in cytokine responses and enhancement in levels of iNOS and NO.

The Gut Microbiome and Cardiovascular Disease

Cardiovascular disease (CVD) is currently the leading cause of death worldwide. Although many well-known conditions cause CVD, recent research has suggested that alterations to the gut microbiome may also promote CVD. The gastrointestinal tract houses trillions of bacteria, some of which in large numbers are considered to be part of a healthy gut microbiome profile. These "good" bacteria have the ability to process and digest complex carbohydrates into short-chain fatty acids (SFCA). These SCFA serve as signaling molecules, immune-modulating molecules, and sources of energy. However, with gut dysbiosis, there is an overgrowth of certain bacteria and these bacteria overly produce phosphatidylcholine, choline, and carnitine into the waste product trimethylamine-N-oxide (TMAO). Elevated TMAO levels are associated with an increased risk of atherosclerosis, myocardial infarction, thrombosis, and stroke. Therefore, introducing therapeutic interventions that alter a dysbiotic gut profile back to a healthy gut microbiome may be the key to reducing the incidence of cardiovascular disease in some conditions. The purpose of this review is to critically examine and consolidate the relevant information bearing on this concept. Our goal is to provide the informational framework for the possible use of microbiome modification as an optional therapeutic modality.

Escherichia coli Nissle 1917 Enhances Innate and Adaptive Immune Responses in a Ciprofloxacin-Treated Defined-Microbiota Piglet Model of Human Rotavirus Infection

Human rotavirus (HRV) infection is a major cause of gastroenteritis in children worldwide. Broad-spectrum antibiotic-induced intestinal microbial imbalance and the ensuing immune-metabolic dysregulation contribute to the persistence of HRV diarrhea. Escherichia coli Nissle 1917 (EcN), a Gram-negative probiotic, was shown to be a potent immunostimulant and alleviated HRV-induced diarrhea in monocolonized gnotobiotic (Gn) piglets. Our goal was to determine how EcN modulates immune responses in ciprofloxacin (Cipro)-treated Gn piglets colonized with a defined commensal microbiota (DM) and challenged with virulent HRV (VirHRV). Cipro given in therapeutic doses for a short term reduced serum and intestinal total and HRV-specific antibody titers, while EcN treatment alleviated this effect. Similarly, EcN treatment increased the numbers of total immunoglobulin-secreting cells, HRV-specific antibody-secreting cells, activated antibody-forming cells, resting/memory antibody-forming B cells, and naive antibody-forming B cells in systemic and/or intestinal tissues. Decreased levels of proinflammatory but increased levels of immunoregulatory cytokines and increased frequencies of Toll-like receptor-expressing cells were evident in the EcN-treated VirHRV-challenged group. Moreover, EcN treatment increased the frequencies of T helper and T cytotoxic cells in systemic and/or intestinal tissues pre-VirHRV challenge and the frequencies of T helper cells, T cytotoxic cells, effector T cells, and T regulatory cells in systemic and/or intestinal tissues postchallenge. Moreover, EcN treatment increased the frequencies of systemic and mucosal conventional and plasmacytoid dendritic cells, respectively, and the frequencies of systemic natural killer cells. Our findings demonstrated that Cipro use altered immune responses of DM-colonized neonatal Gn pigs, while EcN supplementation rescued these immune parameters partially or completely.

IMPORTANCE Rotavirus (RV) is a primary cause of malabsorptive diarrhea in children and is associated with significant morbidity and mortality, especially in developing countries. The use of antibiotics exacerbates intestinal microbial imbalance and results in the persistence of RV-induced diarrhea. Probiotics are now being used to treat enteric infections and ulcerative colitis. We showed previously that probiotics partially protected gnotobiotic (Gn) piglets against human RV (HRV) infection and decreased the severity of diarrhea by modulating immune responses. However, the interactions between antibiotic and probiotic treatments and HRV infection in the context of an established gut microbiota are poorly understood. In this study, we developed a Gn pig model to study antibiotic-probiotic-HRV interactions in the context of a defined commensal microbiota (DM) that mimics aspects of the infant gut microbiota. Our results provide valuable information that will contribute to the treatment of antibiotic- and/or HRV-induced diarrhea and may be applicable to other enteric infections in children.

Consumption of Dietary Fiber from Different Sources during Pregnancy Alters Sow Gut Microbiota and Improves Performance and Reduces Inflammation in Sows and Piglets

Although the direct effects of dietary fiber on gut microbiota composition have been studied extensively, systematic evaluation of different fiber sources on gut health and inflammatory responses of sows and their offspring has rarely been conducted. Excessive reactive oxygen species produced by overactive metabolic processes during late pregnancy and lactation of sows leads to increased endotoxin levels, disordered gut microbiota, decreased SCFA production, and secretion of proinflammatory factors, which in turn causes local inflammation of the gut, potential damage of the gut microbial barrier, increased gut permeability, increased blood endotoxin levels (resulting in systemic inflammation), and ultimately decreased sow and piglet performance.

In pregnant and lactating sows, metabolism and immunity undergo drastic changes, which can lead to constipation, abortion, and intrauterine growth restriction (IUGR) and reduce production performance. Dietary fiber can regulate animal gut microbiota, alleviate inflammatory responses, and improve performance. Here, 48 sows (Large × Landrace) were randomly allocated to groups including, control, and with alfalfa meal (AM), beet pulp, and soybean skin dietary supplementation for 60 days of gestation. The AM diet decreased IUGR, increased food intake during lactation, and promoted the reproductive performance and physical condition of sows. Further, the AM diet significantly reduced markers of intestinal permeability (reactive oxygen species and endotoxin) in sow serum, and of systemic inflammation (interleukin-6 [IL-6] and tumor necrosis factor alpha) in sow feces and serum, as well as piglet serum, while it increased the anti-inflammatory marker, IL-10, in sow serum and feces. The AM diet also significantly affected gut microbiota by increasing the relative abundance of proinflammatory bacteria, while decreasing anti-inflammatory bacteria. Moreover, the total short-chain fatty acid (SCFA) content was higher in feces from sows fed an AM diet, with butyric acid content significantly higher during lactation, than in controls. Sow performance was correlated with intestinal permeability, inflammation, and gut microbiota, which were also vertically transmitted to piglets. Our results are significant for guiding feed management in the pig breeding industry. Further, the “sows to piglets” model provides a reference for the effect of dietary fiber on the gastrointestinal function of human mothers and infants.

IMPORTANCE Although the direct effects of dietary fiber on gut microbiota composition have been studied extensively, systematic evaluation of different fiber sources on gut health and inflammatory responses of sows and their offspring has rarely been conducted. Excessive reactive oxygen species produced by overactive metabolic processes during late pregnancy and lactation of sows leads to increased endotoxin levels, disordered gut microbiota, decreased SCFA production, and secretion of proinflammatory factors, which in turn causes local inflammation of the gut, potential damage of the gut microbial barrier, increased gut permeability, increased blood endotoxin levels (resulting in systemic inflammation), and ultimately decreased sow and piglet performance. Our results showed that supplementation of the diet with alfalfa meal in mid and late pregnancy can reverse this process. Our findings lay a foundation for improving the gut health of sows and piglets and provide insights into the study of the gastrointestinal tract function in human mothers and infants.

Receptor-targeted engineered probiotics mitigate lethal Listeria infection

Probiotic bacteria reduce the intestinal colonization of pathogens. Yet, their use in preventing fatal infection caused by foodborne Listeria monocytogenes (Lm), is inconsistent. Here, we bioengineered Lactobacillus probiotics (BLP) to express the Listeria adhesion protein (LAP) from a non-pathogenic Listeria (L. innocua) and a pathogenic Listeria (Lm) on the surface of Lactobacillus casei. The BLP strains colonize the intestine, reduce Lm mucosal colonization and systemic dissemination, and protect mice from lethal infection. The BLP competitively excludes Lm by occupying the surface presented LAP receptor, heat shock protein 60 and ameliorates the Lm-induced intestinal barrier dysfunction by blocking the nuclear factor-κB and myosin light chain kinase-mediated redistribution of the major epithelial junctional proteins. Additionally, the BLP increases intestinal immunomodulatory functions by recruiting FOXP3+T cells, CD11c+ dendritic cells and natural killer cells. Engineering a probiotic strain with an adhesion protein from a non-pathogenic bacterium provides a new paradigm to exclude pathogens and amplify their inherent health benefits.

Effects of REDOX in Regulating and Treatment of Metabolic and Inflammatory Cardiovascular Diseases

Reduction oxidation (REDOX) reaction is crucial in life activities, and its dynamic balance is regulated by ROS. Reactive oxygen species (ROS) is associated with a variety of metabolic diseases involving in multiple cellular signalling in pathologic and physiological signal transduction. ROS are the by-products of numerous enzymatic reactions in various cell compartments, including the cytoplasm, cell membrane, endoplasmic reticulum (ER), mitochondria, and peroxisome. ROS signalling is not only involved in normal physiological processes but also causes metabolic dysfunction and maladaptive responses to inflammatory signals, which depends on the cell type or tissue environment. Excess oxidants are able to alter the normal structure and function of DNA, lipids, and proteins, leading to mutations or oxidative damage. Therefore, excessive oxidative stress is usually regarded as the cause of various pathological conditions, such as cancer, neurodegeneration, cardiovascular diseases (CVDs), diabetes, and kidney diseases. Currently, it has been possible to detect diabetes and other cardiac diseases by detecting derivatives accompanied by oxidative stress in vivo as biomarkers, but there is no effective method to treat these diseases. In consequence, it is essential for us to seek new therapy targeting these diseases through understanding the role of ROS signalling in regulating metabolic activity, inflammatory activation, and cardiac diseases related to metabolic dysfunction. In this review, we summarize the current literature on REDOX and its role in the regulation of cardiac metabolism and inflammation, focusing on ROS, local REDOX signalling pathways, and other mechanisms.

Evaluation of the antitumor immune responses of probiotic Bifidobacterium bifidum in human papillomavirus-induced tumor model

As of present, a number of studies have shown anti-cancer effects of different strains of probiotics, but the precise host immunological mechanisms of these antitumor effects remain unclear. Thus, the aim of current study was to investigate the preventive-therapeutic effects of oral versus intravenous administration of probiotic Bifidobacterium bifidum on immune response and tumor growth of C57BL/6 mice bearing transplanted TC-1 cell of human papillomavirus (HPV)-related tumor, expressing HPV-16 E6/E7 oncogenes. Our major findings are that the intravenous or oral administration of Bifidobacterium bifidum effectively induces antitumor immune responses and inhibits tumor growth in mice. Compared to oral route only, intravenous administration of probiotic Bifidobacterium bifidum into tumor-bearing mice leads to the activation of tumor-specific IL-12 and IFN-γ, lymphocyte proliferation, CD8⁺ cytolytic responses that control and eradicate tumor growth. These observations meant intravenous administration of probiotics is an effective anticancer approach through modulation of the immune system. The potential of probiotic Bifidobacterium bifidum as an immunomodulator in the treatment of cervical cancer could be further explored.

Smad7 in intestinal CD4+ T cells determines autoimmunity in a spontaneous model of multiple sclerosis

Environmental triggers acting at the intestinal barrier are thought to contribute to the initiation of autoimmune disorders. The transforming growth factor beta inhibitor Smad7 determines the phenotype of CD4+ T cells. We hypothesized that Smad7 in intestinal CD4+ T cells controls initiation of opticospinal encephalomyelitis (OSE), a murine model of multiple sclerosis (MS), depending on the presence of gut microbiota. Smad7 was overexpressed or deleted in OSE CD4+ T cells to determine the effect on clinical progression, T cell differentiation, and T cell migration from the intestine to the central nervous system (CNS). Smad7 overexpression worsened the clinical course of OSE and increased CNS inflammation and demyelination. It favored expansion of intestinal CD4+ T cells toward an inflammatory phenotype and migration of intestinal CD4+ T cells to the CNS. Intestinal biopsies from MS patients revealed decreased transforming growth factor beta signaling with a shift toward inflammatory T cell subtypes. Smad7 in intestinal T cells might represent a valuable therapeutic target for MS to achieve immunologic tolerance in the intestine and suppress CNS inflammation.

The Current Evidence on the Association Between the Urinary Microbiome and Urinary Incontinence in Women

Urinary incontinence (UI) is a burdensome condition with high prevalence in middle-aged to older women and an unclear etiology. Advances in our understanding of host-microbe interactions in the urogenital tract have stimulated interest in the urinary microbiome. DNA sequencing and enhanced urine culture suggest that similarly to other mucosal sites, the urinary bladder of healthy individuals harbors resident microbial communities that may play distinct roles in bladder function. This review focused on the urobiome (expanded quantitative urine culture-based or genomic sequencing-based urinary microbiome) associated with different subtypes of UI, including stress, urgency and mixed urinary incontinence, and related syndromes, such as interstitial cystitis and overactive bladder in women, contrasted to urinary tract infections. Furthermore, we examined clinical evidence for the association of the urinary microbiome with responses to pharmacotherapy for amelioration of UI symptoms. Although published studies are still relatively limited in number, study design and sample size, cumulative evidence suggests that certain Lactobacillus species may play a role in maintaining a healthy bladder milieu. Higher bacterial diversity in the absence of Lactobacillus dominance was associated with urgency UI and resistance to anticholinergic treatment for this condition. UI may also facilitate the persistence of uropathogens following antibiotic treatment, which in turn can alter the commensal/potentially beneficial microbial communities. Risk factors of UI, including age, menopausal status, sex steroid hormones, and body mass index may also impact the urinary microbiome. However, it is yet unclear whether the effects of these risks factors on UI are mediated by urinary host-microbe interactions and a mechanistic link with the female urogenital microbiome is still to be established. Strategies for future research are suggested.

Outgrowing the Immaturity Myth: The Cost of Defending From Neonatal Infectious Disease

Newborns suffer high rates of mortality due to infectious disease-this has been generally regarded to be the result of an "immature" immune system with a diminished disease-fighting capacity. However, the immaturity dogma fails to explain (i) greater pro-inflammatory responses than adults in vivo and (ii) the ability of neonates to survive a significantly higher blood pathogen burden than of adults. To reconcile the apparent contradiction of clinical susceptibility to disease and the host immune response findings when contrasting newborn to adult, it will be essential to capture the entirety of available host-defense strategies at the newborn's disposal. Adults focus heavily on the disease resistance approach: pathogen reduction and elimination. Newborn hyperactive innate immunity, sensitivity to immunopathology, and the energetic requirements of growth and development (immune and energy costs), however, preclude them from having an adult-like resistance response. Instead, newborns also may avail themselves of disease tolerance (minimizing immunopathology without reducing pathogen load), as a disease tolerance approach provides a counterbalance to the dangers of a heightened innate immunity and has lower-associated immune costs. Further, disease tolerance allows for the establishment of a commensal bacterial community without mounting an unnecessarily dangerous immune resistance response. Since disease tolerance has its own associated costs (immune suppression leading to unchecked pathogen proliferation), it is the maintenance of homeostasis between disease tolerance and disease resistance that is critical to safe and effective defense against infections in early life. This paradigm is consistent with nearly all of the existing evidence.

Does Modification of the Large Intestinal Microbiome Contribute to the Anti-Inflammatory Activity of Fermentable Fiber?

Fiber is an inadequately understood and insufficiently consumed nutrient. This review examines the possible causal relation between fiber-induced microbiome changes and the anti-inflammatory activity of fiber. To demonstrate the dominant role of fermentable plant fiber in shaping the intestinal microbiome, animal and human fiber-feeding studies are reviewed. Using culture-, PCR-, and sequencing-based microbial analyses, a higher prevalence of Bifidobacterium and Lactobacillus genera was observed from the feeding of different types of fermentable fiber. This finding was reported in studies performed on several host species including human. Health conditions and medications that are linked to intestinal microbial alterations likely also change the nutrient environment of the large intestine. The unique gene clusters of Bifidobacterium and Lactobacillus that enable the catabolism of plant glycans and the ability of Bifidobacterium and Lactobacillus to reduce the colonization of proteobacteria probably contribute to their prevalence in a fiber-rich intestinal environment. The fiber-induced microbiome changes could contribute to the anti-inflammatory activity of fiber. Although most studies did not measure fecal microbial density or total daily fecal microbial output (colon microbial load), limited evidence suggests that the increase in intestinal commensal microbial load plays an important role in the anti-inflammatory activity of fiber. Various probiotic supplements, including Bifidobacterium and Lactobacillus, showed anti-inflammatory activity only in the presence of fiber, which promoted microbial growth as indicated by increasing plasma short-chain fatty acids. Probiotics alone or pure fiber administered under sterile conditions showed no anti-inflammatory activity. The potential mechanisms that could mediate the anti-inflammatory effect of common microbial metabolites are reviewed, but more in vivo trials are needed. Future studies including simultaneous microbial composition and load measurements are also important.

Gut microbiota in cardiovascular disease and heart failure

Accumulating evidence supports a relationship between the complexity and diversity of the gut microbiota and host diseases. In addition to alterations in the gut microbial composition, the metabolic potential of gut microbiota has been identified as a contributing factor in the development of diseases. Recent technological developments of molecular and biochemical analyses enable us to detect and characterize the gut microbiota via assessment and classification of its genomes and corresponding metabolites. These advances have provided emerging data supporting the role of gut microbiota in various physiological activities including host metabolism, neurological development, energy homeostasis, and immune regulation. Although few human studies have looked into the causative associations and underlying pathophysiology of the gut microbiota and host disease, a growing body of preclinical and clinical evidence supports the theory that the gut microbiota and its metabolites have the potential to be a novel therapeutic and preventative target for cardiovascular and metabolic diseases. In this review, we highlight the interplay between the gut microbiota and its metabolites, and the development and progression of hypertension, heart failure, and chronic kidney disease.

Immune-Mediated Mechanisms of Action of Probiotics and Synbiotics in Treating Pediatric Intestinal Diseases

The pediatric population is continually at risk of developing infectious and inflammatory diseases. The treatment for infections, particularly gastrointestinal conditions, focuses on oral or intravenous rehydration, nutritional support and, in certain case, antibiotics. Over the past decade, the probiotics and synbiotics administration for the prevention and treatment of different acute and chronic infectious diseases has dramatically increased. Probiotic microorganisms are primarily used as treatments because they can stimulate changes in the intestinal microbial ecosystem and improve the immunological status of the host. The beneficial impact of probiotics is mediated by different mechanisms. These mechanisms include the probiotics' capacity to increase the intestinal barrier function, to prevent bacterial transferation and to modulate inflammation through immune receptor cascade signaling, as well as their ability to regulate the expression of selected host intestinal genes. Nevertheless, with respect to pediatric intestinal diseases, information pertaining to these key mechanisms of action is scarce, particularly for immune-mediated mechanisms of action. In the present work, we review the biochemical and molecular mechanisms of action of probiotics and synbiotics that affect the immune system.

Dual Effects of Cell Free Supernatants from Lactobacillus acidophilus and Lactobacillus rhamnosus GG in Regulation of MMP-9 by Up-Regulating TIMP-1 and Down-Regulating CD147 in PMADifferentiated THP-1 Cells

Objective

Recent studies have reported dysregulated expression of matrix metalloproteinases (MMPs), especially MMP-2, MMP-9, tissue inhibitor of metalloproteinase-1, -2 (TIMP-1, TIMP-2), and extracellular matrix metalloproteinase inducer (EMMPRIN/CD147) in activated macrophages of patients with inflammatory diseases. Therefore, MMP-2, MMP-9, and their regulators may represent a new target for treatment of inflammatory diseases. Probiotics, which are comprised of lactic acid bacteria, have the potential to modulate inflammatory responses. In this experimental study, we investigated the anti-inflammatory effects of cell-free supernatants (CFS) from Lactobacillus acidophilus (L. acidophilus) and L. rhamnosus GG (LGG) in phorbol myristate acetate (PMA)-differentiated THP-1 cells.

Materials and Methods

In this experimental study, PMA-differentiated THP-1 cells were treated with CFS from L. acidophilus, LGG and uninoculated bacterial growth media (as a control). The expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 mRNAs were determined using real-time quantitative reverse transcription polymerase chain reaction (RT- PCR). The levels of cellular surface expression of CD147 were assessed by flow cytometry, and the gelatinolytic activity of MMP-2 and MMP-9 were determined by zymography.

Results

Our results showed that CFS from both L. acidophilus and LGG significantly inhibited the gene expression of MMP-9 (P=0.0011 and P=0.0005, respectively), increased the expression of TIMP-1 (P<0.0001), decreased the cell surface expression of CD147 (P=0.0307 and P=0.0054, respectively), and inhibited the gelatinolytic activity of MMP-9 (P=0.0003 and P<0.0001, respectively) in PMA-differentiated THP-1 cells. Although, MMP-2 expression and activity and TIMP-2 expression remained unchanged.

Conclusion

Our results indicate that CFS from L. acidophilus and LGG possess anti-inflammatory properties and can modulate the inflammatory response.

Gut Microbiota in Cardiovascular Health and Disease

Significant interest in recent years has focused on gut microbiota-host interaction because accumulating evidence has revealed that intestinal microbiota play an important role in human health and disease, including cardiovascular diseases. Changes in the composition of gut microbiota associated with disease, referred to as dysbiosis, have been linked to pathologies such as atherosclerosis, hypertension, heart failure, chronic kidney disease, obesity, and type 2 diabetes mellitus. In addition to alterations in gut microbiota composition, the metabolic potential of gut microbiota has been identified as a contributing factor in the development of diseases. Recent studies revealed that gut microbiota can elicit a variety of effects on the host. Indeed, the gut microbiome functions like an endocrine organ, generating bioactive metabolites, that can impact host physiology. Microbiota interact with the host through many pathways, including the trimethylamine/trimethylamine N-oxide pathway, short-chain fatty acids pathway, and primary and secondary bile acids pathways. In addition to these metabolism-dependent pathways, metabolism-independent processes are suggested to also potentially contribute to cardiovascular disease pathogenesis. For example, heart failure-associated splanchnic circulation congestion, bowel wall edema, and impaired intestinal barrier function are thought to result in bacterial translocation, the presence of bacterial products in the systemic circulation and heightened inflammatory state. These are thought to also contribute to further progression of heart failure and atherosclerosis. The purpose of the current review is to highlight the complex interplay between microbiota, their metabolites, and the development and progression of cardiovascular diseases. We will also discuss the roles of gut microbiota in normal physiology and the potential of modulating intestinal microbial inhabitants as novel therapeutic targets.

Effect of Inulin on Proteome Changes Induced by Pathogenic Lipopolysaccharide in Human Colon

In the present study, the protective role of inulin against lipopolysaccharide (LPS)-induced oxidative stress was evaluated on human colonic mucosa using a proteomic approach. Human colonic mucosa and submucosa were sealed between two chambers, with the luminal side facing upwards and overlaid with Krebs (control), LPS or LPS+ inulin IQ solution. The solutions on the submucosal side (undernatants) were collected following 30 min of mucosal exposure. iTRAQ based analysis was used to analyze the total soluble proteomes from human colonic mucosa and submucosa treated with different undernatants. Human colonic muscle strips were exposed to the undernatants to evaluate the response to acetylcholine. Inulin exposure was able to counteract, in human colonic mucosa, the LPS-dependent alteration of some proteins involved in the intestinal contraction (myosin light chain kinase (MLCK), myosin regulatory subunit (MYL)), to reduce the up-regulation of two proteins involved in the radical-mediated oxidative stress (the DNA-apurinic or apyrimidinic site) lyase) APEX1 and the T-complex protein 1 subunit eta (CCT7) and to entail a higher level of some detoxification enzymes (the metallothionein-2 MT2A, the glutathione–S-transferase K GSTk, and two UDP- glucuronosyltransferases UGT2B4, UGT2B17). Inulin exposure was also able to prevent the LPS-dependent intestinal muscle strips contraction impairment and the mucosa glutathione level alterations. Exposure of colonic mucosa to inulin seems to prevent LPS-induced alteration in expression of some key proteins, which promote intestinal motility and inflammation, reducing the radical-mediated oxidative stress.

Novel Mechanisms Underlying the Therapeutic Effect of Glycomacropeptide on Allergy: Change in Gut Microbiota, Upregulation of TGF-β, and Inhibition of Mast Cells

BACKGROUND

The prevalence of allergic diseases is globally increasing. We have previously described that glycomacropeptide (GMP), a bioactive milk peptide, has therapeutic value in experimental models of skin hypersensitivity, anaphylaxis, and asthma, as it prevents an excessive T helper type 2 cell immune response. The aim of this study was to analyze the effect of GMP on key elements directly involved in the development or control of allergy, in order to improve the precise knowledge about its mechanism of action.

METHODS

Rats were systemically sensitized with ovalbumin and orally treated with GMP. Levels of Lactobacillus, Bifidobacterium, and Bacteroides were analyzed in their feces. Splenocytes were isolated and the production of transforming growth factor (TGF)-β by allergens was measured. Intradermal skin reactions were developed to evaluate in vivo activation of mast cells. Peritoneal mast cells were isolated and activated by the allergen, and histamine secretion was determined.

RESULTS

GMP administration increased the amount of intestinal Lactobacillus and Bifidobacterium of allergen-sensitized animals after 3 days of treatment. The increase in Bacteroides was also significant, but only after 17 days of GMP administration. Ten days after treatment cessation, Lactobacillus and Bacteroides were still elevated. GMP intake also elevated the production of TGF-β in the splenocytes of sensitized animals. In addition, treatment with GMP attenuated mast cell activation by the allergen and inhibited histamine secretion, without affecting the number of mast cells.

CONCLUSIONS

The prebiotic action of GMP on allergy-protective microbiota, an increase in TGF-β production, and a reduction in mast cell response to allergens are novel mechanisms that explain the antiallergic activity of GMP.

Escherichia coli Nissle 1917 protects gnotobiotic pigs against human rotavirus by modulating pDC and NK-cell responses

Lactobacillus rhamnosus GG (LGG), a gram-positive lactic acid bacterium, is one of the most widely used probiotics; while fewer gram-negative probiotics including Escherichia coli Nissle 1917 (EcN) are characterized. A mechanistic understanding of their individual and interactive effects on human rotavirus (HRV) and immunity is lacking. In this study, noncolonized, EcN-, LGG-, and EcN + LGG-colonized neonatal gnotobiotic (Gn) pigs were challenged with HRV. EcN colonization is associated with a greater protection against HRV, and induces the highest frequencies of plasmacytoid dendritic cells (pDCs), significantly increased NK-cell function and decreased frequencies of apoptotic and TLR4⁺ mononuclear cells (MNCs). Consistent with the highest NK-cell activity, splenic CD172⁺ MNCs (DC enriched fraction) of EcN-colonized pigs produced the highest levels of IL-12 in vitro. LGG colonization has little effect on the above parameters, which are intermediate in EcN + LGG-colonized pigs, suggesting that probiotics modulate each other's effects. Additionally, in vitro EcN-treated splenic or intestinal MNCs produce higher levels of innate, immunoregulatory and immunostimulatory cytokines, IFN-α, IL-12, and IL-10, compared to MNCs of pigs treated with LGG. These results indicate that the EcN-mediated greater protection against HRV is associated with potent stimulation of the innate immune system and activation of the DC-IL-12-NK immune axis.

Gut microbiome as a novel cardiovascular therapeutic target

Over the last two decades, our understanding of gut microbiotal composition and its association with intra-intestinal and extra-intestinal diseases including risk factors of cardiovascular disease (CVD) namely metabolic syndrome and atherosclerosis, have been increased exponentially. A pertinent question which often arises in researchers' community is on how to manipulate the gut microbial ecology to 'cure' the cardiovascular risk factors. Accordingly, in this review we summarized the potential strategies, based on our current knowledge on gut microbiota in modulating CVD, how gut microbiota can be therapeutically exploited by targeting their metabolic activity to alleviate the risk factors of CVD.

PROBIOTIC APPROACHES FOR TARGETING INFLAMMATORY BOWEL DISEASE: AN UPDATE ON ADVANCES AND OPPORTUNITIES IN MANAGING THE DISEASE

Various commensal enteric and pathogenic bacteria may be involved in the pathogenesis of inflammatory bowel diseases (IBDs), a chronic condition with a pathogenic background that involves both immunogenetic and environmental factors. IBDs comprising of Crohn's disease, and ulcerative colitis, and pauchitis are chronic inflammatory conditions, and known for causing disturbed homeostatic balance among the intestinal immune compartment, gut epithelium and microbiome. An increasing trend of IBDs in incidence, prevalence, and severity has been reported during recent years. Probiotic strains have been reported to manage the IBDs and related pathologies, and hence are current hot topics of research for their potential to manage metabolic diseases as well as various immunopathologies. However, the probiotics industry will need to undergo a transformation, with increased focus on stringent manufacturing guidelines and high-quality clinical trials. This article reviews the present state of art of role of probiotic bacteria in reducing inflammation and strengthening the host immune system with reference to the management of IBDs. We infer that t healthcare will move beyond its prevailing focus on human physiology, and embrace the superorganism as a paradigm to understand and ameliorate IBDs.

Antiviral effects of Lactobacillus ruminis SPM0211 and Bifidobacterium longum SPM1205 and SPM1206 on rotavirus-infected Caco-2 cells and a neonatal mouse model

Rotavirus is worldwide cause of severe gastroenteritis including severe diarrhea and fatal dehydration in infants and young children. There is an available vaccination program for preventing rotavirus infection, but it has limits and restrictions. Probiotics therapy could be an alternative method of antiviral prevention and modulation against rotavirus infection. In this study, we screened the antiviral activity of probiotic bacteria such as 3 Lactobacillus spp. and 14 Bifidobacterium spp. isolated from young Korean. Three of the bacteria, Lactobacillus ruminis SPM0211, Bifidobacterium longum SPM1205, and SPM1206, inhibited human strain Wa rotavirus infection in Caco-2 cells. Furthermore, these bacterial strains inhibited rotavirus replication in a rotavirus-infected neonatal mouse model. To clarify the mechanism of inhibition, we investigated gene expression of Interferon (IFN)-signaling components and IFN-inducible antiviral effectors. All 3 probiotics increased IFN-α and IFN-β levels compared with the control. Gene expression of IFNsignaling components and IFN-inducible antiviral effectors also increased. Overall, these results indicate that L. ruminis SPM0211, B. longum SPM1205 and 1206 efficiently inhibit rotavirus replication in vitro and in vivo. Especially, the antiviral effect of Lactobacillus ruminis SPM0211 is worthy of notice. This is the first report of L. ruminis with antiviral activity. Anti-rotaviral effects of the 3 probiotics are likely due to their modulation of the immune response through promoting type I IFNs, which are key regulators in IFN signaling pathway.

Lactobacillus acidophilus attenuates Salmonella-induced intestinal inflammation via TGF-β signaling

BACKGROUND

Salmonella is a common intestinal pathogen that causes acute and chronic inflammatory response. Probiotics reduce inflammatory cytokine production and serve as beneficial commensal microorganisms in the human gastrointestinal tract. TGF-β (transforming growth factor β)/SMAD and NF-κB signaling play important roles in inflammation in intestinal cells. However, the involvement of the signaling in regulating inflammation between Salmonella and probiotics is not fully understood.

METHODS

L. acidophilus and prebiotic inulin were used to treat human intestinal Caco-2 cells prior to infection with Salmonella. The cells were harvested to examine the cytokines and MIR21 expression with immunoblotting and real-time PCR. NF-κB and SMAD3/4 reporter vectors were transfected into cells to monitor inflammation and TGF-β1 signaling, respectively.

RESULTS

In this study, we showed that the probiotic L. acidophilus decreased Salmonella-induced NF-κB activation in human intestinal Caco-2 cells. Expression of the inflammatory cytokines, TNF-α and IL-8, in L. acidophilus-pretreated cells was also significantly lower than that in cells infected with Salmonella alone. Moreover, TGF-β1 and MIR21 expression was elevated in cells pretreated with L. acidophilus or synbiotic, a combination of inulin and L. acidophilus, compared to that in untreated cells or cells infected with S. typhimurium alone. By contrast, expression of SMAD7, a target of MIR21, was accordingly reduced in cells treated with L. acidophilus or synbiotics. Consistent with TGF-β1/MIR21 and SMAD7 expression, SMAD3/4 transcriptional activity was significantly higher in the cells treated with L. acidophilus or synbiotics. Furthermore, TGF-β1 antibody antagonized the SMAD3/4 and NF-κB transcriptional activity modulated by L. acidophilus in intestinal cells.

CONCLUSION

Our results suggest that the TGF-β1/MIR21 signaling pathway may be involved in the suppressive effects of L. acidophilus on inflammation caused by S. typhimurium in intestinal Caco-2 cells.

In vivo selection to identify bacterial strains with enhanced ecological performance in synbiotic applications

One strategy for enhancing the establishment of probiotic bacteria in the human intestinal tract is via the parallel administration of a prebiotic, which is referred to as a synbiotic. Here we present a novel method that allows a rational selection of putative probiotic strains to be used in synbiotic applications: in vivo selection (IVS). This method consists of isolating candidate probiotic strains from fecal samples following enrichment with the respective prebiotic. To test the potential of IVS, we isolated bifidobacteria from human subjects who consumed increasing doses of galactooligosaccharides (GOS) for 9 weeks. A retrospective analysis of the fecal microbiota of one subject revealed an 8-fold enrichment in Bifidobacterium adolescentis strain IVS-1 during GOS administration. The functionality of GOS to support the establishment of IVS-1 in the gastrointestinal tract was then evaluated in rats administered the bacterial strain alone, the prebiotic alone, or the synbiotic combination. Strain-specific quantitative real-time PCR showed that the addition of GOS increased B. adolescentis IVS-1 abundance in the distal intestine by nearly 2 logs compared to rats receiving only the probiotic. Illumina 16S rRNA sequencing not only confirmed the increased establishment of IVS-1 in the intestine but also revealed that the strain was able to outcompete the resident Bifidobacterium population when provided with GOS. In conclusion, this study demonstrated that IVS can be used to successfully formulate a synergistic synbiotic that can substantially enhance the establishment and competitiveness of a putative probiotic strain in the gastrointestinal tract.

Maternal influences on fetal microbial colonization and immune development

While critical for normal development, the exact timing of establishment of the intestinal microbiome is unknown. For example, although preterm labor and birth have been associated with bacterial colonization of the amniotic cavity and fetal membranes for many years, the prevailing dogma of a sterile intrauterine environment during normal term pregnancies has been challenged more recently. While found to be a key contributor of evolution in the animal kingdom, maternal transmission of commensal bacteria may also constitute a critical process during healthy pregnancies in humans with yet unclear developmental importance. Metagenomic sequencing has elucidated a rich placental microbiome in normal term pregnancies likely providing important metabolic and immune contributions to the growing fetus. Conversely, an altered microbial composition during pregnancy may produce aberrant metabolites impairing fetal brain development and life-long neurological outcomes. Here we review the current understanding of microbial colonization at the feto-maternal interface and explain how normal gut colonization drives a balanced neonatal mucosal immune system, while dysbiosis contributes to aberrant immune function early in life and beyond. We discuss how maternal genetics, diet, medications, and probiotics inform the fetal microbiome in preparation for perinatal and postnatal bacterial colonization.

Modulation of immunity and inflammatory gene expression in the gut, in inflammatory diseases of the gut and in the liver by probiotics

The potential for the positive manipulation of the gut microbiome through the introduction of beneficial microbes, as also known as probiotics, is currently an active area of investigation. The FAO/WHO define probiotics as live microorganisms that confer a health benefit to the host when administered in adequate amounts. However, dead bacteria and bacterial molecular components may also exhibit probiotic properties. The results of clinical studies have demonstrated the clinical potential of probiotics in many pathologies, such as allergic diseases, diarrhea, inflammatory bowel disease and viral infection. Several mechanisms have been proposed to explain the beneficial effects of probiotics, most of which involve gene expression regulation in specific tissues, particularly the intestine and liver. Therefore, the modulation of gene expression mediated by probiotics is an important issue that warrants further investigation. In the present paper, we performed a systematic review of the probiotic-mediated modulation of gene expression that is associated with the immune system and inflammation. Between January 1990 to February 2014, PubMed was searched for articles that were published in English using the MeSH terms “probiotics" and "gene expression" combined with “intestines", "liver", "enterocytes", "antigen-presenting cells", "dendritic cells", "immune system", and "inflammation". Two hundred and five original articles matching these criteria were initially selected, although only those articles that included specific gene expression results (77) were later considered for this review and separated into three major topics: the regulation of immunity and inflammatory gene expression in the gut, in inflammatory diseases of the gut and in the liver. Particular strains of Bifidobacteria, Lactobacilli, Escherichia coli, Propionibacterium, Bacillus and Saccharomyces influence the gene expression of mucins, Toll-like receptors, caspases, nuclear factor-κB, and interleukins and lead mainly to an anti-inflammatory response in cultured enterocytes. In addition, the interaction of commensal bacteria and probiotics with the surface of antigen-presenting cells in vitro results in the downregulation of pro-inflammatory genes that are linked to inflammatory signaling pathways, whereas other anti-inflammatory genes are upregulated. The effects of probiotics have been extensively investigated in animal models ranging from fish to mice, rats and piglets. These bacteria induce a tolerogenic and hyporesponsive immune response in which many genes that are related to the immune system, in particular those genes expressing anti-inflammatory cytokines, are upregulated. By contrast, information related to gene expression in human intestinal cells mediated by the action of probiotics is scarce. There is a need for further clinical studies that evaluate the mechanism of action of probiotics both in healthy humans and in patients with chronic diseases. These types of clinical studies are necessary for addressing the influence of these microorganisms in gene expression for different pathways, particularly those that are associated with the immune response, and to better understand the role that probiotics might have in the prevention and treatment of disease.

Maternal and postnatal dietary probiotic supplementation enhances splenic regulatory T helper cell population and reduces peanut allergen-induced hypersensitivity responses in mice

Neonatal to early childhood is the critical period for establishing a balance of T helper 1 (Th1) versus T helper 2 (Th2) cellular immunity within the gut, which is strongly influenced by the source and establishment of gut microflora. Probiotic administration has been shown to attenuate Th2-biased cellular immunity and predisposition to food allergies. To test this hypothesis we provided ad libitum a probiotic-supplemented (Primalac 454 Feed Grade Microbials) or control diet to lactating dams with suckling pups and weaned pups until 10 weeks of age. Weaned mice were sensitized/challenged with peanut extract, saline or adjuvant at 6, 8 and 10 weeks of age. At 3, 6, 8 and 10 weeks, fecal samples were collected for microbial analysis, while blood samples were analyzed for total plasma IgE levels. At termination (10 weeks of age), splenic T lymphocyte population subtypes were determined using FACS analysis and Th1/Th2/Th17 gene expression by PCR array. Mice given the probiotic-supplemented diet had significantly enhanced probiotic fecal counts compared to controls at 3, 6, 8 and 10 weeks. Moreover, mice fed the probiotic-supplemented diet had enhanced splenic naturally occurring T regulatory cell populations, and reduced splenic gene expression of allergic mediator IL-13 compared to controls. These results provide evidence that early probiotic supplementation may provide host protection to hypersensitivity reactions to food allergens by attenuating food allergen inflammatory responses.

Lactobacilli and bifidobacteria promote immune homeostasis by modulating innate immune responses to human rotavirus in neonatal gnotobiotic pigs

The effects of co-colonization with Lactobacillus rhamnosus GG (LGG) and Bifidobacterium lactis Bb12 (Bb12) on 3-dose vaccination with attenuated HRV and challenge with virulent human rotavirus (VirHRV) were assessed in 4 groups of gnotobiotic (Gn) pigs: Pro+Vac (probiotic-colonized/vaccinated), Vac (vaccinated), Pro (probiotic-colonized, non-vaccinated) and Control (non-colonized, non-vaccinated). Subsets of pigs were euthanized pre- [post-challenge day (PCD) 0] and post (PCD7)-VirHRV challenge to assess diarrhea, fecal HRV shedding and dendritic cell/innate immune responses. Post-challenge, Pro+Vac and Vac groups were completely protected from diarrhea; protection rates against HRV shedding were 100% and 83%, respectively. Diarrhea and HRV shedding were reduced in Pro compared to Control pigs following VirHRV challenge. Diarrhea scores and virus shedding were significantly higher in Controls, compared to all other groups, coincident with significantly higher serum interferon-alpha levels post-challenge. LGG+Bb12 colonization ±vaccine promoted immunomaturation as reflected by increased frequencies of CD4, SWC3a, CD11R1, MHCII expressing mononuclear cells (MNCs) and conventional dendritic cells in intestinal tissues and blood post-challenge. Colonization decreased frequencies of toll-like receptors (TLR) 2 and TLR4 expressing MNCs from vaccinated pigs (Pro+Vac) pre-challenge and increased frequencies of TLR3 expressing MNCs from Pro pigs post-challenge, suggesting that probiotics likely exert anti-inflammatory (TLR2 and 4 down-regulation) and antiviral (TLR3 up-regulation by HRV dsRNA) actions via TLR signaling. Probiotic colonization alone (Pro) increased frequencies of intestinal and systemic apoptotic MNCs pre-challenge, thereby regulating immune hyperreactivity and tolerance. However, these frequencies were decreased in intestinal and systemic tissues post-challenge, moderating HRV-induced apoptosis. Additionally, post-challenge, Pro+Vac and Pro groups had significantly decreased MNC proliferation, suggesting that probiotics control excessive lymphoproliferative reactions upon VirHRV challenge. We conclude that in the neonatal Gn pig disease model, selected probiotics contribute to immunomaturation, regulate immune homeostasis and modulate vaccine and virulent HRV effects, thereby moderating HRV diarrhea.

Probiotic Lactobacillus reuteri attenuates the stressor-enhanced severity of Citrobacter rodentium infection

Stressor exposure has been shown to enhance host susceptibility and the severity of a plethora of illnesses, including gastrointestinal disease. In mice, susceptibility to Citrobacter rodentium has been shown to be dependent on host genetics as well as the composition of the intestinal microbiota, but the effects of stressor exposure on this gastrointestinal pathogen have not been elucidated fully. Previously, our lab showed that exposure to the prolonged-restraint stressor prior to a challenge with C. rodentium alters the intestinal microbiota community structure, including a reduction of beneficial genera such as Lactobacillus, which may contribute to stressor-enhanced C. rodentium-induced infectious colitis. To test the effects of stressor exposure on C. rodentium infection, we exposed resistant mice to a prolonged-restraint stressor concurrent with pathogen challenge. Exposure to prolonged restraint significantly enhanced C. rodentium-induced infectious colitis in resistant mice, as measured by increases in colonic histopathology, colonic inflammatory mediator gene production, and pathogen translocation from the colon to the spleen. It was further tested if the beneficial bacterium Lactobacillus reuteri could reduce the stressor-enhanced susceptibility to C. rodentium-enhanced infectious colitis. While L. reuteri treatment did not reduce all aspects of stressor-enhanced infectious colitis, it did significantly reduce pathogen translocation from the colon to the spleen. Taken together, these data demonstrate the deleterious effects that prolonged stressor exposure can have at the onset of a gastrointestinal infection by its ability to render a resistant mouse highly susceptible to C. rodentium. Probiotic treatment ameliorated the systemic manifestations of stress on colonic infection.

The interplay between fiber and the intestinal microbiome in the inflammatory response

Fiber intake is critical for optimal health. This review covers the anti-inflammatory roles of fibers using results from human epidemiological observations, clinical trials, and animal studies. Fiber has body weight-related anti-inflammatory activity. With its lower energy density, a diet high in fiber has been linked to lower body weight, alleviating obesity-induced chronic inflammation evidenced by reduced amounts of inflammatory markers in human and animal studies. Body weight-unrelated anti-inflammatory activity of fiber has also been extensively studied in animal models in which the type and amount of fiber intake can be closely monitored. Fermentable fructose-, glucose-, and galactose-based fibers as well as mixed fibers have shown systemic and local intestinal anti-inflammatory activities when plasma inflammatory markers and tissue inflammation were examined. Similar anti-inflammatory activities have also been demonstrated in some human studies that controlled total fiber intake. The anti-inflammatory activities of synbiotics (probiotics plus fiber) were reviewed as well, but there was no convincing evidence indicating higher efficacy of synbiotics compared with that of fiber alone. Adverse effects have not been observed with the amount of fiber intake or supplementation used in studies, although patients with Crohn's disease may be more sensitive to inulin intake. Several possible mechanisms that may mediate the body weight-unrelated anti-inflammatory activity of fibers are discussed based on the in vitro and in vivo evidence. Fermentable fibers are known to affect the intestinal microbiome. The immunomodulatory role of the intestinal microbiome and/or microbial metabolites could contribute to the systemic and local anti-inflammatory activities of fibers.