Probiotic bacteria regulate intestinal epithelial permeability in experimental ileitis by a TNF-dependent mechanism

Parkinson's disease and gut microbiota: from clinical to mechanistic and therapeutic studies

Parkinson's disease (PD) is one of the most prevalent neurodegenerative diseases. The typical symptomatology of PD includes motor symptoms; however, a range of nonmotor symptoms, such as intestinal issues, usually occur before the motor symptoms. Various microorganisms inhabiting the gastrointestinal tract can profoundly influence the physiopathology of the central nervous system through neurological, endocrine, and immune system pathways involved in the microbiota-gut-brain axis. In addition, extensive evidence suggests that the gut microbiota is strongly associated with PD. This review summarizes the latest findings on microbial changes in PD and their clinical relevance, describes the underlying mechanisms through which intestinal bacteria may mediate PD, and discusses the correlations between gut microbes and anti-PD drugs. In addition, this review outlines the status of research on microbial therapies for PD and the future directions of PD-gut microbiota research.

Therapeutic and Prophylactic Role of Vitamin D and Curcumin in Acetic Acid-Induced Acute Ulcerative Colitis Model

Ulcerative Colitis (UC) is a disease that negatively affects quality of life and is associated with sustained oxidative stress, inflammation and intestinal permeability. Vitamin D and Curcumin; It has pharmacological properties beneficial to health, including antioxidant and anti-inflammatory properties. Our study investigates the role of Vitamin D and Curcumin in acetic acid-induced acute colitis model. To investigate the effect of Vitamin D and Curcumin, Wistar-albino rats were given 0.4 mcg/kg Vitamin D (Post-Vit D, Pre-Vit D) and 200 mg/kg Curcumin (Post-Cur, Pre-Cur) for 7 days and acetic acid was injected into all rats except the control group. Our results; colon tissue TNF-α, IL-1β, IL-6, IFN-γ and MPO levels were found significantly higher and Occludin levels were found significantly lower in the colitis group compared to the control group (p < 0.05). TNF-α and IFN-γ levels decreased and Occludin levels increased in colon tissue of Post-Vit D group compared to colitis group (p < 0.05). IL-1β, IL-6 and IFN-γ levels were decreased in colon tissue of Post-Cur and Pre-Cur groups (p < 0.05). MPO levels in colon tissue decreased in all treatment groups (p < 0.05). Vitamin D and Curcumin treatment significantly reduced inflammation and restored the normal histoarchitecture of the colon. From the present study findings, we can conclude that Vitamin D and Curcumin protect the colon from acetic acid toxicity with their antioxidant and anti-inflammatory potential.

Disease mechanisms as subtypes: Microbiome

Abnormalities in gut microbiota have been suggested to be involved in the pathophysiology and progression of Parkinson's disease (PD). Gastrointestinal nonmotor symptoms often precede the onset of motor features in PD, suggesting a role for gut dysbiosis in neuroinflammation and α-synuclein (α-syn) aggregation. In the first part of this chapter, we analyze critical features of healthy gut microbiota and factors (environmental and genetic) that modify its composition. In the second part, we focus on the mechanisms underlying the gut dysbiosis and how it alters anatomically and functionally the mucosal barrier, triggering neuroinflammation and subsequently α-syn aggregation. In the third part, we describe the most common alterations in the gut microbiota of PD patients, dividing the gastrointestinal system in higher and lower tract to examine the association between microbiota abnormalities and clinical features. In the final section, we report on current and future therapeutic approaches to gut dysbiosis aiming to either reduce the risk for PD, modify the disease course, or improve the pharmacokinetic profile of dopaminergic therapies. We also suggest that further studies will be needed to clarify the role of the microbiome in PD subtyping and of pharmacological and nonpharmacological interventions in modifying specific microbiota profiles in individualizing disease-modifying treatments in PD.

Complexification of In Vitro Models of Intestinal Barriers, A True Challenge for a More Accurate Alternative Approach

The use of cell models is common to mimic cellular and molecular events in interaction with their environment. In the case of the gut, the existing models are of particular interest to evaluate food, toxicants, or drug effects on the mucosa. To have the most accurate model, cell diversity and the complexity of the interactions must be considered. Existing models range from single-cell cultures of absorptive cells to more complex combinations of two or more cell types. This work describes the existing solutions and the challenges that remain to be solved.

Protective effects of amoxicillin and probiotics on colon disorders in an experimental model of acute diverticulitis disease

Acute diverticulitis disease is associated with inflammation and infection in the colon diverticula and may lead to severe morbidity. This study aimed to evaluate and compare the protective effects of amoxicillin antibiotic, either alone or in combination with probiotics (Lactobacillus acidophilus and Bifidobacterium lactis), in a rat model of acute diverticulitis disease. Acute diverticulitis was induced, in albino rats, by adding 3% weight/volume of dextran sulfate sodium (DSS) to the rats’ drinking water; daily for 7 days, in addition to injecting lipopolysaccharide (LPS) enema (4 mg/kg). The impact of treatments was assessed by measuring the physiological and immunological parameters and evaluating colon macroscopic and microscopic lesions. The results showed that both treatments (especially probiotics with amoxicillin) alleviated the adverse effects of DSS and LPS. This was obvious through the modulation of the rats’ body weight and the colon weight-to-length ratio. Also, there was a significant (p < 0.001) decrease in the colon macroscopic lesion score. The pro-inflammatory cytokines [(TNF)-α, (IL)-1β, (IFN)-γ, and (IL)-18]; in the colon tissue; were significantly (p < 0.001) decreased. Also, both treatments significantly ameliorated the elevation of myeloperoxidase activity and C-reactive protein levels, in addition to improving the histopathological alterations in the colon tissue. In conclusion, amoxicillin and probiotics–amoxicillin were effective in preventing the development of experimentally induced acute diverticulitis, through their anti-inflammatory and immunomodulatory effects. Furthermore, this study has explored the role of probiotics in preventing DSS/LPS-induced acute diverticulitis, so it can be applied as a promising treatment option for acute diverticulitis disease.

A Multi-Strain Probiotic Formulation Improves Intestinal Barrier Function by the Modulation of Tight and Adherent Junction Proteins

In healthy individuals, tight junction proteins (TJPs) maintain the integrity of the intestinal barrier. Dysbiosis and increased intestinal permeability are observed in several diseases, such as inflammatory bowel disease. Many studies highlight the role of probiotics in preventing intestinal barrier dysfunction. The present study aims to investigate the effects of a commercially available probiotic formulation of L. rhamnosus LR 32, B. lactis BL 04, and B. longum BB 536 (Serobioma, Bromatech s.r.l., Milan, Italy) on TJPs and the integrity of the intestinal epithelial barrier, and the ability of this formulation to prevent lipopolysaccharide-induced, inflammation-associated damage. An in vitro model of the intestinal barrier was developed using a Caco-2 cell monolayer. The mRNA expression levels of the TJ genes were analyzed using real-time PCR. Changes in the amounts of proteins were assessed with Western blotting. The effect of Serobioma on the intestinal epithelial barrier function was assessed using transepithelial electrical resistance (TEER) measurements. The probiotic formulation tested in this study modulates the expression of TJPs and prevents inflammatory damage. Our findings provide new insights into the mechanisms by which probiotics are able to prevent damage to the gut epithelial barrier.

The role of nutrition on Parkinson's disease: a systematic review

BACKGROUND

Parkinson's disease (PD) in elderly patients is the second most prevalent neurodegenerative disease. The pathogenesis of PD is associated with dopaminergic neuron degeneration of the substantia nigra in the basal ganglia, causing classic motor symptoms. Oxidative stress, mitochondrial dysfunction, and neuroinflammation have been identified as possible pathways in laboratory investigations. Nutrition, a potentially versatile factor from all environmental factors affecting PD, has received intense research scrutiny.

METHODS

A systematic search was conducted in the MEDLINE, EMBASE, and WEB OF SCIENCE databases from 2000 until the present. Only randomized clinical trials (RCTs), observational case-control studies, and follow-up studies were included.

RESULTS

We retrieved fifty-two studies that met the inclusion criteria. Most selected studies investigated the effects of malnutrition and the Mediterranean diet (MeDiet) on PD incidence and progression. Other investigations contributed evidence on the critical role of microbiota, vitamins, polyphenols, dairy products, coffee, and alcohol intake.

CONCLUSIONS

There are still many concerns regarding the association between PD and nutrition, possibly due to underlying genetic and environmental factors. However, there is a body of evidence revealing that correcting malnutrition, gut microbiota, and following the MeDiet reduced the onset of PD and reduced clinical progression. Other factors, such as polyphenols, polyunsaturated fatty acids, and coffee intake, can have a potential protective effect. Conversely, milk and its accessory products can increase PD risk. Nutritional intervention is essential for neurologists to improve clinical outcomes and reduce the disease progression of PD.

Effects of Dietary Nutrients on Fatty Liver Disease Associated With Metabolic Dysfunction (MAFLD): Based on the Intestinal-Hepatic Axis

Non-alcoholic fatty liver disease (NAFLD) has recently become the most common liver disease with a global prevalence of over 25% and is expected to increase. Recently, experts have reached a consensus that “fatty liver disease associated with metabolic dysfunction or MAFLD” may be a more appropriate and inclusive definition than NAFLD. Like the former name NAFLD, MAFLD, as a manifestation of multiple system metabolic disorders involving the liver, has certain heterogeneity in its pathogenesis, clinical manifestations, pathological changes and natural outcomes. We found that there is a delicate dynamic balance among intestinal microflora, metabolites and host immune system to maintain a healthy intestinal environment and host health. On the contrary, this imbalance is related to diseases such as MAFLD. However, there are no clear studies on how dietary nutrients affect the intestinal environment and participate in the pathogenesis of MAFLD. This review summarizes the interactions among dietary nutrients, intestinal microbiota and MAFLD in an attempt to provide evidence for the use of dietary supplements to regulate liver function in patients with MAFLD. These dietary nutrients influence the development and progression of MAFLD mainly through the hepatic-intestinal axis by altering dietary energy absorption, regulating bile acid metabolism, changing intestinal permeability and producing ethanol. Meanwhile, the nutrients have the ability to combat MAFLD in terms of enriching abundance of intestinal microbiota, reducing Firmicutes/Bacteroidetes ratio and promoting abundance of beneficial gut microbes. Therefore, family therapy with MAFLD using a reasonable diet could be considered.

Novel probiotic treatment of autism spectrum disorder associated social behavioral symptoms in two rodent models

The prevalence of autism spectrum disorder (ASD) has rapidly increased in the past decades, and several studies report about the escalating use of antibiotics and the consequent disruption of the gastrointestinal microbiome leading to the development of neurobehavioral symptoms resembling to those of ASD. The primary purpose of this study was to investigate whether depletion of the gastrointestinal microbiome via antibiotics treatment could induce ASD-like behavioral symptoms in adulthood. To reliably evaluate that, validated valproic acid (VPA) ASD animal model was introduced. At last, we intended to demonstrate the assessed potential benefits of a probiotic mixture (PM) developed by our research team. Male Wistar rats were used to create antibiotics treated; antibiotics and PM treated; PM treated, VPA treated; VPA and PM treated; and control groups. In all investigations we focused on social behavioral disturbances. Antibiotics-induced microbiome alterations during adulthood triggered severe deficits in social behavior similar to those observed in the VPA model. Furthermore, it is highlighted that our PM proved to attenuate both the antibiotics- and the VPA-generated antisocial behavioral symptoms. The present findings underline potential capacity of our PM to improve social behavioral alterations thus, indicate its promising therapeutic power to attenuate the social-affective disturbances of ASD.

Are We What We Eat? Impact of Diet on the Gut-Brain Axis in Parkinson's Disease

Parkinson’s disease is characterized by motor and non-motor symptoms, such as defects in the gut function, which may occur before the motor symptoms. To date, there are therapies that can improve these symptoms, but there is no cure to avoid the development or exacerbation of this disorder. Dysbiosis of gut microbiota could have a crucial role in the gut–brain axis, which is a bidirectional communication between the central nervous system and the enteric nervous system. Diet can affect the microbiota composition, impacting gut–brain axis functionality. Gut microbiome restoration through probiotics, prebiotics, synbiotics or other dietary means could have the potential to slow PD progression. In this review, we will discuss the influence of diet on the bidirectional communication between gut and brain, thus supporting the hypothesis that this disorder could begin in the gut. We also focus on how food-based therapies might then have an influence on PD and could ameliorate non-motor as well as motor symptoms.

Hyaluronan: A Neuroimmune Modulator in the Microbiota-Gut Axis

The commensal microbiota plays a fundamental role in maintaining host gut homeostasis by controlling several metabolic, neuronal and immune functions. Conversely, changes in the gut microenvironment may alter the saprophytic microbial community and function, hampering the positive relationship with the host. In this bidirectional interplay between the gut microbiota and the host, hyaluronan (HA), an unbranched glycosaminoglycan component of the extracellular matrix, has a multifaceted role. HA is fundamental for bacterial metabolism and influences bacterial adhesiveness to the mucosal layer and diffusion across the epithelial barrier. In the host, HA may be produced and distributed in different cellular components within the gut microenvironment, playing a role in the modulation of immune and neuronal responses. This review covers the more recent studies highlighting the relevance of HA as a putative modulator of the communication between luminal bacteria and the host gut neuro-immune axis both in health and disease conditions, such as inflammatory bowel disease and ischemia/reperfusion injury.

Exploring the Early Phase of Crohn's Disease

The development of Crohn's disease (CD) is characterized by a breakdown of homeostatic immune-bacterial communication, which takes place at the intestinal mucosa when environmental triggers impact genetically predisposed individuals. Converging lines of evidence support the hypothesis that this pathogenetic model develops through sequential, although inter-related, steps that indicate failure of mucosal defense mechanisms at various stages. In this context, immunologic phenomena that mediate the initial appearance of inflammatory lesions across the intestinal tissue may differ substantially from those that mediate and perpetuate chronic inflammatory responses. A compromise in the integrity of the epithelial barrier is among the earliest events and leads to accelerated influx of intraluminal antigens and intact microorganisms within the immunologically rich lamina propria. Inadequate clearance of invading microorganisms also may occur as a result of defects in innate immunity, preventing the timely and complete resolution of acute inflammatory responses. The final step is the development of persistent adaptive responses, which also differ between early and late Crohn's disease. Current progress in our ability to delineate single-cell transcriptomics and proteomics has allowed the discovery of cellular and molecular mechanisms that participate in each sequential step of CD development. This not only will advance our understanding of CD pathogenesis, but also facilitate the design of targeted therapeutic approaches.

Tumor Necrosis Factor's Pathway in Crohn's Disease: Potential for Intervention

Crohn’s disease (CD) is a chronic disorder characterized by full thickness patchy inflammation of the gastrointestinal tract. The pathogenesis is multifactorial and involves defective innate immune responses, microbiome alterations, and dysregulated activation of the acquired component of mucosal immunity. One of the molecular mediators that is involved at different levels in the initiation and progression of intestinal inflammation characteristic of CD is tumor necrosis factor (TNF). The present manuscript provides a comprehensive review focused on the potential role of TNF in the different phases of CD pathogenesis, particularly in light of its potential clinical implications. Currently available drugs blocking TNF are evaluated and discussed, specifically for open issues that still remain utilizing such therapy. TNF exerts a paramount role in the established phase of intestinal inflammation that characterizes CD patients, and anti-TNF biologics have definitely changed patient management, offering effective and safe options of treatment. Nonetheless, many patients still do not respond to anti-TNF therapy or experience unwanted side-effects. This could partially be due to the role that TNF plays in intestinal homeostasis that is particularly important during the early phase of the inflammatory process. In fact, emerging evidence supporting the dichotomous role of TNF and the identification of molecular markers will guide a more tailored and refined therapy for CD patients in the near future.

Angiocrine Regulation of Epithelial Barrier Integrity in Inflammatory Bowel Disease

Inflammatory bowel disease describes chronic inflammatory disorders. The incidence of the disease is rising. A major step in disease development is the breakdown of the epithelial cell barrier. Numerous blood vessels are directly located underneath this barrier. Diseased tissues are heavily vascularized and blood vessels significantly contribute to disease progression. The gut-vascular barrier (GVB) is an additional barrier controlling the entry of substances into the portal circulation and to the liver after passing the first epithelial barrier. The presence of the GVB rises the question, whether the vascular and endothelial barriers may communicate bi-directionally in the regulation of selective barrier permeability. Communication from epithelial to endothelial cells is well-accepted. In contrast, little is known on the respective backwards communication. Only recently, perfusion-independent angiocrine functions of endothelial cells were recognized in a way that endothelial cells release specific soluble factors that may directly act on the epithelial barrier. This review discusses the putative involvement of angiocrine inter-barrier communication in the pathogenesis of IBD.

Bifidobacterium bifidum Enhances the Intestinal Epithelial Tight Junction Barrier and Protects against Intestinal Inflammation by Targeting the Toll-like Receptor-2 Pathway in an NF-κB-Independent Manner

Defective intestinal tight junction (TJ) barrier is a hallmark in the pathogenesis of inflammatory bowel disease (IBD). To date, there are no effective therapies that specifically target the intestinal TJ barrier. Among the various probiotic bacteria, Bifidobacterium, is one of the most widely studied to have beneficial effects on the intestinal TJ barrier. The main purpose of this study was to identify Bifidobacterium species that cause a sustained enhancement in the intestinal epithelial TJ barrier and can be used therapeutically to target the intestinal TJ barrier and to protect against or treat intestinal inflammation. Our results showed that Bifidobacterium bifidum caused a marked, sustained enhancement in the intestinal TJ barrier in Caco-2 monolayers. The Bifidobacterium bifidum effect on TJ barrier was strain-specific, and only the strain designated as BB1 caused a maximal enhancement in TJ barrier function. The mechanism of BB1 enhancement of intestinal TJ barrier required live bacterial cell/enterocyte interaction and was mediated by the BB1 attachment to Toll-like receptor-2 (TLR-2) at the apical membrane surface. The BB1 enhancement of the intestinal epithelial TJ barrier function was mediated by the activation of the p38 kinase pathway, but not the NF-κB signaling pathway. Moreover, the BB1 caused a marked enhancement in mouse intestinal TJ barrier in a TLR-2-dependent manner and protected against dextran sodium sulfate (DSS)-induced increase in mouse colonic permeability, and treated the DSS-induced colitis in a TJ barrier-dependent manner. These studies show that probiotic bacteria BB1 causes a strain-specific enhancement of the intestinal TJ barrier through a novel mechanism involving BB1 attachment to the enterocyte TLR-2 receptor complex and activation of p38 kinase pathway.

Diversion Colitis and Probiotic Stimulation: Effects of Bowel Stimulation Prior to Ileostomy Closure

Background: Diversion colitis is a non-specific inflammation of a defunctionalised segment of the colon after a temporary stoma has been performed. This inflammation is associated with a change in the colonic flora. Aim: To evaluate the efficacy and safety of preoperative stimulation of the efferent loop with probiotics prior to closure of the protective ileostomy in patients operated on colorectal carcinoma and its effect on diversion colitis. A prospective, randomised, double-blind, controlled study is carried out. Methods: Patients who underwent surgery for colorectal carcinoma with protective ileostomy pending reconstructive surgery and with diversion colitis as diagnosis are included. Randomised and divided into two groups. Histological and endoscopic changes were evaluated after stimulation, after restorative surgery and during the short-term follow-up after surgery. Results: Patients in CG were distributed according to the endoscopic index of severity in pre-stimulation/post-stimulation as follows: severe n = 9/9 (25.7%), moderate n = 23/23 (65.7%), and mild n = 3/3 (8.6%); compared to the distribution in SG, severe n = 9/0 (26.5/0%), moderate n = 23/3 (67.6/8.8%), mild n = 2/19 (5.9/55.9%) and normal colonoscopy in 0/12 patients (0/35.3%). Conclusion: Probiotic stimulation of the efferent loop is a safe and effective method, managing to reduce both macroscopic and microscopic colitis, as well as a decrease in symptoms in the short term after reconstructive surgery.

Probiotics: an Antibiotic Replacement Strategy for Healthy Broilers and Productive Rearing

Pathogens develop resistance to antibiotics at a rate much faster than the discovery of new antimicrobial compounds. Reports of multidrug-resistant bacteria isolated from broilers, and the possibility that these strains may spread diseases amongst humans, prompted many European countries to ban the inclusion of antibiotics in feed. Probiotics added to broiler feed controlled a number of bacterial infections. A combination of Enterococcus faecium, Pediococcus acidilactici, Bacillus animalis, Lactobacillus salivarius and Lactobacillus reuteri decreased the colonisation of Campylobacter jejuni and Salmonella Enteritidis in the gastro-intestinal tract (GIT) of broilers, whereas Bacillus subtilis improved feed conversion, intestinal morphology, stimulated the immune system and inhibited the colonisation of Campylobacter jejuni, Escherichia coli and Salmonella Minnesota. Lactobacillus salivarius and Pediococcus parvulus improved weight gain, bone characteristics, intestinal morphology and immune response, and decreased the colonisation of S. Enteritidis. Lactobacillus crispatus, L. salivarius, Lactobacillus gallinarum, Lactobacillus johnsonii, Enterococcus faecalis and Bacillus amyloliquefaciens decreased the Salmonella count and led to an increase in lysozyme and T lymphocytes. Probiotics may also improve feed digestion through production of phytases, lipases, amylases and proteases or stimulate the GIT to secrete digestive enzymes. Some strains increase the nutritional value of feed by production of vitamins, exopolysaccharides and antioxidants. Bacteriocins, if produced, regulate pathogen numbers in the GIT and keep pro-inflammatory and anti-inflammatory reactions in balance.

Impact of the Trophic Effects of the Secretome From a Multistrain Probiotic Preparation on the Intestinal Epithelia

BACKGROUND

Probiotics are defined as live, nonpathogenic bacteria that confer health benefits beyond their nutritional value. In particular, VSL#3 exhibits demonstrated efficacy in the management of diseases characterized by an increased intestinal permeability. Our study aimed to understand how VSL#3 promotes gut health by secreting bioactive factors and identify which human pathways are modulated by secretome derived from the VSL#3 formula.

METHODS

Two different lots of VSL#3 were used, and Caco-2 cell line was treated with conditioned media (CM) prepared using 1 g of the probiotic formula. We evaluated the effects of the probiotics on cellular proliferation and apoptosis by cytometry and the expression of tight junction proteins by western blotting. A proteomics analysis of both culture media and the whole proteome of Caco-2 cells treated with VSL#3-CM was performed by nano-ultra performance liquid chromatography - tandem mass (nUPLC MS/MS) spectrometry.

RESULTS

The probiotic formula increased cell proliferation, decreased cellular apoptosis cells, and increased re-epithelialization in the scratch assay. Several peptides specifically synthetized by all the species within the probiotic preparation were recognized in the proteomics analysis. Human proteins synthesized by CaCo-2 cells were also identified.

CONCLUSIONS

To our knowledge, this manuscript describes the first evaluation of the probiotic secretome, and the results showed that the improvement in intestinal barrier functions induced by probiotics seems to be accompanied by the modulation of some human cellular pathways.

Serological Biomarkers and Diversion Colitis: Changes after Stimulation with Probiotics

Diversion colitis is a non-specific inflammation of a defunctionalised segment of the colon after a temporary stoma has been performed. This inflammation is associated with an alteration of certain inflammatory serum markers. The aims of this study were, firstly, to evaluate the modification of inflammatory biomarkers after stimulation with probiotics prior to closure of the protective ileostomy. Secondly, to identify if a relationship could be established between the severity of diversion colitis and the alteration of inflammatory biomarkers in the blood. A prospective, randomized, double-blind, controlled study was conducted. Patients who underwent surgery for colorectal carcinoma with protective ileostomy between January 2017 and December 2018 were included, pending reconstructive surgery and with diversion colitis as diagnosis. The sample was randomly divided into a group stimulated with probiotics (SG) (n = 34) and a control group (CG) (n = 35). Histological and endoscopic changes were evaluated after stimulation, after restorative surgery and during the short-term follow-up after surgery, including the correlation with pro-inflammatory biomarkers in blood. As main findings, a significant decrease in C-reactive protein (CRP), Neutrophil/lymphocyte ratio (NLR ratio), and monocyte/lymphocyte ratio (LMR ratio) was observed in the SG versus the CG with a p < 0.001. A significant increase in transferrin values and in the platelet/lymphocyte ratio (PLR) was observed in the SG versus CG after stimulation with probiotics with a p < 0.001. A normalisation of CRP and transferrin levels was observed in the third month of follow-up after closure ileostomy, and NLR, LMR and PLR ratios were equal in both groups. Decreased modified Glasgow prognostic score was found in SG compared to CG after probiotic stimulation (p < 0.001). The endoscopic and histological severity of diversion colitis is associated with a greater alteration of blood inflammatory biomarkers. The stimulation with probiotics prior to reconstructive surgery promotes an early normalization of these parameters.

Evaluation of the efficacy of probiotic VSL#3 and synbiotic VSL#3 and yacon-based product in reducing oxidative stress and intestinal permeability in mice induced to colorectal carcinogenesis

The objective of the present study was to evaluate the effect of probiotic VSL#3 isolated or associated with a yacon-based product (synbiotic) on oxidative stress modulation and intestinal permeability in an experimental model of colorectal carcinogenesis. Forty-five C57BL/6J mice were divided into three groups: control (standard diet AIN-93 M); probiotic (standard diet AIN-93 M and multispecies probiotic VSL#3, 2.25 × 10⁹ CFU), and synbiotic (standard diet AIN-93 M with yacon-based product, 6% fructooligosaccharides and inulin, and probiotic VSL#3, 2.25 × 10⁹ CFU). The experimental diets were provided for 13 weeks. The probiotic and the yacon-based product showed antioxidant activity, with the percentage of DPPH radical scavenging equal to 69.7 ± 0.4% and 74.3 ± 0.1%, respectively. These findings contributed to reduce hepatic oxidative stress: the control group showed higher concentration of malondialdehyde (1.8-fold, p = 0.007 and 1.5-fold, p = 0.035) and carbonylated protein (2-fold, p = 0.008 and 5.6-fold, p = 0.000) compared to the probiotic and synbiotic groups, respectively. Catalase enzyme activity increased 1.43-fold (p = 0.014) in synbiotic group. The crypt depth increased 1.2-fold and 1.4-fold with the use of probiotic and synbiotic, respectively, compared to the control diet (p = 0.000). These findings corroborate the reduction in intestinal permeability in the probiotic and synbiotic groups, as measured by the percentage of urinary lactulose excretion (CON: 0.93 ± 0.62% × PRO: 0.44 ± 0.05%, p = 0.048; and CON: 0.93 ± 0.62% × SYN: 0.41 ± 0.12%, p = 0.043). In conclusion, the probiotic and synbiotic showed antioxidant activity, which contributed to the reduction of oxidative stress markers. In addition, they protected the mucosa from damage caused by chemical carcinogen and reduced intestinal permeability. PRACTICAL APPLICATION: The relationship between intestinal health and the occurrence of various organic disorders has been demonstrated in many studies. The use of probiotics and prebiotics is currently one of the main targets for modulation of intestinal health. We demonstrated that the use of a commercial mix of probiotic bacteria (VSL#3) isolated or associated with a yacon-based prebiotic, rich in fructooligosaccharides and inulin, is able to reduce the oxidative stress and intestinal permeability in a colorectal carcinogenesis model. These compounds have great potential to be used as a food supplement, or as ingredients in the development of food products.

Effects of Synbiotic Supplementation on Chronic Inflammation and the Gut Microbiota in Obese Patients with Type 2 Diabetes Mellitus: A Randomized Controlled Study

The aim of this study was to investigate the effects of 24-week synbiotic supplementation on chronic inflammation and the gut microbiota in obese patients with type 2 diabetes. We randomized 88 obese patients with type 2 diabetes to one of two groups for 24 weeks: control or synbiotic (Lacticaseibacillus paracasei strain Shirota (previously Lactobacillus casei strain Shirota) and Bifidobacterium breve strain Yakult, and galactooligosaccharides). The primary endpoint was the change in interleukin-6 from baseline to 24 weeks. Secondary endpoints were evaluation of the gut microbiota in feces and blood, fecal organic acids, high-sensitivity C-reactive protein, lipopolysaccharide-binding protein, and glycemic control. Synbiotic administration for 24 weeks did not significantly affect changes in interleukin-6 from baseline to 24 weeks (0.35 ± 1.99 vs. −0.24 ± 1.75 pg/mL, respectively). Relative to baseline, however, at 24 weeks after synbiotic administration there were positive changes in the counts of Bifidobacterium and total lactobacilli, the relative abundances of Bifidobacterium species such as Bifidobacterium adolescentis and Bifidobacterium pseudocatenulatum, and the concentrations of acetic and butyric acids in feces. No significant changes in inflammatory markers were found in the synbiotic group compared to the control group. However, synbiotic administration at least partially improved the gut environment in obese patients with type 2 diabetes.

Impact of Microbial Metabolites on Microbiota-Gut-Brain Axis in Inflammatory Bowel Disease

The complex bidirectional communication system existing between the gastrointestinal tract and the brain initially termed the "gut-brain axis" and renamed the "microbiota-gut-brain axis", considering the pivotal role of gut microbiota in sustaining local and systemic homeostasis, has a fundamental role in the pathogenesis of Inflammatory Bowel Disease (IBD). The integration of signals deriving from the host neuronal, immune, and endocrine systems with signals deriving from the microbiota may influence the development of the local inflammatory injury and impacts also more distal brain regions, underlying the psychophysiological vulnerability of IBD patients. Mood disorders and increased response to stress are frequently associated with IBD and may affect the disease recurrence and severity, thus requiring an appropriate therapeutic approach in addition to conventional anti-inflammatory treatments. This review highlights the more recent evidence suggesting that alterations of the microbiota-gut-brain bidirectional communication axis may concur to IBD pathogenesis and sustain the development of both local and CNS symptoms. The participation of the main microbial-derived metabolites, also defined as "postbiotics", such as bile acids, short-chain fatty acids, and tryptophan metabolites in the development of IBD-associated gut and brain dysfunction will be discussed. The last section covers a critical evaluation of the main clinical evidence pointing to the microbiome-based therapeutic approaches for the treatment of IBD-related gastrointestinal and neuropsychiatric symptoms.

Two-Stage Interpretation of Changes in TEER of Intestinal Epithelial Layers Protected by Adhering Bifidobacteria During E. coli Challenges

Mechanisms of gastrointestinal protection by probiotic bacteria against infection involve amongst others, modulation of intestinal epithelial barrier function. Trans-epithelial electrical resistance (TEER) is widely used to evaluate cellular barrier functions. Here, we developed a two-stage interpretative model of the time-dependence of the TEER of epithelial layers grown in a transwell during Escherichia coli challenges in the absence or presence of adhering bifidobacteria. E. coli adhesion in absence or presence of adhering bifidobacteria was enumerated using selective plating. After 4-8 h, E. coli challenges increased TEER to a maximum due to bacterial adhesion and increased expression of a tight-junction protein [zonula occludens-1 (ZO-1)], concurrent with a less dense layer structure, that is indicative of mild epithelial layer damage. Before the occurrence of a TEER-maximum, decreases in electrical conductance (i.e., the reciprocal TEER) did not relate with para-cellular dextran-permeability, but after occurrence of a TEER-maximum, dextran-permeability and conductance increased linearly, indicative of more severe epithelial layer damage. Within 24 h after the occurrence of a TEER maximum, TEER decreased to below the level of unchallenged epithelial layers demonstrating microscopically observable holes and apoptosis. Under probiotic protection by adhering bifidobacteria, TEER-maxima were delayed or decreased in magnitude due to later transition from mild to severe damage, but similar linear relations between conductance and dextran permeability were observed as in absence of adhering bifidobacteria. Based on the time-dependence of the TEER and the relation between conductance and dextran-permeability, it is proposed that bacterial adhesion to epithelial layers first causes mild damage, followed by more severe damage after the occurrence of a TEER-maximum. The mild damage caused by E. coli prior to the occurrence of TEER maxima was reversible upon antibiotic treatment, but the severe damage after occurrence of TEER maxima could not be reverted by antibiotic treatment. Thus, single-time TEER is interpretable in two ways, depending whether increasing to or decreasing from its maximum. Adhering bifidobacteria elongate the time-window available for antibiotic treatment to repair initial pathogen damage to intestinal epithelial layers.

Effect of Clostridium butyricum and Butyrate on Intestinal Barrier Functions: Study of a Rat Model of Severe Acute Pancreatitis With Intra-Abdominal Hypertension

BACKGROUND/AIMS

Severe acute pancreatitis (SAP) is associated with intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS), but treatment of these conditions is difficult. We studied a rat model of SAP + IAH to determine the effect of oral administration of Clostridium butyricum and butyrate (its major metabolite) on intestinal barrier functions.

METHODS

A total of 48 rats were assigned to four groups, with 12 rats per group: Sham, SAP+IAH, SAP+IAH+C. butyricum, and SAP + IAH + butyrate. SAP was induced by sodium taurocholate infusion into the biliopancreatic duct, intra-abdominal pressure (IAP), mortality was measured 24 h later, and then rats were euthanized. The plasma levels of several markers [amylase, diamine oxidase (DAO), fluorescein isothiocyanate (FITC)-dextran, tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-1β, IL-12, lipopolysaccharide (LPS)] and fecal butyric acid level were determined. The pancreas and intestine were examined using histology, and RT-PCR and Western blotting of intestinal tissues were used to measure the expression of six markers {tight junction proteins [zonula occludens protein-1 (ZO-1), claudin-1, claudin-2, occluding], matrix metalloproteinase 9 [MMP9], and TNF-α}. The gut flora of the rats was examined by 16S rRNA sequencing.

RESULTS

Induction of SAP + IAH altered several functions of the intestinal barrier, and enhanced intestinal permeability, decreased the levels of ZO-1, claudin-1, occludin, the richness and diversity of the microflora community, the relative abundance (RA) of Firmicutes, and the number of probiotic organisms. However, induction of SAP+IAH increased the expression of claudin-2, MMP9, and TNF-α, and the RA of Proteobacteria and pathogens in the feces. Rats that received oral C. butyricum or butyrate had reduced intestinal injury and plasma levels of DAO, LPS, and inflammatory cytokines.

CONCLUSION

This study of rats with SAP+IAH indicated that oral dosing of C. butyricum or butyrate reduced intestinal injury, possibly by altering the functions of the intestinal mucosal barrier.

Lactobacillus salivarius alleviates inflammation via NF-κB signaling in ETEC K88-induced IPEC-J2 cells

Background

Enterotoxigenic Escherichia coli (ETEC) K88 commonly colonize in the small intestine and keep releasing enterotoxins to impair the intestinal barrier function and trigger inflammatory reaction. Although Lactobacillus salivarius (L. salivarius) has been reported to enhance intestinal health, it remains to be seen whether there is a functional role of L. salivarius in intestinal inflammatory response in intestinal porcine epithelial cell line (IPEC-J2) when stimulated with ETEC K88. In the present study, IPEC-J2 cells were first treated with L. salivarius followed by the stimulation of ETEC K88 for distinct time period. ETEC K88 adherent status, pattern recognition receptors (PRRs) mRNA, mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) activation, the release of pro-inflammation cytokines and cell integrity were examined.

Results

Aside from an inhibited adhesion of ETEC K88 to IPEC-J2 cells, L. salivarius was capable of remarkably attenuating the expression levels of interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), IL-8, Toll-like receptor (TLR) 4, nucleotide-binding oligomerization domain (NOD)-like receptor pyrin domain-containing protein (NLRP) 3 and NLRP6. This alternation was accompanied by a significantly decreased phosphorylation of p38 MAPK and p65 NF-κB during ETEC K88 infection with L. salivarius pretreatment. Western blot analysis revealed that L. salivarius increased the expression levels of zona occludens 1 (ZO-1) and occludin (P < 0.05) in ETEC K88-infected IPEC-J2 cells. Compared with ETEC K88-infected groups, the addition of L. salivarius as well as extra inhibitors for MAPKs and NF-κB to ETEC K88-infected IPEC-J2 cells had the capability to reduce pro-inflammatory cytokines.

Conclusions

Collectively, our results suggest that L. salivarius might reduce inflammation-related cytokines through attenuating phosphorylation of p38 MAPK and blocking the NF-κB signaling pathways. Besides, L. salivarius displayed a potency in the enhancement of IPEC-J2 cell integrity.

Diet Supplementation, Probiotics, and Nutraceuticals in SARS-CoV-2 Infection: A Scoping Review

The severe acute respiratory syndrome coronavirus 2 (Sars-CoV-2) global pandemic is a devastating event that is causing thousands of victims every day around the world. One of the main reasons of the great impact of coronavirus disease 2019 (COVID-19) on society is its unexpected spread, which has not allowed an adequate preparation. The scientific community is fighting against time for the production of a vaccine, but it is difficult to place a safe and effective product on the market as fast as the virus is spreading. Similarly, for drugs that can directly interfere with viral pathways, their production times are long, despite the great efforts made. For these reasons, we analyzed the possible role of non-pharmacological substances such as supplements, probiotics, and nutraceuticals in reducing the risk of Sars-CoV-2 infection or mitigating the symptoms of COVID-19. These substances could have numerous advantages in the current circumstances, are generally easily available, and have negligible side effects if administered at the already used and tested dosages. Large scientific evidence supports the benefits that some bacterial and molecular products may exert on the immune response to respiratory viruses. These could also have a regulatory role in systemic inflammation or endothelial damage, which are two crucial aspects of COVID-19. However, there are no specific data available, and rigorous clinical trials should be conducted to confirm the putative benefits of diet supplementation, probiotics, and nutraceuticals in the current pandemic.

Pharmabiotic beads with improved encapsulation and gut survival for management of colonic inflammation associated gut derangements

Encapsulation techniques and materials, explored for addressing compromised probiotic gut survival, report significant production losses resulting in <10% entrapment. Presently, we report three-time enhanced entrapment (30 ± 1.2%) of Lactobacillus acidophilus (LAB) in calcium-alginate beads, by modifying process parameters and employing polyethylene glycol (PEG). Water-loving, viscolysing and osmotic-building effects of PEG create numerous, fine voids in the alginate gel allowing efficient diffusion of crosslinking calcium ions, resulting in less leaky beads. Eudragit S100 overcoat improved LAB survival by 690 times in simulated GIT stresses.In DMH-DSS induced colitis and precancerous lesions in rats, while free LAB failed to show any protection, pharmabiotic beads significantly (p < .05) reduced lipid peroxidation, increased antioxidant levels; decreased serum inflammatory burden; downregulated COX-2, iNOS, and c-Myc expression; elevated levels of the selected gut bacteria and SCFAs especially butyrate, all of which add up to antioxidant, anti-inflammatory, balanced gut biota, and ultimately anticancer effects.

Probiotic mixture VSL#3: An overview of basic and clinical studies in chronic diseases

Probiotics are known as “live microorganisms” and have been proven to have a health effect on hosts at the proper dose. Recently, a kind of probiotic mixture including eight live bacterial strains, VSL#3, has attracted considerable attention for its combined effect. VSL#3 is the only probiotic considered as a kind of medical food; it mainly participates in the regulation of the intestinal barrier function, including improving tight junction protein function, balancing intestinal microbial composition, regulating immune-related cytokine expression and so on. The objective of this review is to discuss the treatment action and mechanism for the administration of VSL#3 in chronic diseases of animals and humans (including children). We found that VSL#3 has a therapeutic or preventive effect in various systemic diseases per a large number of studies, including digestive systemic diseases (gastrointestinal diseases and hepatic diseases), obesity and diabetes, allergic diseases, nervous systemic diseases, atherosclerosis, bone diseases, and female reproductive systemic diseases.

Knockdown of ghrelin-O-acyltransferase attenuates colitis through the modulation of inflammatory factors and tight junction proteins in the intestinal epithelium

Ghrelin-O-acyltransferase (GOAT) is a membrane-bound enzyme that attaches eight-carbon octanoate to a serine residue in ghrelin and thereby acylates inactive ghrelin to produce active ghrelin. In this study, we investigated the function of GOAT in the intestinal mucosal barrier. The intestinal mucosal barrier prevents harmful substances such as bacteria and endotoxin from entering the other tissues, organs, and blood circulation through the intestinal mucosa. Here, we established 5% dextran sodium sulfate (DSS)-induced colitis in mice and found that the body weight and colon weight were significantly decreased in these mice. Furthermore, increased inflammation and apoptosis were observed in the tissues of DSS-induced colitis mice, with increased expression of tumor necrosis factor-α, interleukin-6, phosphorylation of nuclear factor kappa B-p65 (p-NF-κB-p65), and cleaved caspase-3, and decreased expression of tight junction (TJ) proteins such as zonula occluden-1 and occludin. The knockdown of GOAT significantly attenuated colitis-induced inflammation responses and apoptosis, while GOAT overexpression significantly enhanced the induction of colitis. These results suggest that knockdown of GOAT may attenuate colitis-induced inflammation, ulcers, and fecal occult blood by decreasing the intestinal mucosal permeability via the modulation of inflammatory factors and TJ proteins.

Flaxseed oil supplementation improves intestinal function and immunity, associated with altered intestinal microbiome and fatty acid profile in pigs with intrauterine growth retardation

Flaxseed oil (FO), enriched in n-3 polyunsaturated fatty acids (PUFAs), is an important oil source for intestinal development and health. We aimed to study the different effects of FO versus soybean oil (SO) on growth, intestinal health and immune function of neonates with intrauterine growth retardation (IUGR) using a weaned piglet model. Forty pairs of male IUGR and normal birth weight piglets, weaned at 21 ± 1 d, were fed diets containing either 4% FO or SO for 3 weeks consecutively. Growth performance, nutrient digestibility and intestinal function parameters, immunology and microbiota composition were determined. IUGR led to a poor growth rate, nutrient digestibility and abnormal immunology variables, whereas feeding FO diet improved systemic and gut immunity, as indicated by increased plasma concentration of immunoglobulin G and decreased CD3+CD8+ T lymphocytes, and down-regulated intestinal expression of genes (MyD88, NF-κB, TNF-α, IL-10). Although IUGR tended to decrease villous height, feeding FO diet tended to increase the villi-crypt ratio and up-regulated expressions of tight junction genes (Claudin-1 and ZO-1), together with increased mucosa contents of n-3 PUFAs and a lower Σn-6/Σn-3 ratio. Besides, FO diet decreased the abundance of pathogenic bacteria Spirochaetes, and increased phylum Actinobacteria, and genera Blautia and Bifidobacterium in colonic digesta. Our findings indicate that IUGR impairs growth rate, nutrient digestibility, and partly immunology variables, whereas feeding FO-supplemented diet could improve intestinal function and immunity of both IUGR and NBW pigs, associated with the altered gut microbiome and mucosal fatty acid profile.

Probiotic Propionibacterium freudenreichii requires SlpB protein to mitigate mucositis induced by chemotherapy

Propionibacterium freudenreichii CIRM-BIA 129 (P. freudenreichii wild type, WT) is a probiotic bacterium, which exerts immunomodulatory effects. This strain possesses extractable surface proteins, including SlpB, which are involved in anti-inflammatory effect and in adhesion to epithelial cells. We decided to investigate the impact of slpB gene mutation on immunomodulation in vitro and in vivo. In an in vitro assay, P. freudenreichii WT reduced expression of IL-8 (p<0.0001) and TNF-α (p<0.0001) cytokines in LPS-stimulated HT-29 cells. P. freudenreichii ΔslpB, lacking the SlpB protein, failed to do so. Subsequently, both strains were investigated in vivo in a 5-FU-induced mucositis mice model. Mucositis is a common side effect of cytotoxic chemotherapy with 5-FU, characterized by mucosal injury, inflammation, diarrhea, and weight loss. The WT strain prevented weight loss, reduced inflammation and consequently histopathological scores. Furthermore, it regulated key markers, including Claudin-1 (cld1, p<0.0005) and IL-17a (Il17a, p<0.0001) genes, as well as IL-12 (p<0.0001) and IL-1β (p<0.0429) cytokines levels. Mutant strain displayed opposite regulatory effect on cld1 expression and on IL-12 levels. This work emphasizes the importance of SlpB in P. freudenreichii ability to reduce mucositis inflammation. It opens perspectives for the development of probiotic products to decrease side effects of chemotherapy using GRAS bacteria with immunomodulatory surface protein properties.

Probiotics for Parkinson's Disease

Parkinson’s disease (PD) is a complex neurological disorder classically characterized by impairments in motor system function associated with loss of dopaminergic neurons in the substantia nigra. After almost 200 years since the first description of PD by James Parkinson, unraveling the complexity of PD continues to evolve. It is now recognized that an interplay between genetic and environmental factors influences a diverse range of cellular processes, reflecting on other clinical features including non-motor symptoms. This has consequently highlighted the extensive value of early clinical diagnosis to reduce difficulties of later stage management of PD. Advancement in understanding of PD has made remarkable progress in introducing new tools and strategies such as stem cell therapy and deep brain stimulation. A link between alterations in gut microbiota and PD has also opened a new line. Evidence exists of a bidirectional pathway between the gastrointestinal tract and the central nervous system. Probiotics, prebiotics and synbiotics are being examined that might influence gut-brain axis by altering gut microbiota composition, enteric nervous system, and CNS. This review provides status on use of probiotics for PD. Limitations and future directions will also be addressed to promote further research considering use of probiotics for PD.

Milk Fermented with Lactobacillus fermentum Ameliorates Indomethacin-Induced Intestinal Inflammation: An Exploratory Study

The aim of this study was to evaluate the effect of milk fermented with Lactobacillus fermentum J20 (FMJ20) or J28 (FMJ28) on ameliorating indomethacin-induced inflammation. Twenty-eight male C57Bl/6 mice were divided into four experimental groups: indomethacin, indomethacin + FMJ20, indomethacin + FMJ28, and untreated (control). Groups were fed fermented milk for 15 days, followed by administration of indomethacin supplied in three sub-doses over experimental period. Body weight, and food consumption were recorded. Additionally, spleen, kidney, and liver were weighed, and the small intestine length was measured. The cytokines in serum (IL-2, IL-4, IL-6, IL-10, IL-17, IL-23 and TNFα) and in intestinal mucosa (IL-17 and IFNγ) were also determined. Compared to the control, all indomethacin-supplemented groups lost weight (~2.7 g; p < 0.05), but no changes were found in the organ-specific morphometry analysis. FMJ28 showed better results in attenuating serum and intestinal IL-17 levels. Furthermore, showed less epithelial cell loss and inflammatory infiltrates than the other indomethacin-treated groups. These results suggest that FMJ28 may be effective in reducing intestinal and systemic acute inflammation, specifically in mice.

A Review: The Fate of Bacteriocins in the Human Gastro-Intestinal Tract: Do They Cross the Gut-Blood Barrier?

The intestinal barrier, consisting of the vascular endothelium, epithelial cell lining, and mucus layer, covers a surface of about 400 m2. The integrity of the gut wall is sustained by transcellular proteins forming tight junctions between the epithelial cells. Protected by three layers of mucin, the gut wall forms a non-permeable barrier, keeping digestive enzymes and microorganisms within the luminal space, separate from the blood stream. Microorganisms colonizing the gut may produce bacteriocins in an attempt to outcompete pathogens. Production of bacteriocins in a harsh and complex environment such as the gastro-intestinal tract (GIT) may be below minimal inhibitory concentration (MIC) levels. At such low levels, the stability of bacteriocins may be compromised. Despite this, most bacteria in the gut have the ability to produce bacteriocins, distributed throughout the GIT. With most antimicrobial studies being performed in vitro, we know little about the migration of bacteriocins across epithelial barriers. The behavior of bacteriocins in the GIT is studied ex vivo, using models, flow cells, or membranes resembling the gut wall. Furthermore, little is known about the effect bacteriocins have on the immune system. It is generally believed that the peptides will be destroyed by macrophages once they cross the gut wall. Studies done on the survival of neurotherapeutic peptides and their crossing of the brain-blood barrier, along with other studies on small peptides intravenously injected, may provide some answers. In this review, the stability of bacteriocins in the GIT, their effect on gut epithelial cells, and their ability to cross epithelial cells are discussed. These are important questions to address in the light of recent papers advocating the use of bacteriocins as possible alternatives to, or used in combination with, antibiotics.

The Effect of Co-infection of Food-Borne Pathogenic Bacteria on the Progression of Campylobacter jejuni Infection in Mice

Campylobacter is a well-known food-borne pathogen that causes human gastroenteritis. Food products that contain Campylobacter may also be contaminated by other pathogens, however, whether this multiple contamination leads to more severe infection remains unclear. In this study, mice were gavaged with Campylobacter jejuni and other food-borne pathogenic bacteria to mimic a multiple infection. It was demonstrated that the C. jejuni load was elevated when the mice were co-infected with C. jejuni and Salmonella typhimurium, and the campylobacteriosis that followed was also enhanced, with features of decreased body weight, heavier bloody stools and more pronounced inflammatory changes to the colon. In addition, infection with C. jejuni was also promoted by co-infection with entero-invasive Escherichia coli but unaffected over time. In contrast to S. typhimurium and entero-invasive E. coli, co-infection by Listeria monocytogenes showed little effect on C. jejuni infection and even hindered its progress. In addition, the intestinal microecology was also affected by co-infection of C. jejuni with other pathogens, with an increased relative abundance of unclassified Enterobacteriaceae, decreased levels of butyric acid and changes in the abundance of several genera of gut microbe, which suggests that some food-borne pathogenic bacteria might affect the progression of C. jejuni infection in mice by influencing the composition of the gut microbiota and the resulting changes in SCFA levels. Collectively, our findings suggest that co-infection of Campylobacter with other pathogenic bacteria can impact on the progression of infection by C. jejuni in mice, which may also have implication for the etiology of Campylobacter on human health.

Impaired intestinal immune barrier and physical barrier function by phosphorus deficiency: Regulation of TOR, NF-κB, MLCK, JNK and Nrf2 signalling in grass carp (Ctenopharyngodon idella) after infection with Aeromonas hydrophila

In aquaculture, the occurrence of enteritis has increased and dietary nutrition is considered as one of the major strategies to solve this problem. In the present study, we assume that dietary phosphorus might enhance intestinal immune barrier and physical barrier function to reduce the occurrence of enteritis in fish. To test this assumption, a total of 540 grass carp (Ctenopharyngodon idella) were investigated by feeding graded levels of available phosphorus (0.95-8.75 g/kg diet) and then infection with Aeromonas hydrophila. The results firstly showed that phosphorus deficiency decreased the ability to combat enteritis, which might be related to the impairment of intestinal immune barrier and physical barrier function. Compared with optimal phosphorus level, phosphorus deficiency decreased fish intestinal antimicrobial substances activities or contents and down-regulated antimicrobial peptides mRNA levels leading to the impairment of intestinal immune response. Phosphorus deficiency down-regulated fish intestinal anti-inflammatory cytokines mRNA levels and up-regulated the mRNA levels of pro-inflammatory cytokines [except IL-1β and IL-12p35 in distal intestine (DI) and IL-12p40] causing aggravated of intestinal inflammatory responses, which might be related to the signalling molecules target of rapamycin and nuclear factor kappa B. In addition, phosphorus deficiency disturbed fish intestinal tight junction function and induced cell apoptosis as well as oxidative damage leading to impaired of fish intestinal physical barrier function, which might be partially associated with the signalling molecules myosin light chain kinase, c-Jun N-terminal protein kinase and NF-E2-related factor 2, respectively. Finally, based on the ability to combat enteritis, dietary available phosphorus requirement for grass carp (254.56-898.23 g) was estimated to be 4.68 g/kg diet.

Vitamin D Axis in Inflammatory Bowel Diseases: Role, Current Uses and Future Perspectives

Increasing evidence supports the concept that the vitamin D axis possesses immunoregulatory functions, with vitamin D receptor (VDR) status representing the major determinant of vitamin D’s pleiotropic effects. Vitamin D promotes the production of anti-microbial peptides, including β-defensins and cathelicidins, the shift towards Th2 immune responses, and regulates autophagy and epithelial barrier integrity. Impairment of vitamin D-mediated pathways are associated with chronic inflammatory conditions, including inflammatory bowel diseases (IBD). Interestingly, inhibition of vitamin D pathways results in dysbiosis of the gut microbiome, which has mechanistically been implicated in the development of IBD. Herein, we explore the role of the vitamin D axis in immune-mediated diseases, with particular emphasis on its interplay with the gut microbiome in the pathogenesis of IBD. The potential clinical implications and therapeutic relevance of this interaction will also be discussed, including optimizing VDR function, both with vitamin D analogues and probiotics, which may represent a complementary approach to current IBD treatments.

A consumer's guide for probiotics: 10 golden rules for a correct use

Probiotics are used all over the world as their beneficial effects on the human organism have been widely demonstrated. Certain probiotics can down-regulate production of pro-inflammatory cytokines and promote intestinal epithelial barrier functions, increasing an anti-inflammatory response and contributing to the host's overall health. The main mechanisms by which probiotic microorganisms can interact with the host are by modulating the immune system and the epithelial cell functions and interacting with intestinal gut microbiota. To date, hundreds of different microorganisms are used for the formulation of numerous probiotic products; therefore, it is very difficult to choose the best probiotic product for specific or more general needs. Therefore, physicians are getting more and more confused due to the high number of commercial products which are often lacking healthy effects on the host. Therefore, the aim of this paper is to demonstrate the main characteristics that probiotic microorganisms and products should possess to have a positive impact on the host's health. To this purpose, this review suggests "10 golden rules" or "commandments" that clinicians should follow to properly select the optimal probiotic product and avoid misidentifications, mislabelling and "pie in the sky" stories.

Interplay of GTPases and Cytoskeleton in Cellular Barrier Defects during Gut Inflammation

An essential role of the intestine is to build and maintain a barrier preventing the luminal gut microbiota from invading the host. This involves two coordinated physical and immunological barriers formed by single layers of intestinal epithelial and endothelial cells, which avoid the activation of local immune responses or the systemic dissemination of microbial agents, and preserve tissue homeostasis. Accordingly, alterations of epithelial and endothelial barrier functions have been associated with gut inflammation, for example during inflammatory bowel disease (IBD). The discriminative control of nutriment uptake and sealing toward potentially pathological microorganisms requires a profound regulation of para- and transcellular permeability. On the subcellular level, the cytoskeleton exerts key regulatory functions in the maintenance of cellular barriers. Increased epithelial/endothelial permeability occurs primarily as a result of a reorganization of cytoskeletal–junctional complexes. Pro-inflammatory mediators such as cytokines can induce cytoskeletal rearrangements, causing inflammation-dependent defects in gut barrier function. In this context, small GTPases of the Rho family and large GTPases from the Dynamin superfamily appear as major cellular switches regulating the interaction between intercellular junctions and actomyosin complexes, and in turn cytoskeleton plasticity. Strikingly, some of these proteins, such as RhoA or guanylate-binding protein-1 (GBP-1) have been associated with gut inflammation and IBD. In this review, we will summarize the role of small and large GTPases for cytoskeleton plasticity and epithelial/endothelial barrier in the context of gut inflammation.

Metabolic Variability of a Multispecies Probiotic Preparation Impacts on the Anti-inflammatory Activity

Background: In addition to strain taxonomy, the ability of probiotics to confer beneficial effects on the host rely on a number of additional factors including epigenetic modulation of bacterial genes leading to metabolic variability and might impact on probiotic functionality.

Aims: To investigate metabolism and functionality of two different batches of a probiotic blend commercialized under the same name in Europe in models of intestinal inflammation.

Methods: Boxes of VSL#3, a probiotic mixture used in the treatment of pouchitis, were obtained from pharmacies in UK subjected to metabolomic analysis and their functionality tested in mice rendered colitis by treatment with DSS or TNBS.

Results: VSL#3-A (lot DM538), but not VSL#3-B (lot 507132), attenuated “clinical” signs of colitis in the DSS and TNBS models. In both models, VSL#3-A, but not VSL#3-B, reduced macroscopic scores, intestinal permeability, and expression of TNFα, IL-1β, and IL-6 mRNAs, while increased the expression of TGFβ and IL-10, occludin, and zonula occludens-1 (ZO-1) mRNAs and shifted colonic macrophages from a M1 to M2 phenotype (P < 0.05 vs. TNBS). In contrast, VSL#3-B failed to reduce inflammation, and worsened intestinal permeability in the DSS model (P < 0.001 vs. VSL#3-A). A metabolomic analysis of the two formulations allowed the identification of two specific patterns, with at least three-folds enrichment in the concentrations of four metabolites, including 1–3 dihydroxyacetone (DHA), an intermediate in the fructose metabolism, in VSL#3-B supernatants. Feeding mice with DHA, increased intestinal permeability.

Conclusions: Two batches of a commercially available probiotic show divergent metabolic activities. DHA, a product of probiotic metabolism, increases intestinal permeability, highlighting the complex interactions between food, microbiota, probiotics, and intestinal inflammation.

Randomized, controlled trial evaluating the effect of multi-strain probiotic on the mucosal microbiota in canine idiopathic inflammatory bowel disease

The intestinal microbiota is increasingly linked to the pathogenesis of idiopathic inflammatory bowel disease (IBD) in dogs. While studies have reported alterations in fecal (luminal) microbial populations, only limited information is available about the mucosal microbiota of IBD dogs at diagnosis and following medical therapy. Our aim was to characterize the mucosal microbiota and determine the clinical, microbiological, and mucosal homeostatic effects of probiotic treatment in dogs with IBD. Thirty four IBD dogs were randomized to receive standard therapy (ST = diet + prednisone) with or without probiotic. Tissue sections from endoscopic biopsies were evaluated by fluorescence in situ hybridization (FISH) on a quantifiable basis. Disease activity and changes in mucosal microbiota and tight junction protein (TJP) expression were assessed before and after 8 weeks of IBD therapy. ST and ST/probiotic therapy modulated the number of mucosal bacteria of IBD dogs in a similar fashion. Both treatments increased the numbers of total bacteria and individual species residing within adherent mucus, with ST therapy increasing Bifidobacterium spp. and ST/probiotic therapy increasing Lactobacillus spp (P < 0.05 for both), respectively. Both treatments were associated with rapid clinical remission but not improvement in histopathologic inflammation. Probiotic therapy was associated with upregulated (P < 0.05) expression of TJPs E-cadherin, occludin, and zonulin versus ST. The probiotic effect on mucosal bacteria is similar to that of IBD dogs receiving ST. IBD dogs fed probiotic had increased TJP expression suggesting that probiotic may have beneficial effects on mucosal homeostasis.

Host-probiotic interaction: new insight into the role of the endocannabinoid system by in vivo and ex vivo approaches

The endocannabinoid system plays an important role in regulating inflammation in several chronic or anomalous gut inflammatory diseases. In vivo and ex vivo studies showed that 30 days treatment with a probiotic mix activated the endocannabinoid system in zebrafish. These results highlight the potential of this probiotic mixture to regulate immune cell function, by inducing gene expression of toll-like receptors and other immune related molecules. Furthermore, TUNEL assay showed a decrease in the number of apoptotic cells, and this finding was supported by a reduction in pro-apoptotic factors and an increase in anti-apoptotic molecules. The results presented here strengthen the molecular mechanisms activated by probiotic mix controlling immune response and inflammation.

The Effects of Probiotics and Symbiotics on Risk Factors for Hepatic Encephalopathy: A Systematic Review

Alterations in the levels of intestinal microbiota, endotoxemia, and inflammation are novel areas of interest in the pathogenesis of hepatic encephalopathy (HE). Probiotics and symbiotics are a promising treatment option for HE due to possible beneficial effects in modulating gut microflora and might be better tolerated and more cost-effective than the traditional treatment with lactulose, rifaximin or L-ornithine-L-aspartate. A systematic search of the electronic databases PubMed, ISI Web of Science, EMBASE, and Cochrane Library was conducted for randomized controlled clinical trials in adult patients with cirrhosis, evaluating the effect of probiotics and symbiotics in changes on intestinal microflora, reduction of endotoxemia, inflammation, and ammonia, reversal of minimal hepatic encephalopathy (MHE), prevention of overt hepatic encephalopathy (OHE), and improvement of quality of life. Nineteen trials met the inclusion criteria. Probiotics and symbiotics increased beneficial microflora and decreased pathogenic bacteria and endotoxemia compared with placebo/no treatment, but no effect was observed on inflammation. Probiotics significantly reversed MHE [risk ratio, 1.53; 95% confidence interval (CI): 1.14, 2.05; P=0.005] and reduced OHE development (risk ratio, 0.62; 95% CI: 0.48, 0.80; P=0.0002) compared with placebo/no treatment. Symbiotics significantly decreased ammonia levels compared with placebo (15.24; 95% CI: -26.01, -4.47; P=0.006). Probiotics did not show any additional benefit on reversal of MHE and prevention of OHE development when compared with lactulose, rifaximin, and L-ornithine-L-aspartate. Only 5 trials considered tolerance with minimal side effects reported. Although further research is warranted, probiotics and symbiotics should be considered as an alternative therapy for the treatment and management of HE given the results reported in this systematic review.

Epithelial-specific Toll-like Receptor (TLR)5 Activation Mediates Barrier Dysfunction in Experimental Ileitis

BACKGROUND

A large body of evidence supports a central role of TLR5 and its natural ligand, flagellin, in Crohn's disease (CD), with the precise mechanism(s) still unresolved.

METHODS

We investigated the role of flagellin/TLR5 in SAMP1/YitFc (SAMP) mice, a spontaneous model of Crohn's disease-like ileitis.

RESULTS

Ileal Tlr5 and serum antiflagellin IgG antibodies were increased in SAMP before the onset of inflammation and during established disease; these trends were abrogated in the absence of colonizing commensal bacteria. Irradiated SAMP receiving either wild-type (AKR) or SAMP bone marrow (BM) developed severe ileitis and displayed increased ileal Tlr5 compared with AKR recipients of either SAMP or AKR bone marrow, neither of which conferred ileitis, suggesting that elevated TLR5 in native SAMP is derived primarily from a nonhematopoietic (e.g., epithelial) source. Indeed, ileal epithelial TLR5 in preinflamed SAMP was increased compared with age-matched AKR and germ-free SAMP. TLR5-specific ex vivo activation of SAMP ileal tissues decreased epithelial barrier resistance, indicative of increased permeability, and was accompanied by altered expression of the tight junction proteins, claudin-3, occludin, and zonula occludens-1.

CONCLUSIONS

Our results provide evidence that aberrant, elevated TLR5 expression is present in the ileal epithelium of SAMP mice, is augmented in the presence of the gut microbiome, and that TLR5 activation in response to bacterial flagellin results in a deficiency to maintain appropriate epithelial barrier integrity. Together, these findings represent a potential mechanistic pathway leading to the exacerbation and perpetuation of chronic gut inflammation in experimental ileitis and possibly, in patients with Crohn's disease.

Secretions of Bifidobacterium infantis and Lactobacillus acidophilus Protect Intestinal Epithelial Barrier Function

OBJECTIVES

The secreted metabolites of probiotics are cytoprotective to intestinal epithelium and have been shown to attenuate inflammation and reduce gut permeability. The present study was designed to determine the protective effects of probiotic conditioned media (PCM) from Bifidobacterium infantis (BCM) and Lactobacillus acidophilus (LCM) on interleukin (IL)-1β-induced intestinal barrier compromise.

METHODS

The epithelial barrier was determined by measuring the transepithelial electrical resistance (TER) across a Caco-2 cell monolayer using a Transwell model. The paracellular permeability was determined by fluorescein isothiocyanate-labeled dextran flux. The expression of tight junction (TJ) proteins and nuclear factor-kappa B (NF-κB) p65 were determined using Western blot and the distribution of NF-κB p65 was determined by immunofluorescence staining.

RESULTS

BCM and LCM induced a dose-dependent increase in Caco-2 TER after 4 and 24 hours of incubation (P < 0.05). The maximal increase of Caco-2 TER occurred at 4 hours of treatment with a PCM concentration of 15%. Preincubation with BCM and LCM for 4 hours significantly prevented the decrease of Caco-2 TER induced by 24 hours of stimulation with 10 ng/mL IL-1β. BCM and LCM decreased paracellular permeability in both stimulated and unstimulated Caco-2 monolayers (P < 0.05). IL-1β stimulation decreased occludin expression and increased claudin-1 expression in Caco-2 cells (P < 0.05), which was prevented in cells treated with BCM or LCM. The changes of claudin-1 expression in H4 cells were similar to Caco-2 cells in response to PCM treatment and IL-1β stimulation; however, a similar response in occludin was not demonstrated. The IL-1β-induced nuclear translocation of NF-κB p65 in Caco-2 cells was prevented by pretreatment with both PCMs.

CONCLUSIONS

BCM and LCM protected the intestinal barrier against IL-1β stimulation by normalizing the protein expression of occludin and claudin-1 and preventing IL-1β-induced NF-κB activation in Caco-2 cells, which may be partly responsible for the preservation of intestinal permeability.

VSL#3 Probiotic Stimulates T-cell Protein Tyrosine Phosphatase-mediated Recovery of IFN-γ-induced Intestinal Epithelial Barrier Defects

BACKGROUND

VSL#3 is a probiotic compound that has been used in the treatment of inflammatory bowel disease. T-cell protein tyrosine phosphatase (TCPTP) is the protein product of the inflammatory bowel disease candidate gene, PTPN2, and we have previously shown that it protects epithelial barrier function. The aim of this study was to investigate whether VSL#3 improves intestinal epithelial barrier function against the effects of the inflammatory bowel disease-associated proinflammatory cytokine, interferon-gamma (IFN-γ) through activation of TCPTP.

METHODS

Polarized monolayers of T84 intestinal epithelial cells were treated with increasing concentrations of VSL#3 to determine effects on TCPTP expression and enzymatic activity. Therapeutic effects of VSL#3 against barrier disruption by IFN-γ were measured by transepithelial electrical resistance and fluorescein isothiocyanate-dextran permeability. A novel TCPTP-deficient HT-29 intestinal epithelial cell line was generated to study the role of TCPTP in mediating the effects of VSL#3. Tight junction protein distribution was assessed with confocal microscopy.

RESULTS

VSL#3 increased TCPTP protein levels and enzymatic activity, correlating with a VSL#3-induced decrease in IFN-γ signaling. VSL#3 corrected the decrease in transepithelial electrical resistance and the increase in epithelial permeability induced by IFN-γ. Moreover, the restorative effect of VSL#3 against IFN-γ signaling, epithelial permeability defects, altered expression and localization of the tight junction proteins claudin-2, occludin, and zonula occludens-1, were not realized in stable TCPTP/(PTPN2)-deficient HT-29 intestinal epithelial cells.

CONCLUSIONS

VSL#3 reduces IFN-γ signaling and IFN-γ-induced epithelial barrier defects in a TCPTP-dependent manner. These data point to a key role for TCPTP as a therapeutic target for restoration of barrier function using probiotics.

Dietary choline deficiency and excess induced intestinal inflammation and alteration of intestinal tight junction protein transcription potentially by modulating NF-κB, STAT and p38 MAPK signaling molecules in juvenile Jian carp

This study investigated the effects of choline on intestinal mucosal immune and the possible mechanisms in fish by feeding juvenile Jian carp (Cyprinus carpio var. Jian) with graded levels of dietary choline (165-1820 mg/kg diet) for 65 days. The results firstly showed that choline deficiency induced inflammatory infiltration in the proximal intestine (PI), mid intestine (MI) and distal intestine (DI) of fish. Meanwhile, compared with the optimal choline group, choline deficiency decreased the activities of lysozyme and acid phosphatase, contents of complement 3 and IgM in the intestine, downregulated the mRNA levels of antimicrobial peptides (liver-expressed antimicrobial peptide (LEAP) 2A and defensin-3 in the PI and MI, LEAP-2B and hepcidin in the PI, MI and DI), anti-inflammatory cytokines (interleukin (IL) 10 and transforming growth factor β2 in the PI, MI and DI), and signaling molecule IκB in the PI, MI and DI; while upregulated the mRNA levels of pro-inflammatory cytokines (IL-6a and tumor necrosis factor α in the MI and DI, interferon γ2b in the PI and MI, IL-1β and IL-6b in the PI, MI and DI), and signaling molecules (Toll-like receptor 4 in the MI, myeloid differentiation primary response 88 in the PI and MI, Janus kinase 3 and tyrosine kinase 2 in the MI and DI, nuclear factor kappa B (NF-κB), signal transducers and activators of transcription (STAT) 4 and STAT5 in the PI, MI and DI) of juvenile Jian carp, further indicating that choline deficiency caused inflammation and immunity depression in the intestine of fish. But choline deficiency decreased the PI IL-6a mRNA level, and increased the DI LEAP-2A and defensin-3 mRNA levels with unknown reasons. Furthermore, dietary choline deficiency downregulated mRNA levels of tight junction (TJ) proteins (claudin 3c in the PI and MI, claudin 7, claudin 11 and occludin in the PI, MI and DI) and signaling molecule mitogen-activated protein kinases p38 in the PI, MI and DI of juvenile Jian carp, whereas upregulated the mRNA levels of claudin 3b in the MI and DI, and claudin 3c in the DI. Moreover, the excessive choline exhibited negative effects on intestinal immunity and TJ proteins that were similar to the choline deficiency. In summary, dietary choline deficiency or excess caused the depression of intestinal mucosal immune by inducing inflammation and dysfunction of the intestinal physical barrier, and regulating related signaling molecules of fish.

Effects of probiotics (Vivomixx®) in obese pregnant women and their newborn: study protocol for a randomized controlled trial

Background

Maternal obesity is associated with increased risks of adverse pregnancy-related complications and outcomes for both mothers and infants. Overweight and obese women have an increased risk of pregnancy-induced hypertension, preeclampsia and gestational diabetes mellitus (GDM). Infant Body Mass index (BMI) and the risk of obesity in adulthood are related to maternal gestational weight gain (GWG). Preventive lifestyle and dietary interventions are time-consuming and do not always reduce GWG or the risk of maternal pregnancy complications. Recent research has indicated that the gut microbiota may play a significant role in the development of obesity. Some studies have indicated that the daily consumption of probiotics may reduce the risk of preeclampsia, maintain serum insulin levels and reduce the frequency of GDM in pregnant women. The aims of this study are to investigate whether daily probiotic supplements in obese women during pregnancy can limit gestational weight gain, improve glucose homeostasis and thereby improve maternal, fetal and infant health outcomes.

Methods

A pilot study including 50 obese pregnant nulliparous women with a prepregnancy BMI of between 30 and 35 kg/m² will be randomized to receive daily probiotics (four capsules of Vivomixx®; total of 450 billion CFU/day, including eight probiotic bacterial strains) or placebo from gestational age 14–20 weeks until delivery. The infants will be followed until 9 months of age. The women will be monitored by weight, blood, fecal, vaginal and urine samples, diet questionnaires and hospital record review. Primary outcomes are: maternal weight gain, glycated hemoglobin (HbA1c) level and changes in glucose concentration measured during an oral glucose tolerance test. Secondary outcomes are: microbiota and inflammatory markers in mother and child, pregnancy complications, pregnancy outcomes, physical activity and the body composition of the neonate.

Discussion

We expect to find alterations in the metabolic profiles, microbiota and possibly pregnancy outcomes. From a clinical point of view the effects of Vivomixx® could control weight gain and reduce complications during pregnancy by inducing changes in the gut microbiota. Furthermore, this intervention during pregnancy could influence the infant’s microbiota, which could have important implications for infant development and health.

Trial registration

ClincalTrials.gov Identifier: NCT02508844, registered on 11 May 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1617-5) contains supplementary material, which is available to authorized users.