Effects of Supplementation of the Synbiotic Ecologic® 825/FOS P6 on Intestinal Barrier Function in Healthy Humans: A Randomized Controlled Trial

Spatio-temporal dynamics of the human small intestinal microbiome and its response to a synbiotic

Although fecal microbiota composition is considered to preserve relevant and representative information for distal colonic content, it is evident that it does not represent microbial communities inhabiting the small intestine. Nevertheless, studies investigating the human small intestinal microbiome and its response to dietary intervention are still scarce. The current study investigated the spatio-temporal dynamics of the small intestinal microbiome within a day and over 20 days, as well as its responses to a 14-day synbiotic or placebo control supplementation in 20 healthy subjects. Microbial composition and metabolome of luminal content of duodenum, jejunum, proximal ileum and feces differed significantly from each other. Additionally, differences in microbiota composition along the small intestine were most pronounced in the morning after overnight fasting, whereas differences in composition were not always measurable around noon or in the afternoon. Although overall small intestinal microbiota composition did not change significantly within 1 day and during 20 days, remarkable, individual-specific temporal dynamics were observed in individual subjects. In response to the synbiotic supplementation, only the microbial diversity in jejunum changed significantly. Increased metabolic activity of probiotic strains during intestinal passage, as assessed by metatranscriptome analysis, was not observed. Nevertheless, synbiotic supplementation led to a short-term spike in the relative abundance of genera included in the product in the small intestine approximately 2 hours post-ingestion. Collectively, small intestinal microbiota are highly dynamic. Ingested probiotic bacteria could lead to a transient spike in the relative abundance of corresponding genera and ASVs, suggesting their passage through the entire gastrointestinal tract. This study was registered to http://www.clinicaltrials.gov, NCT02018900.

Unveiling the Probiotic Potential of the Anaerobic Bacterium Cetobacterium sp. nov. C33 for Enhancing Nile Tilapia (Oreochromis niloticus) Cultures

The bacterium strain Cetobacterium sp. C33 was isolated from the intestinal microbial content of Nile tilapia (O. niloticus) under anaerobic conditions. Given that Cetobacterium species are recognized as primary constituents of the intestinal microbiota in cultured Nile tilapia by culture-independent techniques, the adaptability of the C33 strain to the host gastrointestinal conditions, its antibacterial activity against aquaculture bacterial and its antibiotic susceptibility were assessed. The genome of C33 was sequenced, assembled, annotated, and subjected to functional inference, particularly regarding pinpointed probiotic activities. Furthermore, phylogenomic comparative analyses were performed including closely reported strains/species relatives. Comparative genomics with closely related species disclosed that the isolate is not phylogenetically identical to other Cetobacterium species, displaying an approximately 5% sequence divergence from C. somerae and a 13% sequence divergence from Cetobacterium ceti. It can be distinguished from other species through physiological and biochemical criteria. Whole-genome annotation highlighted that Cetobacterium sp. nov. C33 possesses a set of genes that may contribute to antagonism against competing bacteria and has specific symbiotic adaptations in fish. Additional in vivo experiments should be carried out to verify favorable features, reinforcing its potential as a probiotic bacterium.

Zonulin as a Potential Therapeutic Target in Microbiota-Gut-Brain Axis Disorders: Encouraging Results and Emerging Questions

The relationship between dysbiosis and central nervous diseases has been proved in the last 10 years. Microbial alterations cause increased intestinal permeability, and the penetration of bacterial fragment and toxins induces local and systemic inflammatory processes, affecting distant organs, including the brain. Therefore, the integrity of the intestinal epithelial barrier plays a central role in the microbiota-gut-brain axis. In this review, we discuss recent findings on zonulin, an important tight junction regulator of intestinal epithelial cells, which is assumed to play a key role in maintaining of the blood-brain barrier function. In addition to focusing on the effect of microbiome on intestinal zonulin release, we also summarize potential pharmaceutical approaches to modulate zonulin-associated pathways with larazotide acetate and other zonulin receptor agonists or antagonists. The present review also addresses the emerging issues, including the use of misleading nomenclature or the unsolved questions about the exact protein sequence of zonulin.

Dynamic effects of probiotic formula ecologic®825 on human small intestinal ileostoma microbiota: a network theory approach

The gut microbiota plays a pivotal role in health and disease. The use of probiotics as microbiota-targeted therapies is a promising strategy to improve host health. However, the molecular mechanisms involved in such therapies are often not well understood, particularly when targeting the small intestinal microbiota. In this study, we investigated the effects of a probiotic formula (Ecologic®825) on the adult human small intestinal ileostoma microbiota. The results showed that supplementation with the probiotic formula led to a reduction in the growth of pathobionts, such as Enterococcaceae and Enterobacteriaceae, and a decrease in ethanol production. These changes were associated with significant alterations in nutrient utilization and resistance to perturbations. These probiotic mediated alterations which coincided with an initial increase in lactate production and decrease in pH were followed by a sharp increase in the levels of butyrate and propionate. Moreover, the probiotic formula increased the production of multiple N-acyl amino acids in the stoma samples. The study demonstrates the utility of network theory in identifying novel microbiota-targeted therapies and improving existing ones. Overall, the findings provide insights into the dynamic molecular mechanisms underlying probiotic therapies, which can aid in the development of more effective treatments for a range of conditions.

Synergy between oligosaccharides and probiotics: From metabolic properties to beneficial effects

Synbiotic is defined as the dietary mixture that comprises both probiotic microorganisms and prebiotic substrates. The concept has been steadily gaining attention owing to the rising recognition of probiotic, prebiotics, and gut health. Among prebiotic substances, oligosaccharides demonstrated considerable health beneficial effects in varieties of food products and their combination with probiotics have been subjected to full range of evaluations. This review delineated the landscape of studies using microbial cultures, cell lines, animal model, and human subjects to explore the functional properties and host impacts of these combinations. Overall, the results suggested that these combinations possess respective metabolic properties that could facilitate beneficial activities therefore could be employed as dietary interventions for human health improvement and therapeutic purposes. However, uncertainties, such as applicational practicalities, underutilized analytical tools, contradictory results in studies, unclear mechanisms, and legislation hurdles, still challenges the broad utilization of these combinations. Future studies to address these issues may not only advance current knowledge on probiotic-prebiotic-host interrelationship but also promote respective applications in food and nutrition.

Celiac Disease and Possible Dietary Interventions: From Enzymes and Probiotics to Postbiotics and Viruses

Celiac Disease (CeD) is a chronic small intestinal immune-mediated enteropathy caused by the ingestion of dietary gluten proteins in genetically susceptible individuals. CeD is one of the most common autoimmune diseases, affecting around 1.4% of the population globally. To date, the only acceptable treatment for CeD is strict, lifelong adherence to a gluten-free diet (GFD). However, in some cases, GFD does not alter gluten-induced symptoms. In addition, strict adherence to a GFD reduces patients’ quality of life and is often a socio-economic burden. This narrative review offers an interdisciplinary overview of CeD pathomechanism and the limitations of GFD, focusing on current research on possible dietary interventions. It concentrates on the recent research on the degradation of gluten through enzymes, the modulation of the microbiome, and the different types of “biotics” strategies, from probiotics to the less explored “viromebiotics” as possible beneficial complementary interventions for CeD management. The final aim is to set the context for future research that may consider the role of gluten proteins and the microbiome in nutritional and non-pharmacological interventions for CeD beyond the sole use of the GFD.

Celiac Disease and Possible Dietary Interventions: From Enzymes and Probiotics to Postbiotics and Viruses

Celiac Disease (CeD) is a chronic small intestinal immune-mediated enteropathy caused by the ingestion of dietary gluten proteins in genetically susceptible individuals. CeD is one of the most common autoimmune diseases, affecting around 1.4% of the population globally. To date, the only acceptable treatment for CeD is strict, lifelong adherence to a gluten-free diet (GFD). However, in some cases, GFD does not alter gluten-induced symptoms. In addition, strict adherence to a GFD reduces patients' quality of life and is often a socio-economic burden. This narrative review offers an interdisciplinary overview of CeD pathomechanism and the limitations of GFD, focusing on current research on possible dietary interventions. It concentrates on the recent research on the degradation of gluten through enzymes, the modulation of the microbiome, and the different types of "biotics" strategies, from probiotics to the less explored "viromebiotics" as possible beneficial complementary interventions for CeD management. The final aim is to set the context for future research that may consider the role of gluten proteins and the microbiome in nutritional and non-pharmacological interventions for CeD beyond the sole use of the GFD.

Lactobacillus paracasei BD5115-Derived 2-Hydroxy-3-Methylbutyric Acid Promotes Intestinal Epithelial Cells Proliferation by Upregulating the MYC Signaling Pathway

Metabolites of probiotics that are beneficial to human health have been isolated from the intestinal tract and natural dairy products. However, many studies on probiotics and prebiotics are limited to the observation of human cohorts and animal phenotypes. The molecular mechanisms by which metabolites of probiotics regulate health are still need further exploration. In this work, we isolated a strain of Lactobacillus Paracasei from human milk samples. We numbered it as Lactobacillus Paracasei BD5115. The mouse model of high-fat diet confirmed that the metabolites of this strain also promotes intestinal epithelial cells (IECs) proliferation. Single-cell sequencing showed that a bZIP transcription factor MAFF was specifically expressed in some IECs. We found that MAFF interacted with MBP1 to regulate the expression of MYC. Analysis of the active components in BD5115 metabolites confirmed that 2-hydroxy-3-methylbutyric acid promotes the expression of the MYC gene. This promotes the proliferation of IECs. Our findings indicate that 2-hydroxy-3-methylbutyric acid regulate MYC gene expression mediated by MAFF/MBP1 interaction. This study not only screened a strain with promoted IECs proliferation, but also discovered a new signal pathway that regulates MYC gene expression.

Overview of the Importance of Biotics in Gut Barrier Integrity

Increased gut permeability is suggested to be involved in the pathogenesis of a growing number of disorders. The altered intestinal barrier and the subsequent translocation of bacteria or bacterial products into the internal milieu of the human body induce the inflammatory state. Gut microbiota maintains intestinal epithelium integrity. Since dysbiosis contributes to increased gut permeability, the interventions that change the gut microbiota and correct dysbiosis are suggested to also restore intestinal barrier function. In this review, the current knowledge on the role of biotics (probiotics, prebiotics, synbiotics and postbiotics) in maintaining the intestinal barrier function is summarized. The potential outcome of the results from in vitro and animal studies is presented, and the need for further well-designed randomized clinical trials is highlighted. Moreover, we indicate the need to understand the mechanisms by which biotics regulate the function of the intestinal barrier. This review is concluded with the future direction and requirement of studies involving biotics and gut barrier.

Intestinal Barrier and Permeability in Health, Obesity and NAFLD

The largest surface of the human body exposed to the external environment is the gut. At this level, the intestinal barrier includes luminal microbes, the mucin layer, gastrointestinal motility and secretion, enterocytes, immune cells, gut vascular barrier, and liver barrier. A healthy intestinal barrier is characterized by the selective permeability of nutrients, metabolites, water, and bacterial products, and processes are governed by cellular, neural, immune, and hormonal factors. Disrupted gut permeability (leaky gut syndrome) can represent a predisposing or aggravating condition in obesity and the metabolically associated liver steatosis (nonalcoholic fatty liver disease, NAFLD). In what follows, we describe the morphological-functional features of the intestinal barrier, the role of major modifiers of the intestinal barrier, and discuss the recent evidence pointing to the key role of intestinal permeability in obesity/NAFLD.

The Effect of Bacterial Infections, Probiotics and Zonulin on Intestinal Barrier Integrity

The intestinal barrier plays an extremely important role in maintaining the immune homeostasis of the gut and the entire body. It is made up of an intricate system of cells, mucus and intestinal microbiota. A complex system of proteins allows the selective permeability of elements that are safe and necessary for the proper nutrition of the body. Disturbances in the tightness of this barrier result in the penetration of toxins and other harmful antigens into the system. Such events lead to various digestive tract dysfunctions, systemic infections, food intolerances and autoimmune diseases. Pathogenic and probiotic bacteria, and the compounds they secrete, undoubtedly affect the properties of the intestinal barrier. The discovery of zonulin, a protein with tight junction regulatory activity in the epithelia, sheds new light on the understanding of the role of the gut barrier in promoting health, as well as the formation of diseases. Coincidentally, there is an increasing number of reports on treatment methods that target gut microbiota, which suggests that the prevention of gut-barrier defects may be a viable approach for improving the condition of COVID-19 patients. Various bacteria-intestinal barrier interactions are the subject of this review, aiming to show the current state of knowledge on this topic and its potential therapeutic applications.

Leaky Gut: Effect of Dietary Fiber and Fats on Microbiome and Intestinal Barrier

Intestinal tract is the boundary that prevents harmful molecules from invading into the mucosal tissue, followed by systemic circulation. Intestinal permeability is an index for intestinal barrier integrity. Intestinal permeability has been shown to increase in various diseases-not only intestinal inflammatory diseases, but also systemic diseases, including diabetes, chronic kidney dysfunction, cancer, and cardiovascular diseases. Chronic increase of intestinal permeability is termed 'leaky gut' which is observed in the patients and animal models of these diseases. This state often correlates with the disease state. In addition, recent studies have revealed that gut microbiota affects intestinal and systemic heath conditions via their metabolite, especially short-chain fatty acids and lipopolysaccharides, which can trigger leaky gut. The etiology of leaky gut is still unknown; however, recent studies have uncovered exogenous factors that can modulate intestinal permeability. Nutrients are closely related to intestinal health and permeability that are actively investigated as a hot topic of scientific research. Here, we will review the effect of nutrients on intestinal permeability and microbiome for a better understanding of leaky gut and a possible mechanism of increase in intestinal permeability.

Using naso- and oro-intestinal catheters in physiological research for intestinal delivery and sampling in vivo: practical and technical aspects to be considered

Intestinal catheters have been used for decades in human nutrition, physiology, pharmacokinetics, and gut microbiome research, facilitating the delivery of compounds directly into the intestinal lumen or the aspiration of intestinal fluids in human subjects. Such research provides insights about (local) dynamic metabolic and other intestinal luminal processes, but working with catheters might pose challenges to biomedical researchers and clinicians. Here, we provide an overview of practical and technical aspects of applying naso- and oro-intestinal catheters for delivery of compounds and sampling luminal fluids from the jejunum, ileum, and colon in vivo. The recent literature was extensively reviewed, and combined with experiences and insights we gained through our own clinical trials. We included 60 studies that involved a total of 720 healthy subjects and 42 patients. Most of the studies investigated multiple intestinal regions (24 studies), followed by studies investigating only the jejunum (21 studies), ileum (13 studies), or colon (2 studies). The ileum and colon used to be relatively inaccessible regions in vivo. Custom-made state-of-the-art catheters are available with numerous options for the design, such as multiple lumina, side holes, and inflatable balloons for catheter progression or isolation of intestinal segments. These allow for multiple controlled sampling and compound delivery options in different intestinal regions. Intestinal catheters were often used for delivery (23 studies), sampling (10 studies), or both (27 studies). Sampling speed decreased with increasing distance from the sampling syringe to the specific intestinal segment (i.e., speed highest in duodenum, lowest in ileum/colon). No serious adverse events were reported in the literature, and a dropout rate of around 10% was found for these types of studies. This review is highly relevant for researchers who are active in various research areas and want to expand their research with the use of intestinal catheters in humans in vivo.

A multiple-strain probiotic product provides a better enzymatic antioxidant response in individuals with constipation in a double-blind randomized controlled trial

OBJECTIVES

Probiotics may have beneficial effects on intestinal dysbiosis. However, the effects of probiotics on redox and inflammatory responses in intestinal constipation remain unknown. The aim of this study was to investigate the effect of a multiple-strain probiotic on the redox and inflammatory responses in individuals with intestinal constipation.

METHODS

A randomized, double-blind, placebo controlled clinical trial was conducted with individuals diagnosed with constipation (defined according to the Rome IV criteria). The participants were randomized into two groups to receive either a probiotic capsule (PC; n = 25) containing probiotic strains or to receive a control capsule (CC; n = 20) containing a matching placebo for 30 d. In the baseline and at the end of the study, biomarkers of the redox (malondialdehyde, carbonylated protein, antioxidant enzymes, and ferric-reducing antioxidant power) and inflammatory responses, and Rome IV criteria for constipation were analyzed.

RESULTS

The consumption of a multiple-strain probiotic attenuated the reduction of glutathione peroxidase (PC = -9.41 and CC = -19.60; P = 0.041) and glutathione-s-transferase activity (PC = -3.28 and CC = -12.08, P < 0.0001) in erythrocytes and marginally improved the symptom of feeling incomplete defecation in ≥25% of bowel movements, compared with the placebo group. No changes were observed in total antioxidant capacity, oxidative damage, and levels of inflammatory markers in the serum.

CONCLUSIONS

Our data suggested that a multiple-strain probiotic may provide a better enzymatic antioxidant response and partially alleviate the feeling of incomplete defecation in ≥25% of bowel movements in individuals with intestinal constipation.

Effect of supplemental prebiotics, probiotics and bioactive proteins on the microbiome composition and fecal calprotectin in C57BL6/j mice

The composition and metabolic activity of the microbiome affect many aspects of health, and there is current interest in dietary constituents that may affect this system. The purpose of this study was to evaluate the effects of a mix of probiotics, a mix of prebiotics and a bioactive protein fraction on the microbiome, when fed to mice alone and in combination at physiologically relevant doses. Mice were fed the total western diet (TWD) supplemented with prebiotics, probiotics, and bioactive proteins individually and in combination for four weeks. Subsequently, effects on the composition of the gut microbiome, gut short-chain fatty acids (SCFAs) concentration, and gut inflammation were measured. Ruminococcus gnavus was increased in mice gut microbiome after feeding prebiotics. Bifidobacterium longum was increased after feeding probiotics. The treatments significantly affected beta-diversity with minor treatment effects on cecal or fecal SCFAs levels, and the treatments did not affect gut inflammation as measured by fecal calprotectin.

Human Intestinal Barrier: Effects of Stressors, Diet, Prebiotics, and Probiotics

The objectives of this article are to understand the effects of stressors (nonsteroidal antiinflammatory drug, exercise, and pregnancy) and components in the diet, specifically prebiotics and probiotics, on intestinal barrier function. Stressors generally reduce barrier function, and these effects can be reversed by supplements such as zinc or glutamine that are among the substances that enhance the barrier. Other dietary factors in the diet that improve the barrier are vitamins A and D, tryptophan, cysteine, and fiber; by contrast, ethanol, fructose, and dietary emulsifiers increase permeability. Effects of prebiotics on barrier function are modest; on the other hand, probiotics exert direct and indirect antagonism of pathogens, and there are documented effects of diverse probiotic species, especially combination agents, on barrier function in vitro, in vivo in animal studies, and in human randomized controlled trials conducted in response to stress or disease. Clinical observations of benefits with combination probiotics in inflammatory diseases have simultaneously not appraised effects on intestinal permeability. In summary, probiotics and synbiotics enhance intestinal barrier function in response to stressor or disease states. Future studies should address the changes in barrier function and microbiota concomitant with assessment of clinical outcomes.

Probiotic Treatment in Individuals with Euthymic Bipolar Disorder: A Pilot-Study on Clinical Changes and Compliance

The importance of the microbiome for psychological well-being has gained rising interest in the last decade. A strategy to examine the role of the microbiome in different diseases is the intake of supplements that modulate the gut microbiome. Despite promising results in animal studies, research in humans is sparse to date and especially in individuals with psychiatric disorders almost missing. The current report of the ProbioBIP-one pilot study aims at describing general effects of the intake of the probiotic OMNi-BiOTiC Stress repair® on psychological parameters as well as gastrointestinal symptoms and general compliance in a cohort of euthymic individuals with bipolar disorder (BD), receiving daily probiotic treatment over a time period of 3 months. Twenty-seven individuals with BD took part in the present study (mean age = 50.7 years, SD = 12.2; females 40.7%). In sum, there was a high compliance rate with 81.5% of the study participants completing all 3 study visits and 85% of planned probiotic ingestions taken. Gastrointestinal problems were prevalent in more than half of the patients at the time of inclusion (t1). Expectedly, in the whole cohort, a high proportion of study participants experienced changes concerning digestion during probiotic treatment, around one third reported positive changes (reduced flatulence and easier and more frequent bowel movements) after 1 month (t2) and further after 3 months (t3). In contrast, a smaller part of study participants reported gastrointestinal discomfort after 1 and after 3 months (mainly flatulence and obstipation). We found a significantly reduced cognitive reactivity to sad mood between t2 and t3 indicating that participants under probiotic supplementation perceived themselves to be less distracted by ruminative thoughts. Further changes in psychiatric symptoms were small due to the euthymic state and already low scoring at the time of inclusion. Nevertheless, we found a significant symptom reduction in the rating scales measuring manic symptoms. From a clinical point of view, probiotic supplementation might provide a well-tolerated tool to positively influence gastrointestinal quality of life as well as mental and somatic health, cognition and immune response and potentially have effects on psychiatric symptoms.

Effects of dietary components on intestinal permeability in health and disease

Altered intestinal permeability plays a role in many pathological conditions. Intestinal permeability is a component of the intestinal barrier. This barrier is a dynamic interface between the body and the food and pathogens that enter the gastrointestinal tract. Therefore, dietary components can directly affect this interface, and many metabolites produced by the host enzymes or the gut microbiota can act as signaling molecules or exert direct effects on this barrier. Our aim was to examine the effects of diet components on the intestinal barrier in health and disease states. Herein, we conducted an in-depth PubMed search based on specific key words (diet, permeability, barrier, health, disease, and disorder), as well as cross references from those articles. The normal intestinal barrier consists of multiple components in the lumen, epithelial cell layer and the lamina propria. Diverse methods are available to measure intestinal permeability. We focus predominantly on human in vivo studies, and the literature is reviewed to identify dietary factors that decrease (e.g., emulsifiers, surfactants, and alcohol) or increase (e.g., fiber, short-chain fatty acids, glutamine, and vitamin D) barrier integrity. Effects of these dietary items in disease states, such as metabolic syndrome, liver disease, or colitis are documented as examples of barrier dysfunction in the multifactorial diseases. Effects of diet on intestinal barrier function are associated with precise mechanisms in some instances; further research of those mechanisms has potential to clarify the role of dietary interventions in treating diverse pathologic states.

Effect of multispecies probiotic on gut microbiota composition in individuals with intestinal constipation: A double-blind, placebo-controlled randomized trial

OBJECTIVE

The aim of this study was to evaluate the effect of a multispecies probiotic on gut microbiota composition and constipation symptoms.

METHODS

A randomized, double-blind, placebo-controlled clinical trial was conducted with 35 individuals with constipation for 30 days. The individuals were randomized into two groups: the control capsule (CC) and the probiotic capsule (PC) groups. Constipation symptoms were evaluated by the ROME IV criteria and by evacuation diaries. Fecal microbiota was analyzed by 16 S rRNA gene sequencing.

RESULTS

The majority of participants were women (85.7%). There was a significant reduction in the percent of participants who had incomplete defecation (P = 0.034), blockage sensation (P = 0.025), and rarely present liquid stools without the aid of laxatives (P = 0.046) only within the PC group (but no significant difference between groups). There was a significant increase in the relative abundance percentage of Blautia faecis and Ruminococcus torques in the CC group (P = 0.003 and P = 0.011, respectively), although there was no significant change in the PC group (P = 0.794 and P = 0.958, respectively), with a significant difference between groups (P = 0.029 and P 0.013, respectively), suggesting that probiotic treatment prevented the increase of percent relative abundance of these two species.

CONCLUSION

These results suggest that multispecies probiotics in capsule form may modulate gut microbiota by reducing the bacteria that are commonly increased in patients with constipation, contributing to the balance of microbiota and, consequently, to the well-being of the individual. Future studies with larger numbers of patients are required.

The Effects of Probiotic/Synbiotic on Serum Level of Zonulin as a Biomarker of Intestinal Permeability: A Systematic Review and Meta-Analysis

Background:

This systematic review and meta-analysis was conducted to obtain a conclusive result on the influence of probiotics/synbiotic on serum levels of zonulin. Data related to serum levels of zonulin were extracted to determine the effects of probiotic/synbiotic on intestinal permeability.

Methods:

The literature search was conducted across the Cochrane Central Register of Controlled Trials, Pub-Med, Scopus and ISI Web of Science, Search up to Nov 2018. Clinical trials evaluating the effect of probiotic/synbiotic on serum zonulin levels of all human subjects were included.

Results:

Nine studies (including 496 intervention and 443 control subjects) met the inclusion criteria for the meta-analysis. According to the meta-analysis, probiotic/synbiotic has a significant effect on serum zonulin reduction (WMD=−10.55 [95% CI: −17.76, −3.34]; P=0.004). However, the high level of heterogeneity was observed among the studies (I²=97.8, P<0.001). The subgroup analysis suggested study quality, blinding, study duration, Participants age, subject’s health status and supplement type as sources of heterogeneity.

Conclusion:

Probiotic/synbiotic have favorable effects on serum levels of zonulin as a measure of intestinal permeability. However, the results should be interpreted with caution due to the high heterogeneity and further evidence is required before definitive recommendations can be made.

Intestinal Permeability in Children with Celiac Disease after the Administration of Oligofructose-Enriched Inulin into a Gluten-Free Diet-Results of a Randomized, Placebo-Controlled, Pilot Trial

Abnormalities in the intestinal barrier are a possible cause of celiac disease (CD) development. In animal studies, the positive effect of prebiotics on the improvement of gut barrier parameters has been observed, but the results of human studies to date remain inconsistent. Therefore, this study aimed to evaluate the effect of twelve-week supplementation of a gluten-free diet (GFD) with prebiotic oligofructose-enriched inulin (10 g per day) on the intestinal permeability in children with CD treated with a GFD. A pilot, randomized, placebo-controlled nutritional intervention was conducted in 34 children with CD, being on a strict GFD. Sugar absorption test (SAT) and the concentrations of intestinal permeability markers, such as zonulin, intestinal fatty acid-binding protein, claudin-3, calprotectin, and glucagon-like peptide-2, were measured. We found that the supplementation with prebiotic did not have a substantial effect on barrier integrity. Prebiotic intake increased excretion of mannitol, which may suggest an increase in the epithelial surface. Most children in our study seem to have normal values for intestinal permeability tests before the intervention. For individuals with elevated values, improvement in calprotectin and SAT was observed after the prebiotic intake. This preliminary study suggests that prebiotics may have an impact on the intestinal barrier, but it requires confirmation in studies with more subjects with ongoing leaky gut.

Muscone/RI7217 co-modified upward messenger DTX liposomes enhanced permeability of blood-brain barrier and targeting glioma

Rationale: The dual-targeted drug delivery system was designed for enhancing permeation of the blood-brain barrier (BBB) and providing an anti-glioma effect. As transferrin receptor (TfR) is over-expressed by the brain capillary endothelial (hCMEC/D3) and glioma cells, a mouse monoclonal antibody, RI7217, with high affinity and selectivity for TfR, was used to study the brain targeted drug delivery system. Muscone, an ingredient of traditional Chinese medicine (TCM) musk, was used as the "guide" drug to probe the permeability of the BBB for drug delivery into the cerebrospinal fluid. This study investigated the combined effects of TCM aromatic resuscitation and modern receptor-targeted technology by the use of muscone/RI7217 co-modified docetaxel (DTX) liposomes for enhanced drug delivery to the brain for anti-glioma effect. Methods: Cellular drug uptake from the formulations was determined using fluorescence microscopy and flow cytometry. The drug penetrating ability into tumor spheroids were visualized using confocal laser scanning microscopy (CLSM). In vivo glioma-targeting ability of formulations was evaluated using whole-body fluorescent imaging system. The survival curve study was performed to evaluate the anti-glioma effect of the formulations. Results: The results showed that muscone and RI7217 co-modified DTX liposomes enhanced uptake into both hCMEC/D3 and U87-MG cells, increased penetration to the deep region of U87-MG tumor spheroids, improved brain targeting in vivo and prolonged survival time of nude mice bearing tumor. Conclusion: Muscone and RI7217 co-modified DTX liposomes were found to show improved brain targeting and enhanced the efficacy of anti-glioma drug treatment in vivo.

Intestinal barrier function is maintained with aging - a comprehensive study in healthy subjects and irritable bowel syndrome patients

Animal studies have shown that intestinal barrier function is compromised with aging. We aimed to assess the effects of aging on intestinal barrier function in humans in vivo and ex vivo. In this cross-sectional study, healthy subjects and subjects with irritable bowel syndrome (IBS) of older (65–75 years) and young adult age (18–40 years) were compared. In vivo gastrointestinal site-specific permeability was assessed by a multi-sugar test, taking into account potential confounders. Sigmoid biopsies were collected from subgroups of healthy young adults and elderly for ex vivo Ussing chamber experiments, gene transcription of barrier-related genes and staining of junctional proteins. No significant differences between healthy young adults and elderly were found for small intestinal, colonic and whole gut permeability (P ≥ 0.142). In IBS patients, gastroduodenal and colonic permeability did not differ significantly (P ≥ 0.400), but small intestinal and whole gut permeability were higher in elderly versus young adults (P ≤ 0.009), mainly driven by the IBS-diarrhea subtype. Ussing chamber experiments with or without stressor (P ≥ 0.052), and relative expression of intestinal barrier-related genes (P ≥ 0.264) showed no significant differences between healthy elderly and young adults, as confirmed by immunofluorescent stainings. Overall, the functional capacity of the intestinal barrier is maintained in elderly.

Yeast fermentate prebiotic improves intestinal barrier integrity during heat stress by modulation of the gut microbiota in rats

Aims

To evaluate efficacy of Saccharomyces cerevisiae fermentate prebiotic (EH) in protection of intestinal barrier integrity in rats during heat stress, to analyze the impact of heat stress and preventive treatment with EH on the structure of the gut microbiota.

Methods and Results

Two groups of rats were treated orally with EH or phosphate‐buffered saline for 14 days. On day 15, half of the rats in each group were exposed to heat stress conditions, while control animals were kept at room temperature. Histological and Western blot analyses of the intestine, culture‐based microbiological analysis and high‐throughput 16S rRNA sequencing for the gut microbiota were performed for each rat. Exposure of animals to heat stress conditions resulted in inhibition of tight junction (TJ) proteins expression, decrease of Paneth and goblet cells, decrease of beneficial and increase of pathogenic bacteria. Oral treatment of rats with EH before stress significantly prevents these adverse effects by elevation of the gut beneficial bacteria, particularly butyrate‐producing bacteria.

Conclusions

Essential effect of EH in protection of intestinal barrier integrity during heat stress is connected with beneficial modulation of the gut microbiota.

Significance and Impact of the Study

Our results will contribute to the development of new approaches to prevention of heat stress‐related complications.

Role for diet in normal gut barrier function: developing guidance within the framework of food-labeling regulations

A reduction in intestinal barrier function is currently believed to play an important role in pathogenesis of many diseases, as it facilitates passage of injurious factors such as lipopolysaccharide, peptidoglycan, whole bacteria, and other toxins to traverse the barrier to damage the intestine or enter the portal circulation. Currently available evidence in animal models and in vitro systems has shown that certain dietary interventions can be used to reinforce the intestinal barrier to prevent the development of disease. The relevance of these studies to human health is unknown. Herein, we define the components of the intestinal barrier, review available modalities to assess its structure and function in humans, and review the available evidence in model systems or perturbations in humans that diet can be used to fortify intestinal barrier function. Acknowledging the technical challenges and the present gaps in knowledge, we provide a conceptual framework by which evidence could be developed to support the notion that diet can reinforce human intestinal barrier function to restore normal function and potentially reduce the risk for disease. Such evidence would provide information on the development of healthier diets and serve to provide a framework by which federal agencies such as the US Food and Drug Administration can evaluate evidence linking diet with normal human structure/function claims focused on reducing risk of disease in the general public.

Synergistic and antagonistic interactions between antibiotics and synbiotics in modifying the murine fecal microbiome

Purpose

Pro- and synbiotics have been reported to ameliorate the adverse (dysbiotic) effects of antibiotics on the gut microbial architecture, but little is known how synbiotics and antibiotics interact with each other in shaping the gut microbiota. To explore this mutual interaction we examined, first, the effect of a multi-strain synbiotic on antibiotic-induced dysbiosis and, second, the dysbiotic effect of antibiotics followed by prolonged synbiotic exposure.

Methods

The synbiotic containing nine bacterial strains was administered to male mice via the drinking water, while the antibiotic mix containing bacitracin, meropenem, neomycin, and vancomycin was administered via oral gavage. Two experimental protocols were used. In protocol 1, mice were administered placebo or synbiotic for 3 weeks prior to and during an 11-day vehicle or antibiotic treatment. In protocol 2 the synbiotic was administered for a prolonged period of time, starting 3 weeks prior and continuing for 12 weeks after an 11-day vehicle or antibiotic treatment. Subsequently, the fecal microbiome was analyzed by 16S rRNA sequencing using oligonucleotide primers 16s_515_S3_fwd: GATTGCCAGCAGCCGCGGTAA and 16s_806_S2_rev: GGACTACCAGGGTATCTAAT followed by sequencing using the Ion Torrent One. The final sequence files were analyzed by QIIME 1.8 workflow scripts.

Results

Antibiotic treatment markedly decreased the bacterial richness and diversity of the fecal microbiota. Synbiotic administration for 3 weeks prior to and during an 11-day antibiotic treatment preserved the Lactobacillales and expanded the Verrucomicrobiales and Bifidobacteriales order, but did not prevent the depletion of Bacteroidales and the short-term proliferation of Enterobacteriales. When the synbiotic administration was continued for 12 weeks after the end of antibiotic treatment, the rise of Verrucomicrobiales was maintained, whereas the preservation of Lactobacillales and boost of Bifidobacteriales was lost. The abundance of Clostridiales was enhanced by long-term synbiotic treatment after short-term exposure to antibiotics, while the antibiotic-depleted Bacteroidales underwent a delayed recovery.

Conclusions

There are complex synergistic and antagonistic interactions of synbiotics and antibiotics in influencing distinct bacterial orders of the fecal microbiota. The impact of a short-term antibiotic exposure is profoundly different when analyzed after synbiotic pretreatment or following prolonged synbiotic administration in the post-antibiotic period.

Effect of probiotic and synbiotic supplementation on inflammatory markers in health and disease status: A systematic review and meta-analysis of clinical trials

The current systematic review and meta-analysis investigated the effect of probiotic/synbiotic on a wide range of inflammatory and anti-inflammatory markers in healthy and various disease conditions. PubMed, SCOPUS and Web of Science databases were searched. All clinical trials which investigated the effect of oral administration of probiotic or synbiotic on inflammatory markers (C-reactive protein (CRP), interleukin (IL) 1β, IL-4, IL-6, IL-8, IL-10, IL-12, tumor necrosis factor (TNF) α, interferon (IFN) γ and transforming growth factor (TGF) β) for more than one week with concurrent control groups were included. One-hundred sixty seven publications was analysed. Results were as follows: CRP decreased in healthy, metabolic disorders, inflammatory bowel disease (IBD), arthritis and critically ill condition but not in renal failure. IL-1B: no change in healthy subjects and arthritis. TNF-α: decreased in healthy, fatty liver, IBD and hepatic cirrhosis, no change in diabetes, metabolic syndrome (MS) + PCOS (polycystic ovary syndrome) and arthritis. IL-6: no change in healthy, metabolic disorders and arthritis, increased in cirrhosis and renal failure, decreased in PCOS + MS. IL-10: no change in healthy, IBD and metabolic disorders, increased in arthritis. IL-4, IL-8, IL-12, IFN-g and TGF-b: no change in healthy subjects. In conclusion, probiotic/synbiotic decreased some of the inflammatory markers. The intervention was most effective in CRP and TNF-α reduction in healthy or disease state. Moreover, the intervention decreased inflammation most effectively in the following disease conditions, respectively: IBD, arthritis, fatty liver. PROSPERO REGISTRATION NUMBER: CRD42018088688.

The Profile of Urinary Headspace Volatile Organic Compounds After 12-Week Intake of Oligofructose-Enriched Inulin by Children and Adolescents with Celiac Disease on a Gluten-Free Diet: Results of a Pilot, Randomized, Placebo-Controlled Clinical Trial

The concentration of volatile organic compounds (VOCs) can inform about the metabolic condition of the body. In the small intestine of untreated persons with celiac disease (CD), chronic inflammation can occur, leading to nutritional deficiencies, and consequently to functional impairments of the whole body. Metabolomic studies showed differences in the profile of VOCs in biological fluids of patients with CD in comparison to healthy persons; however, there is scarce quantitative and nutritional intervention information. The aim of this study was to evaluate the effect of the supplementation of a gluten-free diet (GFD) with prebiotic oligofructose-enriched inulin (Synergy 1) on the concentration of VOCs in the urine of children and adolescents with CD. Twenty-three participants were randomized to the group receiving Synergy 1 (10 g per day) or placebo for 12 weeks. Urinary VOCs were analyzed using solid-phase microextraction and gas chromatography⁻mass spectrometry. Sixteen compounds were identified and quantified in urine samples. The supplementation of GFD with Synergy 1 resulted in an average concentration drop (36%) of benzaldehyde in urine samples. In summary, Synergy 1, applied as a supplement of GFD for 12 weeks had a moderate impact on the VOC concentrations in the urine of children with CD.

Intestinal Permeability Measured by Urinary Sucrose Excretion Correlates with Serum Zonulin and Faecal Calprotectin Concentrations in UC Patients in Remission

Background and Aims

Ulcerative colitis (UC) is associated with an increased intestinal permeability, possibly through a dysbiosis of intestinal bacteria. We investigated which markers are most relevant to assess intestinal permeability in UC patients and whether probiotics had an effect on these markers.

Methods

In this twelve-week placebo-controlled randomized double-blind study, twenty-five subjects with UC in remission received either placebo or a multispecies probiotics. Samples of blood, urine, and faeces were taken at baseline, week 6, and week 12 to assess intestinal permeability and inflammation. Diaries and Bristol stool scale were kept to record stool frequency and consistency. Quality of life was scored from 32–224 with the inflammatory bowel disease questionnaire (IBD-Q).

Results

This group of UC patients, in clinical remission, did not show increased intestinal permeability at baseline of this study. During the study, no significant group or time effects were found for intestinal permeability measured by the 5-sugar absorption test, serum zonulin, and faecal zonulin. Likewise, the inflammatory markers C-reactive protein (CRP), calprotectin, and the cytokines IFNγ, TNFα, IL-6, and IL-10 were not significantly affected. Stool frequency and consistency were not significantly affected either. The IBD-Q score, 194 for the probiotics group and 195 for the placebo group, remained unaffected. Correlations were tested between all outcomes; urinary sucrose excretion was significantly correlated with serum zonulin (r = 0.62) and faecal calprotectin (r = 0.55). Faecal zonulin was not significantly correlated with any of the other markers.

Conclusion

Serum zonulin may be a more relevant biomarker of intestinal permeability than faecal zonulin, due to its correlation with other biomarkers of intestinal permeability. UC patients in remission did not show an effect of the probiotic treatment or a change in gut permeability. This should not discourage further studies because effects might be present during active disease or shortly after a flare up.

Synbiotics for Improved Human Health: Recent Developments, Challenges, and Opportunities

Research on combining pro- and prebiotics as synbiotics to enhance human and animal health has accelerated in the past 10 years, including many clinical trials that have assessed a diverse range of synbiotic formulations. In this review, we summarize these studies as well as the commercial applications of synbiotics that are available. In particular, we critically assess the claimed health benefits of synbiotic applications and the ecological and therapeutic factors to consider when designing synbiotics and discuss the implications of these concepts for future research in this field.

Oral Supplementation with Bovine Colostrum Decreases Intestinal Permeability and Stool Concentrations of Zonulin in Athletes

Increased intestinal permeability has been implicated in various pathologies, has various causes, and can develop during vigorous athletic training. Colostrum bovinum is a natural supplement with a wide range of supposed positive health effects, including reduction of intestine permeability. We assessed influence of colostrum supplementation on intestinal permeability related parameters in a group of 16 athletes during peak training for competition. This double-blind placebo-controlled study compared supplementation for 20 days with 500 mg of colostrum bovinum or placebo (whey). Gut permeability status was assayed by differential absorption of lactulose and mannitol (L/M test) and stool zonulin concentration. Baseline L/M tests found that six of the participants (75%) in the colostrum group had increased intestinal permeability. After supplementation, the test values were within the normal range and were significantly lower than at baseline. The colostrum group Δ values produced by comparing the post-intervention and baseline results were also significantly lower than the placebo group Δ values. The differences in stool zonulin concentration were smaller than those in the L/M test, but were significant when the Δ values due to intervention were compared between the colostrum group and the placebo group. Colostrum bovinum supplementation was safe and effective in decreasing of intestinal permeability in this series of athletes at increased risk of its elevation.