Neuroimmunophysiology of the gastrointestinal tract.

Gut physiology is the epicenter of a web of internal communication systems (i.e., neural, immune, hormonal) mediated by cell-cell contacts, soluble factors, and external influences, such as the microbiome, diet, and the physical environment. Together these provide the signals that shape enteric homeostasis and, when they go awry, lead to disease. Faced with the seemingly paradoxical tasks of nutrient uptake (digestion) and retarding pathogen invasion (host defense), the gut integrates interactions between a variety of cells and signaling molecules to keep the host nourished and protected from pathogens. When the system fails, the outcome can be acute or chronic disease, often labeled as "idiopathic" in nature (e.g., irritable bowel syndrome, inflammatory bowel disease). Here we underscore the importance of a holistic approach to gut physiology, placing an emphasis on intercellular connectedness, using enteric neuroimmunophysiology as the paradigm. The goal of this opinion piece is to acknowledge the pace of change brought to our field via single-cell and -omic methodologies and other techniques such as cell lineage tracing, transgenic animal models, methods for culturing patient tissue, and advanced imaging. We identify gaps in the field and hope to inspire and challenge colleagues to take up the mantle and advance awareness of the subtleties, intricacies, and nuances of intestinal physiology in health and disease by defining communication pathways between gut resident cells, those recruited from the circulation, and "external" influences such as the central nervous system and the gut microbiota.

Impact of short-chain fatty acid supplementation on gut inflammation and microbiota composition in a murine colitis model.

Short-chain fatty acids (SCFAs) play a pivotal role in maintaining intestinal homeostasis. We aimed to investigate the effects of SCFA supplementation on gut inflammation and microbiota composition in a murine colitis model. Mice were fed with sodium butyrate or a mixture of SCFAs in the drinking water for 2 weeks, followed by 2% dextran sulfate sodium (DSS) for 7 d. After euthanasia, mouse colons were extracted to examine histological findings. Flow cytometry of the mouse colon tissues was performed to assess T cell differentiation. Changes in gut microbiota were assessed by high-throughput sequencing of the mouse feces. There were no significant differences in weight change, colonic length, or histologic inflammation score between the DSS, butyrate, and SCFA mix groups. However, flow cytometry revealed that both the expression of CD4+Foxp3+ regulatory T cells and of IL-17-producing T cells were increased in the butyrate and SCFA mix groups. Microbial compositions of the butyrate and SCFA mix groups were significantly different from those of the control and DSS groups in principal coordinate analysis. Relative abundances of the phyla Verrucomicrobia and Proteobacteria, species Akkermansia muciniphila and Escherichia fergusonii were increased in the butyrate and SCFA mix groups. Genera Roseburia and Lactobacillus showed a negative correlation with the degree of colitis, whereas genera Escherichia and Mucispirillum showed a positive correlation. SCFA supplementation did not result in a significant reduction in colon inflammation, but it promoted both regulatory T cell and IL-17-producing T cell expression, and increased both protective and aggressive gut microbiota.

Modulating host gene expression via gut microbiome-microRNA interplay to treat human diseases.

The human gastrointestinal (GI) tract hosts trillions of microbial inhabitants involved in maintaining intestinal homeostasis, dysbiosis of which provokes a motley of pathogenic and autoimmune disorders. While the mechanisms by which the microbiota modulates human health are manifold, their liberated metabolites from ingested dietary supplements play a crucial role by bidirectionally regulating the expression of micro-ribonucleic acids (miRNAs). miRNAs are small endogenous non-coding RNAs (ncRNAs) that have been confirmed to be involved in an interplay with microbiota to regulate host gene expression. This comprehensive review focuses on key principles of miRNAs, their regulation, and crosstalk with gut microbiota to influence host gene expression in various human disorders, by bringing together important recent findings centric around miRNA-microbiota interactions in diseases along various axis of the gut with other organs. We also attempt to lay emphasis on exploiting the avenues of gut-directed miRNA therapeutics using rudimentary dietary supplements to regulate abnormal host gene expression in diseases, opening doors to an accessible and economical therapeutic strategy.

Timing of Tributyrin Supplementation Differentially Modulates Gastrointestinal Inflammation and Gut Microbial Recolonization Following Murine Ileocecal Resection.

BACKGROUND: Gastrointestinal surgery imparts dramatic and lasting imbalances, or dysbiosis, to the composition of finely tuned microbial ecosystems. The aim of the present study was to use a mouse ileocecal resection (ICR) model to determine if tributyrin (TBT) supplementation could prevent the onset of microbial dysbiosis or alternatively enhance the recovery of the gut microbiota and reduce gastrointestinal inflammation. METHODS: Male wild-type (129 s1/SvlmJ) mice aged 8-15 weeks were separated into single cages and randomized 1:1:1:1 to each of the four experimental groups: control (CTR), preoperative TBT supplementation (PRE), postoperative TBT supplementation (POS), and combined pre- and postoperative supplementation (TOT). ICR was performed one week from baseline assessment with mice assessed at 1, 2, 3, and 4 weeks postoperatively. Primary outcomes included evaluating changes to gut microbial communities occurring from ICR to 4 weeks. RESULTS: A total of 34 mice that underwent ICR (CTR n = 9; PRE n = 10; POS n = 9; TOT n = 6) and reached the primary endpoint were included in the analysis. Postoperative TBT supplementation was associated with an increased recolonization and abundance of anaerobic taxa including Bacteroides thetaiotomicorn, Bacteroides caecimuris, Parabacteroides distasonis, and Clostridia. The microbial recolonization of PRE mice was characterized by a bloom of aerotolerant organisms including Staphylococcus, Lactobacillus, Enteroccaceae, and Peptostreptococcacea. PRE mice had a trend towards decreased ileal inflammation as evidenced by decreased levels of IL-1ß (p = 0.09), IL-6 (p = 0.03), and TNF-α (p < 0.05) compared with mice receiving TBT postoperatively. In contrast, POS mice had trends towards reduced colonic inflammation demonstrated by decreased levels of IL-6 (p = 0.07) and TNF-α (p = 0.07). These changes occurred in the absence of changes to fecal short-chain fatty acid concentrations or histologic injury scoring. CONCLUSIONS: Taken together, the results of our work demonstrate that the timing of tributyrin supplementation differentially modulates gastrointestinal inflammation and gut microbial recolonization following murine ICR.

The Immunomodulatory Properties of ß-2,6 Fructans: A Comprehensive Review.

Polysaccharides such as ß-2,1-linked fructans including inulin or fructose oligosaccharides are well-known prebiotics with recognised immunomodulatory properties. In recent years, other fructan types covering ß-2,6-linked fructans, particularly microbial levans, have gained increasing interest in the field. ß-2,6-linked fructans of different degrees of polymerisation can be synthesised by plants or microbes including those that reside in the gastrointestinal tract. Accumulating evidence suggests a role for these ß-2,6 fructans in modulating immune function. Here, we provide an overview of the sources and structures of ß-2,6 fructans from plants and microbes and describe their ability to modulate immune function in vitro and in vivo along with the suggested mechanisms underpinning their immunomodulatory properties. Further, we discuss the limitations and perspectives pertinent to current studies and the potential applications of ß-2,6 fructans including in gut health.

Examining the Gastrointestinal and Immunomodulatory Effects of the Novel Probiotic Bacillus subtilis DE111.

Probiotics make up a large and growing segment of the commercial market of dietary supplements and are touted as offering a variety of human health benefits. Some of the purported positive impacts of probiotics include, but are not limited to, stabilization of the gut microbiota, prevention of gastrointestinal disorders and modulation of the host immune system. Current research suggests that the immunomodulatory effects of probiotics are strain-specific and vary in mode of action. Here, we examined the immunomodulatory properties of Bacillus subtilis strain DE111 in a healthy human population. In a pilot randomized, double blind, placebo-controlled four-week intervention, we examined peripheral blood mononuclear cells (PBMCs) at basal levels pre- and post-intervention, as well as in response to stimulation with bacterial lipopolysaccharide (LPS). We observed an increase in anti-inflammatory immune cell populations in response to ex vivo LPS stimulation of PBMCs in the DE111 intervention group. Overall perceived gastrointestinal health, microbiota, and circulating and fecal markers of inflammation (Il-6, sIgA) and gut barrier function (plasma zonulin) were largely unaffected by DE111 intervention, although the study may have been underpowered to detect these differences. These pilot data provide information and justification to conduct an appropriately powered clinical study to further examine the immunomodulatory potential of B. subtilis DE111 in human populations.

[Orexin A as mediator in the gut-brain dialogue]. / Orexina A como mediadora en el diálogo intestino-cerebro.

INTRODUCTION: The orexinergic system is one of the chemical mediators that modulate the gut-brain axis, given the involvement of hypothalamic orexin A (OXA) in gastrointestinal motility and secretion, and the presence of OXA in enteroendocrine cells of the intestinal mucosa and in primary afferent neurons of the mesenteric plexus, permitting its participation in gut-brain signaling. AIM: The source of OXA and the signal(s) triggering its peripheral release are not fully understood, and it is not known whether it acts on orexigenic receptors in peripheral tissues to meet physiological or pathological demands. The aim of this review is to address these questions in the light of new data indicating that OXA may have functions in the gut-brain axis that go beyond its participation in energy homeostasis. DEVELOPMENT: OXA in the enteric system protects against systemic and central inflammation, and hypothalamic OXA orchestrates numerous peripheral effects to suppress the systemic inflammatory response. For this reason, OXA may act as an immunomodulator in chronic inflammations or autoimmune diseases. OXA is also involved in the stress response, regulating physiological responses to emotional or stressful stimuli. CONCLUSIONS: OXA exerts anti-inflammatory and gastroprotective effects on the intestinal mucosa; however, it may increase the response to external and/or internal stress in individuals with chronic inflammation, exacerbating the gastrointestinal inflammation. Hence, pharmacologic interventions in the orexinergic system have been proposed to treat diseases in which intestinal hypersensitivity is combined with appetite loss, sleep disturbance, stress, and anxiety.

TITLE: Orexina A como mediadora en el diálogo intestino-cerebro.Introducción. Entre los mediadores químicos que modulan el eje intestino-cerebro debe incluirse el sistema orexinérgico, ya que la orexina A (OXA) hipotalámica interviene en la motilidad y en la secreción gastrointestinal. También está presente en las células enteroendocrinas de la mucosa intestinal y en las neuronas aferentes primarias del plexo mientérico, y puede intervenir en la señalización intestino-cerebro. Objetivo. No se conoce con exactitud la fuente ni la señal que originan la liberación de OXA periférica, ni tampoco si actúa en los receptores orexinérgicos de los tejidos periféricos ante demandas fisiológicas o patológicas. Esta revisión intenta analizar estas cuestiones a la luz de nuevos datos que indican que la OXA en el eje intestino-cerebro puede tener funciones más allá de su participación en la homeostasis energética. Desarrollo. La OXA en el sistema entérico protege de la inflamación sistémica y central, y en el hipotálamo orquesta numerosos efectos periféricos para suprimir la respuesta inflamatoria sistémica. Por ello, podría actuar como sustancia inmunomoduladora en inflamaciones crónicas o en enfermedades autoinmunitarias. La OXA también se relaciona con la respuesta de estrés, regulando las respuestas fisiológicas a estímulos emocionales o estresantes. Conclusiones. Aunque la OXA tiene efectos antiinflamatorios y gastroprotectores de la mucosa intestinal, en procesos de inflamación crónica podría incrementar la respuesta a estímulos estresantes, tanto externos como internos, y exacerbar la inflamación gastrointestinal. Por ello, se han propuesto intervenciones farmacológicas sobre el sistema orexinérgico como tratamiento para enfermedades en las que la hipersensibilidad intestinal coexiste con pérdida de apetito, alteraciones del sueño, estrés y ansiedad.

Impact of in-feed sodium butyrate or sodium heptanoate protected with medium-chain fatty acids on gut health in weaned piglets challenged with Escherichia coli F4.

Short and medium-chain fatty acids (SCFA and MCFA, respectively) are commonly used as feed additives in piglets to promote health and prevent post-weaning diarrhoea. Considering that the mechanism and site of action of these fatty acids can differ, a combined supplementation could result in a synergistic action. Considering this, it was aimed to assess the potential of two new in-feed additives based on butyrate or heptanoate, protected with sodium salts of MCFA from coconut distillates, against enterotoxigenic Escherichia coli (ETEC) F4+ using an experimental disease model. Two independent trials were performed in 48 early-weaned piglets fed a control diet (CTR) or a diet supplemented with MCFA-protected sodium butyrate (BUT+; Trial 1) or sodium heptanoate (HPT+; Trial 2). After 1 week of adaptation, piglets were challenged with a single oral inoculum of ETEC F4+ (minimum 1.4 · 109 cfu). One animal per pen was euthanised on days 4 and 8 post-inoculation (PI) and the following variables assessed: growth performance, clinical signs, gut fermentation, intestinal morphology, inflammatory mediators, pathogen excretion and colon microbiota. None of the additives recovered growth performance or reduced diarrhoea when compared to the respective negative controls. However, both elicited different responses against ETEC F4+. The BUT+ additive did not lead to reduce E. coli F4 colonisation but enterobacterial counts and goblet cell numbers in the ileum were increased on day 8 PI and this followed higher serum TNF-α concentrations on day 4 PI. The Firmicutes:Bacteroidetes ratio was nevertheless increased. Findings in the HPT+ treatment trial included fewer animals featuring E. coli F4 in the colon and reduced Enterobacteriaceae (determined by 16S RNA sequencing) on day 4 PI. In addition, while goblet cell numbers were lower on day 8 PI, total SCFA levels were reduced in the colon. Results indicate the efficacy of MCFA-protected heptanoate against ETEC F4+ and emphasise the potential trophic effect of MCFA-protected butyrate on the intestinal epithelium likely reinforcing the gut barrier.

Effect of the complete replacement of dietary fish meal by soybean meal on histopathology and immune response of the hindgut in grass carp (Ctenopharyngodon idellus).

A 14-day experiment was conducted to explore the pathological process and immune response of soybean meal (SBM) induced enteritis (SBMIE) in grass carp (Ctenopharyngodon idellus). The complete replacement of dietary fish meal (FM) with SBM resulted in a remarkable reduction in final body weight, weight gain ratio, and feed conversion efficiency (p < 0.05). The typical histopathological changes of SBMIE appeared starting at day 4, and progressively increased in severity until day 8, then gradually subsided after day 11. The course of SBMIE could be divided into incubation period (days 1-2), prodromal period (days 3-6), symptomatic period (days 7-10), and convalescent period (days 11-14). Transcription levels of pro-inflammatory cytokines, including IL-1ß, TNF-α, IL-6, IL-8, IL-17A/F1 and IFN-γ2, were up-regulated during the prodromal period, and then down-regulated during the convalescent period. Transcript levels of anti-inflammatory cytokines (IL-10 and TGFß1) and their receptors (IL-10R1 and TßRII), were up-regulated during the prodromal and convalescent periods. Transcript levels of MHCIIß, Igµ, Igτ, TCRδ, TCRß, CD4, and CD8α were altered in SBMIE. Furthermore, expression levels of T-bet, IFN-γ2, RORγ2 and IL-17A/F1 were significantly increased in the initiation of enteritis, whereas the transcript levels of Foxp3 and IL-2/15Ra were significantly up-regulated in the repair of enteritis. In conclusion, grass carp SBMIE is regulated by the adjustment of SBM-based diet intake, and the changes of the above-mentioned genes expression suggest that these genes may be involved in SBMIE.

Listening to your gut: immune challenge to the gut sensitizes body wall nociception in the caterpillar Manduca sexta.

Immune-nociceptor connections are found in animals across phyla. Local inflammation and/or damage results in increased nociceptive sensitivity of the affected area. However, in mammals, immune responses far from peripheral nociceptors, such as immune responses in the gut, produce a general increase in peripheral nociceptive sensitivity. This phenomenon has not, to our knowledge, been found in other animal groups. We found that consuming heat-killed pathogens reduced the tactile force needed to induce a defensive strike in the caterpillar Manduca sexta. This increase in the nociceptive sensitivity of the body wall is probably part of the reconfiguration of behaviour and physiology that occurs during an immune response (e.g. sickness behaviour). This increase may help enhance anti-predator behaviour as molecular resources are shifted towards the immune system. This article is part of the Theo Murphy meeting issue 'Evolution of mechanisms and behaviour important for pain'.

The Preterm Gut Microbiota: An Inconspicuous Challenge in Nutritional Neonatal Care.

The nutritional requirements of preterm infants are unique and challenging to meet in neonatal care, yet crucial for their growth, development and health. Normally, the gut microbiota has distinct metabolic capacities, making their role in metabolism of dietary components indispensable. In preterm infants, variation in microbiota composition is introduced while facing a unique set of environmental conditions. However, the effect of such variation on the microbiota's metabolic capacity and on the preterm infant's growth and development remains unresolved. In this review, we will provide a holistic overview on the development of the preterm gut microbiota and the unique environmental conditions contributing to this, in addition to maturation of the gastrointestinal tract and immune system in preterm infants. The role of prematurity, as well as the role of human milk, in the developmental processes is emphasized. Current research stresses the early life gut microbiota as cornerstone for simultaneous development of the gastrointestinal tract and immune system. Besides that, literature provides clues that prematurity affects growth and development. As such, this review is concluded with our hypothesis that prematurity of the gut microbiota may be an inconspicuous clinical challenge in achieving optimal feeding besides traditional challenges, such as preterm breast milk composition, high nutritional requirements and immaturity of the gastrointestinal tract and immune system. A better understanding of the metabolic capacity of the gut microbiota and its impact on gut and immune maturation in preterm infants could complement current feeding regimens in future neonatal care and thereby facilitate growth, development and health in preterm infants.

Early-Life Nutrition and Gut Immune Development.

Gut immune function conditions the development of local and systemic diseases that result from defects in immune regulation, such as inflammatory bowel disease, allergy and obesity. As epidemiological studies support the developmental origin of health and disease, deciphering the critical factors modulating gut immune development should allow the advance of primary prevention strategies specifically adapted to the early-life immune system. Here, we will review gut mucosal immunity development and cover in more detail the recent understanding of the impact of early nutrition on this process. We will emphasize how nutrition can shape microbiota composition and metabolic function and thereby the production of metabolites with immune-modulatory properties. We will also focus on the role of dietary compounds recently demonstrated to be essential in immune development and function, such as dietary antigens, vitamin A, and aryl hydrocarbon receptor ligands. Finally, we will discuss that early-life physiologic food for mammals contains factors capable of compensating for neonatal immune deficiencies, but also factors that are decisive for immune maturation towards a maternal milk-independent and efficient immune system.

Lactobacillus plantarum IS-10506 supplementation increases faecal sIgA and immune response in children younger than two years.

The immature intestinal immune system in young children develops as it comes into contact with dietary and microbial antigens in the gut. Intestinal microbiota plays a significant role in host defence mechanisms as shown by inflammatory responses towards potential pathogens. We investigated the probiotic function of Lactobacillus plantarum IS-10506 of 'dadih' origin in modulating immune response in young children. We aimed to assess its effect on their immune response by assessing transforming growth factor-ß1 (TGF-ß1) and tumour necrosis factor-α (TNF-α) responses and faecal secretory immunoglobulin A (sIgA) titre in a randomised, double-blinded placebo-controlled trial in 12-24-month-old children (n=38). We used four treatment groups for a 90-day supplementation period: placebo (n=11), probiotic (n=9), zinc (n=8) and probiotic and zinc (n=10). Faecal sIgA, plasma TGF-ß1 and TNF-α titre were evaluated using the enzyme-linked immunosorbent assay standard technique. Statistical analysis divided the results (pre/post treatment) into high (>1) and low (<1) ratios. The results showed that faecal sIgA titre increased in all treatment groups compared with the control (placebo) and significantly increased in the probiotic group (P=0.05). In addition, the TGF-ß1 ratio in the zinc group was significantly higher (P=0.05) than that in the placebo group. We observed a significant positive correlation between TGF-ß1/TNF-α and faecal sIgA (r=0.27, P=0.04). Post hoc test results revealed that zinc supplementation has a significant effect on body-weight gain. Taken together, probiotic L. plantarum IS-10506 supplementation stimulates TGF-ß1, which in turn increases the production of sIgA, in line with the significant correlation between TGF-ß1/TNF-α and faecal sIgA.

Modulation of innate immunity in Nile tilapia (Oreochromis niloticus) by dietary supplementation of Bacillus subtilis endospores.

Dietary supplementation of probiotics is growing as a scientifically valid alternative to antibiotics for enhancement of overall animal health and productivity in aquaculture. Strains of Bacillus subtilis are regarded as attractive probiotic candidates to the fish farming industry; however, there is a limited number of studies focused on the use of specific strains probiotics in tilapia, and therefore complicating replication. The objective of this study was to examine the effect of the strains NZ86 (NRRL B-50136) and O14VRQ (NRRL B-67221) of B. subtilis on various parameters of the innate immunity in Nile tilapia (Oreochromis niloticus) in a 51-day feeding trial. Supplementation of tilapia with either strain resulted in significant increases (p < 0.05) in plasma lysozyme concentration of varying degrees throughout the trial. Meanwhile, alternative complement activity was significantly elevated (p < 0.05) only after feeding of the NZ86 strain after 14 and 51 days. Conversely, supplementation with O14VRQ resulted in a significant increase (p < 0.05) in the percent of neutrophils in the peripheral blood of tilapia by day 28. At the end of the trial, there was a trend towards increased phagocytic and respiratory burst activities observed in immune organ derived leukocytes. Feeding with either probiotic appeared to have an up-regulation on the gene expression of both pro-inflammatory cytokines in the intestine, yet only O14VRQ was significantly different than the control. Moreover, the occurrence of these results could be associated with supplementation of the probiotic strains, given that Bacillus bacteria were observed to populate the intestines of the dietary treatment groups. These results suggest the potential roles of these B. subtilis probiotic candidates to stimulate immune responses both locally and systemically in tilapia.

Effects of dietary taurine on growth, non-specific immunity, anti-oxidative properties and gut immunity in the Chinese mitten crab Eriocheir sinensis.

Taurine has been widely researched as a growth-promoting additive or as an antioxidant in aquatic animals because of its multiple functions, however, few studies have explored its effects on crustacean in spite of the occurrence of serious diseases. We studied the effects of taurine supplementation on the growth, non-specific immunity, anti-oxidative properties and gut immunity of the Chinese mitten crab Eriocheir sinensis. Healthy crabs (8.0 ±â€¯0.5 g) were fed diets supplemented with taurine at 0% (control), 0.2%, 0.4%, 0.8%, and 1.6% for 65 days. At the end of this 65 days feeding trial, the final weight, weight gain, specific growth rate, and feed conversion ratio were best in crabs fed the 0.4% taurine diet, followed by that in those fed the 0.8% taurine diet; the parameters were worst for the control group. Carapace length (CL) and carapace width (CW) were significantly increased in the crab fed the 0.4% and 0.8% taurine diet than that of the other three groups. Total haemocyte count (THC) and acid phosphatase (ACP) activity were significantly higher in the crab fed the 0.8% taurine diet than in those belonging to the other groups, the crabs fed the 0.4% taurine diet had the highest phenoloxidase (PO), lysozyme (LZM), and alkaline phosphatase (AKP) activities, however, there was no obvious change in their haemocyanin (Hc) content. According to superoxide dismutase (SOD), glutathione Peroxidase (GSH-PX), total anti-oxidant capacity (T-AOC) activities and malondialdehyde (MDA) content, the antioxidant capacity was significantly induced by taurine diet, while was higher in crabs fed 0.4 %-0.8% taurine diet than that of the other groups. Taurine supplementation significantly up-regulated the expression of gut immune genes (EsToll2, EsRelish) and antimicrobial peptides (EsALF1, EsALF2, EsCrus1, EsCrus2) in crabs gut fed the 0.2-0.8% taurine diet group compared to control. Thus, these study results indicate that dietary taurine is important for improving growth, regulating immunity, and enhancing the antioxidant capacity in crabs, with the recommended optimum dietary allowance being 0.4 %-0.8% taurine for E. sinensis.

Influence of monostrain and multistrain probiotics on immunity, intestinal ultrastructure and microbiota in experimental dysbiosis.

The biological effects of three probiotic strains Lactobacillus rhamnosus K32, Bifidobacterium longum GT15, Enterococcus faecium L3 and their mixture were studied using a model of dysbiosis induced in rats by antibiotics. It was found that after taking different probiotics intestinal microbiota changed in a strain-specific manner. The maximal activity against pathogens was revealed after the administration of a mixture of bacterial strains under study or a single strain of enterococci. The strain E. faecium L3 showed the most activity against both Klebsiella spp. and Bacteroides fragilis. It helped to restore the original content of Faecalibacterium prausnitzii. The number of Klebsiella spp. was the same in the group receiving L. rhamnosus K32 and the group of animals, which was not consuming probiotics. Different probiotic strains included in the composition had various immunological effects. Probiotic bifidobacteria, enterococci and the mixture of three probiotics stimulated of mRNA expression of interleukin (IL)-10 in mesenteric lymph nodes. The changes in microbiota after consuming an enterococcal probiotic correlated with an increase in transforming growth factor (TGF)-ß and IL-10 content in blood serum and an increase of the intestinal mucus layer. Consumption of L. rhamnosus K32 led to the stimulation of IL-8 expression in mesenteric lymph nodes. Control group not receiving probiotics was characterised by expression of pro-inflammatory cytokines, damage of epithelial cells and the destruction of their tight junctions. The damage to the ultrastructure of the mucosa was prevented in all the groups taking probiotics.

Dietary non-fermentable fiber prevents autoimmune neurological disease by changing gut metabolic and immune status.

The autoimmune neurological disease, Multiple Sclerosis (MS), have increased at alarming rates in the Western society over the last few decades. While there are numerous efforts to develop novel treatment approaches, there is an unmet need to identify preventive strategies. We explored whether central nervous system (CNS) autoimmunity can be prevented through dietary manipulation using a spontaneous autoimmune encephalomyelitis mouse model. We report that the nutritional supplementation of non-fermentable fiber, common components of a vegetarian diet, in early adult life, prevents autoimmune disease. Dietary non-fermentable fiber alters the composition of the gut microbiota and metabolic profile with an increase in the abundance of long-chain fatty acids. Immune assays revealed that cecal extracts and a long chain fatty acid but not cecal lysates promoted autoimmune suppressive TH2 immune responses, demonstrating that non-fermentable fiber-induced metabolic changes account for the beneficial effects. Overall, these findings identify a non-invasive dietary strategy to prevent CNS autoimmunity and warrants a focus on nutritional approaches in human MS.

CD8+ T-Cell Density Imaging with 64Cu-Labeled Cys-Diabody Informs Immunotherapy Protocols.

Purpose: Noninvasive and quantitative tracking of CD8+ T cells by PET has emerged as a potential technique to gauge response to immunotherapy. We apply an anti-CD8 cys-diabody, labeled with 64Cu, to assess the sensitivity of PET imaging of normal and diseased tissue.Experimental Design: Radiolabeling of an anti-CD8 cys-diabody (169cDb) with 64Cu was developed. The accumulation of 64Cu-169cDb was evaluated with PET/CT imaging (0, 5, and 24 hours) and biodistribution (24 hours) in wild-type mouse strains (n = 8/group studied with imaging and IHC or flow cytometry) after intravenous administration. Tumor-infiltrating CD8+ T cells in tumor-bearing mice treated with CpG and αPD-1 were quantified and mapped (n = 6-8/group studied with imaging and IHC or flow cytometry).Results: We demonstrate the ability of immunoPET to detect small differences in CD8+ T-cell distribution between mouse strains and across lymphoid tissues, including the intestinal tract of normal mice. In FVB mice bearing a syngeneic HER2-driven model of mammary adenocarcinoma (NDL), 64Cu-169cDb PET imaging accurately visualized and quantified changes in tumor-infiltrating CD8+ T cells in response to immunotherapy. A reduction in the circulation time of the imaging probe followed the development of treatment-related liver and splenic hypertrophy and provided an indication of off-target effects associated with immunotherapy protocols.Conclusions: 64Cu-169cDb imaging can spatially map the distribution of CD8+ T cells in normal organs and tumors. ImmunoPET imaging of tumor-infiltrating cytotoxic CD8+ T cells detected changes in T-cell density resulting from adjuvant and checkpoint immunotherapy protocols in our preclinical evaluation. Clin Cancer Res; 24(20); 4976-87. ©2018 AACR.

A Mouse Model of Peanut Allergy Induced by Sensitization Through the Gastrointestinal Tract.

Animal models of disease enable the study of the pathology, biomarkers, and treatments for the disease being studied. These models become particularly useful in the study of diseases, such as peanut allergy, that currently have no FDA-approved therapy options. Here, we describe a mouse model of peanut allergy using a peanut extract and cholera toxin that can be applied to both BALB/c and C3H/HeJ mouse strains. Sensitization is induced through the gastrointestinal tract resulting in elevated levels of peanut-specific IgE and anaphylaxis upon challenge with peanut proteins. This model has been used to study the cells and molecules involved in the development of peanut allergy and to evaluate novel immunotherapy approaches and the underlying mechanisms of immunotherapy. Potential utilities of this model are numerous and may include studies on microbial influences on peanut allergy and discovery of biomarkers of anaphylaxis.

Is psoriasis a bowel disease? Successful treatment with bile acids and bioflavonoids suggests it is.

The gut is the largest lymphoid organ in the body. The human microbiome is composed of trillions of bacteria. The DNA of these bacteria dwarfs the human genome. Diet and ethanol can cause rapid shifts in the number and types of bacteria in the gut. The psoriatic microbiome is similar to that seen in alcoholics; there is a decrease in bacterial diversity and overgrowth of bacteria in the small bowel. Psoriatics often have liver disease and deficiencies in bile acids. Psoriasis is a disease characterized by a leaky gut. All of the comorbidities of this disease are due to systemic endotoxemia. Bacterial peptidoglycans absorbed from the gut have direct toxic effects on the liver and skin. Their absorption, as well as endotoxin absorption, must be eliminated to treat psoriasis successfully. Endotoxin absorption is markedly increased by ethanol and peppers. Bioflavonoids, such as quercetin and citrus bioflavonoids, prevent this absorption. Bile acids, given orally, break up endotoxin in the intestinal lumen. Pathogens, including Helicobacter pylori and Streptococcus pyogenes, must be eliminated with antimicrobial therapy for any treatment to work. A complete protocol for curing psoriasis is provided.