Nutrition, microbiomes, and intestinal inflammation

Causal relationship between 150 skin microbiomes and prostate cancer: insights from bidirectional mendelian randomization and meta-analysis

Background

Despite relevant research, the relationship between skin microbiomes and prostate cancer remains controversial. This study utilizes bidirectional Mendelian randomization (MR) analysis combined with meta-analysis to explore the potential link between the two.

Objective

This study aims to identify the causal relationship between 150 skin microbiomes and prostate cancer (PCa) using bidirectional Mendelian randomization (MR) and meta-analysis.

Methods

This study employed a comprehensive Bidirectional Two-sample MR analysis using publicly available genetic data to ascertain the relationship between 150 skin microbiomes and PCa. We conducted extensive sensitivity analyses, tests for heterogeneity, and assessments of horizontal pleiotropy to ensure the accuracy of our results. Subsequently, we conducted a meta-analysis to strengthen our conclusions' robustness further. Finally, we performed reverse causal verification on the positive skin microbiomes and PCa.

Results

After conducting a meta-analysis and multiple corrections of the MR analysis results, our findings reveal a correlation between Neisseria in dry skin and PCa risk, identifying it as a risk factor. The IVW result shows an Odds Ratio (OR) of 1.009 (95% Confidence Interval [CI]: 1.004-1.014, P = 0.027). Furthermore, the reverse MR analysis indicates the absence of an inverse causal relationship between the two. Apart from the identified skin microbiome, no significant associations were found between the other microbiomes and PCa.

Conclusions

The study identified a correlation between Neisseria in dry skin, one of the 150 skin microbiomes, and the risk of developing PCa, establishing it as a risk factor for increased susceptibility to PCa.

Association between oral nutrition and inflammation after intestinal transplantation

Intestinal transplantation (Itx) can be a life-saving treatment for certain patient populations, including those patients with intestinal failure (IF) who develop life-threatening complications due to the use of parenteral nutrition (PN). Most patients who have undergone Itx are eventually able to tolerate a full oral diet. However, little guidance or consensus exists regarding optimizing the specific components of an oral diet for Itx patients, including macronutrients, micronutrients and dietary patterns. While oral dietary prescriptions have moved to the forefront of primary and preventive care, this movement has yet to occur across the field of organ transplantation. Evidence to date points to the role of systemic chronic inflammation (SCI) in a wide variety of chronic diseases as well as post-transplant graft dysfunction. This review will discuss current trends in oral nutrition for Itx patients and also offer novel insights into nutritional management techniques that may help to decrease SCI and chronic disease risk as well as optimize graft function.

Postdiagnostic intake of a more proinflammatory diet is associated with a higher risk of recurrence and all-cause mortality in colorectal cancer survivors

BACKGROUND

The inflammatory potential of the diet has been associated with colorectal cancer (CRC) risk, but its association with CRC prognosis is unclear.

OBJECTIVE

To investigate the inflammatory potential of the diet in relation to recurrence and all-cause mortality among persons diagnosed with stage I to III CRC.

METHODS

Data of the COLON study, a prospective cohort among CRC survivors were used. Dietary intake, 6 mo after diagnosis, was assessed by using a food frequency questionnaire and was available for 1631 individuals. The empirical dietary inflammatory pattern (EDIP) score was used as a proxy for the inflammatory potential of the diet. The EDIP score was created by using reduced rank regression and stepwise linear regression to identify food groups that explained most of the variations in plasma inflammatory markers (IL6, IL8, C-reactive protein, and tumor necrosis factor-α) measured in a subgroup of survivors (n = 421). Multivariable Cox proportional hazard models with restricted cubic splines were used to investigate the relation between the EDIP score and CRC recurrence and all-cause mortality. Models were adjusted for age, sex, BMI, PAL, smoking status, stage of disease, and tumor location.

RESULTS

The median follow-up time was 2.6 y (IQR: 2.1) for recurrence and 5.6 y (IQR: 3.0) for all-cause mortality, during which 154 and 239 events occurred, respectively. A nonlinear positive association between the EDIP score and recurrence and all-cause mortality was observed. For example, a more proinflammatory diet (EDIP score +0.75) compared with the median (EDIP score 0) was associated with a higher risk of CRC recurrence (HR: 1.15; 95% CI: 1.03, 1.29) and all-cause mortality (HR: 1.23; 95% CI: 1.12, 1.35).

CONCLUSIONS

A more proinflammatory diet was associated with a higher risk of recurrence and all-cause mortality in CRC survivors. Further intervention studies should investigate whether a switch to a more anti-inflammatory diet improves CRC prognosis.

Non-alcoholic fatty liver disease: molecular and cellular interplays of the lipid metabolism in a steatotic liver

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) affects ~25% of world population and cases have increased in recent decades. These anomalies have several etiologies; however, obesity and metabolic dysfunctions are the most relevant causes. Despite being considered a public health problem, no effective therapeutic approach to treat NAFLD is available. For that, a deep understanding of metabolic routes that support hepatic diseases is needed.

AREAS COVERED

This review covers aspects of the onset of NAFLD. Thereby, biochemistry routes as well as cellular and metabolic effects of the gut microbiota in body's homeostasis and epigenetics are contextualized.

EXPERT OPINION

Recently, the development of biological sciences has generated innovative knowledge, bringing new insights and perspectives to clarify the systems biology of liver diseases. A detailed comprehension of epigenetics mechanisms will offer possibilities to develop new therapeutic and diagnostic strategies for NAFLD. Different epigenetic processes have been reported that are modulated by the environment such as gut microbiota, suggesting strong interplays between cellular behavior and pathology. Thus, a more complete description of such mechanisms in hepatic diseases will help to clarify how to control the establishment of fatty liver, and precisely describe molecular interplays that potentially control NAFLD.

Immunopathology and modulation induced by hookworms: From understanding to intervention

Hookworm infection is considered the most prevalent human soil-transmitted helminth infection affecting approximately 500 million people and accounting for 3.2 million disability-adjusted life years lost annually. As with many other neglected tropical diseases, no international surveillance mechanisms that show accurate data on the prevalence of hookworm infection are in place, thus hindering strategies to control parasite transmission. In this review, we unravel the current knowledge in immunopathology and immunoregulation of hookworm infection and present discoveries in drug therapies based on the capability of hookworms to regulate inflammation to treat allergic, inflammatory and metabolic diseases. Additionally, we highlight potential vaccine development and treatments and propose avenues for further inquiry.

Understanding the Role of the BAI Subfamily of Adhesion G Protein-Coupled Receptors (GPCRs) in Pathological and Physiological Conditions

Brain-specific angiogenesis inhibitors (BAIs) 1, 2, and 3 are members of the adhesion G protein-coupled receptors, subfamily B, which share a conserved seven-transmembrane structure and an N-terminal extracellular domain. In cell- and animal-based studies, these receptors have been shown to play diverse roles under physiological and pathological conditions. BAI1 is an engulfment receptor and performs major functions in apoptotic-cell clearance and interacts (as a pattern recognition receptor) with pathogen components. BAI1 and -3 also participate in myoblast fusion. Furthermore, BAI1–3 have been linked to tumor progression and neurological diseases. In this review, we summarize the current understanding of the functions of BAI1–3 in pathological and physiological conditions and discuss future directions in terms of the importance of BAIs as pharmacological targets in diseases.

Dingchuan tang essential oil inhibits the production of inflammatory mediators via suppressing the IRAK/NF-κB, IRAK/AP-1, and TBK1/IRF3 pathways in lipopolysaccharide-stimulated RAW264.7 cells

Background

Dingchuan tang (asthma-relieving decoction), a formula of nine herbs, has been used for treating respiratory inflammatory diseases for >400 years in the People’s Republic of China. However, the mechanisms underlying the anti-inflammatory action of dingchuan tang is not fully understood. This study aims to investigate the effects of Dingchuan tang essential oil (DCEO) on inflammatory mediators and the underlying mechanism of action.

Materials and methods

DCEO was extracted by steam distillation. Lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages were used as the cell model. Production of nitric oxide (NO) was determined by the Griess test. Protein secretion and mRNA levels of inflammatory mediators were measured by the enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. Protein levels were examined by Western blot. Nuclear localization of nuclear factor-kappa B (NF-κB) was detected using immunofluorescence analyses.

Results

DCEO significantly reduced LPS-triggered production of NO and prostaglandin E2 (PGE2) and decreased protein and mRNA levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). LPS induced upregulation of protein and mRNA levels of cytokines (interleukin-1β [IL-1β], interleukin-6 [IL-6], tumor necrosis factor-α [TNF-α]), and chemokines (monocyte chemoattractant protein-1 [MCP-1], chemokine [C-C motif] ligand 5 [CCL-5], and macrophage inflammatory protein [MIP]-1α) were suppressed by DCEO treatment. Phosphorylation and nuclear protein levels of transcription factors (activator protein-1 [AP-1], NF-κB, interferon regulatory factor 3 [IRF3]) were decreased by DCEO. Protein levels of phosphorylated IκB-α, IκB kinase α/β (IKKα/β), phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), TGF β-activated kinase 1 (TAK1), TANK-binding kinase 1 (TBK1), extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (p38), and c-Jun N-terminal kinase (JNK) were lowered by DCEO. Moreover, degradation of interleukin-1 receptor-associated kinase 1 (IRAK1) and IRAK4 induced by LPS was inhibited by DCEO treatment.

Conclusion

Suppression of the interleukin-1 receptor-associated kinase (IRAK)/NF-κB, IRAK/AP-1 and TBK1/IRF3 pathways was associated with the inhibitory effects of DCEO on inflammatory mediators in LPS-stimulated RAW264.7 macrophages. This study provides a pharmacological justification for the use of dingchuan tang in managing inflammatory disorders.

Lifestyle Medicine: A Brief Review of Its Dramatic Impact on Health and Survival

By ignoring the root causes of disease and neglecting to prioritize lifestyle measures for prevention, the medical community is placing people at harm. Advanced nations, influenced by a Western lifestyle, are in the midst of a health crisis, resulting largely from poor lifestyle choices. Epidemiologic, ecologic, and interventional studies have repeatedly indicated that most chronic illnesses, including cardiovascular disease, cancer, and type 2 diabetes, are the result of lifestyles fueled by poor nutrition and physical inactivity.In this article, we describe the practice of lifestyle medicine and its powerful effect on these modern instigators of premature disability and death. We address the economic benefits of prevention-based lifestyle medicine and its effect on our health care system: A system on the verge of bankruptcy. We recommend vital changes to a disastrous course. Many deaths and many causes of pain, suffering, and disability could be circumvented if the medical community could effectively implement and share the power of healthy lifestyle choices. We believe that lifestyle medicine should become the primary approach to the management of chronic conditions and, more importantly, their prevention. For future generations, for our own health, and for the Hippocratic Oath we swore to uphold ("First do no harm"), the medical community must take action. It is our hope that the information presented will inspire our colleagues to pursue lifestyle medicine research and incorporate such practices into their daily care of patients. The time to make this change is now.

Responses of earthworms and microbial communities in their guts to Triclosan

Responses of the earthworm (Eisenia fetida) and compositions of associated microbial communities were determined after exposure to various concentrations of Triclosan (TCS) for 7 d. Concentrations of TCS were greater in intestines than in epidermis of earthworms, which suggested that earthworms accumulate TCS mainly by ingestion rather than by epidermic penetration. Exposure to TCS caused a concentration-dependent increase in activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) and in malondialdehyde (MDA) in E. fetida. Analyses of both the bacterial and eukaryotic community by next generation sequencing (NGS), demonstrated that TCS caused a concentration-dependent decrease in sensitive genera. While relative abundances of Pseudomonas, Stenotrophomonas, and Achromobacter were increased. Nine susceptible microbial groups were more sensitive to exposure to TCS, than were activities of enzymes in earthworms. Thus, rapid genomic measures of gut flora can be used as indicators to assess adverse effects of chemicals on earthworms.

Complementary and Alternative Medicine Use in Children With Inflammatory Bowel Diseases: A Single-Center Survey

OBJECTIVES

The prevalence of inflammatory bowel diseases (IBD) and use of complementary and alternative medicine (CAM) are both common and increasing. The definition of CAM therapy among both practitioners and patients is variable. The aim of our study was to update our understanding of how pediatric IBD patients use, perceive, and define CAM therapies.

METHODS

We surveyed families of patients with IBD followed in the Gastroenterology Division at Nationwide Children's Hospital in summer 2014 during a routine clinic visit. The survey included questions about the following demographic and disease information; use and side effects associated with prior conventional therapies (CT); and attitudes toward, and use of CAM.

RESULTS

The questionnaire was completed by 104 of 118 patients approached (14 ± 3 years; 43% women). Patients had previously used an average of 3 CT. CAM therapy was used by 84% of patients surveyed, although only 24% of patients/families considered themselves to be using CAM. Common CAM therapies included vitamins/supplements, stress management techniques, and/or dietary changes. Factors associated with using specific CAM therapies included self-reported prior CT-related side effects (P < 0.01) and moderate/severe disease activity (P < 0.01). Most families (77%) desired to learn more about CAM.

CONCLUSIONS

Patients seen in a tertiary care center for pediatric IBD frequently integrated CAM therapies into their treatment regimen. Patients with prior side effects from CT or more severe disease were more likely to use CAM. Given the high prevalence of CAM use, pediatric gastrointestinal physicians should be knowledgeable and open to discussions about CAM therapies with their patients.

An overview of the bacterial contribution to Crohn disease pathogenesis

Crohn disease (CD) is a chronic inflammatory condition primarily affecting the gastro-intestinal tract and is characterized by reduced bacterial diversity. The exact cause of disease is unknown; however, evidence suggests that several components, including microbiota, may contribute to the underlying pathology and disease development. Perturbation of the host-microbe commensal relationship is considered the main driving force of tissue destruction and pathological changes seen in CD. Several putative bacterial pathogens including species from Mycobacterium, Campylobacter and Helicobacter are postulated in the aetiology of CD. However, to date, no strong evidence supports a single bacterium contributing overall to CD pathogenesis. Alternatively, dysbiosis or bacterial imbalance is more widely accepted as a leading factor in the disrupted host-immune system cross-talk resulting in subsequent intestinal inflammation. Depletion of symbiont microbes including Firmicutes, Bifidobacterium and Clostridia, in conjunction with an increase in pathobiont microbes from Bacteroidetes and Enterobacteria, is a striking feature observed in CD. No single factor has been identified as driving this dysbiosis, although diet, antibiotic exposure and possible early life events in presence of underlying genetic susceptibility may contribute. The aim of this review is to highlight the current accumulating literature on the proposed role of bacteria in the pathogenesis of CD.

Boosting Apoptotic Cell Clearance by Colonic Epithelial Cells Attenuates Inflammation In Vivo

Few apoptotic corpses are seen even in tissues with high cellular turnover, leading to the notion that the capacity for engulfment in vivo is vast. Whether corpse clearance can be enhanced in vivo for potential benefit is not known. In a colonic inflammation model, we noted that the expression of the phagocytic receptor Bai1 was progressively downmodulated. Consistent with this, BAI1-deficient mice had more pronounced colitis and lower survival, with many uncleared apoptotic corpses and inflammatory cytokines within the colonic epithelium. When we engineered and tested transgenic mice overexpressing BAI1, these had fewer apoptotic cells, reduced inflammation, and attenuated disease. Boosting BAI1-mediated uptake by intestinal epithelial cells (rather than myeloid cells) was important in attenuating inflammation. A signaling-deficient BAI1 transgene could not provide a similar benefit. Collectively, these complementary genetic approaches showed that cell clearance could be boosted in vivo, with potential to regulate tissue inflammation in specific contexts.

Personalized Medicine for Sepsis

Sepsis is a complex syndrome triggered by infection and characterized by systemic deregulation of immune and inflammatory pathways. It is a major cause of death worldwide and results in the widespread use of antibiotics and substantial health care costs. In a vicious circle, sepsis treatment promotes the emergence of highly virulent and resistant pathogens and devastating nosocomial infections. Sepsis is a heterogeneous disease affecting many people worldwide. Because individual patients have different inflammatory responses and unique profiles of immune activation against pathogens, the most effective way to advance the treatment of sepsis is probably through a tailored approach. The advent of high-throughput technologies and the remarkable progress in the field of bioinformatics has allowed the subclassification of many pathological conditions. This has potential to provide better understanding of life-threatening infections in people. The study of host factors, however, needs to be integrated with studies on bacterial signaling in both symbiotic and pathogenic bacteria. Sepsis is certainly the sum of multiple host-microbial interactions and the metagenome should be extensively investigated. Personalized medicine is probably the only strategy able to deconstruct and reassemble our knowledge about sepsis, and its use should allow us to understand and manipulate sepsis as a wide, interconnected phenomenon with myriad variables and peculiarities. In this study, the recent advances in this area, the major challenges that remain, and the reasons why the septic patient should be approached as a superorganism are discussed.

Epigenetic Regulation of Enteric Neurotransmission by Gut Bacteria

The Human Microbiome Project defined microbial community interactions with the human host, and provided important molecular insight into how epigenetic factors can influence intestinal ecosystems. Given physiological context, changes in gut microbial community structure are increasingly found to associate with alterations in enteric neurotransmission and disease. At present, it is not known whether shifts in microbial community dynamics represent cause or consequence of disease pathogenesis. The discovery of bacterial-derived neurotransmitters suggests further studies are needed to establish their role in enteric neuropathy. This mini-review highlights recent advances in bacterial communications to the autonomic nervous system and discusses emerging epigenetic data showing that diet, probiotic and antibiotic use may regulate enteric neurotransmission through modulation of microbial communities. A particular emphasis is placed on bacterial metabolite regulation of enteric nervous system function in the intestine.

Sesamol suppresses the inflammatory response by inhibiting NF-κB/MAPK activation and upregulating AMP kinase signaling in RAW 264.7 macrophages

OBJECTIVES AND DESIGN

Sesamol is a lignan isolated from sesame seed oil. In recent years, it was found that sesamol could decrease lung inflammation and lipopolysaccharide (LPS)-induced lung injury in rats. In this study, we investigated whether sesamol exhibited anti-inflammatory activity in LPS-stimulated macrophages.

MATERIALS AND METHODS

RAW 264.7 cells were treated with sesamol, then treated with LPS to induce inflammation. The levels of proinflammatory cytokines were analyzed with ELISA. The gene and protein expression of cyclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS), and nuclear factor erythroid-2-related factor 2 (Nrf2) were evaluated with real-time PCR and Western blots, respectively. We also examined inflammatory signaling pathways, including nuclear transcription factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways.

RESULTS

Sesamol inhibited production of nitric oxide, prostaglandin E2 (PGE2), and proinflammatory cytokines. Sesamol markedly suppressed mRNA and protein expression of iNOS and COX-2. Sesamol enhanced the protective antioxidant pathway represented by Nrf2 and HO-1. Moreover, sesamol suppressed NF-κB transport into the nucleus and decreased MAPK activation, but it promoted adenosine monophosphate-activated protein kinase (AMPK) activation.

CONCLUSIONS

These data suggested that sesamol ameliorated inflammatory and oxidative damage by upregulating AMPK activation and Nrf2 signaling and blocking the NF-κB and MAPK signaling pathways.

Casticin inhibits COX-2 and iNOS expression via suppression of NF-κB and MAPK signaling in lipopolysaccharide-stimulated mouse macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

The fruits of Vitex rotundifolia L. are widely used to treat inflammation of the airway in Traditional Chinese medicine. Previous studies found that casticin, isolated from Vitex rotundifolia, could induce apoptosis of tumor cells. In this study, we evaluated the anti-inflammatory effects of casticin and its underlying molecular mechanism in lipopolysaccharide (LPS)-stimulated macrophages.

MATERIALS AND METHODS

RAW264.7 cells were pretreated with various concentrations of casticin (0.3-10μM), and then treated with LPS to induce inflammation. We assayed the levels of proinflammatory cytokines and prostaglandin E2 (PGE2) using ELISA, and examined the protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, and heme oxygenase (HO)-1 by Western blot. We also investigated the anti-inflammatory molecular mechanism by analyzing inflammatory-associated signaling pathways, including the nuclear transcription factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways.

RESULTS

We found casticin inhibited the levels of nitric oxide and PGE2, and decreased the production of proinflammatory cytokines such as interleukin (IL)-1β, IL-6, and tumor necrosis factor α (TNF-α). In addition, iNOS and COX-2 expression levels were suppressed and casticin increased HO-1 and Nrf2 production in a concentration-dependent manner. Furthermore, casticin significantly inhibited NF-κB subunit p65 proteins in the nucleus and decreased Akt and MAPK activation.

CONCLUSION

These results suggest that the anti-inflammatory effect of casticin is due to inhibition of proinflammatory cytokines and mediators by blocking the NF-κB, Akt, and MAPK signaling pathways.

A review on prebiotics and probiotics for the control of dysbiosis: present status and future perspectives

Dysbiosis or dysbacteriosis is defined as a shift in the intestinal microbiota composition resulting in an imbalance between beneficial and harmful bacteria. Since the ban on the use of growth-promoting antibiotics in animal feed in the EU, dysbiosis has emerged as a major problem in intensive animal production. Prebiotics and probiotics are currently under investigation as possible alternatives to growth-promoting antibiotics, as their mode of action is thought to be based largely on a modulation of the composition and function of the intestinal microbiota. In this review, we analyse the currently available data from both animal and human nutrition that document the potential and limitations of prebiotics and probiotics for the control of dysbiosis. An impressive number of empirical feeding trials have been carried out in healthy animals, yielding sometimes contradictory results. More in-depth studies have revealed the complexity of the interactions taking place in the lower intestinal tract, thus illustrating that pre- and probiotics cannot be a simple replacement for growth-promoting antibiotics. Although there are indications that the strategic use of pre- and probiotics can provide major benefits, there is still a lack of basic knowledge on the delicate interactions between the microbiota, the host and the feed components, which hampers the widespread use of these valuable feed additives.

Human microbiome science: vision for the future, Bethesda, MD, July 24 to 26, 2013

A conference entitled ‘Human microbiome science: Vision for the future’ was organized in Bethesda, MD from July 24 to 26, 2013. The event brought together experts in the field of human microbiome research and aimed at providing a comprehensive overview of the state of microbiome research, but more importantly to identify and discuss gaps, challenges and opportunities in this nascent field. This report summarizes the presentations but also describes what is needed for human microbiome research to move forward and deliver medical translational applications.

Midichlorians--the biomeme hypothesis: is there a microbial component to religious rituals?

Background

Cutting edge research of human microbiome diversity has led to the development of the microbiome-gut-brain axis concept, based on the idea that gut microbes may have an impact on the behavior of their human hosts. Many examples of behavior-altering parasites are known to affect members of the animal kingdom. Some prominent examples include Ophiocordyceps unilateralis (fungi), Toxoplasma gondii (protista), Wolbachia (bacteria), Glyptapanteles sp. (arthropoda), Spinochordodes tellinii (nematomorpha) and Dicrocoelium dendriticum (flat worm). These organisms belong to a very diverse set of taxonomic groups suggesting that the phenomena of parasitic host control might be more common in nature than currently established and possibly overlooked in humans.

Presentation of the hypothesis

Some microorganisms would gain an evolutionary advantage by encouraging human hosts to perform certain rituals that favor microbial transmission. We hypothesize that certain aspects of religious behavior observed in the human society could be influenced by microbial host control and that the transmission of some religious rituals could be regarded as the simultaneous transmission of both ideas (memes) and parasitic organisms.

Testing the hypothesis

We predict that next-generation microbiome sequencing of samples obtained from gut or brain tissues of control subjects and subjects with a history of voluntary active participation in certain religious rituals that promote microbial transmission will lead to the discovery of microbes, whose presence has a consistent and positive association with religious behavior. Our hypothesis also predicts a decline of participation in religious rituals in societies with improved sanitation.

Implications of the hypothesis

If proven true, our hypothesis may provide insights on the origin and pervasiveness of certain religious practices and provide an alternative explanation for recently published positive associations between parasite-stress and religiosity. The discovery of novel microorganisms that affect host behavior may improve our understanding of neurobiology and neurochemistry, while the diversity of such organisms may be of interest to evolutionary biologists and religious scholars.

Reviewers

This article was reviewed by Prof. Dan Graur, Dr. Rob Knight and Dr. Eugene Koonin

Systemic impact of intestinal helminth infections

In this review, we examine the evidence that intestinal helminths can control harmful inflammatory responses and promote homeostasis by triggering systemic immune responses. Induction of separable components of immunity by helminths, which includes type 2 and immune regulatory responses, can both contribute toward the reduction in harmful type 1 immune responses that drive certain inflammatory diseases. Despite inducing type 2 responses, intestinal helminths may also downregulate harmful type 2 immune responses including allergic responses. We consider the possibility that intestinal helminth infection may indirectly affect inflammation by influencing the composition of the intestinal microbiome. Taken together, the studies reviewed herein suggest that intestinal helminth-induced responses have potent systemic effects on the immune system, raising the possibility that whole parasites or specific molecules produced by these metazoans may be an important resource for the development of future immunotherapies to control inflammatory diseases.

Diet, microbiota, and inflammatory bowel disease: lessons from Japanese foods

The incidence and prevalence of inflammatory bowel diseases (IBDs) including ulcerative colitis and Crohn disease are rapidly increasing in Western countries and in developed Asian countries. Although biologic agents targeting the immune system have been effective in patients with IBD, cessation of treatment leads to relapse in the majority of patients, suggesting that intrinsic immune dysregulation is an effect, not a cause, of IBD. Dramatic changes in the environment, resulting in the dysregulated composition of intestinal microbiota or dysbiosis, may be associated with the fundamental causes of IBD. Japan now has upgraded water supply and sewerage systems, as well as dietary habits and antibiotic overuse that are similar to such features found in developed Western countries. The purpose of this review article was to describe the association of diet, particularly Japanese food and microbiota, with IBD.

Reprint of: Role of enteric neurotransmission in host defense and protection of the gastrointestinal tract

Host defense is a vital role played by the gastrointestinal tract. As host to an enormous and diverse microbiome, the gut has evolved an elaborate array of chemical and physicals barriers that allow the digestion and absorption of nutrients without compromising the mammalian host. The control of such barrier functions requires the integration of neural, humoral, paracrine and immune signaling, involving redundant and overlapping mechanisms to ensure, under most circumstances, the integrity of the gastrointestinal epithelial barrier. Here we focus on selected recent developments in the autonomic neural control of host defense functions used in the protection of the gut from luminal agents, and discuss how the microbiota may potentially play a role in enteric neurotransmission. Key recent findings include: the important role played by subepithelial enteric glia in modulating intestinal barrier function, identification of stress-induced mechanisms evoking barrier breakdown, neural regulation of epithelial cell proliferation, the role of afferent and efferent vagal pathways in regulating barrier function, direct evidence for bacterial communication to the enteric nervous system, and microbial sources of enteric neurotransmitters. We discuss these new and interesting developments in our understanding of the role of the autonomic nervous system in gastrointestinal host defense.

Role of enteric neurotransmission in host defense and protection of the gastrointestinal tract

Host defense is a vital role played by the gastrointestinal tract. As host to an enormous and diverse microbiome, the gut has evolved an elaborate array of chemical and physicals barriers that allow the digestion and absorption of nutrients without compromising the mammalian host. The control of such barrier functions requires the integration of neural, humoral, paracrine and immune signaling, involving redundant and overlapping mechanisms to ensure, under most circumstances, the integrity of the gastrointestinal epithelial barrier. Here we focus on selected recent developments in the autonomic neural control of host defense functions used in the protection of the gut from luminal agents, and discuss how the microbiota may potentially play a role in enteric neurotransmission. Key recent findings include: the important role played by subepithelial enteric glia in modulating intestinal barrier function, identification of stress-induced mechanisms evoking barrier breakdown, neural regulation of epithelial cell proliferation, the role of afferent and efferent vagal pathways in regulating barrier function, direct evidence for bacterial communication to the enteric nervous system, and microbial sources of enteric neurotransmitters. We discuss these new and interesting developments in our understanding of the role of the autonomic nervous system in gastrointestinal host defense.