1 3804 81 INTESTINAL MICROBIOTA, CHRONIC INFLAMMATION, AND COLORECTAL CANCER. IN ADDITION TO GENETIC AND EPIGENETIC FACTORS, VARIOUS ENVIRONMENTAL FACTORS, INCLUDING DIET, PLAY IMPORTANT ROLES IN THE DEVELOPMENT OF COLORECTAL CANCER (CRC). RECENTLY, THERE IS INCREASING INTEREST IN THE INTESTINAL MICROBIOTA AS AN ENVIRONMENTAL RISK FACTOR FOR CRC, BECAUSE DIET ALSO INFLUENCES THE COMPOSITION OF THE INTESTINAL MICROBIOTA. THE HUMAN INTESTINAL MICROBIOTA COMPRISES ABOUT 100 TRILLION MICROBES. THIS MICROBIOME THRIVES ON UNDIGESTED DIETARY RESIDUES IN THE INTESTINAL LUMEN AND PRODUCES VARIOUS METABOLITES. IT IS WELL KNOWN THAT THE DIETARY RISK FACTORS FOR CRC ARE MEDIATED BY DYSBIOSIS OF THE INTESTINAL MICROBIOTA AND THEIR METABOLITES. IN THIS REVIEW, WE DESCRIBE THE BACTERIAL TAXA ASSOCIATED WITH CRC, INCLUDING FUSOBACTERIUM NUCLEATUM, ENTEROTOXIGENIC BACTEROIDES FRAGILIS, ESCHERICHIA COLI, AND BUTYRATE-PRODUCING BACTERIA. WE ALSO DISCUSS THE HOST-DIET INTERACTION IN COLORECTAL CARCINOGENESIS. 2018 2 2804 20 FETAL EPIGENETIC MECHANISMS AND INNATE IMMUNITY IN ASTHMA. ALLERGY AND ASTHMA ARE CHRONIC INFLAMMATORY DISEASES THAT RESULT FROM COMPLEX GENE-ENVIRONMENT INTERACTIONS. RECENT EVIDENCE POINTS TO THE IMPORTANCE OF PRENATAL AND POSTNATAL DEVELOPMENTAL PROCESSES IN THE MATURATION OF BALANCED IMMUNE RESPONSES. NOVEL DATA INDICATE THAT EPIGENETIC MECHANISMS CONTRIBUTE TO THE DEVELOPMENT OF T-HELPER-CELL FUNCTION. ENVIRONMENTAL FACTORS, INCLUDING DIESEL EXHAUST PARTICLES, VITAMINS, AND TOBACCO SMOKE, OPERATE THROUGH SUCH MECHANISMS. FURTHERMORE, THE ROLE OF ENVIRONMENTAL MICROBES PROVIDES ANOTHER-AND MAYBE AN EVEN MORE IMPORTANT-GROUP OF EXOGENOUS EXPOSURES THAT OPERATE IN THIS CRITICAL TIME FRAME. A BETTER UNDERSTANDING OF FETAL IMMUNO-MATURATION CONDITIONS WILL PROVIDE THE BASIS FOR THE DEVELOPMENT OF NOVEL ALLERGO-PROTECTIVE CLINICAL STRATEGIES. 2010 3 4271 35 MICROBIAL DYSBIOSIS-INDUCED OBESITY: ROLE OF GUT MICROBIOTA IN HOMOEOSTASIS OF ENERGY METABOLISM. THE GLOBAL OBESITY EPIDEMIC HAS NECESSITATED THE SEARCH FOR BETTER INTERVENTION STRATEGIES INCLUDING THE EXPLOITATION OF THE HEALTH BENEFITS OF SOME GUT MICROBIOTA AND THEIR METABOLIC PRODUCTS. THEREFORE, WE EXAMINED THE GUT MICROBIAL COMPOSITION AND MECHANISMS OF INTERACTION WITH THE HOST IN RELATION TO HOMOEOSTATIC ENERGY METABOLISM AND PATHOPHYSIOLOGY OF DYSBIOSIS-INDUCED METABOLIC INFLAMMATION AND OBESITY. WE ALSO DISCUSSED THE EUBIOTIC, HEALTH-PROMOTING EFFECTS OF PROBIOTICS AND PREBIOTICS AS WELL AS EPIGENETIC MODIFICATIONS ASSOCIATED WITH GUT MICROBIAL DYSBIOSIS AND RISK OF OBESITY. HIGH-FAT/CARBOHYDRATE DIET PROGRAMMES THE GUT MICROBIOTA TO ONE PREDOMINATED BY FIRMICUTES (CLOSTRIDIUM), PREVOTELLA AND METHANOBREVIBACTER BUT DEFICIENT IN BENEFICIAL GENERA/SPECIES SUCH AS BACTEROIDES, BIFIDOBACTERIUM, LACTOBACILLUS AND AKKERMANSIA. ALTERED GUT MICROBIOTA IS ASSOCIATED WITH DECREASED EXPRESSION OF SCFA THAT MAINTAIN INTESTINAL EPITHELIAL BARRIER INTEGRITY, REDUCE BACTERIAL TRANSLOCATION AND INFLAMMATION AND INCREASE EXPRESSION OF HUNGER-SUPPRESSING HORMONES. REDUCED AMOUNTS OF BENEFICIAL MICRO-ORGANISMS ALSO INHIBIT FASTING-INDUCED ADIPOCYTE FACTOR EXPRESSION LEADING TO DYSLIPIDAEMIA. A LOW-GRADE CHRONIC INFLAMMATION (METABOLIC ENDOTOXAEMIA) ENSUES WHICH CULMINATES IN OBESITY AND ITS CO-MORBIDITIES. THE SYNERGY OF HIGH-FAT DIET AND DYSBIOTIC GUT MICROBIOTA INITIATES A RECIPE THAT EPIGENETICALLY PROGRAMMES THE HOST FOR INCREASED ADIPOSITY AND POOR GLYCAEMIC CONTROL. INTERESTINGLY, THESE OBESOGENIC MECHANISTIC PATHWAYS THAT ARE TRANSMITTABLE FROM ONE GENERATION TO ANOTHER CAN BE MODULATED THROUGH THE ADMINISTRATION OF PROBIOTICS, PREBIOTICS AND SYNBIOTICS. THOUGH THE INFLUENCE OF GUT MICROBIOTA ON THE RISK OF OBESITY AND SEVERAL INTERVENTION STRATEGIES HAVE BEEN EXTENSIVELY DEMONSTRATED IN ANIMAL MODELS, APPLICATION IN HUMANS STILL REQUIRES FURTHER ROBUST INVESTIGATION. 2020 4 4094 22 MATERNAL SIGNALS FOR PROGENY PREVENTION AGAINST ALLERGY AND ASTHMA. ALLERGY AND ASTHMA ARE CHRONIC INFLAMMATORY DISEASES WHICH RESULT FROM COMPLEX GENE-ENVIRONMENT INTERACTIONS. RECENT EVIDENCE INDICATES THE IMPORTANCE OF PRENATAL AND POSTNATAL DEVELOPMENTAL PROCESSES IN TERMS OF MATURATION OF BALANCED IMMUNE RESPONSES. ACCORDING TO THE CURRENT VIEW, GENE-ENVIRONMENT INTERACTIONS DURING A RESTRICTED TIME FRAME ARE RESPONSIBLE FOR PROGRAMMING OF THE IMMUNE SYSTEM IN FAVOR OF ALLERGIC IMMUNE MECHANISMS LATER IN LIFE. THE INTERACTION BETWEEN GENES AND ENVIRONMENT IS COMPLEX AND ONLY PARTIALLY UNDERSTOOD; HOWEVER, HERITABLE EPIGENETIC MODIFICATIONS INCLUDING CHEMICAL ADDITIONS IN AND ALTERNATIVE PACKAGING OF THE DNA HAVE BEEN SHOWN TO PLAY A CRUCIAL ROLE IN THIS CONTEXT. NOVEL DATA INDICATE THAT EPIGENETIC MECHANISMS CONTRIBUTE TO THE DEVELOPMENT OF T-HELPER CELL FUNCTION. ENVIRONMENTAL FACTORS, INCLUDING DIESEL EXHAUST PARTICLES (DEP), VITAMINS AND TOBACCO SMOKE, OPERATE THROUGH SUCH MECHANISMS. FURTHERMORE, THE ROLE OF ENVIRONMENTAL MICROBES PROVIDES ANOTHER AND MAYBE EVEN MORE IMPORTANT GROUP OF EXOGENOUS EXPOSURES WHICH OPERATES IN THIS CRITICAL TIME FRAME. 2011 5 4116 24 MECHANISMS OF AIRWAY EPITHELIAL INJURY AND ABNORMAL REPAIR IN ASTHMA AND COPD. THE AIRWAY EPITHELIUM COMPRISES OF DIFFERENT CELL TYPES AND ACTS AS A PHYSICAL BARRIER PREVENTING PATHOGENS, INCLUDING INHALED PARTICLES AND MICROBES, FROM ENTERING THE LUNGS. GOBLET CELLS AND SUBMUCOSAL GLANDS PRODUCE MUCUS THAT TRAPS PATHOGENS, WHICH ARE EXPELLED FROM THE RESPIRATORY TRACT BY CILIATED CELLS. BASAL CELLS ACT AS PROGENITOR CELLS, DIFFERENTIATING INTO DIFFERENT EPITHELIAL CELL TYPES, TO MAINTAIN HOMEOSTASIS FOLLOWING INJURY. ADHERENS AND TIGHT JUNCTIONS BETWEEN CELLS MAINTAIN THE EPITHELIAL BARRIER FUNCTION AND REGULATE THE MOVEMENT OF MOLECULES ACROSS IT. IN THIS REVIEW WE DISCUSS HOW ABNORMAL EPITHELIAL STRUCTURE AND FUNCTION, CAUSED BY CHRONIC INJURY AND ABNORMAL REPAIR, DRIVES AIRWAY DISEASE AND SPECIFICALLY ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). IN BOTH DISEASES, INHALED ALLERGENS, POLLUTANTS AND MICROBES DISRUPT JUNCTIONAL COMPLEXES AND PROMOTE CELL DEATH, IMPAIRING THE BARRIER FUNCTION AND LEADING TO INCREASED PENETRATION OF PATHOGENS AND A CONSTANT AIRWAY IMMUNE RESPONSE. IN ASTHMA, THE INFLAMMATORY RESPONSE PRECIPITATES THE EPITHELIAL INJURY AND DRIVES ABNORMAL BASAL CELL DIFFERENTIATION. THIS LEADS TO REDUCED CILIATED CELLS, GOBLET CELL HYPERPLASIA AND INCREASED EPITHELIAL MESENCHYMAL TRANSITION, WHICH CONTRIBUTE TO IMPAIRED MUCOCILIARY CLEARANCE AND AIRWAY REMODELLING. IN COPD, CHRONIC OXIDATIVE STRESS AND INFLAMMATION TRIGGER PREMATURE EPITHELIAL CELL SENESCENCE, WHICH CONTRIBUTES TO LOSS OF EPITHELIAL INTEGRITY AND AIRWAY INFLAMMATION AND REMODELLING. INCREASED NUMBERS OF BASAL CELLS SHOWING DEREGULATED DIFFERENTIATION, CONTRIBUTES TO CILIARY DYSFUNCTION AND MUCOUS HYPERPRODUCTION IN COPD AIRWAYS. DEFECTIVE ANTIOXIDANT, ANTIVIRAL AND DAMAGE REPAIR MECHANISMS, POSSIBLY DUE TO GENETIC OR EPIGENETIC FACTORS, MAY CONFER SUSCEPTIBILITY TO AIRWAY EPITHELIAL DYSFUNCTION IN THESE DISEASES. THE CURRENT EVIDENCE SUGGESTS THAT A CONSTANT CYCLE OF INJURY AND ABNORMAL REPAIR OF THE EPITHELIUM DRIVES CHRONIC AIRWAY INFLAMMATION AND REMODELLING IN ASTHMA AND COPD. MECHANISTIC UNDERSTANDING OF INJURY SUSCEPTIBILITY AND DAMAGE RESPONSE MAY LEAD TO IMPROVED THERAPIES FOR THESE DISEASES. 2023 6 1400 24 DIET-REGULATING MICROBIOTA AND HOST IMMUNE SYSTEM IN LIVER DISEASE. THE GUT MICROBIOTA HAS BEEN KNOWN TO MODULATE THE IMMUNE RESPONSES IN CHRONIC LIVER DISEASES. RECENT EVIDENCE SUGGESTS THAT EFFECTS OF DIETARY FOODS ON HEALTH CARE AND HUMAN DISEASES ARE RELATED TO BOTH THE IMMUNE REACTION AND THE MICROBIOME. THE GUT-MICROBIOME AND INTESTINAL IMMUNE SYSTEM PLAY A CENTRAL ROLE IN THE CONTROL OF BACTERIAL TRANSLOCATION-INDUCED LIVER DISEASE. DYSBIOSIS, SMALL INTESTINAL BACTERIAL OVERGROWTH, TRANSLOCATION, ENDOTOXEMIA, AND THE DIRECT EFFECTS OF METABOLITES ARE THE MAIN EVENTS IN THE GUT-LIVER AXIS, AND IMMUNE RESPONSES ACT ON EVERY PATHWAYS OF CHRONIC LIVER DISEASE. MICROBIOME-DERIVED METABOLITES OR BACTERIA THEMSELVES REGULATE IMMUNE CELL FUNCTIONS SUCH AS RECOGNITION OR ACTIVATION OF RECEPTORS, THE CONTROL OF GENE EXPRESSION BY EPIGENETIC CHANGE, ACTIVATION OF IMMUNE CELLS, AND THE INTEGRATION OF CELLULAR METABOLISM. HERE, WE REVIEWED RECENT REPORTS ABOUT THE IMMUNOLOGIC ROLE OF GUT MICROBIOTAS IN LIVER DISEASE, HIGHLIGHTING THE ROLE OF DIET IN CHRONIC LIVER DISEASE. 2021 7 1395 34 DIET AND MICROBIOME IN THE BEGINNING OF THE SEQUENCE OF GUT INFLAMMATION. INFLAMMATORY BOWEL DISEASE (IBD) IS A CHRONIC INFLAMMATORY CONDITION OF THE GASTROINTESTINAL TRACT DUE, AT LEAST PARTIALLY, TO AN ABERRANT AND EXCESSIVE MUCOSAL IMMUNE RESPONSE TO GUT BACTERIA IN GENETICALLY-PREDISPOSED INDIVIDUALS UNDER CERTAIN ENVIRONMENTAL FACTORS. THE INCIDENCE OF IBD IS RISING IN WESTERN AND NEWLY INDUSTRIALIZED COUNTRIES, PARALLELING THE INCREASE OF WESTERNIZED DIETARY PATTERNS, THROUGH NEW ANTIGENS, EPITHELIAL FUNCTION AND PERMEABILITY, EPIGENETIC MECHANISMS (E.G., DNA METHYLATION), AND ALTERATION OF THE GUT MICROBIOME. ALTERATION IN THE COMPOSITION AND FUNCTIONALITY OF THE GUT MICROBIOME (INCLUDING BACTERIA, VIRUSES AND FUNGI) SEEMS TO BE A NUCLEAR PATHOGENIC FACTOR. THE MICROBIOME ITSELF IS DYNAMIC, AND THE CHANGES IN FOOD QUALITY, DIETARY HABITS, LIVING CONDITIONS AND HYGIENE OF THESE WESTERN SOCIETIES, COULD INTERACT IN A COMPLEX MANNER AS MODULATORS OF DYSBIOSIS, THEREBY INFLUENCING THE ACTIVATION OF IMMUNE CELLS' PROMOTING INFLAMMATION. THE MICROBIOME PRODUCES DIVERSE SMALL MOLECULES VIA SEVERAL METABOLIC WAYS, WITH THE FIBER-DERIVED SHORT-CHAIN FATTY ACIDS (I.E., BUTYRATE) AS MAIN ELEMENTS AND HAVING ANTI-INFLAMMATORY EFFECTS. THESE METABOLITES AND SOME MICRONUTRIENTS OF THE DIET (I.E., VITAMINS, FOLIC ACID, BETA CAROTENE AND TRACE ELEMENTS) ARE REGULATORS OF INNATE AND ADAPTIVE INTESTINAL IMMUNE HOMEOSTASIS. AN EXCESSIVE AND UNHEALTHY CONSUMPTION OF SUGAR, ANIMAL FAT AND A LOW-VEGETABLE AND -FIBER DIET ARE RISK FACTORS FOR IBD APPEARANCE. FURTHERMORE, METABOLISM OF NUTRIENTS IN INTESTINAL EPITHELIUM AND IN GUT MICROBIOTA IS ALTERED BY INFLAMMATION, CHANGING THE DEMAND FOR NUTRIENTS NEEDED FOR HOMEOSTASIS. THIS ROLE OF FOOD AND A REDUCED GUT MICROBIAL DIVERSITY IN CAUSING IBD MIGHT ALSO HAVE A PROPHYLACTIC OR THERAPEUTIC ROLE FOR IBD. THE RELATIONSHIP BETWEEN DIETARY INTAKE, SYMPTOMS, AND BOWEL INFLAMMATION COULD LEAD TO DIETARY AND LIFESTYLE RECOMMENDATIONS, INCLUDING DIETS WITH ABUNDANT FRUITS, VEGETABLES, OLIVE OIL AND OILY FISH, WHICH HAVE ANTI-INFLAMMATORY EFFECTS AND COULD PREVENT DYSBIOSIS AND IBD. DIETARY MODULATION AND APPROPRIATE EXCLUSION DIETS MIGHT BE A NEW COMPLEMENTARY MANAGEMENT FOR TREATMENT AT DISEASE FLARES AND IN REFRACTORY PATIENTS, EVEN REDUCING COMPLICATIONS, HOSPITALIZATIONS AND SURGERY, THROUGH MODIFYING THE LUMINAL INTESTINAL ENVIRONMENT. 2021 8 4082 31 MATERNAL MODIFIERS OF THE INFANT GUT MICROBIOTA: METABOLIC CONSEQUENCES. TRANSMISSION OF METABOLIC DISEASES FROM MOTHER TO CHILD IS MULTIFACTORIAL AND INCLUDES GENETIC, EPIGENETIC AND ENVIRONMENTAL INFLUENCES. EVIDENCE IN RODENTS, HUMANS AND NON-HUMAN PRIMATES SUPPORT THE SCIENTIFIC PREMISE THAT EXPOSURE TO MATERNAL OBESITY OR HIGH-FAT DIET DURING PREGNANCY CREATES A LONG-LASTING METABOLIC SIGNATURE ON THE INFANT INNATE IMMUNE SYSTEM AND THE JUVENILE MICROBIOTA, WHICH PREDISPOSES THE OFFSPRING TO OBESITY AND METABOLIC DISEASES. IN NEONATES, GASTROINTESTINAL MICROBES INTRODUCED THROUGH THE MOTHER ARE NOTED FOR THEIR ABILITY TO SERVE AS DIRECT INDUCERS/REGULATORS OF THE INFANT IMMUNE SYSTEM. NEONATES HAVE A LIMITED CAPACITY TO INITIATE AN IMMUNE RESPONSE. THUS, DISRUPTION OF MICROBIAL COLONIZATION DURING THE EARLY NEONATAL PERIOD RESULTS IN DISRUPTED POSTNATAL IMMUNE RESPONSES THAT HIGHLIGHT THE NEONATAL PERIOD AS A CRITICAL DEVELOPMENTAL WINDOW. ALTHOUGH THE MECHANISMS ARE POORLY UNDERSTOOD, INCREASING EVIDENCE SUGGESTS THAT MATERNAL OBESITY OR POOR DIET INFLUENCES THE DEVELOPMENT AND MODULATION OF THE INFANT LIVER AND OTHER END ORGANS THROUGH DIRECT COMMUNICATION VIA THE PORTAL SYSTEM, METABOLITE PRODUCTION, ALTERATIONS IN GUT BARRIER INTEGRITY AND THE HEMATOPOIETIC IMMUNE CELL AXIS. THIS REVIEW WILL FOCUS ON HOW MATERNAL OBESITY AND DIETARY INTAKE INFLUENCE THE COMPOSITION OF THE INFANT GUT MICROBIOTA AND HOW AN IMBALANCE OR MALADAPTATION IN THE MICROBIOTA, INCLUDING CHANGES IN EARLY PIONEERING MICROBES, MIGHT CONTRIBUTE TO THE PROGRAMMING OF OFFSPRING METABOLISM WITH SPECIAL EMPHASIS ON MECHANISMS THAT PROMOTE CHRONIC INFLAMMATION IN THE LIVER. COMPREHENSION OF THESE PATHWAYS AND MECHANISMS WILL ELUCIDATE OUR UNDERSTANDING OF DEVELOPMENTAL PROGRAMMING AND MAY EXPAND THE AVENUE OF OPPORTUNITIES FOR NOVEL THERAPEUTICS. 2017 9 2368 21 EPIGENETIC REGULATION OF T HELPER CELLS AND INTESTINAL PATHOGENICITY. INFLAMMATORY BOWEL DISEASES (IBDS) ARE CHARACTERIZED BY RELAPSING AND REMITTING CHRONIC INTESTINAL INFLAMMATION. PREVIOUS STUDIES HAVE DEMONSTRATED THE CONTRIBUTIONS OF GENETIC BACKGROUND, ENVIRONMENTAL FACTORS (FOOD, MICROBIOTA, USE OF ANTIBIOTICS), AND HOST IMMUNITY IN THE DEVELOPMENT OF IBDS. MORE THAN 200 GENES HAVE BEEN SHOWN TO INFLUENCE IBD SUSCEPTIBILITY, MOST OF WHICH ARE INVOLVED IN IMMUNITY. THE VERTEBRATE IMMUNE SYSTEM COMPRISES A COMPLEX NETWORK OF INNATE AND ADAPTIVE IMMUNE CELLS THAT PROTECT THE HOST FROM INFECTION AND CANCER. DYSREGULATION OF THE MUTUALISTIC RELATIONSHIP BETWEEN THE IMMUNE SYSTEM AND THE GUT ENVIRONMENT RESULTS IN IBD. CONSIDERING THE FUNDAMENTAL ROLE OF EPIGENETIC REGULATION IN IMMUNE CELLS, EPIGENETIC MECHANISMS, PARTICULARLY IN T HELPER (TH) CELLS, MAY PLAY A MAJOR ROLE IN THE COMPLEX REGULATION OF MUCOSAL IMMUNITY. EPIGENETIC REGULATION AND DYSREGULATION OF TH CELLS ARE INVOLVED IN THE MAINTENANCE OF INTESTINAL HOMEOSTASIS AND ITS BREAKDOWN IN IBD. 2019 10 2731 22 EXPLORING THE COMPLEX RELATIONSHIP BETWEEN MICROBIOTA AND SYSTEMIC LUPUS ERYTHEMATOSUS. PURPOSE OF REVIEW: SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC AUTOIMMUNE DISEASE CHARACTERIZED BY VARIOUS AUTOANTIBODIES AND MULTI-ORGAN. MICROBIOTA DYSBIOSIS IN THE GUT, SKIN, ORAL, AND OTHER SURFACES HAS A SIGNIFICANT IMPACT ON SLE DEVELOPMENT. THIS ARTICLE SUMMARIZES RELEVANT RESEARCH AND PROVIDES NEW MICROBIOME-RELATED STRATEGIES FOR EXPLORING THE MECHANISMS AND TREATING PATIENTS WITH SLE. RECENT FINDINGS: SLE PATIENTS HAVE DISRUPTIONS IN MULTIPLE MICROBIOMES, WITH THE GUT MICROBIOTA (BACTERIA, VIRUSES, AND FUNGI) AND THEIR METABOLITES BEING THE MOST THOROUGHLY RESEARCHED. THIS DYSBIOSIS CAN PROMOTE SLE PROGRESSION THROUGH MECHANISMS SUCH AS THE LEAKY GUT, MOLECULAR MIMICRY, AND EPIGENETIC REGULATION. NOTWITHSTANDING STUDY CONSTRAINTS ON THE RELATIONSHIP BETWEEN MICROBIOTA AND SLE, SPECIFIC INTERVENTIONS TARGETING THE GUT MICROBIOTA, SUCH AS PROBIOTICS, DIETARY MANAGEMENT, AND FECAL MICROBIOTA TRANSPLANTATION, HAVE EMERGED AS PROMISING SLE THERAPEUTICS. 2023 11 566 33 BASES FOR THE ADEQUATE DEVELOPMENT OF NUTRITIONAL RECOMMENDATIONS FOR PATIENTS WITH INFLAMMATORY BOWEL DISEASE. INFLAMMATORY BOWEL DISEASE (IBD) IS A CHRONIC AND RELAPSING INFLAMMATORY CONDITION OF THE GASTROINTESTINAL TRACT; IT IS A HETEROGENEOUS AND MULTIFACTORIAL DISORDER RESULTING FROM A COMPLEX INTERPLAY BETWEEN GENETIC VARIATION, INTESTINAL MICROBIOTA, THE HOST IMMUNE SYSTEM AND ENVIRONMENTAL FACTORS SUCH AS DIET, DRUGS, BREASTFEEDING AND SMOKING. THE INTERACTIONS BETWEEN DIETARY NUTRIENTS AND INTESTINAL IMMUNITY ARE COMPLEX. THERE IS A COMPELLING ARGUMENT FOR ENVIRONMENTAL FACTORS SUCH AS DIET PLAYING A ROLE IN THE CAUSE AND COURSE OF IBD, GIVEN THAT THREE IMPORTANT FACTORS IN THE PATHOGENESIS OF IBD CAN BE MODULATED AND CONTROLLED BY DIET: INTESTINAL MICROBIOTA, THE IMMUNE SYSTEM AND EPITHELIAL BARRIER FUNCTION. THE AIM OF THIS REVIEW IS TO SUMMARIZE THE EPIDEMIOLOGICAL FINDINGS REGARDING DIET AND TO FOCUS ON THE EFFECTS THAT NUTRIENTS EXERT ON THE INTESTINAL MUCOSA-MICROBIOTA-PERMEABILITY INTERACTION. THE NATURE OF THESE INTERACTIONS IN IBD IS INFLUENCED BY ALTERATIONS IN THE NUTRITIONAL METABOLISM OF THE GUT MICROBIOTA AND HOST CELLS THAT CAN INFLUENCE THE OUTCOME OF NUTRITIONAL INTERVENTION. A BETTER UNDERSTANDING OF DIET-HOST-MICROBIOTA INTERACTIONS IS ESSENTIAL FOR UNRAVELLING THE COMPLEX MOLECULAR BASIS OF EPIGENETIC, GENETIC AND ENVIRONMENTAL INTERACTIONS UNDERLYING IBD PATHOGENESIS AS WELL AS FOR OFFERING NEW THERAPEUTIC APPROACHES FOR THE TREATMENT OF IBD. 2019 12 2065 19 EPIGENETIC CONTROL OF INTESTINAL BARRIER FUNCTION AND INFLAMMATION IN ZEBRAFISH. THE INTESTINAL EPITHELIUM FORMS A BARRIER PROTECTING THE ORGANISM FROM MICROBES AND OTHER PROINFLAMMATORY STIMULI. THE INTEGRITY OF THIS BARRIER AND THE PROPER RESPONSE TO INFECTION REQUIRES PRECISE REGULATION OF POWERFUL IMMUNE HOMING SIGNALS SUCH AS TUMOR NECROSIS FACTOR (TNF). DYSREGULATION OF TNF LEADS TO INFLAMMATORY BOWEL DISEASES (IBD), BUT THE MECHANISM CONTROLLING THE EXPRESSION OF THIS POTENT CYTOKINE AND THE EVENTS THAT TRIGGER THE ONSET OF CHRONIC INFLAMMATION ARE UNKNOWN. HERE, WE SHOW THAT LOSS OF FUNCTION OF THE EPIGENETIC REGULATOR UBIQUITIN-LIKE PROTEIN CONTAINING PHD AND RING FINGER DOMAINS 1 (UHRF1) IN ZEBRAFISH LEADS TO A REDUCTION IN TNFA PROMOTER METHYLATION AND THE INDUCTION OF TNFA EXPRESSION IN INTESTINAL EPITHELIAL CELLS (IECS). THE INCREASE IN IEC TNFA LEVELS IS MICROBE-DEPENDENT AND RESULTS IN IEC SHEDDING AND APOPTOSIS, IMMUNE CELL RECRUITMENT, AND BARRIER DYSFUNCTION, CONSISTENT WITH CHRONIC INFLAMMATION. IMPORTANTLY, TNFA KNOCKDOWN IN UHRF1 MUTANTS RESTORES IEC MORPHOLOGY, REDUCES CELL SHEDDING, AND IMPROVES BARRIER FUNCTION. WE PROPOSE THAT LOSS OF EPIGENETIC REPRESSION AND TNF INDUCTION IN THE INTESTINAL EPITHELIUM CAN LEAD TO IBD ONSET. 2015 13 6253 34 THE MICROBIOME AND HEPATOCELLULAR CARCINOMA. THE HUMAN MICROBIOME IS A VAST AND COMPLEX SYSTEM ENCOMPASSING ALL OF THE MICROBES AND THEIR GENES THAT OCCUPY THE ENVIRONMENTALLY EXPOSED SURFACES OF THE HUMAN BODY. THE GUT MICROBIOTA AND ITS ASSOCIATED MICROBIOME PLAY AN INTEGRAL ROLE IN MAMMALIAN METABOLISM AND IMMUNE TOLERANCE AS WELL AS IN IMMUNOCOMPETENCE. DISRUPTIONS IN THE HUMAN GUT MICROBIOME ARE ASSOCIATED WITH A CYCLE OF HEPATOCYTE INJURY AND REGENERATION CHARACTERISTIC OF CHRONIC LIVER DISEASE. THE PERSISTENCE OF THIS INFLAMMATION HAS BEEN SHOWN TO INDUCE THE ACCUMULATION OF GENETIC AND EPIGENETIC CHANGES LEADING TO HEPATOCELLULAR CARCINOMA (HCC). THEREFORE, THE IMPORTANCE AND PROGNOSTIC INFLUENCE OF THE GUT MICROBIOME ON HEPATOCARCINOGENESIS HAS BEEN INCREASINGLY STUDIED IN RECENT YEARS. THIS REVIEW DISCUSSES THE MECHANISMS BY WHICH IMBALANCES IN THE GUT MICROBIOME DISTURB THE GUT-LIVER AXIS TO IMPACT HEPATOCARCINOGENESIS, INCLUDING DISRUPTION OF THE INTESTINAL BARRIER, CHANGES IN BILE ACID METABOLISM, AND REDUCTION IN TUMOR-SUPPRESSING MICRORNA. FURTHERMORE, THIS REVIEW SUMMARIZES RECENT ADVANCES IN POTENTIAL MICROBIOME-BASED THERAPEUTIC OPPORTUNITIES IN HCC. 2020 14 1404 32 DIETARY COMPOSITION AND EFFECTS IN INFLAMMATORY BOWEL DISEASE. DRAMATIC CHANGES IN THE ENVIRONMENT AND HUMAN LIFESTYLE HAVE BEEN ASSOCIATED WITH THE RISE OF VARIOUS CHRONIC COMPLEX DISEASES, SUCH AS INFLAMMATORY BOWEL DISEASE (IBD). A DYSBIOTIC GUT MICROBIOTA HAS BEEN PROPOSED AS A CRUCIAL PATHOGENIC ELEMENT, CONTRIBUTING TO IMMUNE IMBALANCES AND FOSTERING A PROINFLAMMATORY MILIEU, WHICH MAY BE ASSOCIATED WITH DISEASE RELAPSES OR EVEN THE INITIATION OF IBD. IN ADDITION TO REPRESENTING IMPORTANT REGULATORS OF THE MUCOSAL IMMUNITY AND THE COMPOSITION OF THE GUT MICROBIOTA, FOOD COMPONENTS HAVE BEEN SHOWN TO BE POTENTIAL ENVIRONMENTAL TRIGGERS OF EPIGENETIC MODIFICATIONS. IN THE CONTEXT OF CHRONIC INTESTINAL INFLAMMATION, DIETARY HABITS AND SPECIFIC FOOD COMPONENTS HAVE BEEN IMPLICATED AS IMPORTANT MODULATORS OF EPIGENETIC MECHANISMS, INCLUDING DNA METHYLATION, WHICH MAY PREDISPOSE A PERSON TO THE INCREASED RISK OF THE INITIATION AND EVOLUTION OF IBD. THIS REVIEW PROVIDES NOVEL INSIGHTS ABOUT HOW DIETARY FACTORS MAY INTERACT WITH THE INTESTINAL MUCOSA AND MODULATE IMMUNE HOMEOSTASIS BY SHAPING THE INTESTINAL ECOSYSTEM, AS WELL AS THE POTENTIAL INFLUENCE OF DIET IN THE ETIOPATHOGENESIS AND MANAGEMENT OF IBD. 2019 15 3678 25 INFLAMMATION AND REGENERATION IN THE DENTIN-PULP COMPLEX: A DOUBLE-EDGED SWORD. DENTAL TISSUE INFECTION AND DISEASE RESULT IN ACUTE AND CHRONIC ACTIVATION OF THE INNATE IMMUNE RESPONSE, WHICH IS MEDIATED BY MOLECULAR AND CELLULAR SIGNALING. DIFFERENT CELL TYPES WITHIN THE DENTIN-PULP COMPLEX ARE ABLE TO DETECT INVADING BACTERIA AT ALL STAGES OF THE INFECTION. INDEED, AT RELATIVELY EARLY DISEASE STAGES, ODONTOBLASTS WILL RESPOND TO BACTERIAL COMPONENTS, AND AS THE DISEASE PROGRESSES, CORE PULPAL CELLS INCLUDING FIBROBLASTS, STEMS CELLS, ENDOTHELIAL CELLS, AND IMMUNE CELLS WILL BECOME INVOLVED. PATTERN RECOGNITION RECEPTORS, SUCH AS TOLL-LIKE RECEPTORS EXPRESSED ON THESE CELL TYPES, ARE RESPONSIBLE FOR DETECTING BACTERIAL COMPONENTS, AND THEIR LIGAND BINDING LEADS TO THE ACTIVATION OF THE NUCLEAR FACTOR-KAPPA B AND P38 MITOGEN-ACTIVATED PROTEIN (MAP) KINASE INTRACELLULAR SIGNALING CASCADES. SUBSEQUENT NUCLEAR TRANSLOCATION OF THE TRANSCRIPTION FACTOR SUBUNITS FROM THESE PATHWAYS WILL LEAD TO PROINFLAMMATORY MEDIATOR EXPRESSION, INCLUDING INCREASES IN CYTOKINES AND CHEMOKINES, WHICH TRIGGER HOST CELLULAR DEFENSE MECHANISMS. THE COMPLEX MOLECULAR SIGNALING WILL RESULT IN THE RECRUITMENT OF IMMUNE SYSTEM CELLS TARGETED AT COMBATING THE INVADING MICROBES; HOWEVER, THE TRAFFICKING AND ANTIBACTERIAL ACTIVITY OF THESE CELLS CAN LEAD TO COLLATERAL TISSUE DAMAGE. RECENT EVIDENCE SUGGESTS THAT IF INFLAMMATION IS RESOLVED RELATIVELY LOW LEVELS OF PROINFLAMMATORY MEDIATORS MAY PROMOTE TISSUE REPAIR, WHEREAS IF CHRONIC INFLAMMATION ENSUES REPAIR MECHANISMS BECOME INHIBITED. THUS, THE EFFECTS OF MEDIATORS ARE TEMPORAL CONTEXT DEPENDENT. ALTHOUGH CONTAINMENT AND REMOVAL OF THE INFECTION ARE KEYS TO ENABLE DENTAL TISSUE REPAIR, IT IS FEASIBLE THAT THE DEVELOPMENT OF ANTI-INFLAMMATORY AND IMMUNOMODULATORY APPROACHES, BASED ON MOLECULAR, EPIGENETIC, AND PHOTOBIOMODULATORY TECHNOLOGIES, MAY ALSO BE BENEFICIAL FOR FUTURE ENDODONTIC TREATMENTS. 2014 16 2617 34 EPIGENOME TARGETING BY PROBIOTIC METABOLITES. BACKGROUND: THE INTESTINAL MICROBIOTA PLAYS AN IMPORTANT ROLE IN IMMUNE DEVELOPMENT AND HOMEOSTASIS. A DISTURBED MICROBIOTA DURING EARLY INFANCY IS ASSOCIATED WITH AN INCREASED RISK OF DEVELOPING INFLAMMATORY AND ALLERGIC DISEASES LATER IN LIFE. THE MECHANISMS UNDERLYING THESE EFFECTS ARE POORLY UNDERSTOOD BUT ARE LIKELY TO INVOLVE ALTERATIONS IN MICROBIAL PRODUCTION OF FERMENTATION-DERIVED METABOLITES, WHICH HAVE POTENT IMMUNE MODULATING PROPERTIES AND ARE REQUIRED FOR MAINTENANCE OF HEALTHY MUCOSAL IMMUNE RESPONSES. PROBIOTICS ARE BENEFICIAL BACTERIA THAT HAVE THE CAPACITY TO ALTER THE COMPOSITION OF BACTERIAL SPECIES IN THE INTESTINE THAT CAN IN TURN INFLUENCE THE PRODUCTION OF FERMENTATION-DERIVED METABOLITES. PRINCIPAL AMONG THESE METABOLITES ARE THE SHORT-CHAIN FATTY ACIDS BUTYRATE AND ACETATE THAT HAVE POTENT ANTI-INFLAMMATORY ACTIVITIES IMPORTANT IN REGULATING IMMUNE FUNCTION AT THE INTESTINAL MUCOSAL SURFACE. THEREFORE STRATEGIES AIMED AT RESTORING THE MICROBIOTA PROFILE MAY BE EFFECTIVE IN THE PREVENTION OR TREATMENT OF ALLERGIC AND INFLAMMATORY DISEASES. PRESENTATION OF THE HYPOTHESIS: PROBIOTIC BACTERIA HAVE DIVERSE EFFECTS INCLUDING ALTERING MICROBIOTA COMPOSITION, REGULATING EPITHELIAL CELL BARRIER FUNCTION AND MODULATING OF IMMUNE RESPONSES. THE PRECISE MOLECULAR MECHANISMS MEDIATING THESE PROBIOTIC EFFECTS ARE NOT WELL UNDERSTOOD. SHORT-CHAIN FATTY ACIDS SUCH AS BUTYRATE ARE A CLASS OF HISTONE DEACETYLASE INHIBITORS IMPORTANT IN THE EPIGENETIC CONTROL OF HOST CELL RESPONSES. IT IS HYPOTHESIZED THAT THE BIOLOGICAL FUNCTION OF PROBIOTICS MAY BE A RESULT OF EPIGENETIC MODIFICATIONS THAT MAY EXPLAIN THE WIDE RANGE OF EFFECTS OBSERVED. STUDIES DELINEATING THE EFFECTS OF PROBIOTICS ON SHORT-CHAIN FATTY ACID PRODUCTION AND THE EPIGENETIC ACTIONS OF SHORT-CHAIN FATTY ACIDS WILL ASSIST IN UNDERSTANDING THE ASSOCIATION BETWEEN MICROBIOTA AND ALLERGIC OR AUTOIMMUNE DISORDERS. TESTING THE HYPOTHESIS: WE PROPOSE THAT TREATMENT WITH SPECIFIC PROBIOTIC BACTERIA UNDER IN VIVO CONDITIONS WOULD OFFER THE IDEAL CONDITIONS TO EXAMINE THE MICROBIOLOGICAL, IMMUNOLOGICAL AND EPIGENETIC MECHANISMS OF ACTION. ADVANCES IN EPIGENETIC TECHNOLOGY NOW ALLOW INVESTIGATORS TO BETTER UNDERSTAND THE COMPLEX BIOLOGICAL PROPERTIES OF PROBIOTICS AND THEIR METABOLITES. IMPLICATIONS OF THE HYPOTHESIS: DETERMINING THE PRECISE MECHANISMS OF PROBIOTIC ACTION WILL LEAD TO MORE SPECIFIC AND EFFICACIOUS THERAPEUTIC STRATEGIES IN THE PREVENTION OR TREATMENT OF CHRONIC INFLAMMATORY CONDITIONS. 2010 17 3692 29 INFLAMMATORY BOWEL DISEASES: THE ROLE OF GUT MICROBIOTA. INFLAMMATORY BOWEL DISEASES (IBD) ARE CHRONIC MULTIFACTORIAL DISEASES CHARACTERIZED BY PARTIALLY UNCLEAR PATHOGENIC MECHANISMS INCLUDING CHANGES IN INTESTINAL MICROBIOTA. DESPITE THE MICROBIOTA, ALTERATION IS WELL ESTABLISHED IN IBD PATIENTS, AS REPORTED BY 16RNA SEQUENCING ANALYSIS, AN IMPORTANT GOAL IS TO DEFINE IF IT IS JUST A CONSEQUENCE OF THE DISEASE PROGRESSION OR A TRIGGER FACTOR OF THE DISEASE ITSELF. TO DATE, GUT MICROBIOTA COMPOSITION AND GUT MICROBIOTA-RELATED METABOLITES SEEM TO AFFECT THE HOST HEALTHY STATE BOTH BY MODULATING METABOLIC PATHWAYS OR ACTING ON THE EXPRESSION OF DIFFERENT GENES THROUGH EPIGENETIC EFFECTS. BECAUSE OF THIS, IT HAS BEEN SUGGESTED THAT INTESTINAL MICROBIOTA MIGHT REPRESENT A PROMISING THERAPEUTIC TARGET FOR IBD PATIENTS. THE AIM OF THIS REVIEW IS TO SUMMARIZE BOTH THE MOST RECENT ACQUISITIONS IN THE FIELD OF GUT MICROBIOTA AND ITS INVOLVEMENT IN INTESTINAL INFLAMMATION TOGETHER WITH THE AVAILABLE STRATEGIES FOR THE MODULATION OF MICROBIOTA, SUCH AS PREBIOTICS AND/OR PROBIOTICS ADMINISTRATION OR FECAL MICROBIOTA TRANSPLANTATION. 2020 18 1149 30 CONNECTING THE IMMUNE SYSTEM, SYSTEMIC CHRONIC INFLAMMATION AND THE GUT MICROBIOME: THE ROLE OF SEX. UNRESOLVED LOW GRADE SYSTEMIC INFLAMMATION REPRESENTS THE UNDERLYING PATHOLOGICAL MECHANISM DRIVING IMMUNE AND METABOLIC PATHWAYS INVOLVED IN AUTOIMMUNE DISEASES (AID). MECHANISTIC STUDIES IN ANIMAL MODELS OF AID AND OBSERVATIONAL STUDIES IN PATIENTS HAVE FOUND ALTERATIONS IN GUT MICROBIOTA COMMUNITIES AND THEIR METABOLITES, SUGGESTING A MICROBIAL CONTRIBUTION TO THE ONSET OR PROGRESSION OF AID. THE GUT MICROBIOTA AND ITS METABOLITES HAVE BEEN SHOWN TO INFLUENCE IMMUNE FUNCTIONS AND IMMUNE HOMEOSTASIS BOTH WITHIN THE GUT AND SYSTEMATICALLY. MICROBIAL DERIVED-SHORT CHAIN FATTY ACID (SCFA) AND BIO-TRANSFORMED BILE ACID (BA) HAVE BEEN SHOWN TO INFLUENCE THE IMMUNE SYSTEM ACTING AS LIGANDS SPECIFIC CELL SIGNALING RECEPTORS LIKE GPRCS, TGR5 AND FXR, OR VIA EPIGENETIC PROCESSES. SIMILARLY, INTESTINAL PERMEABILITY (LEAKY GUT) AND BACTERIAL TRANSLOCATION ARE IMPORTANT CONTRIBUTORS TO CHRONIC SYSTEMIC INFLAMMATION AND, WITHOUT REPAIR OF THE INTESTINAL BARRIER, MIGHT REPRESENT A CONTINUOUS INFLAMMATORY STIMULUS CAPABLE OF TRIGGERING AUTOIMMUNE PROCESSES. RECENT STUDIES INDICATE GENDER-SPECIFIC DIFFERENCES IN IMMUNITY, WITH THE GUT MICROBIOTA SHAPING AND BEING CONCOMITANTLY SHAPED BY THE HORMONAL MILIEU GOVERNING DIFFERENCES BETWEEN THE SEXES. A BI-DIRECTIONAL CROSS-TALK BETWEEN MICROBIOTA AND THE ENDOCRINE SYSTEM IS EMERGING WITH BACTERIA BEING ABLE TO PRODUCE HORMONES (E.G. SEROTONIN, DOPAMINE AND SOMATOSTATINE), RESPOND TO HOST HORMONES (E.G. ESTROGENS) AND REGULATE HOST HORMONES' HOMEOSTASIS (E.G BY INHIBITING GENE PROLACTIN TRANSCRIPTION OR CONVERTING GLUCOCORTICOIDS TO ANDROGENS). WE REVIEW HEREIN HOW GUT MICROBIOTA AND ITS METABOLITES REGULATE IMMUNE FUNCTION, INTESTINAL PERMEABILITY AND POSSIBLY AID PATHOLOGICAL PROCESSES. FURTHER, WE DESCRIBE THE DYSBIOSIS WITHIN THE GUT MICROBIOTA OBSERVED IN DIFFERENT AID AND SPECULATE HOW RESTORING GUT MICROBIOTA COMPOSITION AND ITS REGULATORY METABOLITES BY DIETARY INTERVENTION INCLUDING PREBIOTICS AND PROBIOTICS COULD HELP IN PREVENTING OR AMELIORATING AID. FINALLY, WE SUGGEST THAT, GIVEN CONSISTENT OBSERVATIONS OF MICROBIOTA DYSBIOSIS ASSOCIATED WITH AID AND THE ABILITY OF SCFA AND BA TO REGULATE INTESTINAL PERMEABILITY AND INFLAMMATION, FURTHER MECHANISTIC STUDIES, EXAMINING HOW DIETARY MICROBIOTA MODULATION CAN PROTECT AGAINST AID, HOLD CONSIDERABLE POTENTIAL TO TACKLE INCREASED INCIDENCE OF AID AT THE POPULATION LEVEL. 2018 19 3585 29 IMPACT OF THE EXPOSOME ON THE EPIGENOME IN INFLAMMATORY BOWEL DISEASE PATIENTS AND ANIMAL MODELS. INFLAMMATORY BOWEL DISEASES (IBD) ARE CHRONIC INFLAMMATORY DISORDERS OF THE GASTROINTESTINAL TRACT THAT ENCOMPASS TWO MAIN PHENOTYPES, NAMELY CROHN'S DISEASE AND ULCERATIVE COLITIS. THESE CONDITIONS OCCUR IN GENETICALLY PREDISPOSED INDIVIDUALS IN RESPONSE TO ENVIRONMENTAL FACTORS. EPIGENETICS, ACTING BY DNA METHYLATION, POST-TRANSLATIONAL HISTONES MODIFICATIONS OR BY NON-CODING RNAS, COULD EXPLAIN HOW THE EXPOSOME (OR ALL ENVIRONMENTAL INFLUENCES OVER THE LIFE COURSE, FROM CONCEPTION TO DEATH) COULD INFLUENCE THE GENE EXPRESSION TO CONTRIBUTE TO INTESTINAL INFLAMMATION. WE PERFORMED A SCOPING SEARCH USING MEDLINE TO IDENTIFY ALL THE ELEMENTS OF THE EXPOSOME THAT MAY PLAY A ROLE IN INTESTINAL INFLAMMATION THROUGH EPIGENETIC MODIFICATIONS, AS WELL AS THE UNDERLYING MECHANISMS. THE ENVIRONMENTAL FACTORS EPIGENETICALLY INFLUENCING THE OCCURRENCE OF INTESTINAL INFLAMMATION ARE THE MATERNAL LIFESTYLE (MAINLY DIET, THE OCCURRENCE OF INFECTION DURING PREGNANCY AND SMOKING); BREASTFEEDING; MICROBIOTA; DIET (INCLUDING A LOW-FIBER DIET, HIGH-FAT DIET AND DEFICIENCY IN MICRONUTRIENTS); SMOKING HABITS, VITAMIN D AND DRUGS (E.G., IBD TREATMENTS, ANTIBIOTICS AND PROBIOTICS). INFLUENCED BY BOTH MICROBIOTA AND DIET, SHORT-CHAIN FATTY ACIDS ARE GUT MICROBIOTA-DERIVED METABOLITES RESULTING FROM THE ANAEROBIC FERMENTATION OF NON-DIGESTIBLE DIETARY FIBERS, PLAYING AN EPIGENETICALLY MEDIATED ROLE IN THE INTEGRITY OF THE EPITHELIAL BARRIER AND IN THE DEFENSE AGAINST INVADING MICROORGANISMS. ALTHOUGH THE IMPACT OF SOME ENVIRONMENTAL FACTORS HAS BEEN IDENTIFIED, THE EXPOSOME-INDUCED EPIMUTATIONS IN IBD REMAIN A LARGELY UNDEREXPLORED FIELD. HOW THESE ENVIRONMENTAL EXPOSURES INDUCE EPIGENETIC MODIFICATIONS (IN TERMS OF DURATION, FREQUENCY AND THE TIMING AT WHICH THEY OCCUR) AND HOW OTHER ENVIRONMENTAL FACTORS ASSOCIATED WITH IBD MODULATE EPIGENETICS DESERVE TO BE FURTHER INVESTIGATED. 2022 20 6568 26 TRANSMATERNAL HELICOBACTER PYLORI EXPOSURE REDUCES ALLERGIC AIRWAY INFLAMMATION IN OFFSPRING THROUGH REGULATORY T CELLS. BACKGROUND: TRANSMATERNAL EXPOSURE TO TOBACCO, MICROBES, NUTRIENTS, AND OTHER ENVIRONMENTAL FACTORS SHAPES THE FETAL IMMUNE SYSTEM THROUGH EPIGENETIC PROCESSES. THE GASTRIC MICROBE HELICOBACTER PYLORI REPRESENTS AN ANCESTRAL CONSTITUENT OF THE HUMAN MICROBIOTA THAT CAUSES GASTRIC DISORDERS ON THE ONE HAND AND IS INVERSELY ASSOCIATED WITH ALLERGIES AND CHRONIC INFLAMMATORY CONDITIONS ON THE OTHER. OBJECTIVE: HERE WE INVESTIGATE THE CONSEQUENCES OF TRANSMATERNAL EXPOSURE TO H PYLORI IN UTERO AND/OR DURING LACTATION FOR SUSCEPTIBILITY TO VIRAL AND BACTERIAL INFECTION, PREDISPOSITION TO ALLERGIC AIRWAY INFLAMMATION, AND DEVELOPMENT OF IMMUNE CELL POPULATIONS IN THE LUNGS AND LYMPHOID ORGANS. METHODS: WE USE EXPERIMENTAL MODELS OF HOUSE DUST MITE- OR OVALBUMIN-INDUCED AIRWAY INFLAMMATION AND INFLUENZA A VIRUS OR CITROBACTER RODENTIUM INFECTION ALONG WITH METAGENOMICS ANALYSES, MULTICOLOR FLOW CYTOMETRY, AND BISULFITE PYROSEQUENCING, TO STUDY THE EFFECTS OF H PYLORI ON ALLERGY SEVERITY AND IMMUNOLOGIC AND MICROBIOME CORRELATES THEREOF. RESULTS: PERINATAL EXPOSURE TO H PYLORI EXTRACT OR ITS IMMUNOMODULATOR VACUOLATING CYTOTOXIN CONFERS ROBUST PROTECTIVE EFFECTS AGAINST ALLERGIC AIRWAY INFLAMMATION NOT ONLY IN FIRST- BUT ALSO SECOND-GENERATION OFFSPRING BUT DOES NOT INCREASE SUSCEPTIBILITY TO VIRAL OR BACTERIAL INFECTION. IMMUNE CORRELATES OF ALLERGY PROTECTION INCLUDE SKEWING OF REGULATORY OVER EFFECTOR T CELLS, EXPANSION OF REGULATORY T-CELL SUBSETS EXPRESSING CXCR3 OR RETINOIC ACID-RELATED ORPHAN RECEPTOR GAMMAT, AND DEMETHYLATION OF THE FORKHEAD BOX P3 (FOXP3) LOCUS. THE COMPOSITION AND DIVERSITY OF THE GASTROINTESTINAL MICROBIOTA IS MEASURABLY AFFECTED BY PERINATAL H PYLORI EXPOSURE. CONCLUSION: WE CONCLUDE THAT EXPOSURE TO H PYLORI HAS CONSEQUENCES NOT ONLY FOR THE CARRIER BUT ALSO FOR SUBSEQUENT GENERATIONS THAT CAN BE EXPLOITED FOR INTERVENTIONAL PURPOSES. 2019