Immune disorders and its correlation with gut microbiome

Hydrogel-encapsulation to enhance bacterial diagnosis of colon inflammation

Bacteria can be genetically programmed to sense and report the presence of disease biomarkers in the gastrointestinal (GI) tract. However, diagnostic bacteria are typically delivered via oral administration of liquid cultures, resulting in poor survival and high dispersal in vivo. These limitations confound recovery and analysis of engineered bacteria from GI or stool samples. Here, we demonstrate that encapsulating bacteria inside of alginate core-shell particles enables robust survival, containment, and diagnostic function in vivo. We demonstrate these benefits by encapsulating a strain engineered to report the presence of the biomarker thiosulfate via fluorescent protein expression in order to diagnose dextran sodium sulfate-induced colitis in rats. Hydrogel-encapsulated bacteria engineered to sense and respond to physiological stimuli should enable minimally invasive monitoring of a wide range of diseases and have applications as next-generation smart therapeutics.

Differential oral microbiome in nonhuman primates from periodontitis-susceptible and periodontitis-resistant matrilines

Rhesus monkeys (n = 36) exhibiting a healthy periodontium at baseline were used to induce progressing periodontitis through ligature placement around premolar/molar teeth. Bacterial samples were collected at baseline, 0.5, 1, and 3 months of disease and at 5 months for disease resolution. The animals were distributed into two groups (18/group): 3-7 years (young) and 12-23 years (adult) and stratified based upon matriline susceptibility to periodontitis (PDS, susceptible; PDR, resistant). A total of 444 operational taxonomic units (OTUs) with 100 microbes representing a core microbiome present in ≥75% of the samples were identified. Only 48% of the major phylotypes overlapped in the PDS and PDR samples. Different OTU abundance patterns were seen in young animals from the PDS and PDR matrilines, with qualitative similarities during disease and the relative abundance of phylotypes becoming less diverse. In adults, 23 OTUs were increased during disease in PDS samples and 24 in PDR samples; however, only five were common between these groups. Greater diversity of OTU relative abundance at baseline was observed with adult compared to young oral samples from both the PDS and PDR groups. With disease initiation (2 weeks), less diversity of relative abundance and some distinctive increases in specific OTUs were noted. By 1 month, there was considerable qualitative homogeneity in the major OTUs in both groups; however, by 3 months, there was an exacerbation of both qualitative and quantitative differences in the dominant OTUs between the PDS and PDR samples. These results support that some differences in disease expression related to matriline (familial) periodontitis risk may be explained by microbiome features.

Role of microbiota and microbiota-derived short-chain fatty acids in PDAC

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive lethal diseases among other cancer types. Gut microbiome and its metabolic regulation play a crucial role in PDAC. Metabolic regulation in the gut is a complex process that involves microbiome and microbiome-derived short-chain fatty acids (SCFAs). SCFAs regulate inflammation, as well as lipid and glucose metabolism, through different pathways. This review aims to summarize recent developments in PDAC in the context of gut and oral microbiota and their associations with short-chain fatty acid (SCFA). In addition to this, we discuss possible therapeutic applications using microbiota in PDAC.

Development of a Novel Targeted Metabolomic LC-QqQ-MS Method in Allergic Inflammation

The transition from mild to severe allergic phenotypes is still poorly understood and there is an urgent need of incorporating new therapies, accompanied by personalized diagnosis approaches. This work presents the development of a novel targeted metabolomic methodology for the analysis of 36 metabolites related to allergic inflammation, including mostly sphingolipids, lysophospholipids, amino acids, and those of energy metabolism previously identified in non-targeted studies. The methodology consisted of two complementary chromatography methods, HILIC and reversed-phase. These were developed using liquid chromatography, coupled to triple quadrupole mass spectrometry (LC-QqQ-MS) in dynamic multiple reaction monitoring (dMRM) acquisition mode and were validated using ICH guidelines. Serum samples from two clinical models of allergic asthma patients were used for method application, which were as follows: (1) corticosteroid-controlled (ICS, n = 6) versus uncontrolled (UC, n = 4) patients, and immunotherapy-controlled (IT, n = 23) versus biologicals-controlled (BIO, n = 12) patients. The results showed significant differences mainly in lysophospholipids using univariate analyses in both models. Multivariate analysis for model 1 was able to distinguish both groups, while for model 2, the results showed the correct classification of all BIO samples within their group. Thus, this methodology can be of great importance for further understanding the role of these metabolites in allergic diseases as potential biomarkers for disease severity and for predicting patient treatment response.

Symbiotic microorganisms: prospects for treating atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a common chronic recurrent inflammatory skin disease. The pathogenesis is unclear but may be related to genetic, immune, and environmental factors and abnormal skin barrier function. Symbiotic microorganisms in the gut and on the skin are associated with AD occurrence.

AREAS COVERED

We discuss the metabolism and distribution of intestinal and skin flora and review their relationship with AD, summarizing the recent applications of intestinal and skin flora in AD treatment, and discussing the prospect of research on these two human microbiota systems and their influence on AD treatment. The PubMed database was searched to identify relevant publications from 1949 to 2020 for the bibliometric analysis of atopic dermatitis and symbiotic microorganisms.

EXPERT OPINION

Many studies have suggested a potential contribution of microbes in the intestine and on the skin to AD. Bacteria living on the skin can aggravate AD by secreting numerous virulence factors. Moreover, the metabolism of intestinal flora can influence AD occurrence and development via the circulatory system. Current evidence suggests that by regulating intestinal and skin flora, AD can be treated and prevented.

Immunoglobulin gene expression profiles and microbiome characteristics in periodontitis in nonhuman primates

Colonization of mucosal tissues throughout the body occurs by a wide array of bacteria in the microbiome that stimulate the cells and tissues, as well as respond to changes in the local milieu. A feature of periodontitis is the detection of adaptive immune responses to members of the oral microbiome that show specificity and changes with disease and treatment. Thus, variations in antibody responses are noted across the population and affected by aging, albeit, data are still unclear as to how these differences relate to disease risk and expression. This study used a nonhuman primate model of experimental periodontitis to track local microbiome changes as they related to the use and expression of a repertoire of immunoglobulin genes in gingival tissues. Gingival tissue biopsies from healthy tissues and following ligature-placement for disease initiation and progression provided gene expression analysis. Additionally, following removal of the ligatures, clinical healing occurs with gene expression in disease resolved tissues. Groups of 9 animals (young: <3 yrs., adolescent: 3-7 yrs., adult -12 to 15 yrs.; aged: 17-22 yrs) were used in the investigation. In healthy tissues, young and adolescent animals showed levels of expression of 78 Ig genes that were uniformly less than adults. In contrast, ⅔ of the Ig genes were elevated by > 2-fold in the aged samples. Specific increases in an array of the Ig gene transcripts were detected in adults at disease initiation and throughout progression, while increases in young and adolescent animals were observed only with disease progression, and in aged samples primarily late in disease progression. Resolved lesions continued to demonstrate elevated levels of Ig gene expression in only young, adolescent and adult animals. The array of Ig genes significantly correlated with inflammatory, tissue biology and hypoxia genes in the gingival tissues, with variations associated with age. In the young group of animals, specific members of the oral microbiome positively correlated with Ig gene expression, while in the older animals, many of these correlations were negative. Significant correlations were observed with a select assortment of bacterial OTUs and multiple Ig genes in both younger and older animal samples, albeit the genera/species showed little overlap. Incorporating this array of microbes and host responses clearly discriminated the various time points in transition from health to disease and resolution in both the young and adult animals. The results support a major importance of adaptive immune responses in the kinetics of periodontal lesion formation, and support aging effects on the repertoire of Ig genes that may relate to the increased prevalence and severity of periodontitis with age.

Probiotic mixture reduces gut inflammation and microbial dysbiosis in children with atopic dermatitis

BACKGROUND

Recent data suggested that dysbiosis of the gut microbiome is associated with childhood allergic diseases. Oral administration of probiotic formulations may improve the severity of atopic dermatitis (AD) by restoring imbalanced gut microbiota and reducing intestinal inflammation in children.

OBJECTIVES

The aim of this study was to investigate the effects of a probiotic mixture on the clinical severity of AD, gut inflammatory markers and alterations in microbiome dysbiosis in children with AD.

METHODS

A total of 25 subjects were enrolled in this study and administered with a mixture of probiotic strains consisting of Lactobacilli and Bifidobacteria for 4 weeks. The clinical efficacy of the probiotic mixture was assessed using SCORAD index and TEWL. Faecal calprotectin levels were measured as a marker for intestinal inflammation. The composition and diversity of the gut microbiome were analysed using 16S rRNA pyrosequencing.

RESULTS

The SCORAD (38.9 ± 17.2 vs 29.0 ± 15.4, P < 0.001) and TEWL (58.3 ± 12.5 vs 27.3 ± 8.7 g/m² /h, P = 0.028) were significantly decreased after 4 weeks administration of the probiotic mixture. The faecal calprotectin level (121.5 [27.7-292.9] vs 37.0 μg/g [12.6-108.9 μg/g], P = 0.038) was significantly decreased. The α-diversity and composition of the gut microbiome were not significantly changed, but β-diversity was increased after 4 weeks.

CONCLUSIONS

The oral administration of the probiotic mixture was effective in reducing clinical severity and intestinal inflammation in children with AD. Gut microbial diversity was slightly increased after administration of the probiotic mixture. The results of this study suggest that a probiotic mixture can alleviate AD by decreasing inflammation and modulating the gut microbiota in children with AD.

Autism Spectrum Disorder and Medical Cannabis: Review and Clinical Experience

Autism spectrum disorder (ASD) is a multifactorial, pervasive neurodevelopmental disorder defined by the core symptoms of significant impairment in social interaction and communication as well as restricted, repetitive patterns of behavior. In addition to these core behaviors, persons with ASD frequently have associated noncore behavioral disturbance (ie, self-injury, aggression), as well as several medical comorbidities. Currently, no effective treatment exists for the core symptoms of ASD. This review reports the available preclinical and clinical data regarding the use of cannabis and cannabidiol in the treatment of core symptoms, noncore symptoms and comorbidities associated with ASD. Additionally, we describe our clinical experience working with children and young adults with ASD who have used cannabis or cannabidiol. At present, preclinical and clinical data suggest a potential for therapeutic benefit among some persons with ASD and that it is overall well tolerated. Further research is required to better identify patients who may benefit from treatment without adverse effects.

Targeting Infectious Agents as a Therapeutic Strategy in Alzheimer's Disease

Alzheimer's disease (AD) is the most prevalent dementia in the world. Its cause(s) are presently largely unknown. The most common explanation for AD, now, is the amyloid cascade hypothesis, which states that the cause of AD is senile plaque formation by the amyloid β peptide, and the formation of neurofibrillary tangles by hyperphosphorylated tau. A second, burgeoning theory by which to explain AD is based on the infection hypothesis. Much experimental and epidemiological data support the involvement of infections in the development of dementia. According to this mechanism, the infection either directly or via microbial virulence factors precedes the formation of amyloid β plaques. The amyloid β peptide, possessing antimicrobial properties, may be beneficial at an early stage of AD, but becomes detrimental with the progression of the disease, concomitantly with alterations to the innate immune system at both the peripheral and central levels. Infection results in neuroinflammation, leading to, and sustained by, systemic inflammation, causing eventual neurodegeneration, and the senescence of the immune cells. The sources of AD-involved microbes are various body microbiome communities from the gut, mouth, nose, and skin. The infection hypothesis of AD opens a vista to new therapeutic approaches, either by treating the infection itself or modulating the immune system, its senescence, or the body's metabolism, either separately, in parallel, or in a multi-step way.

Cell surface polysaccharides of Bifidobacterium bifidum induce the generation of Foxp3+ regulatory T cells

Dysregulation of intestinal microflora is linked to inflammatory disorders associated with compromised immunosuppressive functions of Foxp3⁺ T regulatory (T_reg) cells. Although mucosa-associated commensal microbiota has been implicated in T_reg generation, molecular identities of the "effector" components controlling this process remain largely unknown. Here, we have defined Bifidobacterium bifidum as a potent inducer of Foxp3⁺ T_reg cells with diverse T cell receptor specificity to dietary antigens, commensal bacteria, and B. bifidum itself. Cell surface β-glucan/galactan (CSGG) polysaccharides of B. bifidum were identified as key components responsible for T_reg induction. CSGG efficiently recapitulated the activity of whole bacteria and acted via regulatory dendritic cells through a partially Toll-like receptor 2-mediated mechanism. T_reg cells induced by B. bifidum or purified CSGG display stable and robust suppressive capacity toward experimental colitis. By identifying CSGG as a functional component of T_reg-inducing bacteria, our studies highlight the immunomodulatory potential of CSGG and CSGG-producing microbes.

The Post-amyloid Era in Alzheimer's Disease: Trust Your Gut Feeling

The amyloid hypothesis, the assumption that beta-amyloid toxicity is the primary cause of neuronal and synaptic loss, has been the mainstream research concept in Alzheimer's disease for the past two decades. Currently, this model is quietly being replaced by a more holistic, “systemic disease” paradigm which, like the aging process, affects multiple body tissues and organs, including the gut microbiota. It is well-established that inflammation is a hallmark of cellular senescence; however, the infection-senescence link has been less explored. Microbiota-induced senescence is a gradually emerging concept promoted by the discovery of pathogens and their products in Alzheimer's disease brains associated with senescent neurons, glia, and endothelial cells. Infectious agents have previously been associated with Alzheimer's disease, but the cause vs. effect issue could not be resolved. A recent study may have settled this debate as it shows that gingipain, a Porphyromonas gingivalis toxin, can be detected not only in Alzheimer's disease but also in the brains of older individuals deceased prior to developing the illness. In this review, we take the position that gut and other microbes from the body periphery reach the brain by triggering intestinal and blood-brain barrier senescence and disruption. We also surmise that novel Alzheimer's disease findings, including neuronal somatic mosaicism, iron dyshomeostasis, aggressive glial phenotypes, and loss of aerobic glycolysis, can be explained by the infection-senescence model. In addition, we discuss potential cellular senescence targets and therapeutic strategies, including iron chelators, inflammasome inhibitors, senolytic antibiotics, mitophagy inducers, and epigenetic metabolic reprograming.

Dysbiosis of the Gut Microbiome in Lung Cancer

Lung cancer (LC) is one of the most serious malignant tumors, which has the fastest growing morbidity and mortality worldwide. A role of the lung microbiota in LC pathogenesis has been analyzed, but a comparable role of the gut microbiota has not yet been investigated. In this study, the gut microbiota of 30 LC patients and 30 healthy controls were examined via next-generation sequencing of 16S rRNA and analyzed for diversity and biomarkers. We found that there was no decrease in significant microbial diversity (alpha diversity) in LC patients compared to controls (P observed = 0.1422), while the composition (beta diversity) differed significantly between patients and controls (phylum [stress = 0.153], class [stress = 0.16], order [stress = 0.146], family [stress = 0.153]). Controls had a higher abundance of the bacterial phylum Actinobacteria and genus Bifidobacterium, while patients with LC showed elevated levels of Enterococcus. These bacteria were found as possible biomarkers for LC. A decline of normal function of the gut microbiome in LC patients was also observed. These results provide the basic guidance for a systematic, multilayered assessment of the role of the gut microbiome in LC, which has a promising potential for early prevention and targeted intervention.

Origination, change, and modulation of geriatric disease-related gut microbiota during life

The age-related changes in the diversity and composition of the gut microbiota are well described in recent studies. These changes have been suggested to be influenced by age-associated weakening of the immune system and low-grade chronic inflammation, resulting in numerous age-associated pathological conditions. Gut microbiota homeostasis is important throughout the life of the host by providing vital functions to regulate various immunological functions and homeostasis. Based on published results, we summarize the relationship between the gut microbiota and aging-related diseases, especially Parkinson's disease, immunosenescence, rheumatoid arthritis, bone loss, and metabolic syndrome. The change in composition of the gut microbiota and gut ecosystem during life and its influence on the host immunologic and metabolic phenotype are also analyzed to determine factors that affect aging-related diseases. Approaches to maintain host health and prevent or cure geriatric diseases are also discussed.

Neonatal abstinence syndrome and the gastrointestinal tract

Development of a healthy gut microbiome is essential in newborns to establish immunity and protection from pathogens. Recent studies suggest that infants who develop dysbiosis may be at risk for lifelong adverse health consequences. Exposure to opioid drugs during pregnancy is a factor of potential importance for microbiome health that has not yet been investigated. Since these infants are born after an entire gestation exposed to mu opioid receptor agonists and have severe gastrointestinal and neurological symptoms, we hypothesize that these infants are at risk for dysbiosis. We speculate that opioid exposure during gestation and development of NAS at birth may lead to a dysbiotic gut microbiome, which may impair normal microbiome succession and development, and impact future health of these children.

Gut microbiota in renal physiology: focus on short-chain fatty acids and their receptors

A number of recent studies have begun to explore a new and exciting area: the interaction between the gut microbiome and renal physiology. In particular, multiple studies have focused on the role of microbially produced short chain fatty acids, which are generally thought to promote health. This review will focus on what is known to date regarding the influence of the microbiome on renal function, with emphasis on the cell biology, physiology, and clinical implications of short chain fatty acids and short chain fatty acid receptors. It is clear that microbe-host interactions are an exciting and ever-expanding field, which has implications for how we view diseases such as hypertension, acute kidney injury, and chronic kidney disease. However, it is important to recognize that although the potential promise of this area is extremely enticing, we are only the very edge of this new field.

[Effect of probiotics in prevention and treatment of allergic diseases in children]

The increasing incidence rate of allergic diseases has attracted global attention, and these diseases greatly threaten children&prime;s health. The common pathogenesis of allergic diseases is the specific IgE- or cell-mediated immune response to common inhalant or food allergens. Epidemiological investigation, analysis of fecal flora, and clinical studies all suggest that the development and progression of allergic diseases are closely related to the early disturbance of intestinal flora. Probiotics can regulate intestinal immune response, increase the barrier function of epithelial cells, inhibit the adhesion and colonization of pathogenic bacteria, and thus restore or reconstruct normal intestinal flora. With the increasing understanding of allergic diseases, the effect of probiotics in the prevention and treatment of such diseases will be taken more and more seriously.

[Effect of probiotics in prevention and treatment of allergic diseases in children]

The increasing incidence rate of allergic diseases has attracted global attention, and these diseases greatly threaten children′s health. The common pathogenesis of allergic diseases is the specific IgE- or cell-mediated immune response to common inhalant or food allergens. Epidemiological investigation, analysis of fecal flora, and clinical studies all suggest that the development and progression of allergic diseases are closely related to the early disturbance of intestinal flora. Probiotics can regulate intestinal immune response, increase the barrier function of epithelial cells, inhibit the adhesion and colonization of pathogenic bacteria, and thus restore or reconstruct normal intestinal flora. With the increasing understanding of allergic diseases, the effect of probiotics in the prevention and treatment of such diseases will be taken more and more seriously.

Commensals and Foodborne Pathogens can Arbitrate Epithelial-carcinogenesis

Major shifts in intestinal commensal bacteria often result in changes in CD4⁺ T lymphocyte populations, leading to an influx of Th17 cells, chronic inflammation, and eventually cancer. Consequently, the inappropriate propagation of certain commensal species in the gut has been associated with mucosal inflammatory diseases and cancer development. Recent experiments investigating the relationships between food-borne pathogens, enteric bacteria, and cancer have exposed the ability of certain bacterial species to significantly reduce tumor size and tumor progression in mice. In similar studies, pro-inflammatory Th17 and Th1 cells were at times found present along with anti-inflammatory Treg populations in the intestinal mucosa. This antitumor response was mediated by a balanced production of pro- and anti-inflammatory cytokines, resulting in a controlled threshold of mucosal immunity largely moderated by CD4⁺ T lymphocyte populations, through a dendritic cell-dependent pathway. These findings provide new evidence that certain species of bacteria can help manage subcutaneous tumor development by calibrating mucosal and, in some instances, systemic thresholds of innate and adaptive immunity.

Protective effect of probiotics in the treatment of infantile eczema

The aim of the present study was to provide evidence for the application of probiotics in the prevention and treatment of infantile eczema by exploring changes in the intestinal Bifidobacteria levels and the Scoring Atopic Dermatitis (SCORAD) index prior and subsequent to treatment with probiotics in infants with eczema. A total of 40 infants with eczema were randomly divided into treatment and control groups. Prior and subsequent to the treatment, the SCORAD index was evaluated and the content of Bifidobacterium bifidum in the stool of each infant in the two groups was quantified using 16S rRNA/DNA quantitative polymerase chain reaction analysis. After four weeks of treatment with B. bifidum triple viable capsules, the levels of B. bifidum increased sharply (P<0.05) and the SCORAD index was notably reduced (P<0.05) as compared with the values prior to treatment. By contrast, neither the content of B. bifidum nor the SCORAD index changed significantly in the control group after four weeks (P>0.05). Following treatment, the levels of B. bifidum in the stools of the treatment group were significantly higher than those in the stools of the control group (P<0.05), and the SCORAD index was significantly lower than that of the control group (P<0.05). In conclusion, probiotic supplementation has a positive effect on the prevention and treatment of infantile eczema.

Treatment of atopic dermatitis eczema with a high concentration of Lactobacillus salivarius LS01 associated with an innovative gelling complex: a pilot study on adults

GOALS

To evaluate the efficacy of a highly concentrated Lactobacillus salivarius preparation containing a gelling complex formed by Streptococcus thermophilus ST10 and tara gum in the treatment of atopic dermatitis (AD).

BACKGROUND

Previous studies have demonstrated an improvement in AD symptoms after administration of the probiotic strain L. salivarius LS01. S. thermophilus ST10 and tara gum create a gelling complex that adheres to intestinal mucus and improves barrier function.

STUDY

A prospective, controlled pilot trial was carried out to evaluate how the association of S. thermophilus ST10 and tara gum could improve the activity of L. salivarius LS01 administered at high doses to adults with AD. Twenty-five patients were included into the study: 13 were treated for 1 month with the active formulation, whereas 12 represented the placebo group. Scoring Atopic Dermatitis index was determined before and at the end of probiotic administration. Fecal samples were also collected to evaluate changes in bacterial counts of Staphylococcus aureus and clostridia.

RESULTS

A significant improvement in SCORAD index was observed in the probiotic group after 1 month of treatment, whereas no significant changes occurred in placebo patients. A slight decrease in fecal S. aureus count was observed in probiotic-treated patients.

CONCLUSIONS

Data obtained in this study suggest a potential role for L. salivarius LS01 in the treatment of AD. The addition of tara gum and S. thermophilus ST10 seems to improve the overall efficacy of the probiotic strain, in particular shortening the time required for the onset of the positive effects. Further studies to investigate the activity of this preparation are advisable.

From microbe to man: the role of microbial short chain fatty acid metabolites in host cell biology

Recent studies have highlighted a myriad of ways in which the activity and composition of the gut microbiota can affect the host organism. A primary way in which the gut microbiota affect host physiology is by the production of metabolites, such as short-chain fatty acids (SCFAs), which are subsequently absorbed into the bloodstream of the host. Although recent studies have begun to unravel the ways in which gut microbial SCFAs affect host physiology, less is understood regarding the underlying cell biological mechanisms. In this review, we will outline the known receptors and transporters for SCFAs, and review what is known about the cell biological effects of microbial SCFAs.

The effects of the microbiota on the host immune system

The human gastrointestinal track harbors hundreds of species of commensal organisms, collectively known as microbiota. The composition of the intestinal microbiota is changeable by various factors, such as host genotype, diet, antibiotics, pathogen infections, among others. Changes in these factors can cause microbiome disruption known as dysbiosis, leading to the outgrowth of potential pathogenic bacteria or decrease in the number of beneficial bacteria. Dysbiosis has been implicated in numerous inflammatory and autoimmune diseases. This review is focused on host-microbiota interactions, specifically on influence of bacterial-derived signals on immune cell function and the mechanisms by which these signals modulate the development and progression of inflammatory and autoimmune diseases.

Intestinal parasitic infections and atopic dermatitis among Venezuelan Warao Amerindian pre- school children

BACKGROUND

We evaluated the influence of intestinal parasitic infection on food sensitization associated to the severity of Atopic Dermatitis (AD) in a group of Warao Amerindian pre- school children.

METHODS

Feces examinations were performed in fresh stool specimens. Diagnosis of AD was done according to Hannifin and Rajka criteria and SCORAD index. Skin prick tests (SPT) were performed using extracts of cow's milk (CM), hen's egg (HE), Dermatophagoides pteronyssinus and Dermatophagoides farinae . Serum CM and HE-IgE levels (ELISA) were measured. Quantikine (R&D systems) assays were used for the determination of IL-13, TNF-α IL-6, and sCD23 in supernatants of CM- and HE- whole blood stimulated samples.

RESULTS

Atopic Dermatitis was reported in 23% of the children. It was significantly (p < 0.0001) associated toward both CM and HE- SPT positivity (p < 0.001). Giardia duodenalis infection (37%) was associated to the presence of AD (p = 0.005) and to a significant increase in the levels of CM stimulated TNF-α (p=0.006), IL-13 (p = 0.01), sCD23 (p = 0.001), CM-IgE (p = 0.012) and CM-SPT (p < 0.0001). Similarly, G. duodenalis infection was particularly associated with the increase on the levels of HE-stimulated TNF-α (p = 0.001), sCD23 (p = 0.001), HE-IgE levels (p = 0.002) and HE-SPT (p = 0.001).

CONCLUSION

Gut inflammation caused by G. duodenalis may enhance food allergic reactivity contributing to the manifestation of AD in these children. However, other environmental factors (not considered in this work) as well as an atopic background among the Warao population would also contribute to the presence of AD.

A novel SCFA receptor, the microbiota, and blood pressure regulation

The maintenance of blood pressure homeostasis is a complex process which is carefully regulated by a variety of inputs. We recently identified two sensory receptors (Olfactory receptor 78 and G protein couple receptor 41) as novel regulators of blood pressure. Both Olfr78 and Gpr41 are receptors for short chain fatty acids (SCFAs), and we showed that propionate (a SCFA) modifies blood pressure in a manner which is differentially modulated by the absence of either Olfr78 or Gpr41. In addition, propionate modifies renin release in an Olfr78-dependent manner. Our study also demonstrated that antibiotic treatment modulates blood pressure in Olfr78 null mice, indicating that SCFAs produced by the gut microbiota likely influence blood pressure regulation. In this addendum, we summarize the findings of our recent study and provide a perspective on the implications of the interactions between the gut microbiota and blood pressure control.

Gut microbiota disturbance during antibiotic therapy: a multi-omic approach

It is known that the gastrointestinal tract (GIT) microbiota responds to different antibiotics in different ways and that while some antibiotics do not induce disturbances of the community, others drastically influence the richness, diversity, and prevalence of bacterial taxa. However, the metabolic consequences thereof, independent of the degree of the community shifts, are not clearly understood. In a recent article, we used an integrative OMICS approach to provide new insights into the metabolic shifts caused by antibiotic disturbance. The study presented here further suggests that specific bacterial lineage blooms occurring at defined stages of antibiotic intervention are mostly associated with organisms that possess improved survival and colonization mechanisms, such as those of the Enterococcus, Blautia, Faecalibacterium, and Akkermansia genera. The study also provides an overview of the most variable metabolic functions affected as a consequence of a β-lactam antibiotic intervention. Thus, we observed that anabolic sugar metabolism, the production of acetyl donors and the synthesis and degradation of intestinal/colonic epithelium components were among the most variable functions during the intervention. We are aware that these results have been established with a single patient and will require further confirmation with a larger group of individuals and with other antibiotics. Future directions for exploration of the effects of antibiotic interventions are discussed.

External influence of early childhood establishment of gut microbiota and subsequent health implications

Postnatal maturation of immune regulation is largely driven by exposure to microbes. The gastrointestinal tract is the largest source of microbial exposure, as the human gut microbiome contains up to 10(14) bacteria, which is 10 times the number of cells in the human body. Several studies in recent years have shown differences in the composition of the gut microbiota in children who are exposed to different conditions before, during, and early after birth. A number of maternal factors are responsible for the establishment and colonization of gut microbiota in infants, such as the conditions surrounding the prenatal period, time and mode of delivery, diet, mother's age, BMI, smoking status, household milieu, socioeconomic status, breastfeeding and antibiotic use, as well as other environmental factors that have profound effects on the microbiota and on immunoregulation during early life. Early exposures impacting the intestinal microbiota are associated with the development of childhood diseases that may persist to adulthood such as asthma, allergic disorders (atopic dermatitis, rhinitis), chronic immune-mediated inflammatory diseases, type 1 diabetes, obesity, and eczema. This overview highlights some of the exposures during the pre- and postnatal time periods that are key in the colonization and development of the gastrointestinal microbiota of infants as well as some of the diseases or disorders that occur due to the pattern of initial gut colonization.

Acquisition of oral microbes and associated systemic responses of newborn nonhuman primates

The acquisition and development of the complex oral microbiome remain ill defined. While selected species of oral bacteria have been examined in relation to their initial colonization in neonates, a more detailed understanding of the dynamics of the microbiome has been developed only in adults. The current investigation used a nonhuman primate model to document the kinetics of colonization of the oral cavities of newborns and infants by a range of oral commensals and pathogens. Differences in colonization were evaluated in newborns from mothers who were maintained on an oral hygiene regimen pre- and postparturition with those displaying naturally acquired gingivitis/periodontitis. The results demonstrate distinct profiles of acquisition of selected oral bacteria, with the transmission of targeted pathogens, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, being passed on primarily from mothers with gingivitis/periodontitis. This colonization resulted in defined patterns of systemic antibody responses in the infants. The significant relative risk measures for infection with the pathogens, as well as the relationship of oral infection and blood serum antibody levels, were consistent with those of the newborns from mothers with gingivitis/periodontitis. These findings indicate that the early acquisition of potentially pathogenic oral bacterial species might impact the development of mucosal responses in the gingiva and may provide an enhanced risk for the development of periodontitis later in life.

Implications of the human microbiome in inflammatory bowel diseases

The study of the human microbiome or community of microorganisms and collection of genomes found in the human body is one of the fastest growing research areas because many diseases are reported to be associated with microbiome imbalance or dysbiosis. With the improvement in novel sequencing techniques, researchers are now generating millions of sequences of different sites from the human body and evaluating specific differences in microbial communities. The importance of microbiome constituency is so relevant that several consortia like the Human Microbiome project (HMP) and Metagenomics of the Human Intestinal Tract (MetaHIT) project are focusing mainly on the human microbiome. The aim of this review is to highlight points of research in this field, mainly focusing on particular factors that modulate the microbiome and important insights into its potential impact on our health and well-being.

Man and his spaceships: Vehicles for extraterrestrial colonization?

The resiliency and adaptive ability of microbial life in real time on Earth relies heavily upon horizontal gene transfer. Based on that knowledge, how likely is earth based microbial life to colonize extraterrestrial targets such as Mars? To address this question, we consider manned and unmanned space exploration, the resident microbiota that is likely to inhabit those vehicles, the adaptive potential of that microbiota in an extraterrestrial setting especially with regards to mobile genetic elements, and the likelihood that Mars like environments could initiate and sustain colonization.