Microbiome diversity and asthma and allergy risk. Curr Allergy Asthma Rep. 2014;14:466. [PMID: 25149168 DOI: 10.1007/s11882-014-0466-0]

Association Between Adult Antibiotic Use, Microbial Dysbiosis and Atopic Conditions - A Systematic Review

Background

Strong associations between early antibiotic exposure and increased risk of childhood allergies have been established. Antibiotics have the potential to induce microbial dysbiosis that may be linked to allergic conditions. This review examines the limited available evidence on the associations between adult antibiotic use, microbial dysbiosis and atopic conditions.

Methods

A systematic literature search was conducted using PubMed and Embase for relevant studies, published between 01-01-2000 and 08-17-2022. We searched for associations between antibiotic use, microbial dysbiosis, and allergic conditions in adults, defined as over 13 years of age for the purposes of this review.

Results

Twenty-one studies were analyzed, with the inclusion of four narrative reviews as scarce relevant literature was found when stricter selection criteria were employed. Relevant studies predominantly focused on asthma. Significant microbial differences were observed in most measures between healthy subjects and subjects with allergic conditions. However, no system-wise and strain-wise associations were evident. Notably, at the phyla level, the Bacillota and Pseudomonadota phyla were associated with asthmatics, while the Actinobacteria phylum was linked to healthy controls. Asthmatics tends to reflect upregulation in the Bacillota and Pseudomonadota phyla in both airway and gut microbiomes.

Conclusion

No compelling evidence could be found between adult antibiotic exposure, consequent microbial dysbiosis, and allergic conditions in adults. Our review is limited by scarce literature and therefore remains inconclusive. However, potential implications of antibiotic use impacting on allergic conditions justify additional research and heightened pharmacovigilance in this area.

Association between antibiotics and asthma risk among adults aged over 40 years: a nationally representative retrospective cohort study

INTRODUCTION

Several studies have reported that exposure to antibiotics can lead to asthma during early childhood. However, the association between antibiotic use and risk of asthma in the adult population remains unclear. This study aimed to investigate the association between antibiotic use and asthma in adults.

METHODS

We used data from the National Health Insurance Service (NHIS)-Health Screening Cohort, which included participants aged ≥40 years who had health screening examination data in 2005-2006. A total of 248 961 participants with a mean age of 55.43 years were enrolled in this retrospective cohort study. To evaluate antibiotic exposure from the NHIS database for 5 years (2002-2006), cumulative usage and multiclass prescriptions were identified, respectively. During the follow-up period (2007-2019), 42 452 patients were diagnosed with asthma. A multivariate Cox proportional hazard regression model was used to assess the association between antibiotic use and newly diagnosed asthma.

RESULTS

Participants with antibiotic use for ≥91 days showed a higher risk of asthma (adjusted HR (aHR) 1.84, 95% CI 1.72 to 1.96) compared with participants who did not use antibiotics (n=38 450), with a duration-dependent association (ptrend<0.001). Furthermore, ≥4 antibiotic class user group had an increased risk of asthma (aHR 1.44, 95% CI 1.39 to 1.49) compared with one class of antibiotic use (n=64 698). Also, one class of antibiotic use had a higher risk of asthma (aHR 1.21, 95% CI 1.17 to 1.26) compared with non-users, and it also showed a duration-dependent relationship in all classes, including 1, 2, 3 and ≥4 class group (ptrend<0.001). The duration-response relationship between antibiotic use and increased risk of asthma remained in our sensitivity analyses with the washout and shifting of the index date.

CONCLUSIONS

The duration-response pattern observed in antibiotic use and asthma may suggest the implication of proper antibiotic use and management in adults.

Microbiota Profile of the Nasal Cavity According to Lifestyles in Healthy Adults in Santiago, Chile

BACKGROUND

The respiratory microbiome is dynamic, varying between anatomical niches, and it is affected by various host and environmental factors, one of which is lifestyle. Few studies have characterized the upper respiratory tract microbiome profile according to lifestyle. We explored the association between lifestyles and microbiota profiles in the upper respiratory tract of healthy adults.

METHODS

We analyzed nasal samples from 110 healthy adults who were living in Santiago, Chile, using 16S ribosomal RNA gene-sequencing methods. Volunteers completed a structured questionnaire about lifestyle.

RESULTS

The composition and abundance of taxonomic groups varied across lifestyle attributes. Additionally, multivariate models suggested that alpha diversity varied in the function of physical activity, nutritional status, smoking, and the interaction between nutritional status and smoking, although the significant impact of those variables varied between women and men. Although physical activity and nutritional status were significantly associated with all indexes of alpha diversity among women, the diversity of microbiota among men was associated with smoking and the interaction between nutritional status and smoking.

CONCLUSIONS

The alpha diversity of nasal microbiota is associated with lifestyle attributes, but these associations depend on sex and nutritional status. Our results suggest that future studies of the airway microbiome may provide a better resolution if data are stratified for differences in sex and nutritional status.

Comparative Analyses of the Gut Microbiota in Growing Ragdoll Cats and Felinae Cats

Simple Summary

Accumulating studies have revealed that the gut microbiota had intimate relations with the animal gastrointestinal tract diseases. Through regulating the development of the host’s intestinal immune system, the gut microbiota could directly influence the host’s intestinal function. In the current study, the gut microbiota of Ragdoll cats and Felinae cats were investigated and compared. Results demonstrated the diversity and richness of the gut microbiota in the Felinae cats were much higher than in the Ragdoll cats. However, the relative abundances of beneficial microbes in the Ragdoll cats were much higher than those in the Felinae cats. In all, different genetic portraits determined the different microbial communities in the feline gut. The candidate probiotics isolated in the growing cat’s gut might be applied to treat the gastrointestinal tract diseases.

Abstract

Today, domestic cats are important human companion animals for their appearance and favorable personalities. During the history of their domestication, the morphological and genetic portraits of domestic cats changed significantly from their wild ancestors, and the gut microbial communities of different breeds of cats also apparently differ. In the current study, the gut microbiota of Ragdoll cats and Felinae cats were analyzed and compared. Our data indicated that the diversity and richness of the gut microbiota in the Felinae cats were much higher than in the Ragdoll cats. The taxonomic analyses revealed that the most predominant phyla of the feline gut microbiota were Firmicutes, Bacteroidota, Fusobacteriota, Proteobacteria, Actinobacteriota, Campilobacterota, and others, while the most predominant genera were Anaerococcus, Fusobacterium, Bacteroides, Escherichia-Shigella, Finegoldia, Porphyromonas, Collinsella, Lactobacillus, Ruminococcus_gnavus_group, Prevotella, and others. Different microbial communities between the Ragdoll group and the Felinae group were observed, and the compared results demonstrated that the relative abundances of beneficial microbes (such as Lactobacillus, Enterococcus, Streptococcus, Blautia, Roseburia, and so on) in the Ragdoll group were much higher than in the Felinae group. The co-occurrence network revealed that the number of nodes and links in the Felinae group was significantly higher than the Ragdoll group, which meant that the network of the Felinae group was larger and more complex than that of the Ragdoll group. PICRUSt function analyses indicated that the differences in microbial genes might influence the energy metabolism and immune functions of the host. In all, our data demonstrated that the richness and diversity of beneficial microbes in the Ragdoll group were much higher than the Felinae group. Therefore, it is possible to isolate and identify more candidate probiotics in the gut microbiota of growing Ragdoll cats.

Equine keratinocytes in the pathogenesis of insect bite hypersensitivity: Just another brick in the wall?

Equine insect bite hypersensitivity (IBH) is the most common skin disease affecting horses. It is described as an IgE-mediated, Type I hypersensitivity reaction to salivary gland proteins of Culicoides insects. Together with Th2 cells, epithelial barrier cells play an important role in development of Type I hypersensitivities. In order to elucidate the role of equine keratinocytes in development of IBH, we stimulated keratinocytes derived from IBH-affected (IBH-KER) (n = 9) and healthy horses (H-KER) (n = 9) with Culicoides recombinant allergens and extract, allergic cytokine milieu (ACM) and a Toll like receptor ligand 1/2 (TLR-1/2-L) and investigated their transcriptomes. Stimulation of keratinocytes with Culicoides allergens did not induce transcriptional changes. However, when stimulated with allergic cytokine milieu, their gene expression significantly changed. We found upregulation of genes encoding for CCL5, -11, -20, -27 and interleukins such as IL31. We also found a strong downregulation of genes such as SCEL and KRT16 involved in the formation of epithelial barrier. Following stimulation with TLR-1/2-L, keratinocytes significantly upregulated expression of genes affecting Toll like receptor and NOD-receptor signaling pathway as well as NF-kappa B signaling pathway, among others. The transcriptomes of IBH-KER and H-KER were very similar: without stimulations they only differed in one gene (CTSL); following stimulation with allergic cytokine milieu we found only 23 differentially expressed genes (e.g. CXCL10 and 11) and following stimulation with TLR-1/2-L they only differed by expression of seven genes. Our data suggests that keratinocytes contribute to the innate immune response and are able to elicit responses to different stimuli, possibly playing a role in the pathogenesis of IBH.

The Role of Atopy in COPD and Asthma

Common to several allergic diseases is the generation of immunoglobulin E (IgE) by plasma cells, when exposed to an innocuous antigen. Asthma and chronic obstructive pulmonary disease (COPD) are two prevalent chronic airway inflammatory diseases. Asthma is mediated in some patients through eosinophilic inflammatory mechanisms that include allergic sensitization and Th2-mediated immune airway response. COPD, on the other hand is mainly considered a Th1-mediated inflammatory process with neutrophilic predominance or a non-Th2 inflammation, occasionally associated with the presence of airway bacteria or viruses. IgE production appears to play an important role in the development of both COPD and asthma, as it has been associated to respiratory symptoms, lung function, bacterial and viral infections, airway remodeling and bronchial hyperreactivity in both diseases. The aim of this review is to summarize all current data concerning the role of specific and total IgE in COPD and asthma and to highlight similarities and differences in view of possible therapeutic interventions.

Effects of hypersensitivity disorders and environmental factors on the equine intestinal microbiota

Background

Recent evidence suggests that an altered intestinal microbiota, specifically a reduction of bacterial diversity or a shift in microbial composition, is associated with the development of hypersensitivity disorders in humans, but this is unknown for horses.

Objectives

In this study we hypothesized that horses affected by either Culicoides hypersensitivity or severe equine asthma or both show a decreased diversity of their intestinal microbiota. We also investigated environmental effects.

Methods

Rectal swab samples of a total of 140 horses were collected and the owners completed a detailed questionnaire about their horse. For each allergic horse, a healthy peer from the same stable was equally sampled as an environmentally matched control. Microbiota in the swabs was determined by assessing the V4 region of the bacterial 16S rRNA gene. Structures of bacterial communities were investigated by means of alpha and beta diversity indices.

Results

Group wise comparisons between healthy and allergic horses showed no significant differences regarding alpha (p = 0.9) and beta diversity (p = 0.5). However, the microbial structure was associated with environmental factors such as the type of stable (p = 0.001), access to pasture (p = 0.001) or the type of feeding (p = 0.003). There was also a strong location effect meaning that the microbiota was more similar within the same as compared between farms within this study.

Conclusion

Our observations suggest that hypersensitivity disorders in adult horses are not associated with an alteration of the intestinal microbiota, but environmental and/or location factors strongly influence these bacteria.

Consumption of Lamb Meat or Basa Fish Shapes the Gut Microbiota and Aggravates Pulmonary Inflammation in Asthmatic Mice

Objective

In China, lamb and fish are well-known triggers for an asthma attack. Our investigation aims at assessing whether the long-term intake of lamb meat or Basa fish would aggravate pulmonary inflammation as well as exploring changes in the intestinal microbiota and immune cells in asthmatic mice.

Materials and Methods

The murine asthmatic model was established by intraperitoneal injection of ovalbumin (OVA) plus aluminum on day 0 and 14 and nebulization of OVA from day 21 to 27. Lamb meat or fish was administered to asthmatic mice by oral gavage from day 0 to 27.

Results

Our results showed that long-term consumption of lamb meat or Basa fish in asthmatic mice increased the number of inflammatory cells in bronchoalveolar lavage fluid (BALF), enhanced levels of IL-5, IL-13 in BALF and total IgE in serum, aggravated pulmonary inflammatory cell infiltration and mucus secretion. Long-term oral lamb enhanced the proportion of type 2 innate lymphoid cells (ILC2) from small intestine while it inhibited that of Treg from lung in asthmatic mice. Oral fish showed no remarkable effect on that of ILC2 from lung and small intestine but inhibited that of intestinal Treg in asthmatic mice. What’s more, the chao-1 and observed species richness as well as PD whole tree diversity increased in asthmatic mice while these increments were inhibited after lamb treatment. PCA analysis indicated that there were significant differences in the bacterial community composition after lamb or fish treatment in asthmatic mice. Both lamb and fish treatment enhanced the abundance of colonic Alistipes in asthmatic mice.

Conclusion

Collectively, long-term intake of lamb or fish shapes colonic bacterial communities and aggravates pulmonary inflammation in asthmatic mice, which provides reasonable food guidance for asthmatic patients.

Altered vaginal microbiome and relative co-abundance network in pregnant women with penicillin allergy

Background

Penicillin allergy is frequently reported in adults and children. Recent studies suggest that microbiota plays a key role in the development and progression of allergy. In this study, the relationship between vaginal microbiome and pregnant women with penicillin allergy was investigated.

Methods

Vaginal samples before labor from 12 pregnant women with penicillin allergy and 15 non-allergic pregnant women were collected. Bacterial community structure of all study subjects and the discrepancies between the two groups were analyzed using 16S rRNA sequencing based on Illumina Hiseq 2500 platform.

Results

The abundant phyla among all participants were Firmicutes, Actinobacteria and Bacteroidetes. The predominant genus was Lactobacillus. Compared to non-allergic pregnant women, Actinobacteria, Coriobacteriaceae, Lachnospiraceae, Paraprevotella and Anoxybacillus significantly decreased, whereas Deltaproteobacteria, Peptostreptococcaceae, Enterococcus and Megamonas were more abundant in penicillin allergic women. Additionally, obvious discrepancies were observed in the co-abundance network at the genus level between the two groups.

Conclusions

There were differences in the microbial community structure and composition of reproduction tract between penicillin allergic and non-allergic pregnant women. These shifts may be related to maternal and neonatal health.

Dysbiosis of the gut and lung microbiome has a role in asthma

Worldwide 300 million children and adults are affected by asthma. The development of asthma is influenced by environmental and other exogenous factors synergizing with genetic predisposition, and shaping the lung microbiome especially during birth and in very early life. The healthy lung microbial composition is characterized by a prevalence of bacteria belonging to the phyla Bacteroidetes, Actinobacteria, and Firmicutes. However, viral respiratory infections are associated with an abundance of Proteobacteria with genera Haemophilus and Moraxella in young children and adult asthmatics. This dysbiosis supports the activation of inflammatory pathways and contributes to bronchoconstriction and bronchial hyperresponsiveness. Exogenous factors can affect the natural lung microbiota composition positively (farming environment) or negatively (allergens, air pollutants). It is evident that also gut microbiota dysbiosis has a high influence on asthma pathogenesis. Antibiotics, antiulcer medications, and other drugs severely impair gut as well as lung microbiota. Resulting dysbiosis and reduced microbial diversity dysregulate the bidirectional crosstalk across the gut-lung axis, resulting in hypersensitivity and hyperreactivity to respiratory and food allergens. Efforts are undertaken to reconstitute the microbiota and immune balance by probiotics and engineered bacteria, but results from human studies do not yet support their efficacy in asthma prevention or treatment. Overall, dysbiosis of gut and lung seem to be critical causes of the increased emergence of asthma.

Metallothionein-2 is associated with the amelioration of asthmatic pulmonary function by acupuncture through protein phosphorylation

BACKGROUND

Acupuncture has long been used for asthma treatment but the underlying mechanism remains unclear. Previous study showed that metallothionein-2 (MT-2) was significantly decreased in asthmatic lung tissue. However, the relationship between acupuncture treatment and MT-2 expression during asthma is still unknown, and the detailed effect analysis of MT-2 on phosphorylation in airway smooth muscle cells (ASMCs) is also unclear.

METHODS

The acupuncture effect on pulmonary resistance (RL) was investigated in a rat model of asthma, and the mRNA and protein levels of MT-2 in lung tissue were detected. Primary ASMCs were isolated and treated with MT-2 recombinant protein to study the MT-2 effects on ASMC relaxation. A Phospho Explorer antibody microarray was applied to detect protein phosphorylation changes associated with MT-2-induced ASMC relaxation. Bioinformatic analysis were performed with PANTHER database, DAVID and STRING. Phosphorylation changes in key proteins were confirmed by Western blot.

RESULTS

Acupuncture significantly reduced RL at 2-5 min (P < 0.05 vs asthma) in asthmatic rats. Acupuncture continued to increase MT-2 mRNA expression in lung tissue for up to 14 days (P < 0.05 vs asthma). The MT-2 protein expression was significantly decreased in the asthmatic rats (P < 0.05 vs control), while MT-2 protein expression was significantly increased in the asthmatic model group treated with acupuncture (P < 0.05 vs asthma). Primary ASMCs were successfully isolated and recombinant MT-2 protein (100, 200, 400 ng/ml) significantly relaxed ASMCs (P < 0.05 vs control). MT-2 induced phosphorylation changes in 51 proteins. Phosphorylation of 14 proteins were upregulated while 37 proteins were downregulated. PANTHER classification revealed eleven functional groups, and the phosphorylated proteins were identified as transferases (27.8 %), calcium-binding proteins (11.1 %), etc. DAVID functional classification showed that the phosphorylated proteins could be attributed to eight functions, including protein phosphorylation and regulation of GTPase activity. STRING protein-protein interaction network analysis showed that Akt1 was one of the most important hubs for the phosphorylated proteins. The phosphorylation changes of Akt1 and CaMK2β were consistent in both the Phospho Explorer antibody microarray and Western blot.

CONCLUSION

Acupuncture can significantly ameliorate RL, and the MT-2 mRNA and protein levels in lung tissue are increased during treatment. MT-2 significantly relaxes ASMCs and induces a series of protein phosphorylation. These phosphorylation changes, including Akt1 and CaMK2β, may play important roles in the therapeutic effects of acupuncture on asthma.

Metabolic phenotyping of the human microbiome

The human microbiome has been identified as having a key role in health and numerous diseases. Trillions of microbial cells and viral particles comprise the microbiome, each representing modifiable working elements of an intricate bioactive ecosystem. The significance of the human microbiome as it relates to human biology has progressed through culture-dependent (for example, media-based methods) and, more recently, molecular (for example, genetic sequencing and metabolomic analysis) techniques. The latter have become increasingly popular and evolved from being used for taxonomic identification of microbiota to elucidation of functional capacity (sequencing) and metabolic activity (metabolomics). This review summarises key elements of the human microbiome and its metabolic capabilities within the context of health and disease.

Outbreaks of an Emerging Viral Disease Covary With Differences in the Composition of the Skin Microbiome of a Wild United Kingdom Amphibian

There is growing appreciation of the important role of commensal microbes in ensuring the normal function and health of their hosts, including determining how hosts respond to pathogens. A range of infectious diseases are threatening amphibians worldwide, and evidence is accumulating that the host-associated bacteria that comprise the microbiome may be key in mediating interactions between amphibian hosts and infectious pathogens. We used 16S rRNA amplicon sequencing to quantify the skin microbial community structure of over 200 individual wild adult European common frogs (Rana temporaria), from ten populations with contrasting history of the lethal disease ranavirosis, caused by emerging viral pathogens belonging to the genus Ranavirus. All populations had similar species richness irrespective of disease history, but populations that have experienced historical outbreaks of ranavirosis have a distinct skin microbiome structure (beta diversity) when compared to sites where no outbreaks of the disease have occurred. At the individual level, neither age, body length, nor sex of the frog could predict the structure of the skin microbiota. Our data potentially support the hypothesis that variation among individuals in skin microbiome structure drive differences in susceptibility to infection and lethal outbreaks of disease. More generally, our results suggest that population-level processes are more important for driving differences in microbiome structure than variation among individuals within populations in key life history traits such as age and body size.

Probiotic Supplementation for Prevention of Atopic Dermatitis in Infants and Children: A Systematic Review and Meta-analysis

BACKGROUND

Probiotic supplementation in early life may be effective in preventing atopic dermatitis (AD); however, results regarding efficacy have been controversial.

OBJECTIVE

The aim of our study was to investigate the effect of probiotic supplementation on the risk of AD.

METHODS

We systematically searched PubMed, EBSCO, Embase and Web of Science databases up to 8 March 2018 for potentially relevant studies regarding probiotic supplementation and AD. Included infants and children were those with probiotic exposure in utero and/or after birth who were not previously diagnosed with AD. We calculated the odds ratios (ORs) and 95% confidence intervals (CIs) and used the Jadad and Newcastle-Ottawa scales to assess methodologic quality.

RESULTS

A total of 28 studies met the inclusion criteria. Compared with controls, probiotic treatment was associated with a reduced risk of AD (OR 0.69; 95% CI 0.58-0.82, P < 0.0001). The use of probiotics during both the prenatal and the postnatal period significantly reduced the incidence of AD (OR 0.67; 95% CI 0.54-0.82); however, analysis of studies of probiotics given prenatally only or postnatally only did not reach statistical significance.

CONCLUSIONS

Our meta-analysis showed that probiotic supplementation during both the prenatal and the postnatal period reduced the incidence of AD in infants and children. Our findings suggest that starting probiotic treatment during gestation and continuing through the first 6 months of the infant's life may be of benefit in the prevention of AD.

Short-chain fatty acids as a target for prevention against food allergy by regulatory T cells

Objective

Food allergy (FA) has become a public health issue of global concern. Short-chain fatty acids (SCFAs) are one of the most important biomarkers of intestinal metabolites. SCFAs may affect the occurrence and development of FA. Currently, no studies have been reported on the mechanism of FA in response to SCFAs. In this study, the common food allergen ovalbumin (OVA) was used for intestinal sensitization in Balb/c mice to study the effect of FA on intestinal barrier function and regulatory T cells in mice, thus providing a new target for the prevention and treatment of FA.

Methods

Twenty BALB/c mice were randomly divided into the experimental group and control group. The experimental group was given OVA, and the control group was given an equal amount of physiological saline. On the 31st day of modeling, the levels of secretory immunoglobulin A (sIgA) and serum total IgE and diamine oxidase (DAO) were determined using enzyme linked immunosorbent assay (ELISA). At the same time, after in vitro stimulation with different concentrations of SCFAs and histone acetylase inhibitor trichostatin A (TSA), the frequency and function of Treg in OVA-sensitized mice were detected by flow cytometry.

Results

Different concentrations of SCFAs and TSA selectively proliferate Treg cells in a dose-dependent manner. SCFAs and TSA-pretreated PBMCs that were injected intravenously into the OVA-sensitized mice through the tail vein can significantly reduce the expression of IgE, DAO, and sIgA.

Conclusion

SCFAs and TSA can selectively proliferate Tregs and upregulate the expression of anti-inflammatory cytokines, thereby suppressing allergic reactions.

Effect of Commonly Used Pediatric Antibiotics on Gut Microbial Diversity in Preschool Children in Burkina Faso: A Randomized Clinical Trial

BACKGROUND

Exposure to antibiotics may result in alterations to the composition of intestinal microbiota. However, few trials have been conducted, and observational studies are subject to confounding by indication. We conducted a randomized controlled trial to determine the effect of 3 commonly used pediatric antibiotics on the intestinal microbiome in healthy preschool children.

METHODS

Children aged 6-59 months were randomized (1:1:1:1) to a 5-day course of 1 of 3 antibiotics, including amoxicillin (25 mg/kg/d twice-daily doses), azithromycin (10 mg/kg dose on day 1 and then 5 mg/kg once daily for 4 days), cotrimoxazole (240 mg once daily), or placebo. Rectal swabs were obtained at baseline and 5 days after the last dose and were processed using 16S rRNA gene sequencing. The prespecified primary outcome was inverse Simpson's α-diversity index.

RESULTS

Post-treatment Simpson's diversity was significantly different across the 4 arms (P = .003). The mean Simpson's α-diversity among azithromycin-treated children was significantly lower than in placebo-treated children (6.6; 95% confidence interval [CI], 5.5-7.8; vs 9.8; 95% CI, 8.7-10.9; P = .0001). Diversity in children treated with amoxicillin (8.3; 95% CI, 7.0-9.6; P = .09) or cotrimoxazole (8.3; 95% CI, 8.2-9.7; P = .08) was not significantly different than placebo.

CONCLUSIONS

Azithromycin affects the composition of the pediatric intestinal microbiome. The effect of amoxicillin and cotrimoxazole on microbiome composition was less clear.

CLINICAL TRIALS REGISTRATION

clinicaltrials.gov NCT03187834.

Does a carrot a day keep the allergy away?

Vitamin A is an important micronutrient, from plants diet taken up as carotenoids, from animal food sources as retinol. Its active metabolite retinoic acid (RA) binds to nuclear hormone receptors, thereby regulating gene transcription programs in various cells. Adequate nutritional intake of vitamin A is essential for pre- and postnatal development, eyesight and reproduction, and it contributes to the maintenance and regulation of the immune system. Recent molecular studies indicate that lipocalins play an important role in the bioavailability of RA and its immune modulation against Th2 responses. There is emerging evidence that supply with vitamin A determines the susceptibility to allergic diseases: significantly reduced serum vitamin A levels are commonly observed in allergic patients compared to healthy controls. In line, findings from nutritional and clinical trials suggest that sufficient vitamin A supplementation in pregnancy prevents the development of allergic diseases in the offspring, and helps in controlling symptoms in adult asthmatics. Overall, retinoids have a key role in regulating immune homeostasis on mucosal surfaces because they are able to interfere with inflammatory signalling pathways. In this mini-review we will concentrate on the current knowledge about the influence of dietary and supplementary vitamin A on allergic diseases in humans from infancy to adulthood.

The Hygiene Hypothesis in the Age of the Microbiome

The original version of the hygiene hypothesis suggested that infections transmitted early in life by "unhygienic contact" prevented allergies. Examples were endemic fecal-oral infections by viral, bacterial, or protozoic pathogens, such as hepatitis A virus, Helicobacter pylori, or Toxoplasma gondii. Later, this concept also included microorganisms beyond pathogens, such as commensals and symbionts, and the hygiene hypothesis was extended to inflammatory diseases in general. An impressive illustration of the hygiene hypothesis was found in the consistent farm effect on asthma and allergies, which has partly been attributed to immunomodulatory properties of endotoxin as emitted by livestock. Assessment of environmental microorganisms by molecular techniques suggested an additional protective effect of microbial diversity on asthma beyond atopy. Whether microbial diversity stands for a higher probability to encounter protective clusters of microorganisms or whether it is a proxy of a balanced environmental exposure remains elusive. Diversity of the mucosal microbiome of the upper airways probably reflects an undisturbed balance of beneficial microorganisms and pathogens, such as Moraxella catarrhalis, which has been associated with subsequent development of asthma and pneumonia. In addition, specific fermenters of plant fibers, such as the genera Ruminococcus and Bacteroides, have been implied in asthma protection through production of short-chain fatty acids, volatile substances with the capability to reduce T-helper cell type 2-mediated allergic airway inflammation. Evolutionary thinking may offer a key to understanding noncommunicable inflammatory diseases as delayed adaptation to a world of fast and profound environmental changes. Better adaptation may be fostered by growing insight into the interplay between man and microbiome and an adequate choice of the environmental exposure.

Occupational Animal Allergy

PURPOSE OF REVIEW

This review explores animal allergen exposure in research laboratories and other work settings, focusing on causes and prevention.

RECENT FINDINGS

(1) Consistent with the hygiene hypothesis, there is new evidence that early childhood exposure to pets produces changes in the gut microbiome that likely lead to a lower risk of allergy. (2) Anaphylaxis from laboratory animal bites occurs more frequently than suggested by prior literature. (3) Animal allergens represent an occupational hazard in a wide variety of work settings ranging from fields that work with animals to public settings like schools and public transportation where allergens are brought into or are present in the workplace. Exposure to animal allergens can result in allergy, asthma, and anaphylaxis. Animal allergy has been most studied in the research laboratory setting, where exposure reduction can prevent the development of allergy. Similar prevention approaches need to be considered for other animal work environments and in all settings where animal allergens are present.

Antigen-specific Treg cells in immunological tolerance: implications for allergic diseases

Allergic diseases are chronic inflammatory disorders in which there is failure to mount effective tolerogenic immune responses to inciting allergens. The alarming rise in the prevalence of allergic diseases in recent decades has spurred investigations to elucidate the mechanisms of breakdown in tolerance in these disorders and means of restoring it. Tolerance to allergens is critically dependent on the generation of allergen-specific regulatory T (Treg) cells, which mediate a state of sustained non-responsiveness to the offending allergen. In this review, we summarize recent advances in our understanding of mechanisms governing the generation and function of allergen-specific Treg cells and their subversion in allergic diseases. We will also outline approaches to harness allergen-specific Treg cell responses to restore tolerance in these disorders.

A prospective microbiome-wide association study of food sensitization and food allergy in early childhood

BACKGROUND

Alterations in the intestinal microbiome are prospectively associated with the development of asthma; less is known regarding the role of microbiome alterations in food allergy development.

METHODS

Intestinal microbiome samples were collected at age 3-6 months in children participating in the follow-up phase of an interventional trial of high-dose vitamin D given during pregnancy. At age 3, sensitization to foods (milk, egg, peanut, soy, wheat, walnut) was assessed. Food allergy was defined as caretaker report of healthcare provider-diagnosed allergy to the above foods prior to age 3 with evidence of IgE sensitization. Analysis was performed using Phyloseq and DESeq2; P-values were adjusted for multiple comparisons.

RESULTS

Complete data were available for 225 children; there were 87 cases of food sensitization and 14 cases of food allergy. Microbial diversity measures did not differ between food sensitization and food allergy cases and controls. The genera Haemophilus (log2 fold change -2.15, P=.003), Dialister (log2 fold change -2.22, P=.009), Dorea (log2 fold change -1.65, P=.02), and Clostridium (log2 fold change -1.47, P=.002) were underrepresented among subjects with food sensitization. The genera Citrobacter (log2 fold change -3.41, P=.03), Oscillospira (log2 fold change -2.80, P=.03), Lactococcus (log2 fold change -3.19, P=.05), and Dorea (log2 fold change -3.00, P=.05) were underrepresented among subjects with food allergy.

CONCLUSIONS

The temporal association between bacterial colonization and food sensitization and allergy suggests that the microbiome may have a causal role in the development of food allergy. Our findings have therapeutic implications for the prevention and treatment of food allergy.

The Skin Microbiome of Cohabiting Couples

Our work characterizes the influence of cohabitation as a factor influencing the composition of the skin microbiome. Although the body site and sampled individual were stronger influences than other factors collected as metadata in this study, we show that modeling of detected microbial taxa can help with correct identifications of cohabiting partners based on skin microbiome profiles using machine learning approaches. These results show that a cohabiting partner can significantly influence our microbiota. Follow-up studies will be important for investigating the implications of shared microbiome on dermatological health and the shared contributions of cohabiting parents to the microbiome profiles of their infants.

Distinct microbial communities inhabit individuals as part of the human skin microbiome and are continually shed to the surrounding environment. Microbial communities from 17 skin sites of 10 sexually active cohabiting couples (20 individuals) were sampled to test whether cohabitation impacts an individual’s skin microbiome, leading to shared skin microbiota among partner pairs. Amplified 16S rRNA genes of bacteria and archaea from a total of 340 skin swabs were analyzed by high-throughput sequencing, and the results demonstrated that cohabitation was significantly associated with microbial community composition, although this association was greatly exceeded by characteristics of body location and individuality. Random forest modeling demonstrated that the partners could be predicted 86% of the time (P < 0.001) based on their skin microbiome profiles, which was always greater than combinations of incorrectly matched partners. Cohabiting couples had the most similar overall microbial skin communities on their feet, according to Bray-Curtis distances. In contrast, thigh microbial communities were strongly associated with biological sex rather than cohabiting partner. Additional factors that were associated with the skin microbiome of specific body locations included the use of skin care products, pet ownership, allergies, and alcohol consumption. These baseline data identified links between the skin microbiome and daily interactions among cohabiting individuals, adding to known factors that shape the human microbiome and, by extension, its relation to human health.

IMPORTANCE Our work characterizes the influence of cohabitation as a factor influencing the composition of the skin microbiome. Although the body site and sampled individual were stronger influences than other factors collected as metadata in this study, we show that modeling of detected microbial taxa can help with correct identifications of cohabiting partners based on skin microbiome profiles using machine learning approaches. These results show that a cohabiting partner can significantly influence our microbiota. Follow-up studies will be important for investigating the implications of shared microbiota on dermatological health and the contributions of cohabiting parents to the microbiome profiles of their infants.

[Description and role of bacteriological techniques in the management of lung infections]

Les pneumopathies aiguës recouvrent des contextes cliniques variés et les étiologies bactériennes impliquées le sont tout autant. Aucun outil microbiologique n’est 100 % sensible ni 100 % spécifique et malgré les investigations, plus de 30 % des pneumopathies restent sans étiologie identifiée. Si aucun prélèvement n’est indiqué pour les patients traités en ambulatoire, les prélèvements respiratoires non invasifs sont à privilégier pour les pneumopathies aiguës hospitalisées (communautaires ou associées aux soins), tandis que les prélèvements invasifs sont indiqués en seconde ligne pour les pneumopathies aiguës communautaires en réanimation, et en première ligne pour les pneumopathies aiguës de l’immunodéprimé. La culture microbiologique garde une place importante, à condition que le malade soit prélevé avant instauration de l’antibiothérapie. Certains contextes peuvent justifier le recours aux hémocultures, à la recherche d’antigènes urinaires ou aux sérologies. Les PCR rendent déjà service au quotidien mais l’avenir à court terme appartient probablement aux panels moléculaires multiplex capables de détecter de nombreux micro-organismes en quelques heures, surtout dans les pneumopathies communautaires sévères de réanimation et les pneumopathies aiguës de l’immunodéprimé. Le séquençage nucléotidique haut débit révolutionnera bientôt le diagnostic microbiologique, en pneumologie comme dans les autres domaines de l’infectiologie.

Air Pollution and Climate Change Effects on Allergies in the Anthropocene: Abundance, Interaction, and Modification of Allergens and Adjuvants

Air pollution and climate change are potential drivers for the increasing burden of allergic diseases. The molecular mechanisms by which air pollutants and climate parameters may influence allergic diseases, however, are complex and elusive. This article provides an overview of physical, chemical and biological interactions between air pollution, climate change, allergens, adjuvants and the immune system, addressing how these interactions may promote the development of allergies. We reviewed and synthesized key findings from atmospheric, climate, and biomedical research. The current state of knowledge, open questions, and future research perspectives are outlined and discussed. The Anthropocene, as the present era of globally pervasive anthropogenic influence on planet Earth and, thus, on the human environment, is characterized by a strong increase of carbon dioxide, ozone, nitrogen oxides, and combustion- or traffic-related particulate matter in the atmosphere. These environmental factors can enhance the abundance and induce chemical modifications of allergens, increase oxidative stress in the human body, and skew the immune system toward allergic reactions. In particular, air pollutants can act as adjuvants and alter the immunogenicity of allergenic proteins, while climate change affects the atmospheric abundance and human exposure to bioaerosols and aeroallergens. To fully understand and effectively mitigate the adverse effects of air pollution and climate change on allergic diseases, several challenges remain to be resolved. Among these are the identification and quantification of immunochemical reaction pathways involving allergens and adjuvants under relevant environmental and physiological conditions.

FUT2-dependent breast milk oligosaccharides and allergy at 2 and 5 years of age in infants with high hereditary allergy risk

PURPOSE

Manifestation of allergic disease depends on genetic predisposition, diet and commensal microbiota. Genetic polymorphism of mothers determines their breast milk glycan composition. One major determinant is the fucosyltransferase 2 (FUT2, secretor gene) that was shown to be linked to commensal microbiota establishment. We studied whether FUT2-dependent breast milk oligosaccharides are associated with allergic disease in breast-fed infants later in life.

METHODS

We analyzed FUT2-dependent oligosaccharides in breast milk samples of mothers (n = 266) from the placebo group of a randomized placebo-controlled trial of prebiotics and probiotics as preventive against allergic disease in infants with high allergy risk (trial registry number: NCT00298337). Using logistic regression models, we studied associations between FUT2-dependent breast milk oligosaccharides and incidence of allergic disease at 2 and 5 years of age.

RESULTS

At 2 years, but not at 5 years of age, we observed a presumed lower incidence (p < 0.1) for IgE-associated eczema manifestation in C-section-born infants who were fed breast milk containing FUT2-dependent oligosaccharides. By logistic regression, we observed a similar relation (p < 0.1) between presence of FUT2-dependent breast milk oligosaccharides and IgE-associated disease and IgE-associated eczema in C-section-born infants only. When testing with the levels of breast milk oligosaccharide 2'-fucosyllactose as proxy for FUT2 activity, we observed significant (p < 0.05) associations in the C-section-born infants with 'any allergic disease,' IgE-associated disease, eczema and IgE-associated eczema.

CONCLUSION

The data indicate that infants born by C-section and having a high hereditary risk for allergies might have a lower risk to manifest IgE-associated eczema at 2 years, but not 5 years of age, when fed breast milk with FUT2-dependent milk oligosaccharides. Further studies with larger cohorts and especially randomized controlled intervention trials are required to build on these preliminary observations.

Hygiene factors associated with childhood food allergy and asthma

BACKGROUND

Childhood food allergy and asthma rates are increasing. The hygiene hypothesis has been proposed as an explanation for the increased incidence of allergic disease.

OBJECTIVE

To describe the association of childhood food allergy and asthma with hygiene factors, such as the number of siblings, antibiotic use, infection history, pet exposure, child care exposure, and maternalchild factors.

METHODS

Children ages 021 years old (N = 1359) were recruited for a cross-sectional family-based study, including children with food allergy and children without food allergy, and their siblings. We assessed the associations between childhood food allergy and asthma with hygiene factors.

RESULTS

Of the 1359 children, 832 (61.2%) had food allergy, and 406 (30%) had asthma. In the adjusted analysis, the prevalence of food allergy was increased if there was a history of skin infection (prevalence ratio [RRR] 1.12 [95% confidence interval {CI}, 1.011.24]) or eczema (RRR 1.89 [95% CI, 1.702.10]). The prevalence of asthma was increased with a history of respiratory syncytial virus infection (RRR 1.60 [95% CI, 1.341.90]) or eczema (RRR 1.54 [95% CI, 1.271.86]). A greater number of siblings were associated with a decreased prevalence of food allergy (RRR 0.79 [95% CI, 0.750.84]) and asthma (RRR 0.82 [95% CI, 0.740.91]).

CONCLUSION

Our findings supported the accumulating evidence of an association between skin infections and eczema with food allergy. Because these results could be subject to recall bias, additional prospective studies are needed to substantiate these findings.

A comprehensive review of the nasal microbiome in chronic rhinosinusitis (CRS)

Chronic rhinosinusitis (CRS) has been known as a disease with strong infectious and inflammatory components for decades. The recent advancement in methods identifying microbes has helped implicate the airway microbiome in inflammatory respiratory diseases such as asthma and COPD. Such studies support a role of resident microbes in both health and disease of host tissue, especially in the case of inflammatory mucosal diseases. Identifying interactive events between microbes and elements of the immune system can help us to uncover the pathogenic mechanisms underlying CRS. Here we provide a review of the findings on the complex upper respiratory microbiome in CRS in comparison with healthy controls. Furthermore, we have reviewed the defects and alterations of the host immune system that interact with microbes and could be associated with dysbiosis in CRS.

Human gut microbiota plays a role in the metabolism of drugs

BACKGROUND AND AIMS

The gut microbiome, an aggregate genome of trillions of microorganisms residing in the human gastrointestinal tract, is now known to play a critical role in human health and predisposition to disease. It is also involved in the biotransformation of xenobiotics and several recent studies have shown that the gut microbiota can affect the pharmacokinetics of orally taken drugs with implications for their oral bioavailability.

METHODS

Review of Pubmed, Web of Science and Science Direct databases for the years 1957-2016.

RESULTS AND CONCLUSIONS

Recent studies make it clear that the human gut microbiota can play a major role in the metabolism of xenobiotics and, the stability and oral bioavailability of drugs. Over the past 50 years, more than 30 drugs have been identified as a substrate for intestinal bacteria. Questions concerning the impact of the gut microbiota on drug metabolism, remain unanswered or only partially answered, namely (i) what are the molecular mechanisms and which bacterial species are involved? (ii) What is the impact of host genotype and environmental factors on the composition and function of the gut microbiota, (iii) To what extent is the composition of the intestinal microbiome stable, transmissible, and resilient to perturbation? (iv) Has past exposure to a given drug any impact on future microbial response, and, if so, for how long? Answering such questions should be an integral part of pharmaceutical research and personalised health care.

Microbial Dysbiosis: Rethinking Disease in Marine Ecosystems

With growing environmental pressures placed on our marine habitats there is concern that the prevalence and severity of diseases affecting marine organisms will increase. Yet relative to terrestrial systems, we know little about the underlying causes of many of these diseases. Moreover, factors such as saprophytic colonizers and a lack of baseline data on healthy individuals make it difficult to accurately assess the role of specific microbial pathogens in disease states. Emerging evidence in the field of medicine suggests that a growing number of human diseases result from a microbiome imbalance (or dysbiosis), questioning the traditional view of a singular pathogenic agent. Here we discuss the possibility that many diseases seen in marine systems are, similarly, the result of microbial dysbiosis and the rise of opportunistic or polymicrobial infections. Thus, understanding and managing disease in the future will require us to also rethink definitions of disease and pathogenesis for marine systems. We suggest that a targeted, multidisciplinary approach that addresses the questions of microbial symbiosis in both healthy and diseased states, and at that the level of the holobiont, will be key to progress in this area.

Variable risk of atopic disease due to indoor fungal exposure in NHANES 2005-2006

BACKGROUND

Exposure to damp indoor environments is associated with increased risk of eczema, allergy and asthma. The role of dampness-related exposures and risk of allergic diseases are yet to be fully explored in the US population.

OBJECTIVE

We assess whether exposure to fungi, house dust mites and endotoxin increases the risk of eczema, allergy and asthma in children and adults participating in NHANES 2005-2006.

METHODS

A total of 8412 participants (2849 were children aged between 6 and 17 years) were recruited in the 2005-2006 survey. We used multiple logistic regression to investigate whether mildew/musty odour and increased concentrations of Alternaria alternata allergen, Aspergillus fumigatus antigens, house dust mite and endotoxin antigens increase the risk of eczema, allergy and asthma. We stratified models by total IgE < 170 and ≥ 170 KU/L to assess allergic and non-allergic asthma outcomes. Exposure to multiple biological agents and risk of reporting eczema, allergy and asthma were also investigated.

RESULTS

Reporting of a mildew/musty odour was associated with increased risk of childhood asthma (OR 1.60; 95% CI 1.17-2.19), and adult eczema, allergy and asthma (OR 1.92; 95% CI 1.39-2.63, OR 1.59 95% CI 1.26-2.02 and OR 1.61 95% CI 1.00-2.57, respectively). Risk of asthma was associated with total IgE ≥ 170 KU/L in children (OR 1.81; 95% CI 1.01-3.25) and total IgE < 170 KU/L in adults (OR 1.91; 95% CI 1.07-3.42). Children and adults exposed to more than eight biological agents present in the home were at reduced risk of eczema (OR 0.17; 95% CI 0.04-0.77) and asthma (OR 0.49; 95% CI 0.25-0.97), respectively.

CONCLUSION

Exposure to a mildew/musty odour, as a proxy for exposure to fungus, was implicated in an increased risk of atopic diseases. Sensitisation may play a different role in children and adults, and exposure to multiple allergens may reduce the risk of atopic disease.

Anti-Inflammatory Effect of Quercetin on RAW 264.7 Mouse Macrophages Induced with Polyinosinic-Polycytidylic Acid

Quercetin (3,3′,4′,5,6-pentahydroxyflavone) is a well-known antioxidant and a flavonol found in many fruits, leaves, and vegetables. Quercetin also has known anti-inflammatory effects on lipopolysaccharide-induced macrophages. However, the effects of quercetin on virus-induced macrophages have not been fully reported. In this study, the anti-inflammatory effect of quercetin on double-stranded RNA (dsRNA)-induced macrophages was examined. Quercetin at concentrations up to 50 μM significantly inhibited the production of NO, IL-6, MCP-1, IP-10, RANTES, GM-CSF, G-CSF, TNF-α, LIF, LIX, and VEGF as well as calcium release in dsRNA (50 µg/mL of polyinosinic-polycytidylic acid)-induced RAW 264.7 mouse macrophages (p < 0.05). Quercetin at concentrations up to 50 μM also significantly inhibited mRNA expression of signal transducer and activated transcription 1 (STAT1) and STAT3 in dsRNA-induced RAW 264.7 cells (p < 0.05). In conclusion, quercetin had alleviating effects on viral inflammation based on inhibition of NO, cytokines, chemokines, and growth factors in dsRNA-induced macrophages via the calcium-STAT pathway.

The microbial environment and its influence on asthma prevention in early life

There is accumulating evidence to suggest that the environmental microbiome plays a significant role in asthma development. The very low prevalence of asthma in populations highly exposed to microbial environments (farm children and Amish populations) highlights its preventive potential. This microbial diversity might be necessary to instruct a well-adapted immune response and regulated inflammatory responses to other inhaled and ingested environmental elements, such as allergens, particles, and viruses. Like the internal gut microbiome, which is increasingly recognized as an important instructor of immune maturation, the external environmental microbiome might shape immune responses on the skin, airway mucosal surfaces, and potentially also the gut early in life. The diversity of the external microbial world will ensure that of the many maladapted pathways leading to asthma development, most, if not all, will be counterbalanced. Likewise, important contributors to asthma, such as allergen sensitization and allergic manifestations early in life, are being suppressed. Thus the facets of innate immunity targeted by microbes and their compounds and metabolites might be the master switch to asthma and allergy protection, which has been found in environments rich in microbial exposures.

Minimally Invasive Sampling Method Identifies Differences in Taxonomic Richness of Nasal Microbiomes in Young Infants Associated with Mode of Delivery

To date, there is a limited understanding of the role of the airway microbiome in the early life development of respiratory diseases such as asthma, partly due to a lack of simple and minimally invasive sample collection methods. In order to characterize the baseline microbiome of the upper respiratory tract (URT) in infants, a comparatively non-invasive method for sampling the URT microbiome suitable for use in infants was developed. Microbiome samples were collected by placing filter paper in the nostrils of 33 healthy, term infants enrolled as part of the Infant Susceptibility to Pulmonary Infections and Asthma Following RSV Exposure (INSPIRE) study. After bacterial genomic DNA was extracted from the filters, amplicons were generated with universal primers targeting the V1-V3 region of the 16S rRNA gene. This method was capable of capturing a wide variety of taxa expected to inhabit the nasal cavity. Analyses stratifying subjects by demographic and environmental factors previously observed or predicted to influence microbial communities were performed. Microbial community richness was found to be higher in infants who had been delivered via Cesarean section and in those who had been formula-fed; an association was observed between diet and delivery, which confounds this analysis. We have established a baseline URT microbiome using a non-invasive filter paper nasal sampling for this population, and future studies will be performed in this large observational cohort of infants to investigate the relationship between viral infections, the URT microbiota, and the development of childhood wheezing illnesses.

The microbiome of the built environment and mental health

The microbiome of the built environment (MoBE) is a relatively new area of study. While some knowledge has been gained regarding impacts of the MoBE on the human microbiome and disease vulnerability, there is little knowledge of the impacts of the MoBE on mental health. Depending on the specific microbial species involved, the transfer of microorganisms from the built environment to occupant's cutaneous or mucosal membranes has the potential to increase or disrupt immunoregulation and/or exaggerate or suppress inflammation. Preclinical evidence highlighting the influence of the microbiota on systemic inflammation supports the assertion that microorganisms, including those originating from the built environment, have the potential to either increase or decrease the risk of inflammation-induced psychiatric conditions and their symptom severity. With advanced understanding of both the ecology of the built environment, and its influence on the human microbiome, it may be possible to develop bioinformed strategies for management of the built environment to promote mental health. Here we present a brief summary of microbiome research in both areas and highlight two interdependencies including the following: (1) effects of the MoBE on the human microbiome and (2) potential opportunities for manipulation of the MoBE in order to improve mental health. In addition, we propose future research directions including strategies for assessment of changes in the microbiome of common areas of built environments shared by multiple human occupants, and associated cohort-level changes in the mental health of those who spend time in the buildings. Overall, our understanding of the fields of both the MoBE and influence of host-associated microorganisms on mental health are advancing at a rapid pace and, if linked, could offer considerable benefit to health and wellness.

Efficacy of acupuncture for chronic asthma: study protocol for a randomized controlled trial

BACKGROUND

Although asthma symptoms can be temporarily controlled, it is recommended to use effective low-risk, non-drug strategies to constitute a significant advance in asthma management. Acupuncture has been traditionally used to treat asthma; however, the evidence for the efficacy of this treatment is still lacking. Previous clinical trials of acupuncture in treating asthma were limited by methodological defects; therefore, high-quality research is required.

METHODS/DESIGN

This trial is designed as a multi-center, randomized, double-blind, parallel-group controlled trial. Patients with mild to moderate asthma will be randomly allocated to either a verum acupuncture plus as-needed salbutamol aerosol and/or prednisone tablets group or a sham acupuncture plus as-needed salbutamol aerosol and/or prednisone tablets group. Acupoints used in the verum acupuncture group are GV14 (Da Zhui), BL12 (Feng Men), BL13 (Fei Shu) and acupoints used in the sham acupuncture group are DU08 (Jin Suo), BL18 (Gan Shu), BL19 (Dan Shu). After a baseline period of 1 week, the patients in both groups will receive verum/sham acupuncture once every other day with a total of 20 treatment sessions in 6 weeks and a 3-month follow-up. The primary outcome will be measured by using the asthma control test and the secondary outcomes will be measured by using the percentage of symptom-free days, the average dosage of salbutamol aerosol and/or prednisone tablets, lung functions, daily asthma symptom scores, asthma quality of life questionnaire, and so on.

DISCUSSION

This trial will assess the effect of acupuncture on asthma and aims to provide reliable clinical evidence for the efficacy of acupuncture in treating asthma.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01931696 , registered on 26 August 2013.

Are allergic multimorbidities and IgE polysensitization associated with the persistence or re-occurrence of foetal type 2 signalling? The MeDALL hypothesis

Allergic diseases [asthma, rhinitis and atopic dermatitis (AD)] are complex. They are associated with allergen-specific IgE and nonallergic mechanisms that may coexist in the same patient. In addition, these diseases tend to cluster and patients present concomitant or consecutive diseases (multimorbidity). IgE sensitization should be considered as a quantitative trait. Important clinical and immunological differences exist between mono- and polysensitized subjects. Multimorbidities of allergic diseases share common causal mechanisms that are only partly IgE-mediated. Persistence of allergic diseases over time is associated with multimorbidity and/or IgE polysensitization. The importance of the family history of allergy may decrease with age. This review puts forward the hypothesis that allergic multimorbidities and IgE polysensitization are associated and related to the persistence or re-occurrence of foetal type 2 signalling. Asthma, rhinitis and AD are manifestations of a common systemic immune imbalance (mesodermal origin) with specific patterns of remodelling (ectodermal or endodermal origin). This study proposes a new classification of IgE-mediated allergic diseases that allows the definition of novel phenotypes to (i) better understand genetic and epigenetic mechanisms, (ii) better stratify allergic preschool children for prognosis and (iii) propose novel strategies of treatment and prevention.

Immunology in wild nonmodel rodents: an ecological context for studies of health and disease

Transcriptomic methods are set to revolutionize the study of the immune system in naturally occurring nonmodel organisms. With this in mind, the present article focuses on ways in which the use of 'nonmodel' rodents (not the familiar laboratory species) can advance studies into the classical, but ever relevant, epidemiologic triad of immune defence, infectious disease and environment. For example, naturally occurring rodents are an interesting system in which to study the environmental stimuli that drive the development and homeostasis of the immune system and, by extension, to identify where these stimuli are altered in anthropogenic environments leading to the formation of immunopathological phenotypes. Measurement of immune expression may help define individual heterogeneity in infectious disease susceptibility and transmission and facilitate our understanding of infection dynamics and risk in the natural environment; furthermore, it may provide a means of surveillance that can filter individuals carrying previously unknown acute infections of potential ecological or zoonotic importance. Finally, the study of immunology in wild animals may reveal interactions within the immune system and between immunity and other organismal traits that are not observable under restricted laboratory conditions. Potentiating much of this is the possibility of combining gene expression profiles with analytical tools derived from ecology and systems biology to reverse engineer interaction networks between immune responses, other organismal traits and the environment (including symbiont exposures), revealing regulatory architecture. Such holistic studies promise to link ecology, epidemiology and immunology in natural systems in a unified approach that can illuminate important problems relevant to human health and animal welfare and production.

The microbiome at the pulmonary alveolar niche and its role in Mycobacterium tuberculosis infection

Advances in next generation sequencing (NGS) technology have provided the tools to comprehensively and accurately characterize the microbial community in the respiratory tract in health and disease. The presence of commensal and pathogenic bacteria has been found to have important effects on the lung immune system. Until relatively recently, the lung has received less attention compared to other body sites in terms of microbiome characterization, and its study carries special technological difficulties related to obtaining reliable samples as compared to other body niches. Additionally, the complexity of the alveolar immune system, and its interactions with the lung microbiome, are only just beginning to be understood. Amidst this complexity sits Mycobacterium tuberculosis (Mtb), one of humanity's oldest nemeses and a significant public health concern, with millions of individuals infected with Mtb worldwide. The intricate interactions between Mtb, the lung microbiome, and the alveolar immune system are beginning to be understood, and it is increasingly apparent that improved treatment of Mtb will only come through deep understanding of the interplay between these three forces. In this review, we summarize our current understanding of the lung microbiome, alveolar immunity, and the interaction of each with Mtb.

Genomic medicine in gastroenterology: A new approach or a new specialty?

Throughout history, many medical milestones have been achieved to prevent and treat human diseases. Man's early conception of illness was naturally holistic or integrative. However, scientific knowledge was atomized into quantitative and qualitative research. In the field of medicine, the main trade-off was the creation of many medical specialties that commonly treat patients in advanced stages of disease. However, now that we are immersed in the post-genomic era, how should we reevaluate medicine? Genomic medicine has evoked a medical paradigm shift based on the plausibility to predict the genetic susceptibility to disease. Additionally, the development of chronic diseases should be viewed as a continuum of interactions between the individual's genetic make-up and environmental factors such as diet, physical activity, and emotions. Thus, personalized medicine is aimed at preventing or reversing clinical symptoms, and providing a better quality of life by integrating the genetic, environmental and cultural factors of diseases. Whether using genomic medicine in the field of gastroenterology is a new approach or a new medical specialty remains an open question. To address this issue, it will require the mutual work of educational and governmental authorities with public health professionals, with the goal of translating genomic medicine into better health policies.

The importance of bacterial and viral infections associated with adult asthma exacerbations in clinical practice

BACKGROUND

Viral infection is one of the risk factors for asthma exacerbation. However, which pathogens are related to asthma exacerbation in adults remains unclear.

OBJECTIVE

The relation between various infections and adult asthma exacerbations was investigated in clinical practice.

METHODS

The study subjects included 50 adult inpatients due to asthma exacerbations and 20 stable outpatients for comparison. The pathogens from a nasopharyngeal swab were measured by multiplex PCR analysis.

RESULTS

Asthma exacerbations occurred after a common cold in 48 inpatients. The numbers of patients with viral, bacterial, or both infections were 16, 9, and 9, respectively. The dominant viruses were rhinoviruses, respiratory syncytial virus, influenza virus, and metapneumovirus. The major bacteria were S. pneumoniae and H. influenzae. Compared to pathogen-free patients, the patients with pathogens were older and non-atopic and had later onset of disease, lower FeNO levels, lower IgE titers, and a higher incidence of comorbid sinusitis, COPD, or pneumonia. Compared to stable outpatients, asthma exacerbation inpatients had a higher incidence of smoking and comorbid sinusitis, COPD, or pneumonia. Viruses were detected in 50% of stable outpatients, but a higher incidence of rhinovirus, respiratory syncytial virus, and metapneumovirus infections was observed in asthma exacerbation inpatients. H. influenzae was observed in stable asthmatic patients. Other bacteria, especially S. pneumoniae, were important in asthma exacerbation inpatients.

CONCLUSION

Viral or bacterial infections were observed in 70% of inpatients with an asthma exacerbation in clinical practice. Infection with S. pneumoniae was related to adult asthma exacerbation.

Babies Galore; or recent findings and future perspectives of pregnancy cohorts with a focus on immunity

Population-based pregnancy cohorts recruiting women before or at the moment of childbirth allow a longitudinal follow-up on children's health later in life. Important findings arising from pregnancy cohorts are discussed in the present review. These insights have led to revised guidelines on how to minimize disease risks in children, e.g., in the context of chronic immune diseases including allergies and asthma. Moreover, insights from pregnancy cohorts also unveiled a collateral effect of pregnancy on maternal immunity, mirrored by an ameliorated course of certain autoimmune diseases, but also an increased risk of infection with influenza A virus. Future pregnancy cohort studies are still required to close gaps in knowledge on how parameters involved in the developmental origin of health or poor immunity observed in children later in life are operational. We discuss here features that should be covered by future pregnancy cohort studies. Expected insights from such studies will then lay the foundation for biomarker discovery and offer opportunities for interventions to ameliorate adverse immune responses in humans.