Maternal carriage of Prevotella during pregnancy associates with protection against food allergy in the offspring

Biomarkers of Gut Microbiota in Chronic Spontaneous Urticaria and Symptomatic Dermographism

Background

Chronic urticaria (CU) is a chronic inflammatory skin disease associated with Th2 immune response. The two most common subtypes of CU, i.e., chronic spontaneous urticaria and symptomatic dermographism (CSD), often coexist. However, the pathogenesis of CSD is still unclear. Gut microbiota plays an important role in immune-related inflammatory diseases. The purpose of this study was to explore the correlation between gut microbiota and CSD.

Methods

A case-control study was conducted on CSD patients as well as gender- and age-matched normal controls (NCs). The 16S ribosomal DNA sequencing of fecal samples was used to detect the gut microbiota of all subjects. QPCR was used to further verify the species with differences between the two groups.

Results

The alpha diversity of gut microbiota decreased in CSD patients, accompanied by significant changes of the structure of gut microbiota. Subdoligranulum and Ruminococcus bromii decreased significantly in CSD patients and had a potential diagnostic value for CSD according to receiver operating characteristic curve (ROC) analysis. Enterobacteriaceae and Klebsiella were found to be positively correlated with the duration of CSD, while Clostridium disporicum was positively correlated with the dermatology life quality index (DLQI).

Conclusions

The gut microbiota of CSD patients is imbalanced. Subdoligranulum and Ruminococcus bromii are the gut microbiota biomarkers in CSD.

Helicobacter pylori and the intestinal microbiome among healthy school-age children

BACKGROUND

Helicobacter pylori (H. pylori) infection is acquired during childhood and causes chronic gastritis that remains asymptomatic in most infected people. H. pylori alters the gastric microbiota and causes peptic ulcer disease. Evidence on the relationship between asymptomatic H. pylori infection and children's gut microbiota remains elusive.

AIM

We characterized the relationship between H. pylori infection and the intestinal microbiome of healthy children, adjusting for known inter-personal and environmental exposures.

MATERIALS AND METHODS

This cross-sectional study included stool samples obtained from 163 Israeli Arab children aged 6-9 years from different socioeconomic strata. Sociodemographic information was collected through maternal interviews. H. pylori infection was determined using monoclonal antigen detection stool enzyme immunoassay. The gut microbiome was characterized by implementing 16S rRNA gene sequencing of the V4 region and a multivariate downstream analysis.

RESULTS

Overall, 57% of the participants were positive for H. pylori infection and it was significantly associated with low socioeconomic status. There was no significant association between H. pylori infection and bacterial richness of fecal microbiome. H. pylori infection was significantly associated with intestinal bacterial composition, including a strong association with Prevotella copri and Eubacterium biforme. Moreover, socioeconomic status was strongly associated with bacterial composition.

DISCUSSION AND CONCLUSIONS

H. pylori infection in healthy children was significantly associated with altered intestinal microbiome structure. Socioeconomic determinants exhibit a strong effect, related to both H. pylori infection and intestinal diversity and composition in childhood. These findings are clinically important to the understanding of the role of H. pylori infection and other intestinal microbes in health and disease.

Role of the gut-skin axis in IgE-mediated food allergy and atopic diseases

PURPOSE OF REVIEW

In recent years, landmark clinical trials investigating the role of early oral exposure to food antigens for food allergy (FA) prevention have highlighted the importance of immunoregulatory pathways in the 'gut-skin axis'. This review highlights recent literature on the mechanisms of the immune system and microbiome involved in the gut-skin axis, contributing to the development of atopic dermatitis (AD), FA, allergic rhinitis (AR) and asthma. Therapeutic interventions harnessing the gut-skin axis are also discussed.

RECENT FINDINGS

Epicutaneous sensitization in the presence of AD is capable of inducing Th2 allergic inflammation in the intestinal tract and lower respiratory airways, predisposing one to the development of AR and asthma. Probiotics have demonstrated positive effects in preventing and treating AD, though there is no evident relationship of its beneficial effects on other allergic diseases. Prophylactic skin emollients use has not shown consistent protection against AD, whereas there is some evidence for the role of dietary changes in alleviating AD and airway inflammation. More randomized controlled trials are needed to clarify the potential of epicutaneous immunotherapy as a therapeutic strategy for patients with FA.

SUMMARY

The growing understanding of the gut-skin interactions on allergic disease pathogenesis presents novel avenues for therapeutic interventions which target modulation of the gut and/or skin.

Nurturing the Early Life Gut Microbiome and Immune Maturation for Long Term Health

Early life is characterized by developmental milestones such as holding up the head, turning over, sitting up and walking that are typically achieved sequentially in specific time windows. Similarly, the early gut microbiome maturation can be characterized by specific temporal microorganism acquisition, colonization and selection with differential functional features over time. This orchestrated microbial sequence occurs from birth during the first years of age before the microbiome reaches an adult-like composition and function between 3 and 5 years of age. Increasingly, these different steps of microbiome development are recognized as crucial windows of opportunity for long term health, primarily linked to appropriate immune and metabolic development. For instance, microbiome disruptors such as preterm and Cesarean-section birth, malnutrition and antibiotic use are associated with increased risk to negatively affect long-term immune and metabolic health. Different age discriminant microbiome taxa and functionalities are used to describe age-appropriate microbiome development, and advanced modelling techniques enable an understanding and visualization of an optimal microbiome maturation trajectory. Specific microbiome features can be related to later health conditions, however, whether such features have a causal relationship is the topic of intense research. Early life nutrition is an important microbiome modulator, and 'Mother Nature' provides the model with breast milk as the sole source of nutrition for the early postnatal period, while dietary choices during the prenatal and weaning period are to a large extent guided by tradition and culture. Increasing evidence suggests prenatal maternal diet and infant and child nutrition impact the infant microbiome trajectory and immune competence development. The lack of a universal feeding reference for such phases represents a knowledge gap, but also a great opportunity to provide adequate nutritional guidance to maintain an age-appropriate microbiome for long term health. Here, we provide a narrative review and perspective on our current understanding of age-appropriate microbiome maturation, its relation to long term health and how nutrition shapes and influences this relationship.

Potential Biomarkers, Risk Factors and their Associations with IgE-mediated Food Allergy in Early Life: A Narrative Review

Food allergy affects the quality of life of millions of people worldwide and presents a significant psychological and financial burden for both national and international public health. In the past few decades, the prevalence of allergic disease has been on the rise worldwide. Identified risk factors for food allergy include family history, mode of delivery, variations in infant feeding practices, prior diagnosis of other atopic diseases such as eczema, and social economic status. Identifying reliable biomarkers which predict the risk of developing food allergy in early life would be valuable in both preventing morbidity and mortality and by making current interventions available at the earliest opportunity. There is also the potential to identify new therapeutic targets. This narrative review provides details on the genetic, epigenetic, dietary and microbiome influences upon the development of food allergy and synthesizes the currently available data indicating potential biomarkers. While there is a large body of research evidence available within each field of potential risk factors, there are very limited number of studies which span multiple methodological fields, for example including immunology, microbiome, genetic/epigenetic factors and dietary assessment. We recommend that further collaborative research with detailed cohort phenotyping is required to identify biomarkers, and whether these vary between at-risk populations and the wider population. The low incidence of oral food challenge confirmed food allergy in the general population, and the complexities of designing nutritional intervention studies will provide challenges for researchers to address in generating high quality, reliable and reproducible research findings.

STATEMENT OF SIGNIFICANCE

Food allergy affects the quality of life of millions of people worldwide and presents a significant psychological and financial burden for both national and international public health. Identifying reliable biomarkers which predict the risk of developing food allergy would be valuable in both preventing morbidity and mortality and by making current interventions available at the earliest opportunity. This review provides details on the genetic, epigenetic, dietary and microbiome influences upon the development of food allergy. This helps in identifying reliable biomarkers to predict the risk of developing food allergy, which could be valuable in both preventing morbidity and mortality and by making interventions available at the earliest opportunity.

The maternal gut microbiome during pregnancy and offspring allergy and asthma

Environmental exposures during pregnancy that alter both the maternal gut microbiome and the infant's risk of allergic disease and asthma include a traditional farm environment and consumption of unpasteurized cow's milk, antibiotic use, dietary fiber and psychosocial stress. Multiple mechanisms acting in concert may underpin these associations and prime the infant to acquire immune competence and homeostasis following exposure to the extrauterine environment. Cellular and metabolic products of the maternal gut microbiome can promote the expression of microbial pattern recognition receptors, as well as thymic and bone marrow hematopoiesis relevant to regulatory immunity. At birth, transmission of maternally derived bacteria likely leverages this in utero programming to accelerate postnatal transition from a Th2 to Th1 and Th17 dominant immune phenotypes and maturation of regulatory immune mechanisms, which in turn reduce the child's risk of allergic disease and asthma. Although our understanding of these phenomena is rapidly evolving, the field is relatively nascent, and we are yet to translate existing knowledge into interventions that substantially reduce disease risk in humans. Here we review evidence that the maternal gut microbiome impacts the offspring's risk of allergic disease and asthma, discuss challenges and future directions for the field, and propose the hypothesis that maternal carriage of Prevotella copri during pregnancy decreases the offspring's risk of allergic disease via production of succinate which in turn promotes bone marrow myelopoiesis of dendritic cell precursors in the fetus.

Potential of fecal microbiota for detection and postoperative surveillance of colorectal cancer

Background

Colorectal cancer (CRC) is one of the most common cancers. In recent studies, the gut microbiota has been reported to be potentially involved in aggravating or favoring CRC development. However, little is known about the microbiota composition in CRC patients after treatment. In this study, we explored the fecal microbiota composition to obtain a periscopic view of gut microbial communities. We analyzed microbial 16S rRNA genes from 107 fecal samples of Chinese individuals from three groups, including 33 normal controls (NC), 38 CRC patients (Fa), and 36 CRC post-surgery patients (Fb).

Results

Species richness and diversity were decreased in the Fa and Fb groups compared with that of the NC group. Partial least squares discrimination analysis showed clustering of samples according to disease with an obvious separation between the Fa and NC, and Fb and NC groups, as well as a partial separation between the Fa and Fb groups. Based on linear discriminant analysis effect size analysis and a receiver operating characteristic model, Fusobacterium was suggested as a potential biomarker for CRC screening. Additionally, we found that surgery greatly reduced the bacterial diversity of microbiota in CRC patients. Some commensal beneficial bacteria of the intestinal canal, such as Faecalibacterium and Prevotella, were decreased, whereas the drug-resistant Enterococcus was visibly increased in CRC post-surgery group. Meanwhile, we observed a declining tendency of Fusobacterium in the majority of follow-up CRC patients who were still alive approximately 3 y after surgery. We also observed that beneficial bacteria dramatically decreased in CRC patients that recidivated or died after surgery. This revealed that important bacteria might be associated with prognosis.

Conclusions

The fecal bacterial diversity was diminished in CRC patients compared with that in NC. Enrichment and depletion of several bacterial strains associated with carcinomas and inflammation were detected in CRC samples. Fusobacterium might be a potential biomarker for early screening of CRC in Chinese or Asian populations. In summary, this study indicated that fecal microbiome-based approaches could be a feasible method for detecting CRC and monitoring prognosis post-surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02182-6.

Study of the therapeutic effect of raw and processed Vladimiriae Radix on ulcerative colitis based on intestinal flora, metabolomics and tissue distribution analysis

BACKGROUND

The intestinal flora imbalance and metabolic disorders are closely related to the pathogenesis of ulcerative colitis (UC). As a commonly used herb for the treatment of gastrointestinal diseases, Vladimiriae Radix (VR) has been used for hundreds of years, and its main active ingredients are costunolide (COS) and dehydrocostus lactone (DEH). Clinical usage habits and previous studies have shown that the processed Vladimiriae Radix (pVR) seems to be more suitable for treating bowel disease than the raw Vladimiriae Radix (rVR), but there is still no relevant comparative study.

PURPOSE

To investigate the therapeutic effect of rVR and pVR on UC by analyzing the intestinal flora, metabolomics and tissue distribution.

METHODS

UC rat models were established to investigate the anti-inflammatory activities of rVR and pVR by enzyme-linked immunosorbent assay (ELISA), and to study their regulation of intestinal flora and metabolism by 16s rRNA gene analysis and Ultra Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS). Moreover, the distribution of COS and DEH in UC mouse tissues were also observed by High Performance Liquid Chromatography Mass Spectrometry (HPLC-MS).

RESULTS

rVR and pVR reduced tissue damage and the levels of TNF-α, IL-6, IL-1β, IL-10, TGF-β and MPO, especially pVR. 16s rRNA gene analysis showed that rVR superior in ameliorating species evenness and restoring the abundance of Lachnospiraceae and Ruminococcaceae, while pVR is better at increasing the richness and the abundance of Prevotellaceae. Metabolomics analysis suggested that rVR regulates the β-alanine, pantothenic acid and coenzyme A biosynthesis, but pVR regulates more abundant metabolic pathways. The tissue distribution data indicated the accumulation of COS and DEH in the gastrointestinal tract.

CONCLUSION

rVR and pVR had obvious therapeutic effect on UC. The potential mechanisms might be regulating abnormal metabolism, affecting the diversity and structure of intestinal flora, and accumulation of COS and DEH in colon.

Infant pacifier sanitization and risk of challenge-proven food allergy: A cohort study

BACKGROUND

Environmental microbial exposure plays a role in immune system development and susceptibility to food allergy.

OBJECTIVE

We sought to investigate whether infant pacifier use during the first postnatal year, with further consideration of sanitization, alters the risk of food allergy by age 1 year.

METHODS

The birth cohort recruited pregnant mothers at under 28 weeks' gestation in southeast Australia, with 894 families followed up when infants turned 1 year. Infants were excluded if born under 32 weeks, with a serious illness, major congenital malformation, or genetic disease. Questionnaire data, collected at recruitment and infant ages 1, 6, and 12 months, included pacifier use and pacifier sanitization (defined as the joint exposure of a pacifier and cleaning methods). Challenge-proven food allergy was assessed at 12 months.

RESULTS

Any pacifier use at 6 months was associated with food allergy (adjusted odds ratio, 1.94; 95% CI, 1.04-3.61), but not pacifier use at other ages. This overall association was driven by the joint exposure of pacifier-antiseptic use (adjusted odds ratio, 4.83; 95% CI, 1.10-21.18) compared with no pacifier use. Using pacifiers without antiseptic at 6 months was not associated with food allergy. Among pacifier users, antiseptic cleaning was still associated with food allergy (adjusted odds ratio, 3.56; 95% CI, 1.18-10.77) compared with no antiseptic use. Furthermore, persistent and repeated antiseptic use over the first 6 months was associated with higher food allergy risk (P = .029).

CONCLUSIONS

This is the first report of a pacifier-antiseptic combination being associated with a higher risk of subsequent food allergy. Future work should investigate underlying biological pathways.

The Infant Microbiome and Its Impact on Development of Food Allergy

The prevalence of food allergy (FA) has been increasing over the past few decades; recent statistics suggest that FA has an impact on up to 10% of the population and 8% of children. Although the pathogenesis of FA is unclear, studies suggest gut microbiome plays a role in the development of FA. The gut microbiome is influenced by infant feeding method, infant diet, and maternal diet during lactation. Breastfeeding, Mediterranean diet, and probiotics are associated with commensal gut microbiota that protect against FA. This area of research is essential to discovering potential preventive methods or therapeutic targets against FA.

The microbiota-gut-brain axis: A novel nutritional therapeutic target for growth retardation

Growth retardation (GR), which commonly occurs in childhood, is a major health concern globally. However, the specific mechanism remains unclear. It has been increasingly recognized that changes in the gut microbiota may lead to GR through affecting the microbiota-gut-brain axis. Microbiota interacts with multiple factors such as birth to affect the growth of individuals. Microbiota communicates with the nerve system through chemical signaling (direct entry into the circulation system or stimulation of enteroendocrine cells) and nervous signaling (interaction with enteric nerve system and vagus nerve), which modulates appetite and immune response. Besides, they may also influence the function of enteric glial cells or lymphocytes and levels of systemic inflammatory cytokines. Environmental stress may cause leaky gut through perturbing the hypothalamic-pituitary-adrenal axis to further result in GR. Nutritional therapies involving probiotics and pre-/postbiotics are being investigated for helping the patients to overcome GR. In this review, we summarize the role of microbiota in GR with human and animal models. Then, existing and potential regulatory mechanisms are reviewed, especially the effect of microbiota-gut-brain axis. Finally, we propose nutritional therapeutic strategies for GR by the intervention of microbiota-gut-brain axis, which may provide novel perspectives for the treatment of GR in humans and animals.

Dysbiosis in food allergy and implications for microbial therapeutics

The increase in food allergy prevalence in recent years suggests that environmental factors, such as diet and intestinal microbiota, play contributory roles. In this issue of the JCI, Bao et al. compared twins that differed with respect to food allergies. The researchers analyzed sequences from microbe ribosomal RNA and profiled microbe metabolites, identifying health-associated microbes at the species level. In addition to revealing microbes from the Clostridia class enriched in healthy twins, the authors identified two commensal species (Phascolarctobacterium faecium and Ruminococcus bromii) related to the healthy fecal metabolome. This study advances the goal for next-generation probiotic therapies that effectively treat or prevent food allergy.

The Effect of Xylooligosaccharide, Xylan, and Whole Wheat Bran on the Human Gut Bacteria

Wheat bran is a cereal rich in dietary fibers that have high levels of ferulic acid, which has prebiotic effects on the intestinal microbiota and the host. Herein we explored the effect of xylooligosaccharide, xylan, and whole wheat bran on the human gut bacteria and screened for potential ferulic acid esterase genes. Using in vitro fermentation, we analyzed the air pressure, pH-value, and short-chain fatty acid levels. We also performed 16S rRNA gene and metagenomic sequencing. A Venn diagram analysis revealed that 80% of the core operational taxonomic units (OTUs) were shared among the samples, and most of the xylooligosaccharide treatment core OTUs (319/333 OTUs) were shared with the other two treatments’ core OTUs. A significant difference analysis revealed that the relative abundance of Dorea, Bilophila, and Sulfurovum in wheat bran treatment was higher than that in xylan and xylooligosaccharide treatments. The clusters of orthologous groups of proteins functional composition of all samples was similar to the microbiota composition of the control. Using metagenomic sequencing, we revealed seven genes containing the conserved residues, Gly-X-Ser-X-Gly, and the catalytic triad, Ser-His-Asp, which are thus potential ferulic acid esterase genes. All the results indicate that xylan and/or xylooligosaccharide, the main dietary fibers in wheat bran, plays a major role in in vitro fermentation by the human gut microbiota.

Maternal exposures and the infant gut microbiome: a systematic review with meta-analysis

Early life, including the establishment of the intestinal microbiome, represents a critical window of growth and development. Postnatal factors affecting the microbiome, including mode of delivery, feeding type, and antibiotic exposure have been widely investigated, but questions remain regarding the influence of exposures in utero on infant gut microbiome assembly. This systematic review aimed to synthesize evidence on exposures before birth, which affect the early intestinal microbiome. Five databases were searched in August 2019 for studies exploring pre-pregnancy or pregnancy 'exposure' data in relation to the infant microbiome. Of 1,441 publications identified, 76 were included. Factors reported influencing microbiome composition and diversity included maternal antibiotic and probiotic uses, dietary intake, pre-pregnancy body mass index (BMI), gestational weight gain (GWG), diabetes, mood, and others. Eleven studies contributed to three meta-analyses quantifying associations between maternal intrapartum antibiotic exposure (IAP), BMI and GWG, and infant microbiome alpha diversity (Shannon Index). IAP, maternal overweight/obesity and excessive GWG were all associated with reduced diversity. Most studies were observational, few included early recruitment or longitudinal follow-up, and the timing, frequency, and methodologies related to stool sampling and analysis were variable. Standardization and collaboration are imperative to enhance understanding in this complex and rapidly evolving area.

Food Allergy: Searching for the Modern Environmental Culprit

Food allergy is a modern disease. Its exponential increase in prevalence in the last 70 years cannot be explained by genetic factors alone. In this review we discuss the hypotheses that have been suggested previously, and the evidence that supports them, to explain this rise in prevalence as well as the medical treatments that have developed as a result of basic exploration within these paradigms. We argue that one major area of fruitful exploration that would help generate new ideas may be systematic analyses of the unknown factors of the modern environment that may contribute to the formation of food allergy. Through this lens, we review the current understanding of food allergy pathogenesis and propose novel research directions, with implications for the current strategies for managing food allergy.

Role of the Intestinal Epithelium and Its Interaction With the Microbiota in Food Allergy

The intestinal epithelial tract forms a dynamic lining of the digestive system consisting of a range of epithelial cell sub-types with diverse functions fulfilling specific niches. The intestinal epithelium is more than just a physical barrier regulating nutrient uptake, rather it plays a critical role in homeostasis through its intrinsic innate immune function, pivotal regulation of antigen sensitization, and a bi-directional interplay with the microbiota that evolves with age. In this review we will discuss these functions of the epithelium in the context of food allergy.

Can we prevent allergic disease? Understanding the links between the early life microbiome and allergic diseases of childhood

PURPOSE OF REVIEW

The microbiome and immune system are intrinsically linked, and during infancy these crucial biological systems undergo a concurrent and expansive maturation process. As these maturation processes progress, some children develop a sequence of IgE-mediated immune disorders termed the 'Allergic March', and unfortunately the prevalence of these lifelong and burdensome allergic conditions has increased over the past half century. Our current treatment strategies are unable to prevent or cure components of the Allergic March. However, recent discoveries have enhanced our mechanistic understanding of early-life microbiota-immune interactions with exciting implications for preventing these allergic disorders.

RECENT FINDINGS

The current review will detail recent literature regarding perinatal factors (e.g. birth mode, antibiotic exposure, breastmilk seeding of the microbiota, built environment) that shape the infant gut microbiota composition. Furthermore, we will discuss new findings that have highlighted immune cells which are particularly sensitive to microbial influences in utero and during the early-life window of development.

SUMMARY

As our understanding of the dynamic relationship between the developing infant microbiota and immune system grows, a priority toward preserving critical early-life interactions may provide life-long protection to these diseases in the future.

Communal living: glycan utilization by the human gut microbiota

Our lower gastrointestinal tract plays host to a vast consortium of microbes, known as the human gut microbiota (HGM). The HGM thrives on a complex and diverse range of glycan structures from both dietary and host sources, the breakdown of which requires the concerted action of cohorts of carbohydrate-active enzymes (CAZymes), carbohydrate-binding proteins, and transporters. The glycan utilization profile of individual taxa, whether 'specialist' or 'generalist', is dictated by the number and functional diversity of these glycan utilization systems. Furthermore, taxa in the HGM may either compete or cooperate in glycan deconstruction, thereby creating a complex ecological web spanning diverse nutrient niches. As a result, our diet plays a central role in shaping the composition of the HGM. This review presents an overview of our current understanding of glycan utilization by the HGM on three levels: (i) molecular mechanisms of individual glycan deconstruction and uptake by key bacteria, (ii) glycan-mediated microbial interactions, and (iii) community-scale effects of dietary changes. Despite significant recent advancements, there remains much to be discovered regarding complex glycan metabolism in the HGM and its potential to affect positive health outcomes.

Microbial signature in IgE-mediated food allergies

BACKGROUND

Multiple studies suggest a key role for gut microbiota in IgE-mediated food allergy (FA) development, but to date, none has studied it in the persistent state.

METHODS

To characterize the gut microbiota composition and short-chain fatty acid (SCFAs) profiles associated with major food allergy groups, we recruited 233 patients with FA including milk (N = 66), sesame (N = 38), peanut (N = 71), and tree nuts (N = 58), and non-allergic controls (N = 58). DNA was isolated from fecal samples, and 16S rRNA gene sequences were analyzed. SCFAs in stool were analyzed from patients with a single allergy (N = 84) and controls (N = 31).

RESULTS

The gut microbiota composition of allergic patients was significantly different compared to age-matched controls both in α-diversity and β-diversity. Distinct microbial signatures were noted for FA to different foods. Prevotella copri (P. copri) was the most overrepresented species in non-allergic controls. SCFAs levels were significantly higher in the non-allergic compared to the FA groups, whereas P. copri significantly correlated with all three SCFAs. We used these microbial differences to distinguish between FA patients and non-allergic healthy controls with an area under the curve of 0.90, and for the classification of FA patients according to their FA types using a supervised learning algorithm. Bacteroides and P. copri were identified as taxa potentially contributing to KEGG acetate-related pathways enriched in non-allergic compared to FA. In addition, overall pathway dissimilarities were found among different FAs.

CONCLUSIONS

Our results demonstrate a link between IgE-mediated FA and the composition and metabolic activity of the gut microbiota.

Development of qPCR platform with probes for quantifying prevalent and biomedically relevant human gut microbial taxa

Nowadays the advent of innovative high-throughput sequencing allows obtaining high-quality microbiome profiling. However, PCR-based tests are still considered the "golden standard" for many clinical applications. Here, we designed a qPCR-based platform with fluorescent-labeled oligonucleotide probes for assessing human gut microbiome composition. The system allows conducting qualitative and semiquantitative analysis for 12 prokaryotic taxa that are prevalent in the human gut and associated with diseases, diet, age and other factors. The platform was validated by comparing microbiome profile data obtained with two different methods - the platform and high-throughput 16S rRNA sequencing - across 42 stool samples. The test can form the basis for precise and cost-efficient microbiome assay for large-scale surveys including clinical trials with interventions related to diet and disease risks.

Probiotic Supplementation During the Perinatal and Infant Period: Effects on Gut Dysbiosis and Disease

The perinatal period is crucial to the establishment of lifelong gut microbiota. The abundance and composition of microbiota can be altered by several factors such as preterm delivery, formula feeding, infections, antibiotic treatment, and lifestyle during pregnancy. Gut dysbiosis affects the development of innate and adaptive immune responses and resistance to pathogens, promoting atopic diseases, food sensitization, and infections such as necrotizing enterocolitis (NEC). Recent studies have indicated that the gut microbiota imbalance can be restored after a single or multi-strain probiotic supplementation, especially mixtures of Lactobacillus and Bifidobacterium strains. Following the systematic search methodology, the current review addresses the importance of probiotics as a preventive or therapeutic tool for dysbiosis produced during the perinatal and infant period. We also discuss the safety of the use of probiotics in pregnant women, preterm neonates, or infants for the treatment of atopic diseases and infections.

Role of the Microbiome in Allergic Disease Development

PURPOSE OF REVIEW

Evidence suggests that the microbiome of the skin, gastrointestinal tract, and airway contribute to health and disease. As we learn more about the role that the microbiota plays in allergic disease development, we can develop therapeutics to alter this pathway.

RECENT FINDINGS

Epidemiologic studies reveal that an association exists between environmental exposures, which alter the microbiota, and developing atopic dermatitis, food allergy, and/or asthma. In fact, samples from the skin, gastrointestinal tract, and respiratory tract reveal distinct microbiotas compared with healthy controls, with microbial changes (dysbiosis) often preceding the development of allergic disease. Mechanistic studies have confirmed that microbes can either promote skin, gut, and airway health by strengthening barrier integrity, or they can alter skin integrity and damage gut and airway epithelium. In this review, we will discuss recent studies that reveal the link between the microbiota and immune development, and we will discuss ways to influence these changes.