Gut microbiota and allergic diseases in children

Early-life antibiotic dysbiosis impairs microbial tryptophan- nicotinic acid metabolism exacerbating food allergy in adulthood

Food allergy (FA) pathogenesis links to intestinal dysbiosis, with antibiotic exposure a suspected risk factor, yet mechanisms are unclear. Our study shows early life (EL) antibiotic exposure in mice heightens susceptibility to OVA - induced allergic intestinal inflammation. EL - antibiotics cause intestinal dysbiosis, like Clostridia and Muribaculaceae depletion and Sutterellaceae enrichment, disrupting tryptophan metabolism and reducing nicotinic acid (NA). NA deficiency impairs gut barrier and Th2/Treg balance. However, NA supplementation restores these via GPR109A. In human pediatric cohorts, food - allergic children with EL - antibiotic exposure have lower gut NA levels. We integrated mouse and human data with multi - omics, revealing EL - Abx regulates FA through the "microbiota - metabolism - immunity" axis, and suggest targeting NA pathway to counter antibiotic - related FA risk.

Assessment of the Diet Quality Index and Its Constituents in Preschool Children Diagnosed with a Food Allergy as Part of the "Living with an Allergy" Project

Pediatric food allergies (FAs) are health conditions that adversely impact the quality of life of children and their caregivers.

AIM

The primary objective of the present study was to assess the quality of the diets administered to allergic children based on the Healthy Diet Index (HID-10), to determine the influence of parental knowledge about FAs and the elimination diet, and to identify the factors that contribute to healthy food choices.

MATERIAL AND METHODS

This study was conducted as part of the "Living with an Allergy" research and educational program for preschool children, which was implemented between June 2021 and June 2023 in the city of Lublin.

RESULTS

Food allergies were diagnosed and confirmed in 241 children, including 106 boys (44%). A higher number of unhealthy dietary factors (DQI-1) was significantly associated with gender, and lower DQI values were more often noted in boys (p < 0.05). In turn, a higher number of health-promoting dietary factors (DQI-3) was significantly associated with a younger age in children (OR 1.54; 95%CI 1.17-1.74, p < 0.01) and with an older age in parents (OR 1.43; 95%CI 1.2-1.67, p < 0.05).

CONCLUSIONS

Children whose diets, including the necessary modifications, were recommended by a physician or a dietitian were characterized by significantly higher DQI values and a higher number of health-promoting dietary factors. The diets of children with FAs should consist mainly of unprocessed foods to control the intake of unhealthy products that suppress immunity.

Multi-omics technology reveals the changes in gut microbiota to stimulate aromatic amino acid metabolism in children with allergic rhinitis and constipation

Background

Comorbid allergic rhinitis and constipation (ARFC) in children are associated with gut microbiota (GM) dysbiosis and metabolic perturbations; however, the underlying mechanistic interplay remains unclear.

Objective

This multi-omics study aimed to characterize GM and fecal metabolomic signatures in preschool ARFC children and elucidate microbial-metabolite interactions driving dual symptomatology.

Methods

Fecal samples from 16 ARFC and 15 healthy control (HC) children underwent high-throughput absolute quantification 16S rRNA sequencing and untargeted metabolomics. Differential taxa and metabolites were identified via LEfSe and OPLS-DA (VIP > 1, false discovery rate (FDR) q < 0.05). Microbial-metabolite networks were reconstructed using genome-scale metabolic modeling and KEGG pathway analysis.

Results

The ARFC group exhibited distinct β-diversity (P = 0.031), marked by elevated Hungatella, Tyzzerella, and Bifidobacterium longum (P < 0.05). Metabolomics revealed upregulated aromatic amino acids (AAAs), neurotransmitters, and bile acids (FDR q < 0.05), with enrichment in tryptophan/tyrosine pathways (P < 0.01). Bioinformatic modeling linked Hungatella to tryptophan hydroxylase (EC:1.14.16.4), driving serotonin synthesis, and Tyzzerella to indoleamine 2,3-dioxygenase (EC:1.13.11.52), promoting kynurenine production. Bifidobacterium longum correlated with phenylalanine hydroxylase (EC:1.14.16.1), enhancing phenylalanine derivatives. A combined GM-metabolite diagnostic model demonstrated robust accuracy (AUC = 0.8).

Conclusion

GM dysbiosis in ARFC children activates AAA metabolism, generating neuroactive and pro-inflammatory metabolites that may exacerbate allergic and gastrointestinal symptoms. These findings highlight microbial-metabolite axes as therapeutic targets. Study limitations include cohort size and lack of disease-specific controls, necessitating validation in expanded cohorts.

Effects of post-adulthood environmental hygiene improvement on gut microbiota and immune tolerance in mice

Changes in diet, cleanliness, stress, and exercise patterns may contribute to the disappearance of various gut microbes in humans who relocate to developed countries from developing countries. To explore the impact of environmental cleanliness on the gut microbiota, adult mice housed in a general animal room were divided into three groups. The control group was subjected to an unchanged living environment, SPF mice were moved to a specific pathogen-free (SPF) animal room with higher environmental cleanliness, and SPFL (specific pathogen-free specific with a fecal leakage grid) mice were moved to the SPF animal room and reared in cages with the function of preventing mice from eating feces as much as possible. Metagenome sequencing results showed that the gut microbial diversity decreased after the environmental change, accompanied by a substantial loss in gut microbiota, including genera known to have protective effects against allergies and those involved in short-chain fatty acid production. Additionally, the abundance of functional genes involved in short-chain fatty acid metabolism, amino acid synthesis, vitamin metabolism, flagellar assembly, and bacterial chemotaxis decreased. The environmental hygiene improvement also resulted in significant increases in total serum IgE, IL-4, IL-5, and IL-13 levels in mice with artificially induced chronic inflammatory dermatosis. Compared with SPF mice, preventing mice from eating feces as much as possible decreased the gut microbial diversity but did not markedly change functional gene expression or total serum cytokine levels.

IMPORTANCE

Research has indicated that the human gut microbial diversity gradually decreases, while the prevalence of allergic diseases increases after movement from developing countries to developed countries. A healthy gut microbiota is necessary for proper human immune function. Movement from undeveloped to developed regions is often accompanied by an increase in environmental cleanliness. However, whether changes in environmental cleanliness are an important factor contributing to the decreased gut microbial diversity and increased prevalence of allergic diseases has not been reported. This study demonstrates the impact of increased environmental cleanliness on gut microbiota and susceptibility to allergic diseases and contributes to a better understanding of the increased incidence rate of various chronic diseases.

Associations of prenatal organophosphate esters exposure with risk of eczema in early childhood, mediating role of gut microbiota

Few epidemiological evidence has focused on the impact of organophosphate esters (OPEs) and the risk of eczema, and underlying role of gut microbiota. Based on the Shanghai Maternal-Child Pairs Cohort, a nested case-control study including 332 eczema cases and 332 controls was conducted. Umbilical cord blood and stools were collected for OPEs detection and gut microbiota sequencing, separately. Eczema cases were identified using the International Study of Asthma and Allergies in Childhood core questionnaire and clinical diagnosis. The environmental risk score (ERS) for OPEs was developed to quantify OPEs burden. Conditional logistic regression models, multivariate analysis by linear models, negative-binomial hurdle regression, and mediation analysis were employed. Tris(2-butoxyethyl) phosphate (TBP), tris (2-butoxy ethyl) phosphate (TBEP), 2-ethylhexyl diphenyl phosphate (EHDPP), and tris(1,3-dichloro-2-propyl) phosphate (TDCPP) had detection rates > 50 %, with median concentrations ranged from 0.11 to 2.71 μg/L. TBP (OR = 1.12, 95 % CI: 1.01, 1.25), TDCPP (OR = 1.32, 95 % CI: 1.09, 1.59), and ERS (OR = 6.44, 95 % CI: 3.47, 11.94) were associated with elevated risk of eczema. OPEs exposure was correlated with increased alpha diversity and the abundance of several pathogenic bacteria, such as Klebsiella. Negative associations were observed between OPEs exposure and the abundances of Lachnospiraceae genera. Additionally, a positive correlation was identified between alpha diversity and the risk of eczema during childhood. Alpha diversity indices and Lachnospiraceae serve as significant mediators in this relationship. Results of this study indicate that prenatal exposure to OPEs is linked to an elevated risk of eczema and gut microbiota dysbiosis, potentially contributing to immunotoxicity of OPEs during early life.

Akkermansia muciniphila: biology, microbial ecology, host interactions and therapeutic potential

Akkermansia muciniphila is a gut bacterium that colonizes the gut mucosa, has a role in maintaining gut health and shows promise for potential therapeutic applications. The discovery of A. muciniphila as an important member of our gut microbiome, occupying an extraordinary niche in the human gut, has led to new hypotheses on gut health, beneficial microorganisms and host-microbiota interactions. This microorganism has established a unique position in human microbiome research, similar to its role in the gut ecosystem. Its unique traits in using mucin sugars and mechanisms of action that can modify host health have made A. muciniphila a subject of enormous attention from multiple research fields. A. muciniphila is becoming a model organism studied for its ability to modulate human health and gut microbiome structure, leading to commercial products, a genetic model and possible probiotic formulations. This Review provides an overview of A. muciniphila and Akkermansia genus phylogeny, ecophysiology and diversity. Furthermore, the Review discusses perspectives on ecology, strategies for harnessing beneficial effects of A. muciniphila for human mucosal metabolic and gut health, and its potential as a biomarker for diagnostics and prognostics.

Assessing Gut Microbiome Alterations in Children With Allergic Rhinitis: Associations With Allergen-Specific IgE Levels and Sensitization Patterns

Background

The relationship between gut microbiota composition and allergen exposure in children with allergic rhinitis (AR) remains insufficiently explored, particularly concerning variations in gut microbiota at different allergen-specific IgE (sIgE) levels and the distinction between monosensitization and polysensitization to allergens.

Methods

We employed metagenomic shotgun sequencing to compare the fecal microbiota of 50 healthy controls (HC) to 88 children with AR induced by house dust mites (HDM-AR). We further examined differences in gut microbiota among HDM-AR subgroups with extremely high house dust mite-sIgE (EH-HDM), high HDM-sIgE (H-HDM), as well as between monosensitized (mono-HDM) and polysensitized (poly-HDM) individuals.

Results

While no significant differences in overall gut microbiome diversity were observed between the HC and HDM-AR groups, a notable increase in the relative abundance of Streptococcus sanguinis within the genus was identified in children with AR. Further analysis revealed a significant enrichment of the Streptococcus genus in the EH-HDM group, particularly highlighting an increased relative abundance of the Streptococcus salivarius. Functional gene analysis via KEGG pathways indicated substantial enrichment in the salivary secretion pathway. Additionally, in comparisons among the HC, mono-HDM, and poly-HDM groups, Streptococcus salivarius emerged as the key differential species, showing a marked increase in the mono-HDM group.

Conclusion

Our study suggests that specific bacterial strains, particularly Streptococcus salivarius, may be potential biomarkers for assessing varying degrees and patterns of HDM sensitization. These findings open the avenues for developing targeted interventions aimed at mitigating the pathophysiology of AR.

A novel robust network construction and analysis workflow for mining infant microbiota relationships

The gut microbiota plays a crucial role in infant health, with its development during the first 1,000 days influencing health outcomes. Understanding the relationships within the microbiota is essential to linking its maturation process to these outcomes. Several network-based methods have been developed to analyze the developing patterns of infant microbiota, but evaluating the reliability and effectiveness of these approaches remains a challenge. In this study, we created a test data pool using public infant microbiome data sets to assess the performance of four different network-based methods, employing repeated sampling strategies. We found that our proposed Probability-Based Co-Detection Model (PBCDM) demonstrated the best stability and robustness, particularly in network attributes such as node counts, average links per node, and the positive-to-negative link (P/N) ratios. Using the PBCDM, we constructed microbial co-existence networks for infants at various ages, identifying core genera networks through a novel network shearing method. Analysis revealed that core genera were more similar between adjacent age ranges, with increasing competitive relationships among microbiota as the infant microbiome matured. In conclusion, the PBCDM-based networks reflect known features of infant microbiota and offer a promising approach for investigating microbial relationships. This methodology could also be applied to future studies of genomic, metabolic, and proteomic data.

IMPORTANCE

As a research method and strategy, network analysis holds great potential for mining the relationships of bacteria. However, consistency and solid workflows to construct and evaluate the process of network analysis are lacking. Here, we provide a solid workflow to evaluate the performance of different microbial networks, and a novel probability-based co-existence network construction method used to decipher infant microbiota relationships. Besides, a network shearing strategy based on percolation theory is applied to find the core genera and connections in microbial networks at different age ranges. And the PBCDM method and the network shearing workflow hold potential for mining microbiota relationships, even possibly for the future deciphering of genome, metabolite, and protein data.

Gut dysbiosis as a susceptibility factor in childhood idiopathic nephrotic syndrome

Idiopathic nephrotic syndrome (INS) is a relatively common renal disorder of childhood characterized by severe proteinuria and associated hypoproteinemia and edema. Although the pathogenesis of INS remains unknown, the prevailing theory of its pathogenesis is as follows. Antigenic stimulation, such as viral infections or vaccines, in children with susceptibility factors for INS triggers abnormal immune responses, resulting in production of pathogenic substances that injure podocytes (renal glomerular epithelial cells). The injured podocytes then change their function and morphology, resulting in increased permeability of plasma proteins. Consequently, plasma proteins, especially albumin, are leaked into urine and massive proteinuria ensues. Research on susceptibility factors for INS has focused on polymorphisms in several genes including human leukocyte antigen class II genes. However, we propose that dysbiosis of the intestinal microbiota could be a susceptibility factor for relapse. This proposal is based on our research group finding that children with INS and frequent relapses have gut dysbiosis characterized by a decreased proportion of beneficial bacteria such as short-chain fatty acid-producing bacteria. Dysbiosis from the neonatal period to infancy may result from environmental factors, such as cesarean section delivery and antibiotic administration, which prevent the establishment of a normal intestinal microbiota. Dysbiosis leads to aberrant gut immunity and is characterized by a decreased ratio of T helper 1 cells/T helper 2 cells and an increased ratio of T helper 17 cells/regulatory T-cells. Therefore, relapse occurs when immunologically pathogenic factors that injure podocytes are produced in response to trigger events in children with INS and gut dysbiosis. Our recent clinical trial suggested that long-term oral administration of butyric acid-producing bacterium as a probiotic is promising for suppressing relapse. Therefore, studying the causal relationship between dysbiosis and relapses in patients with INS in a larger number of patients is necessary.

Evaluation of Faecal Microbiota Following Probiotics in Infants of Mothers with Gestational Diabetes Mellitus Trial: Protocol for Double-Blind Placebo-Controlled Randomized Trial

(1) Background: The incidence of gestational diabetes mellitus (GDM) is rising globally. The current evidence indicates that GDM, especially in conjunction with maternal overweight, can alter the composition of infants' gut microbiota, potentially increasing the risk of inflammatory diseases, metabolic disorders, and neurodevelopmental issues later in life. Probiotic supplantation early in life might establish eubiosis and mitigate future complications. To best of our knowledge, no study has evaluated the effects of probiotics on gut dysbiosis in the infants of mothers with GDM. (2) Methods: This study will be a single-centre, double-blind, randomized, placebo-controlled trial enrolling sixty neonates born after 35 weeks of gestation to mothers with GDM. The participants will be randomly assigned to receive either a triple-strain probiotic or a placebo for four months. The primary objective is to assess the effectiveness of probiotic supplementation in correcting gut dysbiosis in the infants of mothers with GDM at four months of age. Faecal microbiome composition shall be estimated using 16SrRNA and shotgun sequencing. The secondary outcomes will include the quantification of faecal short-chain fatty acids at birth and at four months, as well as growth and developmental assessments at four, twelve, and twenty-four months. (3) Trial registration: This trial protocol is registered (ACTRN12624000930583p) in the Australian Clinical Trials registry (ANZCTR).

Metagenomic Analysis of Gut Microbiome of Persistent Pulmonary Hypertension of the Newborn

Persistent pulmonary hypertension of the newborn (PPHN) is one of the most common diseases in the neonatal intensive care unit which severely affects neonatal survival. Gut microbes play an increasingly important role in human health, but there are rarely reported how gut microbiota contribute to PPHN. In our study, the metagenomic sequencing of feces from 12 PPHN's neonates and 8 controls were performed to expose the relation between neonatal gut microbes and PPHN disease. Firstly, we found that the abundance of Actinobacteria, Proteobacteria, Bacteroidetes were significantly increased in PPHN compared with controls, but the Firmicutes components was reduced. And some pathogenic strains (like Vibrio metschnikovii) were significantly enriched in the PPHN compared with controls. Secondly, functional annotation of genes found that PPHN up-regulated transmembrane transport, but down-regulated ribosome and ATP binding. Lastly, microbial metabolic pathway enrichment analysis indicated that some metabolic pathway in PPHN were conflicting and contradictory, showed that an abnormally increased metabolism, disturbed protein synthesis and genomic instability in the PPHN neonate. Our results contribute to understanding the changes in the species and function of gut microbiota in PPHN, thus providing a theoretical basis for the explanation and treatment of PPHN.

Impact of urban biodiversity and climate change on children's health and well being

In recent decades, biodiversity loss has greatly impacted planetary and human health. Children are at additional risk of adverse effects due to unique biological, developmental, and behavioral factors, as well as their longer exposure to an altered planet as a function of their young age. These effects are heightened for children living in vulnerable socioeconomic conditions. Here, we review the role of biodiversity loss on accelerating the consequences of climate change from the perspective of pediatric health. With the loss of biodiversity's protective role against the consequences of climate change, the adverse effects of the changing planet are impacting pediatric health. For example, trees provide shelter against heat waves, unsealed soil and wetlands mitigate flooding, and rewilded green space hosts high microbial richness and consequently supports immune and mental health. The effects of the loss of biodiversity may impact the discovery and development of novel pharmaceuticals and thus the future of children's medicine as a whole. We also highlight areas for further study and detail efforts that have been made to restore biodiversity, with the aim to improve the current and future health of local pediatric populations. IMPACT: Loss of biodiversity is occurring at a rapid pace affecting the health of the planet and disproportionately pediatric health. This paper describes the role of biodiversity loss in accelerating the impact of climate change on children's health, and highlights particularly vulnerable populations. This paper details steps that can be taken to maintain and restore biodiversity at the local and global levels to protect these populations and pediatric health in general.

Investigating the Causal Relationship Between Gut Microbiota and Allergic Conjunctivitis: A Two-Sample Mendelian Randomization Study

PURPOSE

To investigate the causal association between gut microbiota and allergic conjunctivitis.

METHODS

A two-sample Mendelian randomization (MR) analysis was performed using the summary statistics of gut microbiota (18,340) from MiBio-Gen consortium and allergic conjunctivitis data (n = 218,792) obtained from the IEU Open GWAS project. F-statistics and sensitivity analyses were used to address potential biases and ensure the reliability of our findings. Reverse MR analysis was conducted to assess the possible of reverse causal relationships.

RESULTS

The inverse variance weighted estimates revealed the protective potential of the phylum Euryarchaeota against allergic conjunctivitis (OR = 0.87, p = 6.17 × 10-4). On the other hand, the genus Christensenellaceae R.7 group (OR = 0.75, p = 2.89 × 10-3), family Peptostreptococcaceae (OR = 0.83, p = 6.22 × 10-3), genus Lachnospiraceae FCS020 group (OR = 0.82, p = 0.02) all showed a suggestive protective association with allergic conjunctivitis. Additionally, sensitivity analysis confirmed the robustness of the above associations. In the reverse MR analysis, no significant causal association was found between gut microbiota and allergic conjunctivitis.

CONCLUSION

This study has revealed a potential causal correlation between the phylum Euryarchaeota and allergic conjunctivitis, offering new insights to improve prevention and treatment of this condition.

Breastfeeding Beyond Six Months: Evidence of Child Health Benefits

Breastfeeding is globally recognized as the optimal method of infant nutrition, offering health benefits for both the child and the mother, making it a public health priority. However, the potential advantages of breastfeeding extend well beyond initial months. Breast milk adapts to the evolving needs of the growing infant, and its immunological, microbiological, and biochemical properties have been associated with enhanced protection against infections and chronic diseases, improved growth and development, and lower rates of hospitalization and mortality. This review explores the evidence supporting the continuation of breastfeeding beyond six months. More meticulous studies employing consistent methodologies and addressing confounders are essential. This will enable a more accurate determination of the extent and mechanisms of the positive impact of prolonged breastfeeding and allow for the implementation of effective public health strategies.

Gut dysbiosis mediates the association between antibiotic exposure and chronic disease

Antibiotics are safe, effective drugs and continue to save millions of lives and prevent long-term illness worldwide. A large body of epidemiological, interventional and experimental evidence shows that exposure to antibiotics has long-term negative effects on human health. We reviewed the literature data on the links between antibiotic exposure, gut dysbiosis, and chronic disease (notably with regard to the "developmental origins of health and disease" ("DOHaD") approach). Molecular biology studies show that the systemic administration of antibiotic to infants has a rapid onset but also often a long-lasting impact on the microbial composition of the gut. Along with other environmental factors (e.g., an unhealthy "Western" diet and sedentary behavior), antibiotics induce gut dysbiosis, which can be defined as the disruption of a previously stable, functionally complete microbiota. Gut dysbiosis many harmful long-term effects on health. Associations between early-life exposure to antibiotics have been reported for chronic diseases, including inflammatory bowel disease, celiac disease, some cancers, metabolic diseases (obesity and type 2 diabetes), allergic diseases, autoimmune disorders, atherosclerosis, arthritis, and neurodevelopmental, neurodegenerative and other neurological diseases. In mechanistic terms, gut dysbiosis influences chronic disease through direct effects on mucosal immune and inflammatory pathways, plus a wide array of direct or indirect effects of short-chain fatty acids, the enteric nervous system, peristaltic motility, the production of hormones and neurotransmitters, and the loss of intestinal barrier integrity (notably with leakage of the pro-inflammatory endotoxin lipopolysaccharide into the circulation). To mitigate dysbiosis, the administration of probiotics in patients with chronic disease is often (but not always) associated with positive effects on clinical markers (e.g., disease scores) and biomarkers of inflammation and immune activation. Meta-analyses are complicated by differences in probiotic composition, dose level, and treatment duration, and large, randomized, controlled clinical trials are lacking in many disease areas. In view of the critical importance of deciding whether or not to prescribe antibiotics (especially to children), we suggest that the DOHaD concept can be logically extended to "gastrointestinal origins of health and disease" ("GOHaD") or even "microbiotic origins of health and disease" ("MOHaD").

Changes in respiratory tract and gut microbiota in AR mice and their relationship with Th1/Th2/Treg

BACKGROUND

The etiology of allergic rhinitis (AR) is not fully understood. Studies have shown that the maturation of children's immune systems is closely related to microecology. However, few studies have focused simultaneously on changes in respiratory and gut microbiota in AR and their correlation between microecological changes and Th1/Th2/Treg.

OBJECTIVE

The aim is to investigate the pathogenesis of AR based on respiratory microecology, gut microecology, and Th1/Th2/Treg levels by applying microbiome techniques and correlation analysis.

METHODS

Standardized OVA-induced AR mice were established. Serum OVA-sIgE, IL-4, IFN-γ, IL-10 were measured by ELISA, Tregs in lymph nodes were determined by flow cytometry, and the histological characteristics of nasal tissues were evaluated by Hematoxylin & Eosin (H&E). Nasal symptoms were observed to determine the reliability of the AR mouse model. Nasal lavage fluid (NALF) and fecal samples were collected after the last OVA challenge. The composition of respiratory microbiota in NALF and gut microbial in feces samples via 16S rRNA gene sequencing between the two groups, further explored the relationship between microbiota and Th1/Th2/Treg levels.

RESULTS

In the AR group, the incidence of nose rubbing and sneezing in each mouse was significantly increased compared with the control group (all P < 0.001) and the inflammatory cell infiltration of NALF shows a significant increase in eosinophilic and neutrophilic infiltrates upon the AR group; H&E showed that the nasal mucosa of AR mice infiltration of massive eosinophils cells and neutrophils cells. OVA-sIgE and IL-4 in the AR group were increased (P < 0.01, P < 0.05) and IFN-γ, IL-10 were significantly decreased (P < 0.01, P < 0.05). Tregs showed a downward trend in the AR group, but there was no statistical difference. Compared with the control group, the respiratory microbiota of AR mice did not change significantly, while the gut microbiota changed significantly. In gut microbiota, compared to the control group, Shannon index in the AR group revealed a significant decrease at the genus level (P < 0.01), and Simpson index was significantly increased at all levels (all P < 0.05). PCoA also showed significant differences in beta diversity between the two groups (all P < 0.05). Compared to the control group, Deferribacteres at phylum level, Roseburia, Ruminiclostridium, Anaerotruncus at genus level were significantly decreased in the AR group (all P < 0.05). Spearman's rank correlation showed that OVA-sIgE was positively correlated with Bacteroidetes, Muribaculaceae and Erysipelotrichaceae (all P < 0.05); IL-4 was significantly negatively correlated with Epsilonbacteraeota and Deferribacteres (all P < 0.05). Treg was significantly positively correlated with Patescibacteria, Lachnospiraceae, and Saccharimonadaceae in gut microecology.

CONCLUSION

Our results showed that the respiratory microbiota of AR mice was not significantly altered, but the gut microbiota varied significantly and there was a correlation between gut microbiota and Th1/Th2/Treg.

Fecal microbiota transplantation alleviates food allergy in neonatal mice via the PD-1/PD-L1 pathway and change of the microbiota composition

BACKGROUND

Food allergy (FA) is a common disorder in children and affects the health of children worldwide. The gut microbiota is closely related to the occurrence and development of FA. Fecal microbiota transplantation (FMT) is a way to treat diseases by reconstituting the microbiota; however, the role and mechanisms of FA have not been validated.

METHODS

In this study, we established an ovalbumin (OVA)-induced juvenile mouse model and used 16S RNA sequencing, pathological histological staining, molecular biology, and flow-through techniques to evaluate the protective effects of FMT treatment on FA and to explore the mechanisms.

RESULTS

OVA-induced dysregulation of the gut microbiota led to impaired intestinal function and immune dysregulation in FA mice. FMT treatment improved the structure, diversity, and composition of the gut microbiota and restored it to a near-donor state. FMT treatment reduced levels of Th2-associated inflammatory factors, decreased intestinal tissue inflammation, and reduced IgE production. In addition, FMT reduced the number of mast cells and eosinophils and suppressed OVA-specific antibodies. Further mechanistic studies revealed that FMT treatment induced immune tolerance by inducing the expression of CD103+DCs and programmed cell death ligand 1 (PD-L1) in mesenteric lymph nodes and promoting the production of Treg through the programmed cell death protein 1 (PD-1)/PD-L1 pathway. Meanwhile, Th2 cytokines, OVA-specific antibodies, and PD-1/PD-L1 showed a significant correlation with the gut microbiota.

CONCLUSIONS

FMT could regulate the gut microbiota and Th1/Th2 immune balance and might inhibit FA through the PD-1/PD-L1 pathway, which would provide a new idea for the treatment of FA.

Gut microbiome features in pediatric food allergy: a scoping review

Increasing evidence suggests that alterations in the gut microbiome (GM) play a pivotal role in the pathogenesis of pediatric food allergy (FA). This scoping review analyzes the current evidence on GM features associated with pediatric FAs and highlights the importance of the GM as a potential target of intervention for preventing and treating this common condition in the pediatric age. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, we searched PubMed and Embase using the keywords (gut microbiome OR dysbiosis OR gut microbiota OR microbiome signatures) AND (food allergy OR IgE-mediated food allergy OR food protein-induced allergic proctocolitis OR food protein-induced enterocolitis OR non-IgE food allergy OR cow milk allergy OR hen egg allergy OR peanut allergy OR fish allergy OR shellfish allergy OR tree nut allergy OR soy allergy OR wheat allergy OR rice allergy OR food sensitization). We included 34 studies reporting alterations in the GM in children affected by FA compared with healthy controls. The GM in pediatric FAs is characterized by a higher abundance of harmful microorganisms (e.g., Enterobacteriaceae, Clostridium sensu stricto, Ruminococcus gnavus, and Blautia spp.) and lower abundance of beneficial bacteria (e.g., Bifidobacteriaceae, Lactobacillaceae, some Bacteroides species). Moreover, we provide an overview of the mechanisms of action elicited by these bacterial species in regulating immune tolerance and of the main environmental factors that can modulate the composition and function of the GM in early life. Altogether, these data improve our knowledge of the pathogenesis of FA and can open the way to innovative diagnostic, preventive, and therapeutic strategies for managing these conditions.

Preventive and Therapeutic Effects of Lactiplantibacillus plantarum HD02 and MD159 through Mast Cell Degranulation Inhibition in Mouse Models of Atopic Dermatitis

As the relationship between the gut microbiome and allergies becomes better understood, targeted strategies to prevent and treat allergies through gut microbiome modulation are being increasingly developed. In the study presented herein, we screened various probiotics for their ability to inhibit mast cell degranulation and identified Lactiplatibacillus plantarum HD02 and MD159 as effective candidates. The two strains significantly attenuated vascular permeability induced by mast cell degranulation in a passive cutaneous anaphylaxis (PCA) model and, in the MC903-induced murine atopic dermatitis (AD) model, demonstrated comparable preventive effects against allergies, reducing blood levels of MCPT-1 (mast cell protease-1) and total IgE. In the house dust mite (HDM)-induced murine AD model, both L. plantarum HD02 and MD159 showed therapeutic effects, with L. plantarum HD02 demonstrating superior efficacy. Nevertheless, L. plantarum MD159 better suppressed transepidermal water loss (TEWL). Furthermore, L. plantarum HD02 and MD159 significantly increased the number of splenic Foxp3+ regulatory T cells, with L. plantarum MD159 having a more pronounced effect. However, only L. plantarum HD02 achieved a reduction in immune cells in the draining lymph nodes. Our findings highlight L. plantarum HD02 and MD159 as promising candidates for the prevention and treatment of allergies, demonstrating significant efficacy in suppressing mast cell degranulation, reducing the number of allergy biomarkers, and modulating immune responses in experimental models of AD. Their distinct mechanisms of action suggest potential complementary roles in addressing allergic diseases, underscoring their therapeutic promise in clinical applications.

Ultra-processed foods, allergy outcomes and underlying mechanisms in children: An EAACI task force report

BACKGROUND

Consumption of ultra-processed foods [UPFs] may be associated with negative health outcomes. Limited data exist regarding the potential role of UPFs in the occurrence of allergic diseases. The underlying mechanisms underpinning any such associations are also poorly elucidated.

METHODS

We performed a systematic review and narrative evidence synthesis of the available literature to assess associations between UPF consumption and pediatric allergy outcomes (n = 26 papers), including data on the association seen with the gut microbiome (n = 16 papers) or immune system (n = 3 papers) structure and function following PRISMA guidelines.

RESULTS

Dietary exposure to fructose, carbonated soft drinks, and sugar intake was associated with an increased risk of asthma, allergic rhinitis, and food allergies in children. Commercial baby food intake was associated with childhood food allergy. Childhood intake of fructose, fruit juices, sugar-sweetened beverages, high carbohydrate UPFs, monosodium glutamate, UPFs, and advanced glycated end-products (AGEs) was associated with the occurrence of allergic diseases. Exposure to UPFs and common ingredients in UPFs seem to be associated with increased occurrence of allergic diseases such as asthma, wheezing, food allergies, atopic dermatitis, and allergic rhinitis, in many, but not all studies.

CONCLUSION

More preclinical and clinical studies are required to better define the link between UPF consumption and the risk of allergies and asthma. These observational studies ideally require supporting data with clearly defined UPF consumption, validated dietary measures, and mechanistic assessments to definitively link UPFs with the risk of allergies and asthma.

Breastfeeding and risk of food allergy and allergic rhinitis in offspring: a systematic review and meta-analysis of cohort studies

The association between breastfeeding and the occurrence of allergic rhinitis (AR) and food allergy (FA) in offspring remains inconclusive. This review aims to comprehensively explore the potential relationships between various patterns and durations of breastfeeding and allergic diseases in offspring. We systematically searched PubMed, EMBASE, Cochrane, WOS databases, and Google Scholar for observational studies published up to March 30, 2023, that investigated the link between breastfeeding and allergies in offspring. The quality of the studies was assessed using the Newcastle-Ottawa Scale (NOS) and Joanna Briggs Institute (JBI). Pooled odds ratios (OR) and 95% confidence intervals (95% CI) were calculated employing an appropriate model based on the degree of heterogeneity. A total of 68 studies, encompassing 772,142 children, were ultimately included. The findings indicated that breastfeeding for more than 6 months was associated with a reduced risk of AR (OR = 0.88, 95% CI: 0.79 to 0.98) but posed a risk for FA (OR = 1.69, 95% CI: 1.27 to 2.25). Exclusive breastfeeding exhibited a protective effect against AR (OR = 0.94, 95% CI: 0.90 to 0.97), whereas non-breastfeeding was identified as a risk factor for AR (OR = 1.48; 95% CI: 1.03 to 2.12). No significant association was observed between breastfeeding patterns and FA.

CONCLUSION

Breastfeeding for more than 6 months proves to be an effective preventive measure against AR. However, large prospective high-quality studies are needed to investigate the potential risk of FA in children with prolonged breastfeeding.

WHAT IS KNOWN

• The impact of breastfeeding on allergic rhinitis and food allergy in offspring is controversial. • Previous meta-analyses fail to prove the effect of breastfeeding on food allergy in offspring of all ages.

WHAT IS NEW

• Breastfeeding for more than 6 months proves to be an effective preventive measure against AR. However, it potentially elevates the risk of FA in children. Non-breastfeeding is linked to an increased risk of AR in children, but there is no evidence of an association between breastfeeding patterns and FA in children. • The impact of breastfeeding on allergic rhinitis and food allergy in offspring may vary with the time and pattern of breastfeeding.

de Vos W. Early-life gut microbiota associates with allergic rhinitis during 13-year follow-up in a Finnish probiotic intervention cohort

Perinatal and early-life factors reported to affect risk of allergic diseases may be mediated by changes in the gut microbiota. Here, we explored the associations between the infant gut microbiota and allergic morbidity in childhood until 13 years of age in a subgroup of the FLORA probiotic intervention cohort. A mixture of four probiotic strains with galacto-oligosaccharides was administrated to the mothers from the 36th week of the pregnancy and later to their infants until 6 months of age. The infants were monitored for the manifestations of atopic eczema, food allergy, allergic rhinitis, and asthma by a pediatrician at 2 and 5 years of age; the allergic status was subsequently verified by a questionnaire at 10 and 13 years of age. The fecal microbiota at 3 months was profiled by 16S rRNA amplicon sequencing targeting the V3-V4 region, with and without adjusting for potentially important early-life factors. Overall, the positive diagnosis for allergic rhinitis between 2 and 13 years was associated with microbiota composition both in non-adjusted and adjusted models. This association was more pronounced in children born to one parent with confirmed atopic diseases compared to those who had two atopic parents and was characterized by a lower relative abundance of Bifidobacterium and Escherichia/Shigella spp. and a higher proportion of Bacteroides. While the probiotic and galacto-oligosaccharides intervention in the entire cohort was previously shown to reduce the prevalence of eczema to a certain extent, no associations were found between the 3-month gut microbiota and childhood eczema in the studied sub-cohort.IMPORTANCEAllergic diseases have increased in prevalence during the past decades globally. Although probiotics have been considered a promising strategy for preventing certain allergy related symptoms, studies connecting the infant gut microbiota and later life allergic morbidity in various populations remain limited. The present study supports an association between the infant microbiota and allergic morbidity after first years of life, which has been rarely examined.CLINICAL TRIALSRegistered at ClinicalTrials.gov (NCT00298337).

Microbiome and its impact on fetal and neonatal brain development: current opinion in pediatrics

PURPOSE OF REVIEW

Emerging evidence suggests that the gut microbiota and its metabolites regulate neurodevelopment and cognitive functioning via a bi-directional communication system known as the microbiota-gut-brain axis (MGBA).

RECENT FINDINGS

The MGBA influences brain development and function via the hypothalamic-pituitary axis, the vagal nerve, immune signaling, bacterial production of neurotransmitters, and microbial metabolites like short-chain fatty acids, tryptophan derivatives, and bile acids. Animal studies show fetal neurodevelopment is mediated by maternal microbiota derivatives, immune activation, and diet. Furthermore, manipulation of the microbiota during critical windows of development, like antibiotic exposure and fecal microbiota transplantation, can affect cognitive functioning and behavior in mice. Evidence from human studies, particularly in preterm infants, also suggests that a disrupted gut microbiota colonization may negatively affect neurodevelopment. Early microbial signatures were linked to favorable and adverse neurodevelopmental outcomes.

SUMMARY

The link between the gut microbiota and the brain is evident. Future studies, including experimental studies, larger participant cohort studies with longitudinal analyses of microbes, their metabolites, and neurotransmitters, and randomized controlled trials are warranted to further elucidate the mechanisms of the MGBA. Identification of early, predictive microbial markers could pave the way for the development of novel early microbiota-based intervention strategies, such as targeted probiotics, and vaginal or fecal microbiota transplantation, aimed at improving infant neurodevelopment.

Notch Signaling Inhibition Alleviates Allergies Caused by Antarctic Krill Tropomyosin through Improving Th1/Th2 Imbalance and Modulating Gut Microbiota

Antarctic krill tropomyosin (AkTM) has been shown in mice to cause IgE-mediated food allergy. The objective of this work was to investigate the role of Notch signaling in AkTM-sensitized mice, as well as to determine the changes in gut microbiota composition and short-chain fatty acids (SCFAs) in the allergic mice. An AkTM-induced food allergy mouse model was built and N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) was used as an γ-secretase inhibitor to inhibit the activation of Notch signaling. Food allergy indices, some key transcription factors, histologic alterations in the small intestine, and changes in gut microbiota composition were examined. The results showed that DAPT inhibited Notch signaling, which reduced AkTM-specific IgE, suppressed mast cell degranulation, decreased IL-4 but increased IFN-γ production, and alleviated allergic symptoms. Quantitative real-time PCR and Western blotting analyses revealed that expressions of Hes-1, Gata3, and IL-4 were down-regulated after DAPT treatment, accompanied by increases in T-bet and IFN-γ, indicating that Notch signaling was active in AkTM-sensitized mice and blocking it could reverse the Th1/Th2 imbalance. Expressions of key transcription factors revealed that Notch signaling could promote Th2 cell differentiation in sensitized mice. Furthermore, 16S rRNA sequencing results revealed that AkTM could alter the diversity and composition of gut microbiota in mice, leading to increases in inflammation-inducing bacteria such as Enterococcus and Escherichia-Shigella. Correlation analysis indicated that reduced SCFA concentrations in AkTM-allergic mice may be related to decreases in certain SCFA-producing bacteria, such as Clostridia_UCG-014. The changes in gut microbiota and SCFAs could be partially restored by DAPT treatment. Our findings showed that inhibiting Notch signaling could alleviate AkTM-induced food allergy by correcting Th1/Th2 imbalance and modulating the gut microbiota.

Genetically predicted causal effects of gut microbiota on spinal pain: a two-sample Mendelian randomization analysis

Background

Observational studies have hinted at a correlation between the gut microbiota and spinal pain (SP). However, the impact of the gut microbiota on SP remains inconclusive.

Methods

In this study, we employed a two-sample Mendelian randomization (MR) analysis to explore the causal relationship between the gut microbiota and SP, encompassing neck pain (NP), thoracic spine pain (TSP), low back pain (LBP), and back pain (BP). The compiled gut microbiota data originated from a genome-wide association study (GWAS) conducted by the MiBioGen consortium (n = 18,340). Summary data for NP were sourced from the UK Biobank, TSP from the FinnGen Biobank, and LBP from both the UK Biobank and FinnGen Biobank. Summary data for BP were obtained from the UK Biobank. The primary analytical approach for assessing causal relationships was the Inverse Variance Weighted (IVW) method, supplemented by various sensitivity analyses to ensure result robustness.

Results

The IVW analysis unveiled 37 bacterial genera with a potential causal relationship to SP. After Benjamini-Hochberg corrected test, four bacterial genera emerged with a strong causal relationship to SP. Specifically, Oxalobacter (OR: 1.143, 95% CI 1.061-1.232, P = 0.0004) and Tyzzerella 3 (OR: 1.145, 95% CI 1.059-1.238, P = 0.0007) were identified as risk factors for LBP, while Ruminococcaceae UCG011 (OR: 0.859, 95% CI 0.791-0.932, P = 0.0003) was marked as a protective factor for LBP, and Olsenella (OR: 0.893, 95% CI 0.839-0.951, P = 0.0004) was recognized as a protective factor for low back pain or/and sciatica. No significant heterogeneity or horizontal pleiotropy was observed through alternative testing methods.

Conclusion

This study establishes a causal relationship between the gut microbiota and SP, shedding light on the "gut-spine" axis. These findings offer novel perspectives for understanding the etiology of SP and provide a theoretical foundation for potential interventions targeting the gut microbiota to prevent and treat SP.

Alterations in the gut microbiota of toddlers with cow milk protein allergy treated with a partially hydrolyzed formula containing synbiotics: A nonrandomized controlled interventional study

Formulas containing intact cow milk protein are appropriate alternatives when human milk (HM) is not feasible. However, for babies with a physician-diagnosed cow milk protein allergy (CMPA), hydrolyzed formulas are needed. We conducted a 3-month, open-label, nonrandomized concurrent controlled trial (ChiCTR2100046909) between June 2021 and October 2022 in Qingdao City, China. In this study, CMPA toddlers were fed with a partially hydrolyzed formula containing synbiotics (pHF, n = 43) and compared with healthy toddlers fed a regular intact protein formula (IF, n = 45) or HM (n = 21). The primary endpoint was weight gain; the secondary endpoints were changes in body length and head circumference of both CMPA and healthy toddlers after 3-month feeding; and the exploratory outcomes were changes in gut microbiota composition. After 3 months, there were no significant group differences for length-for-age, weight-for-age, or head circumference-for-age Z scores. In the gut microbiota, pHF feeding increased its richness and diversity, similar to those of IF-fed and HM-fed healthy toddlers. Compared with healthy toddlers, the toddlers with CMPA showed an increased abundance of phylum Bacteroidota, Firmicutes, class Clostridia, and Bacteroidia, and a decreased abundance of class Negativicutes, while pHF feeding partly eliminated these original differences. Moreover, pHF feeding increased the abundance of short-chain fatty acid producers. Our data suggested that this pHF partly simulated the beneficial effects of HM and shifted the gut microbiota of toddlers with CMPA toward that of healthy individuals. In conclusion, this synbiotic-containing pHF might be an appropriate alternative for toddlers with CMPA.

Bile acid profiles in adult patients with biliary atresia who achieve native liver survival after portoenterostomy

Bile acids have received increasing attention as a marker of the long-term prognosis and a potential therapeutic target in patients with biliary atresia, which is a progressive disease of the hepatobiliary system. A detailed analysis of serum and urinary bile acid compositions was conducted to assess the characteristics of bile acid profiles and the correlation between bile acid profiles and liver fibrosis markers in adult patients with biliary atresia who achieved bilirubin normalization. Serum total bile acids and glucuronide-conjugated (glyco- and tauro-) cholic acids (GCA and TCA) and chenodeoxycholic acids (GCDCA and TCDCA) were significantly higher in patients with biliary atresia than in healthy controls, whereas unconjugated CA and CDCA showed no significant difference. There were no significant differences in CA to CDCA ratios and glycine-to-taurine-conjugated ratios. Urinary glycocholic acid 3-sulfate (GCA-3S) was significantly higher in patients with biliary atresia. Serum GCDCA showed a strong positive correlation with Mac-2 binding protein glycosylation isomer (M2BPGi). These results demonstrate that bile acid congestion persists into adulthood in patients with biliary atresia, even after cholestasis has completely improved after Kasai portoenterostomy. These fundamental data on bile acid profiles also suggest the potential value of investigating bile acid profiles in patients with biliary atresia.

Dietary Polyphenols-Natural Bioactive Compounds with Potential for Preventing and Treating Some Allergic Conditions

In light of the constantly increasing prevalence of allergic diseases, changes in dietary patterns have been suggested as a plausible environmental explanation for the development and progression of these diseases. Nowadays, much attention has been paid to the development of dietary interventions using natural substances with anti-allergy activities. In this respect, dietary polyphenols have been studied extensively as one of the most prominent natural bioactive compounds with well-documented anti-inflammatory, antioxidant, and immunomodulatory properties. This review aims to discuss the mechanisms underlying the potential anti-allergic actions of polyphenols related to their ability to reduce protein allergenicity, regulate immune response, and gut microbiome modification; however, these issues need to be elucidated in detail. This paper reviews the current evidence from experimental and clinical studies confirming that various polyphenols such as quercetin, curcumin, resveratrol, catechins, and many others could attenuate allergic inflammation, alleviate the symptoms of food allergy, asthma, and allergic rhinitis, and prevent the development of allergic immune response. Conclusively, dietary polyphenols are endowed with great anti-allergic potential and therefore could be used either for preventive approaches or therapeutic interventions in relation to allergic diseases. Limitations in studying and widespread use of polyphenols as well as future research directions are also discussed.

Short-chain fatty acid - A critical interfering factor for allergic diseases

Allergy is a growing global public health problem with a high socio-economic impact. The incidence of allergic diseases is increasing year by year, which has attracted more and more attention. In recent years, a number of epidemiological investigations and gut microbiota studies have shown that gut microbiota dysbiosis is associated with an increased prevalence of various allergic diseases, such as food allergy, asthma, allergic rhinitis, and atopic dermatitis. However, the underlying mechanisms are complex and have not been fully clarified. Metabolites are one of the main ways in which the gut microbiota functions. Short-chain fatty acids (SCFAs) are the main metabolites of intestinal flora fermentation and are beneficial to human health. Studies have shown that SCFAs play an important role in maintaining intestinal homeostasis and regulating immune responses by recognizing receptors and inhibiting histone deacetylases, and are key molecules involved in the occurrence and development of allergic diseases. In addition, research on the regulation of gut microbiota and the application of SCFAs in the treatment of allergic diseases is also emerging. This article reviews the clinical and experimental evidence on the correlation between SCFAs and allergic diseases and the potential mechanisms by which SCFAs regulate allergic diseases. Furthermore, SCFAs as therapeutic targets for allergic diseases are also summarized and prospected.

Cesarean section and the risk of allergic rhinitis in children: a systematic review and meta-analysis

Multiple evidence indicates that perinatal factors make impact on immune development and affect offspring allergic rhinitis (AR) risk. In this systematic review and meta-analysis, we examined available published studies to clarify the relationship between cesarean section (C-section) and offspring AR in children. To explore the relationship between C-section, especially the special attention was paid to different cesarean delivery mode, and the risk of AR in children. Articles were searched using PubMed, Web of Science, EMBASE, Cochrane Library, China knowledge Network, Wanfang, and China Science and Technology Journal databases. A meta-analysis of 22 studies published before August 1, 2022, which included 1,464,868 participants, was conducted for statistical analysis with RevMan5.4. The correlation strength between C-section and offspring AR was determined by combining odds ratio (OR) and 95% confidence interval (95% CI). Meta-regression and subgroup analyses were used to explore potential sources of heterogeneity. Publication bias was detected using the funnel chart and Egger tests. Meta-analysis revealed that there was a significant correlation between C-section and children AR (OR = 1.19, 95% CI: 1.12-1.27, P < 0.001), especially C-section with a family history of allergy (OR = 1.82, 95% CI: 1.36-2.43, P < 0.001). Moreover, elective C-section (without genital tract microbe exposure) had the higher risk of offspring AR (OR = 1.24, 95% CI: 1.05-1.46, P = 0.010) compared with the whole study. Meta-regression demonstrated that sample size explained 38.0% of the variability between studies, and year of publication explained 18.8%. Delivery by C-section, particularly elective C-section and C-section with a family history of allergy can increase the risk of AR in children.

Analysis of the gut microbiota in children with gastroesophageal reflux disease using metagenomics and metabolomics

Background

There is no direct evidence of gut microbiota disturbance in children with gastroesophageal reflux disease (GERD). This study aimed to provide direct evidence and a comprehensive understanding of gut microbiota disturbance in children with GERD through combined metagenomic and metabolomic analysis.

Methods

30 children with GERD and 30 healthy controls (HCs) were continuously enrolled, and the demographic and clinical characteristics of the subjects were collected. First, 16S rRNA sequencing was used to evaluate differences in the gut microbiota between children with GERD and HC group, and 10 children with GERD and 10 children in the HC group were selected for metagenomic analysis. Nontargeted metabolomic analysis was performed using liquid chromatography/mass spectrometry (LC/MS), and metagenomic and metabolomic data were analyzed together.

Results

There were significant differences in the gut microbiota diversity and composition between children with GERD and HCs. The dominant bacteria in children with GERD were Proteobacteria and Bacteroidota. At the species level, the top three core bacterial groups were Bacteroides stercoris, Bacteroides vulgatus and Alistipes putredinis. The main differential pathways were identified to be related to energy, amino acid, vitamin, carbohydrate and lipid metabolism. LC/MS detected 288 different metabolites in the positive and negative ion modes between children with GERD and HCs, which were mainly involved in arachidonic acid (AA), tyrosine, glutathione and caffeine metabolism.

Conclusion

This study provides new evidence of the pathogenesis of GERD. There are significant differences in the gut microbiota, metabolites and metabolic pathways between HCs and children with GERD, and the differences in metabolites are related to specific changes in bacterial abundance. In the future, GERD may be treated by targeting specific bacteria related to AA metabolism.

Effect of Probiotic Supplementation on the Gut Microbiota Composition of Infants Delivered by Cesarean Section: An Exploratory, Randomized, Open-label, Parallel-controlled Trial

BACKGROUND

Infants born via cesarean section (CS) are at an increased risk of immune-related diseases later in life, potentially due to altered gut microbiota. Recent research has focused on the administration of probiotics in the prevention of gut microbiota dysbiosis in neonates delivered by CS. This study was performed to investigate the effects of probiotic supplementation on the gut microbiota of CS-delivered infants.

METHODS

Thirty full-term neonates delivered by CS were randomized into the intervention (supplemented orally with a probiotic containing Bifidobacterium longum, Lactobacillus acidophilus, and Enterococcus faecalis for 2 weeks) and control groups. Stool samples were collected at birth and 2 weeks and 42 days after birth. The composition of the gut microbiota was analyzed using 16S rRNA sequencing technology.

RESULTS

The applied bacterial strains were abundant in the CS-delivered infants supplemented with probiotics. Probiotics increased the abundance of some beneficial bacteria, such as Bacteroides, Acinetobacter, Veillonella, and Faecalibacterium. Low colonization of Klebsiella, a potentially pathogenic bacterium, was observed in the intervention group.

CONCLUSIONS

Our results showed that probiotics supplemented immediately after CS enriched the gut microbiota composition and altered the pattern of early gut colonization.

TRIAL REGISTRATION

registration number NCT05086458.

Efficacy of probiotics in pediatric atopic dermatitis: A systematic review and meta-analysis

BACKGROUND

Atopic dermatitis (AD) is a prevailing skin disease in childhood. Several studies have appraised probiotics as a strategy for treating AD. We aimed to assess the validity of probiotics in the treatment of AD in children.

METHODS

We systematically searched the PubMed/MEDLINE, Embase, Scopus, EBSCO, Web of Science and Cochrane library databases for randomized controlled trials (RCTs) that assessed the effect of probiotic treatment on SCORAD value in pediatric patients with AD compared with a placebo group between 1 January 2010 and 1 January 2023. The risk of bias and the certainty of evidence were assessed using Cochrane ROB 2.0.

RESULTS

A total of 10 outcomes from 9 RCTs involving 1000 patients were included. Three of these outcomes were analyzed as dichotomous variables in 373 patients. The other seven were analyzed for continuous variables in 627 patients. A meta-analysis of the random-effect model of the dichotomous variables demonstrated no significant difference between the probiotic and control groups [OR = 1.75, 95% confidence interval (CI) (0.70, 4.35), p = 0.23, I²  = 68%]. A meta-analysis of the random-effect model of continuous variables demonstrated significant differences between the probiotic and control groups [MD = -4.24, 95% CI (-7.78, -0.71), p = 0.002, I²  = 71%]. Subgroup analysis of continuous variables showed that the effects of children's age, treatment duration and probiotic species on the SCORAD value were not statistically significant.

CONCLUSION

Evidence on the improvement effect of probiotics on pediatric patients with AD is limited. This study showed that single-strain probiotic treatment exerts a positive effect on AD. Restricted to the quantity and quality of incorporated studies, these conclusions have yet to be validated by high-quality studies.

Ficolin A knockout alleviates sepsis-induced severe lung injury in mice by restoring gut Akkermansia to inhibit S100A4/STAT3 pathway

Acute lung injury (ALI) is a life-threatening disease with high morbidity and mortality. Our previous results demonstrated that Ficolin A (FcnA) protected against lipopolysaccharide (LPS)-induced mild ALI via activating complement, however the mechanism of severe lung damage caused by sepsis remains unclear. This study aimed to investigate whether FcnA modulated gut microbiota to affect the progression of sepsis-induced severe ALI. Fcna^-/- and Fcnb^-/- C57BL/6 mice were applied to establish the ALI model by injection of LPS intraperitoneally. Mice were treated with antibiotics, fecal microbiota transplantation (FMT), and intratracheal administration of recombinant protein S100A4. Changes in body weight of mice were recorded, and lung injury were assessed. Then lung tissue wet/dry weight was calculated. We found knockout of FcnA, but not FcnB, alleviated sepsis-induced severe ALI evidenced by increased body weight change, decreased wet/dry weight of lung tissue, reduced inflammatory infiltration, decreased lung damage score, decreased Muc-2, TNF-α, IL-1β, IL-6, and Cr levels, and increased sIgA levels. Furthermore, knockout of FcnA restored gut microbiota homeostasis in mice. Correlation analysis showed that Akkermansia was significantly negatively associated with TNF-α, IL-1β, and IL-6 levels in serum and bronchoalveolar lavage fluid (BALF). Moreover, knockout of FcnA regulated gut microbiota to protect ALI through S100A4. Finally, we found knockout of FcnA alleviated ALI by inhibiting S100A4 via gut Akkermansia in mice, which may provide further insights and new targets into treating sepsis-induced severe lung injury.

Relationship between Gut Microbiota and Allergies in Children: A Literature Review

The intestinal microbiota is a diverse and complex microecosystem that lives and thrives within the human body. The microbiota stabilizes by the age of three. This microecosystem plays a crucial role in human health, particularly in the early years of life. Dysbiosis has been linked to the development of various allergic diseases with potential long-term implications. Next-generation sequencing methods have established that allergic diseases are associated with dysbiosis. These methods can help to improve the knowledge of the relationship between dysbiosis and allergic diseases. The aim of this review paper is to synthesize the current understanding on the development of the intestinal microbiota in children, the long-term impact on health, and the relationship between dysbiosis and allergic diseases. Furthermore, we examine the connection between the microbiome and specific allergies such as atopic dermatitis, asthma, and food allergies, and which mechanisms could determine the induction of these diseases. Furthermore, we will review how factors such as mode of delivery, antibiotic use, breastfeeding, and the environment influence the development of the intestinal flora, as well as review various interventions for the prevention and treatment of gut microbiota-related allergies.

Novel Strategy for Alzheimer’s Disease Treatment through Oral Vaccine Therapy with Amyloid Beta

Alzheimer’s disease (AD) is a neuropathology characterized by progressive cognitive impairment and dementia. The disease is attributed to senile plaques, which are aggregates of amyloid beta (Aβ) outside nerve cells; neurofibrillary tangles, which are filamentous accumulations of phosphorylated tau in nerve cells; and loss of neurons in the brain tissue. Immunization of an AD mouse model with Aβ-eliminated pre-existing senile plaque amyloids and prevented new accumulation. Furthermore, its effect showed that cognitive function can be improved by passive immunity without side effects, such as lymphocyte infiltration in AD model mice treated with vaccine therapy, indicating the possibility of vaccine therapy for AD. Further, considering the possibility of side effects due to direct administration of Aβ, the practical use of the safe oral vaccine, which expressed Aβ in plants, is expected. Indeed, administration of this oral vaccine to Alzheimer’s model mice reduced Aβ accumulation in the brain. Moreover, almost no expression of inflammatory IgG was observed. Therefore, vaccination prior to Aβ accumulation or at an early stage of accumulation may prevent Aβ from causing AD.

Dysbiosis of the gut microbiota in children with severe motor and intellectual disabilities receiving enteral nutrition: A pilot study

BACKGROUND

Children with severe motor and intellectual disabilities (SMIDs) frequently and continuously receive enteral nutrition and medications and lack adequate exercise, which may lead to dysbiosis, an imbalance in the composition of the gut microbiota. However, studies on the composition of gut microbiota in children with SMIDs are limited. Therefore, we aimed to examine the characteristics of the gut microbiota in children with SMIDs.

METHODS

16S rRNA gene sequencing was performed using fecal samples of 10 children with SMIDs, who received enteral nutrition through a gastric fistula or gastric tube (SMID group: median age, 10.0 years), and 19 healthy children (healthy control [HC] group: median age, 9.0 years). Microbial diversity, microbial composition, and abundance of butyric acid-producing bacteria were compared between the groups. Daily dietary fiber intake in the SMID group was evaluated using questionnaires.

RESULTS

The Shannon and Simpson indices (alpha diversity indices) were significantly lower in the SMID group than those in the HC group. Beta diversity analysis identified different clusters. Compared with the HC group, Clostridiales and butyric acid-producing bacteria were less abundant and Bacteroidales were more abundant in the SMID group. Dietary fiber intake in the SMID group was approximately two-thirds of the estimated average requirement for healthy Japanese children.

CONCLUSION

Children with SMIDs showed dysbiosis with alteration in the microbial diversity, which could partly be attributed to their low dietary fiber intake. Further studies, with the intervention of prebiotics, probiotics, and synbiotics, are warranted to improve dysbiosis in children with SMIDs.

A cohort study of intrapartum group B streptococcus prophylaxis on atopic dermatitis in 2-year-old children

OBJECTIVE

To understand the occurrence of atopic dermatitis (AD) in children aged 2 years on exposure to maternal group B streptococcus (GBS) antibiotic prophylaxis (IAP).

DESIGN

Retrospective cohort study of 2909 mother-child pairs.

SETTING

Taixing People's Hospital in Eastern China.

PARTICIPANTS

Term infants born 2018-2019, followed longitudinally from birth to 2 years.

EXPOSURES

The GBS-IAP was defined as therapy with intravenous penicillin G or ampicillin or cefazolin ≥ 4 h prior to delivery to the mother. Reference infants were defined as born without or with other intrapartum antibiotic exposure.

OUTCOMES

The logistic regression models were employed to analyze the effect of intrapartum GBS prophylaxis on AD in 2-year-old children during delivery. Analysis was a priori stratified according to the mode of delivery and adjusted for relevant covariates.

RESULTS

The cohorts showed that preventive GBS-IAP was potentially associated with increased incidence of AD in children delivered vaginally according to logistic regression models before and after covariate-adjusted treatment (OR: 6.719,95% CI: 4.730-9.544,P < 0.001;aOR: 6.562,95% CI: 4.302-10.008, P < 0.001).

CONCLUSION

Prophylactic treatment of intrapartum GBS may raise the risk of AD in vaginally delivered children. These findings highlight the need to better understand the risk between childhood AD and current GBS-IAP intervention strategies.