Altered Gut Microbiome and Environmental Factors Associated with Development of Eczema in Hong Kong Infants: A 4-Month Pilot Study

The association of infant and mother gut microbiomes with development of allergic diseases in children: a systematic review

OBJECTIVE

It is believed that gut microbiota alteration leads to both intestinal and non-intestinal diseases in children. Since infants inherit maternal microbiota during pregnancy and lactation, recent studies suggest that changes in maternal microbiota can cause immune disorders as well. This systematic review was designed to assess the association between the child and mother's gut microbiome and allergy development in childhood.

DATA SOURCES

In this systematic review, international databases including PubMed, Scopus, and ISI/WOS were searched until January 2023 to identify relevant studies.

STUDY SELECTIONS

Observational studies that analyzed infant or maternal stool microbiome and their association with allergy development in children were included in this study. Data extraction and quality assessment of the included studies were independently conducted by two researchers.

RESULTS

Of the 1694 papers evaluated, 21 studies examined neonate gut microbiome by analyzing stool samples and six studies examined maternal gut microbiota. A total of 5319 participants were included in this study. Asthma followed by eczema and dermatitis were the most common allergy disorders among children. Urbanization caused a lack of diversity in the bacterial microbiota as well as lower levels of Bifidobacterium and Lachnospira associated with a higher risk of allergy. In contrast, higher levels of Roseburia and Flavonifractor were associated with lower allergy risk.

CONCLUSIONS

This systematic review shows that gut microbiota may be associated with allergy development. Further studies are required to provide a definitive answer.

Bifidobacteria in disease: from head to toe

Bifidobacteria as a strictly anaerobic gram-positive bacteria, is widely distributed in the intestine, vagina and oral cavity, and is one of the first gut flora to colonize the early stages of life. Intestinal flora is closely related to health, and dysbiosis of intestinal flora, especially Bifidobacteria, has been found in a variety of diseases. Numerous studies have shown that in addition to maintaining intestinal homeostasis, Bifidobacteria may be involved in diseases covering all parts of the body, including the nervous system, respiratory system, genitourinary system and so on. This review collects evidence for the variation of Bifidobacteria in typical diseases among various systems, provides mild and effective therapeutic options for those diseases that are difficult to cure, and moves Bifidobacteria from basic research to further clinical applications.

Improvements in Gut Microbiome Composition Predict the Clinical Efficacy of a Novel Synbiotics Formula in Children with Mild to Moderate Atopic Dermatitis

Atopic dermatitis (AD) is a common chronic inflammatory skin disease with a significant association with various type-2 inflammation-related comorbidities. Ongoing research suggests the crucial involvement of gut microbiome, especially in childhood onset AD, and hence, probiotics have emerged as a potential non-steroid-based therapeutics option to complement existing AD management plans. In order to delineate the impact of probiotics in the gut microbiome of pediatric AD patients from southern China, targeted 16S rRNA sequencing and thorough bioinformatic analysis were performed to analyze the gut microbiome profiles of 24 AD children after taking an orally administered novel synbiotics formula with triple prebiotics for 8 weeks. A notable improvement in Eczema Area and Severity Index (EASI) (p = 0.008) was observed after taking an 8-week course of probiotics, with no adverse effects observed. The relative abundances of key microbial drivers including Bacteroides fragilis and Lactobacillus acidophilus were significantly increased at week 8. We also found that the positive responsiveness towards an 8-week course of probiotics was associated with improvements in the gut microbiome profile with a higher relative abundance of probiotic species. Over-represented functional abundance pathways related to vitamin B synthesis and peptidoglycan recycling may imply the underlying mechanism. In summary, our study suggests how the gut microbial landscape shifts upon probiotic supplementation in AD children, and provides preliminary evidence to support targeted probiotic supplementation for the management of childhood AD.

Early-Life Skin Microbial Biomarkers for Eczema Phenotypes in Chinese Toddlers

Eczema is a common inflammatory skin disorder during infancy. Evidence has shown that skin-microbiome fluctuations may precede eczema development, but their predictive value for eczema phenotypes remains unknown. We aimed to investigate the early-life evolution of the skin microbiome and its temporal associations with different pairs of eczema phenotypes (transient versus persistent, atopic versus non-atopic) in Chinese children. We followed 119 term Chinese infants from birth to 24 months old within a Hong Kong birth cohort. The skin microbes at the left antecubital fossa were serially sampled by flocked swabs at 1, 6, and 12 months for bacterial 16S rRNA gene sequencing. The atopic sensitization at 12 months was strongly associated with eczema persisting to 24 months (odds ratio 4.95, 95% confidence interval 1.29-19.01). Compared with those with non-atopic eczema, the children with atopic eczema had reduced alpha diversity at 12 months (p < 0.001) and transiently higher abundance of the genus Janibacter at 6 months (p < 0.001). Our findings suggest that atopic sensitization at 12 months may predict persistent eczema by 24 months, and atopic eczema at 12 months is associated with unique skin microbiome profiles at 6 and 12 months. Non-invasive skin-microbiome profiling may have predictive value for atopic eczema.

Microbial network signatures of early colonizers in infants with eczema

In this longitudinal cohort study, our results demonstrated that there are rhythmic changes in gut microbial network signatures in early life, and healthy infants adopt more complex and stable network structure in their gut microbiota than that of the infants with eczema.

The associations of maternal and children's gut microbiota with the development of atopic dermatitis for children aged 2 years

BACKGROUND

It is critical to investigate the underlying pathophysiological mechanisms in the development of atopic dermatitis. The microbiota hypothesis suggested that the development of allergic diseases may be attributed to the gut microbiota of mother-offspring pairs. The purpose of this study was to investigate the relationship among maternal-offspring gut microbiota and the subsequent development of atopic dermatitis in infants and toddlers at 2 years old.

METHODS

A total of 36 maternal-offspring pairs were enrolled and followed up to 2 years postpartum in central China. Demographic information and stool samples were collected perinatally from pregnant mothers and again postpartum from their respective offspring at the following time intervals: time of birth, 6 months, 1 year and 2 years. Stool samples were sequenced with the 16S Illumina MiSeq platform. Logistic regression analysis was used to explore the differences in gut microbiota between the atopic dermatitis group and control group.

RESULTS

Our results showed that mothers of infants and toddlers with atopic dermatitis had higher abundance of Candidatus_Stoquefichus and Pseudomonas in pregnancy and that infants and toddlers with atopic dermatitis had higher abundance of Eubacterium_xylanophilum_group at birth, Ruminococcus_gauvreauii_group at 1 year and UCG-002 at 2 years, and lower abundance of Gemella and Veillonella at 2 years. Additionally, the results demonstrated a lower abundance of Prevotella in mothers of infants and toddlers with atopic dermatitis compared to mothers of the control group, although no statistical difference was found in the subsequent analysis.

CONCLUSION

The results of this study support that gut microbiota status among mother-offspring pairs appears to be associated with the pathophysiological development of pediatric atopic dermatitis.

The role of gut microbiome in inflammatory skin disorders: A systematic review

The close relationship between the intestine and the skin has been widely stated, seen from gastrointestinal (GI) disorders often accompanied by skin manifestations. Exactly how the gut microbiome is related to skin inflammation and influences the pathophysiology mechanism of skin disorders are still unclear. Many studies have shown a two-way relationship between gut and skin associated with GI health and skin homeostasis and allostasis. This systematic review aimed to explore the associations between the gut microbiome with inflammatory skin disorders, such as acne, psoriasis, atopic dermatitis, and urticaria, and to discover the advanced concept of this relationship. The literature search was limited to any articles published up to December 2020 using PubMed and EBSCOHost. The review followed the PRISMA guidelines for conducting a systematic review. Of the 319 articles screened based on title and abstract, 111 articles underwent full-text screening. Of these, 23 articles met our inclusion criteria, comprising 13 atopic dermatitis (AD), three psoriasis, four acne vulgaris, and four chronic urticaria articles. Acne vulgaris, atopic dermatitis, psoriasis, and chronic urticaria are inflammation skin disorders that were studied recently to ascertain the relationship of these disorders with dysbiosis of the GI microbiome. All acne vulgaris, psoriasis, and chronic urticaria studies stated the association of gut microbiome with skin manifestations. However, the results in atopic dermatitis are still conflicting. Most of the articles agree that Bifidobacterium plays an essential role as anti-inflammation bacteria, and Proteobacteria and Enterobacteria impact inflammation in inflammatory skin disorders.