The infantile cutaneous microbiome: A review

Abstract

Recent focus on the neonatal intestinal microbiome has advanced our knowledge of the complex interplay between the intestinal barrier, the developing immune system, and commensal and pathogenic organisms. Despite the parallel role of the infant skin in serving as both a barrier and an interface for priming the immune system, large gaps exist in our understanding of the infantile cutaneous microbiome. The skin microbiome changes and matures throughout infancy, becoming more diverse and developing the site specificity known to exist in adults. Delivery method initially determines the composition of the cutaneous microbiome, though this impact appears transient. Cutaneous microbes play a critical role in immune system development, particularly during the neonatal period, and microbes and immune cells have closely intertwined, reciprocal effects. The unique structure of newborn skin influences cutaneous microbial colonization and the development of dermatologic pathology. The development of the infantile skin barrier and cutaneous microbiome contributes to future skin pathology. Atopic dermatitis flares and seborrheic dermatitis have been linked to dysbiosis, while erythema toxicum neonatorum is an immune response to the establishment of normal bacterial skin flora. Physicians who care for infants should be aware of the impact of the infantile skin microbiome and its role in the development of pathology. A better understanding of the origin and evolution of the skin microbiome will lead to more effective prevention and treatment of pediatric skin disease.

Features of the Skin Microbiota in Common Inflammatory Skin Diseases

“…Immediately after birth, the skin of the newborn is exposed to environmental microorganisms that begin to inhabit/colonize it, creating a host-microorganism homeostasis. The microbiome of the skin of newborns born vaginally is similar to the vaginal microbiome of the mother, whereas the microbiome of children delivered by caesarean section shows similarities to the skin microbiome of the mother [ 26 ]. The skin microbiome of premature infants has its own specifics.…”

“…Furthermore, the skin of preterm infants (samples collected from the forehead area, cubital fossa and gluteal region) has relatively copious bacteria of the Staphylococcus , Corynebacterium , and Prevotella genera, and sparse Brevundimonas , Flavobacterium, and Sphingobacterium species, compared to term-newborns’ skin [ 27 ]. Research has demonstrated that, the predominant phylum found on the skin of healthy infants is the Firmicutes phylum (genus Staphylococcus and Streptococcus ), followed by Actinobacteria , Proteobacteria , and Bacteroidetes [ 26 , 27 , 28 , 29 , 30 ].…”

Emerging Links between Microbiome Composition and Skin Immunology in Diaper Dermatitis: A Narrative Review

“…Dermal bacterial colonization is generally thought to begin at birth and continues forming throughout the first years of life and into adulthood [ 14 , 15 ]. The mode of fetal delivery is recognized as the major determinant of the newborn′s cutaneous microbiome composition [ 15 ].…”

Extrinsic Factors Shaping the Skin Microbiome

“…Bacterial colonization on the human skin begins at the moment of birth and continues developing and reshaping throughout our first years of life [ 70 ]. Reports on microbial colonization beginning before and during delivery have been thoroughly reviewed by others [ 71 , 72 , 73 ].…”