Antimicrobial Peptides (AMPs) and the Microbiome in Preterm Infants: Consequences and Opportunities for Future Therapeutics.

Antimicrobial peptides (AMPs) are crucial components of the innate immune system in various organisms, including humans. Beyond their direct antimicrobial effects, AMPs play essential roles in various physiological processes. They induce angiogenesis, promote wound healing, modulate immune responses, and serve as chemoattractants for immune cells. AMPs regulate the microbiome and combat microbial infections on the skin, lungs, and gastrointestinal tract. Produced in response to microbial signals, AMPs help maintain a balanced microbial community and provide a first line of defense against infection. In preterm infants, alterations in microbiome composition have been linked to various health outcomes, including sepsis, necrotizing enterocolitis, atopic dermatitis, and respiratory infections. Dysbiosis, or an imbalance in the microbiome, can alter AMP profiles and potentially lead to inflammation-mediated diseases such as chronic lung disease and obesity. In the following review, we summarize what is known about the vital role of AMPs as multifunctional peptides in protecting newborn infants against infections and modulating the microbiome and immune response. Understanding their roles in preterm infants and high-risk populations offers the potential for innovative approaches to disease prevention and treatment.

The Delicate Skin of Preterm Infants: Barrier Function, Immune-Microbiome Interaction, and Clinical Implications.

The skin of preterm infants is a delicate organ with critical structural and functional differences as compared to term born infants. Unique features contribute to an increased susceptibility to injury, infection, thermal instability, and water loss. During rapid, often accelerated adaption of the physical barrier function of preterm skin, a parallel and mutual development of host skin immunity and skin microbiome seem to be crucial for skin homeostasis. Recent advances in molecular biology have enabled researchers to gain a deeper understanding of the microbial community composition of preterm skin and the important relationship with microbiome composition of other body sites. Nevertheless, several questions remain to be answered, including niche factors and environmental influences on skin maturation. In line with that, evidence-based guidelines on skin care practice in preterm infants are missing. This review articles aims to provide an overview of the current knowledge of preterm infant skin development including immune and barrier function, host-microbial interactions, and potential clinical implications.