Factors affecting neutrophil functions during sepsis: human microbiome and epigenetics

Sepsis is a severe disease that occurs when the body's immune system reacts excessively to infection. The body's response, which includes an intense antibacterial reaction, can damage its tissues and organs. Neutrophils are the major components of white blood cells in circulation, play a vital role in innate immunity while fighting against infections, and are considered a feature determining sepsis classification. There is a plethora of basic research detailing neutrophil functioning, among which, the study of neutrophil extracellular traps is providing novel insights into mechanisms and treatments of sepsis. This review explores their functions, dysfunctions, and influences in the context of sepsis. The interplay between neutrophils and the human microbiome and the impact of DNA methylation on neutrophil function in sepsis are crucial areas of study. The interaction between neutrophils and the human microbiome is complex, particularly in the context of sepsis, where dysbiosis may occur. We highlight the importance of deciphering neutrophils' functional alterations and their epigenetic features in sepsis because it is critical for defining sepsis endotypes and opening up the possibility for novel diagnostic methods and therapy. Specifically, epigenetic signatures are pivotal since they will provide a novel implication for a sepsis diagnostic method when used in combination with the cell-free DNA. Research is exploring how specific patterns of DNA methylation in neutrophils, detectable in cell-free DNA, could serve as biomarkers for the early detection of sepsis. Neutrophils' functions change during the course of sepsis; these changes are related to human microbiome and epigenetic alterations, which can be detected in cell-free DNA.