Novel perspectives on the role of the human microbiota in regenerative medicine and surgery

Abstract

Plastic surgery is transitioning from a fine craftsmanship to a regenerative science. In wound healing, the role of microorganisms is no longer considered to be just counteracting, but also promoting. Furthermore, host-microbe interactions are essential for numerous aspects of normal mammalian physiology, from metabolic activity to immune homeostasis. Each area of the human body hosts a unique microbial community, and the composition of microbiota is dependent on the host, age and the anatomical area, and it changes according to the characteristics of the microenvironment. Every squared centimeter of skin contains ~1 billion bacteria. The majority of microorganisms of the skin are commensal or temporary passing members. Skin flora mechanisms interacting or influencing the human physical skin barrier are not well defined. Resident skin bacteria provide the first line of defence against potentially dangerous pathogens and produce small molecules that influence their microbial neighbours. Furthermore, the microbiota activates and assists innate immunity and influences adaptive immunity. Various types of immune and non-immune cells contribute to wound healing. The proliferative phase of wound healing is inversely proportional to the extent of the post-traumatic inflammatory reaction. Topical bacterial lipopolysaccharide application markedly affects wound healing by accelerating the resolution of inflammation, increasing macrophage infiltration, enhancing collagen synthesis and altering the secretion of mediators involved in skin regeneration. Various studies have investigated the biological contents of thermal spring waters, and their anti-inflammatory and immune protective roles. In addition, the regenerative properties of thermal spring waters were analysed in an experimental animal wound model. The areas treated with thermal water healed faster than the areas treated with conventional dressings, and exhibited a collagen and elastic fiber network comparable with the normal skin. Thus, the microbial environment may be considered as a potential tool in regenerative medicine and surgery.

Ex�vivo regenerative effects of a spring water

“…Therefore, the overall non-pathogenic bacterial populations of the Comano spring water, comprehensively termed microbiota, may be responsible for its regenerative properties. These properties may be related to the production of so far unknown substances that promote regeneration, probably in synergy with macro and micro mineral elements of the spring water ( 25 ).…”

Antibiotics Modulate Intestinal Regeneration

“…An alternate hypothesis is that the microbial community induces varying immune responses that potentially promote tissue regeneration through gut healing [ 49 , 127 , 128 , 129 ]. For instance, changes in the microenvironment are observed in gut injuries, where the growth of bacteria, that potentially promotes the wound healing and regeneration of the damaged tissue, is induced [ 130 ].…”

The Role of the Microbiota in Regeneration-Associated Processes

“…This regeneration of mucosal epithelia has been found to be modulated by the microbiota (Thomas, 2016;Hou et al, 2017). Also, the microbiota has been suggested to promote gut healing regeneration through induction of immune responses (Sommer and Bäckhed, 2013;Pellegatta et al, 2016;Thomas, 2016;Hou et al, 2017).…”

“…Only the regeneration of the intestinal luminal epithelium has been studied Hou et al (2017), Thomas (2016), Sommer and Bäckhed (2013), Pellegatta et al (2016), Abrams et al (1963), Uribe et al (1994) Isolated cells/cell lines (mammal models)…”