Language
Country/Area
No result found
The mysterious skin ecosystem: Why are the microbial combinations in different parts of the skin so unique?
Skin microbiota, also known as skin microecology, refers to the microbial community living on the skin, mainly composed of bacteria, fungi and other microorganisms. The microbial diversity on human skin is extremely rich, containing more than a thousand species of bacteria belonging to nineteen categories. Most of these microorganisms gather in the surface layer of the epidermis and the upper part of the hair follicles, forming a natural protective barrier for the skin. Most of these microbes are non-pathogenic, some are commensal, and others provide mutually beneficial relationships that help prevent the invasion of harmful pathogens.
Skin microbes not only prevent colonization by pathogens, but can also further protect the host by competing for nutrients, secreting antimicrobial substances, or stimulating the skin's immune system.
However, these microorganisms living on our skin may also cause skin diseases under certain circumstances, especially for people with weakened immune systems, these microorganisms may become a potential threat. In fact, the diversity of these microorganisms is also closely related to different skin diseases, such as acne, eczema, etc.
Microbial diversity
BacteriaUsing advanced 16S ribosomal RNA technology, our estimates of the bacterial species on the skin have undergone a fundamental transformation. Previous studies have relied on culture techniques, and many types of bacteria have been overlooked. However, new research reveals that the most common bacteria only make up 5% of the skin. Most of these bacteria belong to four major phyla, including Actinobacteria, Bacillus, Proteobacteria, and Bacteroidetes. Among them, Propionibacteria and Staphylococci were the main bacteria in the oil-rich areas, while Corynebacteria and Staphylococci dominated in the moist areas.
Fungi
Fungi on the skin are also a part that cannot be ignored. The study showed that 14 different fungi, including yeast and dermatophytes, were found between the toes of young people. The diversity of these fungi varied greatly between different areas of the skin, with the heels of young people harboring the greatest diversity.
The researchers found that the fungal diversity in the heel area was as high as 80 species, while other locations had relatively few.
Umbilical cord microbiota
The umbilicus, or belly button, is not typically exposed to sunlight and detergents, making it an ideal site for studying the skin microbiome. The Belly Button Biodiversity Project, initiated by North Carolina State University, found that common microorganisms in belly buttons include Staphylococcus and Corynebacterium, which play an important protective role.
Skin's Self-Defense
The skin has multiple mechanisms for self-protection, such as secretion of antimicrobial peptides and an acidic environment. Antimicrobial peptides, such as cathelicidins, play a key role in inhibiting microbial proliferation in the skin. In addition, the pH value of the skin is generally 4 to 4.5. Such an acidic environment is conducive to the growth of symbiotic microorganisms while inhibiting the reproduction of some pathogenic microorganisms.
Vitamin D3 has been shown to be an important factor in regulating antimicrobial peptides, affecting the skin's immune response to pathogenic microorganisms.
Relationship between skin diseases and microorganisms
Microorganisms play an important role in non-infectious skin diseases such as eczema, rosacea, and psoriasis. Certain bacteria, such as Cutibacterium acnes, have been clearly linked to the development of acne. The higher the microbial diversity of the skin, the better it is generally able to resist the development of these skin diseases.
Relevance to eczema
In the skin of people with eczema, colonies of Staphylococcus aureus were significantly increased, indicating a decrease in bacterial diversity. During treatment, the combination of antibiotics and corticosteroids has been shown to be effective.
The effects of rosacea
Rose acne usually appears in oily areas, and the patient's skin will have more skin mites. Excessive growth of these microorganisms can promote an increased inflammatory response.
Like any ecosystem, the microbiome of the skin is a dynamic process that is influenced by many factors, such as age, gender, diet, and living environment. How these factors affect the composition of skin microbes may be an important direction for future scientific exploration, so let us think deeply about it.
