Recent research has uncovered fresh details about the behavior and transmission of two common skin bacteria—Cutibacterium acnes and Staphylococcus epidermidis. By examining the evolutionary history of these bacteria on adult facial skin, scientists have identified new patterns of bacterial migration and stability, which could impact future treatments and therapies.
Understanding the Dynamics of Skin Microbiomes
Researchers have shed light on the complex dynamics of the skin microbiome, particularly focusing on two dominant species, Cutibacterium acnes and Staphylococcus epidermidis. This new study, published in *Cell Host & Microbe*, investigates how these bacteria evolve and interact with their host environments, revealing potential ecological barriers that influence their colonization on the skin.
By analyzing the evolutionary history of these bacteria on the skin, scientists were able to observe how certain ecological barriers either allow or prevent new bacterial strains from colonizing the skin. This process is crucial for understanding how skin microbiomes remain stable and how new strains might take hold, such as through the use of topical probiotics.
The Role of Ecological Barriers in Microbial Communities
One of the key findings of the study was the identification of ecological barriers that affect microbial strain communities. These barriers can either be neutral or selective. Neutral barriers tend to allow new strains to colonize during early life or when disruptions occur. On the other hand, selective barriers maintain the stability of individual-specific microbiomes even as strains change over time.
The study tracked changes in the skin microbiome from childhood to adulthood, focusing on shifts in both species and bacterial lineages. It was observed that during adolescence, anaerobic bacteria like Cutibacterium acnes thrive, and there is also a significant increase in aerobic bacteria populations. This shift suggests that the colonization barriers present in early life may be reduced during adolescence, allowing for the colonization of new strains.
Key Findings from the Research
Over 4,000 bacterial isolates were collected from 57 individuals, including 8 families, allowing for a comprehensive analysis of the microbial dynamics. The researchers used genomic and metagenomic methods to examine changes at both the species and genotype levels.
The results revealed that there is limited lineage sharing within families, suggesting mostly neutral evolutionary patterns. However, the study also found that Cutibacterium acnes and Staphylococcus epidermidis behaved differently. Staphylococcus epidermidis showed a high rate of lineage turnover and selective transmission barriers, making it less suited for long-term probiotic use. In contrast, Cutibacterium acnes demonstrated low turnover and a strong ability to establish itself during adolescence, indicating that it could be a more effective candidate for durable probiotic therapy.
The Role of Multi-Cell Transmission in Cutibacterium acnes
The research also explored the role of multi-cell transmission in Cutibacterium acnes, noting that each sebaceous follicle is colonized independently, forming a structure that resembles an archipelago. This unique setup minimizes competition between different genotypes, allowing multiple strains to coexist more easily.
In contrast, the study found that the finer spatial distribution of Staphylococcus epidermidis on the skin is not yet fully understood, raising questions about whether it has a similar structure that allows multiple strains to coexist. The research suggests that Cutibacterium acnes is better suited to this form of stable colonization, potentially making it more suitable for probiotic therapies aimed at restoring skin microbiome balance.
Implications for Probiotic Therapies
The findings of this study have significant implications for the development of probiotic therapies aimed at managing skin conditions. Since Cutibacterium acnes is better able to establish itself on the skin during adolescence and can survive in a multi-strain environment, it may offer more promise for treatments that require long-term microbial stability. On the other hand, the behavior of Staphylococcus epidermidis suggests that it may not be as effective for such therapies due to its high rate of strain turnover.
Conclusion
This research has revealed important insights into the assembly dynamics of skin microbiomes, specifically the two dominant species, Cutibacterium acnes and Staphylococcus epidermidis. By uncovering these hidden dynamics, the study provides a deeper understanding of how these bacterial communities function and interact with their host environment. This knowledge could lead to more effective treatments and probiotic therapies designed to stabilize and restore the skin microbiome.
Related topics:
