Abstract:
Background
The dermis is the fundamental component of the skin, providing structural support, elasticity, and mechanical
resilience. Dermal remodeling with age is a complex, multifactorial process characterized by reduced collagen and
elastin fiber density, alterations in the extracellular matrix, and decreased regenerative capacity. Clinically, these
changes manifest as wrinkles, skin laxity, and increased susceptibility to external stressors.
Over the past two decades, the skin microbiota has emerged as a key regulator of skin homeostasis. Microbial
communities interact with keratinocytes, fibroblasts, and immune cells, influencing inflammation, tissue repair, and
regeneration. Age-related changes in microbiota composition and diversity can significantly modulate the dynamics
of dermal remodeling.
Material and methods
This is a narrative review of the literature. Data were collected from major biomedical databases, including
PubMed, ScienceDirect, and SpringerLink. Original articles, meta-analyses, clinical and experimental studies, and
systematic reviews published in English between 2004 and 2024, investigating the influence of microbiota on dermal
aging and sex-specific differences, were included.
Results
A balanced skin microbiota promotes collagen synthesis, provides antioxidant protection, regulates chronic in flammation, and supports fibroblast activity, thereby contributing to delaying the appearance of visible signs of aging.
In women, microbial diversity is generally higher; however, post-menopause, there is a marked reduction in ben eficial Gram-positive species. In contrast, men maintain higher levels of these species into older age. The increase in
pro-inflammatory Gram-negative bacteria, more common in women, promotes inflammation and extracellular matrix
degradation post-menopause. In men, dermal structural changes tend to occur earlier, despite higher initial collagen
density, due to lower microbial diversity and the absence of estrogen’s protective effects.
Conclusions
Skin microbiota plays a central role in dermal remodeling and aging by regulating inflammation, collagen syn thesis, and protection against oxidative stress. Age-associated dysbiosis promotes extracellular matrix degradation
and loss of skin elasticity, with pronounced sex-specific differences. Probiotic interventions tailored to individual
microbial profiles and sex may offer a promising strategy to prevent or delay the signs of aging. Understanding the
interactions between microbiota, hormones, and dermal structure opens new avenues in preventive and anti-aging
dermatology.
