We are pleased to announce Prof. Shigefumi Okamoto from the University of Osaka Graduate School of Medicine, Japan join the Skin Ageing & Challenges 2026 congress and will give presentation entitled “Understanding Skin Aging from an Ecosystem Perspective: Biological Dialogue between the Host Environment and Microorganisms“.

Summary of the presentation:

Aging is accompanied by progressive alterations in skin barrier function, immune regulation, tissue repair, and other physiological properties of the skin. Recent studies have demonstrated age-associated changes in the skin microbiome; however, these alterations appear to be influenced not only by chronological aging but also by frailty and deterioration in general health. Prof. Okamoto’s epidemiological studies further suggest that the transition to frailty and bedridden conditions is accompanied by substantial changes in both skin physiology and microbial communities. Although age-related changes in the host skin environment and skin microbiome have been extensively investigated, their biological interactions and clinical implications remain incompletely understood.

In this lecture, Prof. Okamoto will revisit two apparently distinct clinical conditions—post-pressure injury infection and invasive Streptococcus dysgalactiae subsp. equisimilis (SDSE) infection—from the perspective of the aging skin ecosystem. Post-pressure injury infection represents a typical endogenous infection associated with disruption of the resident microbiota and impairment of the skin barrier. In contrast, invasive SDSE infection is generally regarded as an exogenous infection. However, accumulating microbiological, epidemiological, and experimental evidence suggests that age-related alterations in the skin environment may facilitate the transient colonization, persistence, invasion, and pathogenic expression of SDSE. These observations raise the possibility that endogenous and exogenous infections are not entirely independent but instead represent different clinical manifestations arising from a common ecological transition in aging skin.

Based on these observations, Prof. Okamoto proposes not a new disease model but a shift in perspective for understanding skin infection in older adults. Rather than viewing skin infection solely as microbial invasion following tissue damage, he emphasizes the need to investigate the ecological changes that precede clinically apparent infection. Understanding how aging influences the biological dialogue among the host skin environment, resident microorganisms, immune responses, and potentially invasive pathogens may provide a more integrated framework for explaining susceptibility to skin infection. Such an ecological perspective could help bridge microbiology, dermatology, wound healing, and geriatric medicine, ultimately contributing to preventive strategies aimed not only at eliminating pathogens but also at maintaining or restoring a resilient skin ecosystem. Prof. Okamoto hopes this perspective will stimulate further discussion and collaborative research toward preserving skin health and preventing skin injury and infection in older adults.