The accelerated decline in muscle mass and function among older adults, referred to as sarcopenia, has profound implications for both the quality of life and financial well-being. As the global population ages, this disease emerges as a substantial health concern for society. Despite its prevalence, our understanding of the underlying pathophysiological processes is limited, resulting in insufficient treatment options. Recent research has hinted at a potential link between sarcopenia and the oro-intestinal microbiota, though the key players in this relationship remain elusive. Building upon in vitro and initial in vivo findings, our study aims to investigate the role of quorum sensing peptides (QSP) produced by oral and gut bacteria in sarcopenia. Specifically, we will assess the presence of microbial QSP in human biofluids in correlation with the clinical sarcopenia phenotype in 240 older adults. Additionally, we will investigate the human association between QSP and the individual biological factors contributing to the multifactorial disease of sarcopenia. Subsequently, by examining these clinical and biological associations, we intend to evaluate the causality of selected QSP on sarcopenia using preclinical mouse models. Through these comprehensive investigations, our goal is to gain novel insights into the pathophysiology of sarcopenia, ultimately paving the way for personalized therapies that can enhance independent living for older adults.