Ageing and cancer share similar clinical outcomes and underlying mechanisms, notably the hallmarks of dysbiosis, inflammation, genomic instability and epigenetic alterations. Both phenomena pose significant challenges to personal and societal well-being, and are exponentially increasing in prevalence. Therefore, targeted therapies addressing the root causes are urgently needed. Research from our group highlights the impact of Quorum Sensing Peptides (QSP) on neuronal, immune, muscle and cancer cells. Moreover, we recently identified some of these peptides in human biofluids—plasma, saliva and faeces. Considering the QSP presence in these biofluids, their microbial-dependent production (‘dysbiosis’), their inflammation-modulating effects (‘inflammation’) and the demonstrated potential of these molecules to modulate cancer and ageing-related conditions (sarcopenia and dementia) in vitro, we hypothesise that QSP may play a role in both human ageing and cancer. Our translational top-down approach involves (1) investigating human associations between QSP and ageing/cancer clinical phenotypes, (2) examining QSP associations with meta-hallmarks of ageing and cancer and (3) utilizing machine learning to identify patterns. Finally, we will explore the causal relationship between QSP and accelerated ageing using a C. elegans model. This project aims to unveil novel insights into the pathophysiology of cancer/ageing, potentially improving gero-oncologic treatments and quality of life.