Biology in Phases: Menstrual Cycle Influences on Metabolic and Microbial Health

Sex‑based biological differences are increasingly recognised as important determinants of health, yet the menstrual cycle remains largely overlooked in biomedical research. Cyclical fluctuations in ovarian hormones have the potential to systematically influence metabolic regulation, oxidative stress pathways, and host–microbiome interactions, contributing to physiological variability across the cycle. A limited understanding of these dynamic processes restricts accurate interpretation of existing health research and may obscure meaningful associations with disease risk and wellbeing. This PhD project will investigate how key phases of the menstrual cycle influence metabolism and the gut microbiome, and how these biological systems interact to shape health outcomes. Using an integrative approach, the research will characterise cycle‑dependent changes across these domains and explore their interrelationships. This work aims to address a critical gap in women’s health research and support more inclusive, menstrual cycle‑aware approaches to health assessment and intervention.