Hasnain, S. et al. 2026. Dose-Dependent Effects of Caffeine on Cognitive Performance, Hormonal Regulation, and Gut Microbiota across Adulthood: Dose-Dependent Effects of Caffeine on Cognitive Performance and Gut Microbiota. DIET FACTOR (Journal of Nutritional and Food Sciences). 7, 2 (Jun. 2026), 15–20. DOI:https://doi.org/10.54393/df.v7i2.213.