The study used quantitative ecological approaches to quantify the number of species, variety, and how the environment affects plant evolution through time. Psidium guajava has many biological characteristics, including antimicrobial and anticancer properties. This project intends to uncover, define, and assess phytochemical substances as colon cancer antioxidants. The fruit peel extract contained alkaloids (35.5 mg/g), flavonoids (14 mg/g), phenols (39.5 mg/g), and tannins (35 mg/g). Fourier Transform Infrared Spectroscopy identified functional groups in ethanolic guava peel extract. Guava fruit peel extract's antimicrobial properties were examined. Staphylococcus aureus and Enterobacter aerogenes were particularly sensitive. Psidium guajava peel extract inhibited 76.29% of free radicals at 500 mg/ml. Psidium guajava extract was non-toxic to normal cells but harmful to HT29 colon cancer cells (IC50 = 75.51 µg/ml). According to the results, fruit peel extract could treat colon cancer.