<![CDATA[Background: Infectious diarrhea is a major global health burden characterised by gastrointestinal hypermotility, fluid hypersecretion, and mucosal inflammation. Conventional antimotility agents and broad-spectrum antibiotics carry significant limitations, notably antimicrobial resistance and adverse systemic effects. Psidium guajava and Piper betle offer a complementary approach, yet the magnitude of their combined synergy has not been quantified. Objective: To quantify and map the combined antidiarrheal, antimicrobial, and antioxidant synergy of Psidium guajava and Piper betle, and to identify their respective pathophysiological targets. Methods: A systematic review and meta-analysis were conducted following PRISMA 2020. Primary studies reporting quantitative antidiarrheal, antimicrobial, and antioxidant parameters of both extracts were identified across major databases. Standardized Mean Differences (SMD) with 95% confidence intervals (CI) were calculated using a random-effects model, and therapeutic capacity was mapped by Radar Chart Analysis (RCA) and Area Under the Curve (AUC) integration. Results: Psidium guajava markedly suppressed gastrointestinal motility and intestinal fluid accumulation (pooled SMD = −2.45; 95% CI −3.10 to −1.80), whereas Piper betle showed broad-spectrum bactericidal and free-radical-scavenging activity (pooled SMD = 3.85; 95% CI 2.95 to 4.75). AUC integration indicated that combining both phytochemical profiles expanded the total therapeutic coverage by 42%. Conclusion: The framework indicates a synergistic mechanism in which Psidium guajava targets hypermotility and secretory dysfunction while Piper betle addresses the pathogenic etiology and oxidative tissue damage, supporting the development of combined botanical therapeutics.]]>
