What harms gut health is often not a single food but repeated exposures. Top contributors include ultra-processed foods (high refined sugar, low fiber, additive-heavy profiles) and sugary drinks. Heavy alcohol use can disrupt barrier integrity and microbial balance. Irregular sleep and chronic stress amplify symptoms via the gut–brain axis. Unnecessary antibiotics and long-term use of certain medications can adversely affect the microbiome. Food-specific triggers commonly include deep-fried/high-fat meals, very spicy foods eaten quickly, high FODMAP loads in sensitive individuals, dairy in lactose intolerance, and gluten in celiac disease. The key variable is personal tolerance—what works for one person may trigger another. The best strategy is to identify triggers, adjust portions, and build a sustainable pattern. With red-flag symptoms, prioritize medical evaluation over self-directed elimination.