Post-antibiotic gut imbalance refers to digestive and microbial disruption that may occur after antibiotic exposure alters the normal intestinal microbiome. Antibiotics may reduce microbial diversity within the digestive tract, affecting beneficial bacterial populations involved in fermentation, short-chain fatty acid production, intestinal barrier integrity, vitamin synthesis, immune signaling, and metabolic regulation. Loss of microbial diversity may contribute to bloating, irregular bowel activity, digestive discomfort, altered stool consistency, reduced fermentation activity, weakened mucosal barrier support, and increased intestinal sensitivity. The intestinal microbiome plays a major role in maintaining epithelial barrier integrity, nutrient metabolism, immune communication, and production of beneficial metabolites such as butyrate, acetate, and propionate. Dietary fiber and resistant starches serve as substrates for microbial fermentation. When microbial diversity is reduced, intestinal fermentation patterns and mucosal support pathways may become impaired. Reduced production of short-chain fatty acids may weaken epithelial energy supply, inflammatory regulation, and intestinal lining stability. A whole food plant-based dietary pattern rich in legumes, vegetables, fruits, herbs, seeds, mushrooms, and intact whole grains may help support microbial recovery and intestinal resilience following antibiotic exposure. Fiber-rich plant foods provide fermentable substrates including inulin, resistant starch, pectin, beta-glucans, arabinoxylans, oligosaccharides, and polyphenol-associated fibers that may help nourish beneficial microbial species involved in gut ecosystem balance. Jerusalem artichoke, oats, brown lentils, chickpeas, green peas, asparagus, garlic, onions, leeks, apples, bananas, flax seeds, chia seeds, broccoli, cabbage, and mushrooms provide prebiotic fibers and plant compounds associated with microbial fermentation pathways and epithelial support. Polyphenols from berries, green tea, onions, herbs, and cruciferous vegetables may also support antioxidant defense systems and microbial metabolic activity within the digestive tract. Fermentation-derived short-chain fatty acids are associated with epithelial barrier maintenance, immune regulation, intestinal energy metabolism, and gut signaling pathways. Fiber-rich whole plant foods may also help support stool bulk, transit regularity, hydration balance, and microbial diversity recovery. Minimizing highly processed foods, emulsifiers, alcohol exposure, excessive sugar intake, and inflammatory dietary patterns may help reduce additional stress on intestinal barrier systems during microbiome rebuilding phases.