Global Digestive Health Market Size, Share & Demand Report By Product Type (Probiotics, Prebiotics, Digestive Enzymes, Synbiotics, Fiber & Herbal Digestive Supplements), By Application (General Gut Health & Immunity, IBS, Constipation & Bloating, Lactose Intolerance, IBD), By Distribution Channel (Pharmacies & Drug Stores, Online Retail & DTC, Supermarkets & Hypermarkets, Health & Specialty Stores), By End-Use Industry (Nutraceutical & Dietary Supplements, Functional Food & Beverages, Pharmaceutical, Animal Nutrition), By Region & Segment Forecasts, 2026–2031