The Microbiome Fiber Supplement Market is projected to grow from USD 1,235.6 million in 2025 to USD 2,288.3 million by 2035, registering a CAGR of 6.4% over the forecast period. Prebiotic fibers are expected to dominate the ingredient segment with a 28% market share, while digestive health applications are anticipated to lead demand in 2025, accounting for 30% of total value.