The Custom Probiotics Market is projected to expand from USD 635.6 million in 2025 to approximately USD 1,106.6 million by 2035, reflecting a compound annual growth rate (CAGR) of 5.7%. Market leadership is expected to be maintained by Strain-Specific Formulations, which are anticipated to hold the largest share within the customization segment. Among applications, Digestive Health is forecasted to remain the primary driver of adoption in 2025, supported by strong clinical relevance and high consumer familiarity.