Bridging the gap in infant nutrition: precision fermentation of human milk compounds

Background: Human milk (HM) is a unique nutritional source, tailored to meet infants' needs during early life. However, declining breastfeeding rates, influenced by lactation problems, health-related factors, psychological state, and work-related constraints, have increased reliance on infant milk formula (IMF). Most IMF is derived from bovine milk, which differs substantially from HM in protein composition, fat structure, carbohydrate profile, and bioactive components. These compositional gaps limit IMF's ability to replicate HM functionality with respect to digestibility, nutrient absorption, immune support, and microbiome maturation. Consequently, formula-fed infants may experience accelerated growth, increased susceptibility to allergic reactions, and gastrointestinal issues. Scope and approach: This review examines the compositional and functional limitations of IMF relative to HM, focusing on proteins and human milk oligosaccharides (HMOs), and explores how precision fermentation (pFerm), an emerging biotechnology for large-scale production of bioidentical human milk proteins and oligosaccharides, can narrow the HM-IMF gap. We review the pFerm protein and HMO sectors, analysing case studies of both compounds and highlighting challenges and opportunities. Key findings and conclusions: Market analysis shows that pFerm-derived bovine proteins and HMOs are well established, whereas human-derived proteins remain underdeveloped. Case studies of recombinant human lactoferrin and pFerm-derived HMOs demonstrate the ability of these innovations to narrow the HM-IMF gap. Key challenges to adoption include regulatory hurdles, economic scalability, and consumer apprehension regarding the perceived ‘unnatural’ nature of such ingredients. Nevertheless, the rapidly expanding pFerm sector - driven by biotechnological investment and growing consumer acceptance through effective communication - offers considerable opportunities to enhance IMF development through application of pFerm-derived HM compounds. © 2026 The Authors