Genotoxicity and neonatal subchronic toxicity assessment of a novel mixture of the human-identical milk oligosaccharides lacto-N-fucopentaose I and 2′-fucosyllactose

Human milk oligosaccharides (HMOs) are a complex group of bioactive molecules largely observed in human breast milk but also occurring in limited amounts in other mammalian milks. Advances in biotechnology have enabled production of human-identical milk oligosaccharides (HiMOs), structurally identical molecules to HMOs found naturally in human milk, intended for addition to infant formula to more closely replicate breast milk. Biosynthesis of a novel mixture of two major HMOs, lacto-N-fucopentaose I and 2 '-fucosyllactose (LNFP-I/2 '-FL), recently became possible. To support the safety of LNFP-I/2 '-FL for use in infant formula and other foods, it was subject to a safety assessment comprising a bacterial reverse mutation test, anin vitromammalian cell micronucleus test, and a 90-day oral gavage study in neonatal rats. In the 90-day study (the first HiMO study to include the new endocrine-sensitive endpoints described in the 2018 version of OECD Test Guideline 408), LNFP-I/2 '-FL was administered by oral gavage to neonatal rats once daily (from Day 7 of age) for 90 consecutive days, at doses up to 5000 mg/kg bw/day, followed by a 4-week recovery period. Concurrent reference controls received 5000 mg/kg bw/day of the approved infant formula ingredient oligofructose. LNFP-I/2 '-FL was nongenotoxicin vitro. The highest dose tested (5000 mg/kg bw/day) was established as the no-observed-adverse-effect level in the 90-day study, as there were no test article-related adverse effects on clinical observations, body weight, food consumption, clinical pathology, and organ weights nor any noteworthy macroscopic or microscopic findings. This supports the safety of LNFP-I/2 '-FL for its intended uses in food.

Automated summary

Human milk oligosaccharides (HMOs) are bioactive molecules found in human breast milk, with potential applications in infant formula. The safety assessment of LNFP-I/2'-FL, a human-identical milk oligosaccharide, showed it to be non-genotoxic and safe for use in food products.