A review of the safety evidence on recombinant human lactoferrin for use as a food ingredient

Published studies on the glycosylation, absorption, distribution, metabolism, excretion, and safety outcomes of orally ingested recombinant human lactoferrin (rhLF) were reviewed in the context of unanswered safety questions, including alloimmunization, allergenicity, and immunotoxicity potential of rhLF during repeated exposure. The primary objective was to summarize current safety data of rhLF produced in transgenic host expression systems. Overall, results from animal and human studies showed that rhLF was well tolerated and safe. Animal data showed no significant toxicity-related outcomes among any safety or tolerability endpoints. The no observed adverse effect levels (NOAEL) were at the highest level tested in both iron-desaturated and -saturated forms of rhLF. Although one study reported outcomes of rhLF on immune parameters, no animal studies directly assessed immunogenicity or immunotoxicity from a safety perspective. Data from human studies were primarily reported as adverse events (AE). They showed no or fewer rhLF-related AE compared to control and no evidence of toxicity, dose-limiting toxicities, or changes in iron status in various subpopulations. However, no human studies evaluated the immunomodulatory potential of rhLF as a measure of safety. Following this review, a roadmap outlining preclinical and clinical studies with relevant safety endpoints was developed to address the unanswered safety questions.