Pre-clinical safety assessment of biotechnologically produced lacto-N-tetraose (LNT).

Lacto- N -tetraose (LNT) is a human milk oligosaccharide with average concentrations ranging from 0.74 to 1.07 g/L in breastmilk, depending on the lactation stage. In this study, the preclinical safety of LNT produced by the Escherichia coli K-12 E2083 production strain was assessed. LNT was negative in both the bacterial reverse mutation assay and the in vitro micronucleus assay, demonstrating the absence of genotoxic potential for this substance. In the OECD 408 guideline compliant 90-day oral toxicity study rat, LNT did not induce any adverse effects in any treatment group up to and including the highest dose tested, and no LOAEL could be determined. Therefore, the no-observed-adverse effect level (NOAEL) is set at the highest dose level tested, i.e. a dietary level of 5 % (w/w), corresponding to ≥2856 mg/kg bw/day and ≥3253 mg/kg bw/day for males and females, respectively. This might be an underestimation of the NOAEL, caused by the range of dose levels tested. The results obtained in the current study are in good agreement with available data generated using other biotechnologically produced LNT batches and therefore support its safe use as a food ingredient. • Safety assessment of lacto- N -tetraose produced by the Escherichia coli K-12 E2083. • Negative in guideline-compliant bacterial reverse mutation (Ames) assay. • Negative in guideline-compliant in vitro micronucleus assay. • No adverse effects in guideline-compliant 90-day toxicity study in the rat. • NOAEL was ≥2856 mg/kg bw/day and ≥3253 mg/kg bw/day for rat males and females. [ABSTRACT FROM AUTHOR]

Copyright of Regulatory Toxicology & Pharmacology: RTP is the property of Academic Press Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)