Iron uptake from lactoferrin by intestinal brush-border membrane vesicles of human neonates.
Level 5 - mechanism / opinion, no new human data
In vitro bench research using human tissue membrane vesicles
What was done
Investigated iron uptake from human lactoferrin (purified from pooled human colostrum) into brush-border membrane vesicles (BBMV) prepared from the small intestine of human neonates. Uptake was measured by incubating BBMV with 55Fe-citrate or 55Fe-lactoferrin across different pH levels and incubation times, followed by rapid filtration. Uptake was also evaluated using partially degraded lactoferrin.
What was found
Iron uptake from 55Fe-lactoferrin was pH-dependent (maximum at pH 7.5) and reached peak uptake at 1 min. Uptake from 55Fe-citrate was slower (maximum at 5 min) and not pH-dependent. Maximum iron uptake bound to lactoferrin was about twice that bound to citrate (230 pmol vs 105 pmol/mg microvillus protein). Partial degradation of lactoferrin into two fragments abolished its capacity to increase iron uptake.
Why it matters
Provides mechanistic evidence that intact lactoferrin enhances intestinal iron absorption in neonates, helping explain the high bioavailability of iron in human milk.
Limits
In vitro bench study using membrane vesicles that does not capture in vivo digestion, intestinal transit, or systemic regulatory factors. The abstract does not report the number of neonatal tissue donors or statistical variance.
Cited by
- supports Lactoferrin binds iron in the gastrointestinal tract and facilitates its absorption into the body.