Human Milk Feeding Enhances the Urinary Excretion of Immunologic Factors in Low Birth Weight Infants

Abstract

ABSTRACT. The effects of fortified human milk feedings on the urinary excretion of lactoferrin, lysozyme, secretory component, IgA, and secretory IgA antibodies to Escheuichia coli 0 antigens were investigated in very low birth wt infants. Infants were maintained on either a human milk or a cow's milk preparation. The amounts of each immune factor that were ingested and excreted were quantified during balance studies conducted at 2.5 and 5 wk of age. Serum levels of these immune factors were similar in both feeding groups. The urinary excretion of all factors except lysozyme was 7-to 150-fold greater in infants fed human milk than in those fed cow's milk formula. IgA was the only factor for which the amount of the factor excreted correlated with the amount ingested. Fragments as well a s whole molecules of lactoferrin were found in the urine of the infants fed human milk, but the molecular sizes of the excreted proteins exceeded those normally filtered by the kidneys. Therefore, the genesis of the enhanced levels of host defense factors in the urine of infants fed human milk is not clear. Gastrointestinal absorption and subsequent renal excretion a s well as enhanced production of immune factors in the infant's urinary tract are possible explanations. (Pediatu Res 25:184-188, 1989) Abbreviations SIgA, secretory IgA SC, secretory component VLBW, very low birth weight infants FHM, fortified human milk CMF, cow's milk formula ELISA, enzyme-linked immunosorbent assayThe concept that human milk protects the recipient infant is supported by the demonstration of reduced infectious morbidity among breast-fed compared to artificially fed infants and by the presence of certain host defense factors in high concentrations in human milk (1-6). It has been assumed that this protection is Received April 22, 1988; accepted October 12, 1988 mediated by the complex system of immunologic factors in the milk (5,6) or by interaction of milk factors with agents produced by the infant (7). Several studies have examined the effect of human milk feeding on the concentration of immune factors in body fluids and excretions of the infant (8-24). In some studies, the fecal excretion of IgA, lactofenin, and lysozyme was increased in infants fed human milk, a result which suggested that a portion of the ingested factors survived passage through the gastrointestinal tract (8-1 3). However, a maternal origin for the immune factors was not proven in those investigations. Studies of the effects of human milk feeding on immune factors in the saliva and nasal secretions of infants (14-21) have produced conflicting results, perhaps because of variable contamination of the secretions with infants' serum or maternal milk (21). The effect of human milk feeding on the infant's serum immunoglobulin concentrations also remains controversial (22)(23)(24)(25).To investigate the in vivo effects of feeding human milk, we developed a human milk preparation for experimental use in premature infants. It was previously ascertained that this preparation met rea...

Oropharyngeal Colostrum Administration in Extremely Premature Infants: An RCT

“…The half-lives of sIgA and lactoferrin are 3 to 6 days, and their uptake from breast milk via neonatal gut mucosa with subsequent excretion of their intact maternal forms in the urine were well demonstrated in previous studies. 7,[20][21][22] This exceptional mucosal absorption might be expected to occur only in preterm infants, particularly before "gut closure," and our findings support this hypothesis. 23,24 On the other hand, in addition to mucosal absorption, the result of continued increase of urinary sIgA at 2 weeks of age might be reflective that oropharyngeal stimulation by colostrum enhances endogenous production and/or excretion of sIgA.…”

Molecular Forms of Lactoferrin in Stool and Urine from Infants Fed Human Milk

“…It remains unclear, review boards of both institutions. Two groups of VLBW infants however, whether the whole LF molecules that were frag-from the same hospital population were investigated (12,13). mented were derived solely from ingested LF in human One infant received CMF (Similac PM 60140 or Similac 24, milk or in part from LF produced by the infant in response Ross Laboratories, Columbus, OH) and the second received to human milk feedings.…”

“…mented were derived solely from ingested LF in human One infant received CMF (Similac PM 60140 or Similac 24, milk or in part from LF produced by the infant in response Ross Laboratories, Columbus, OH) and the second received to human milk feedings. (Pediatr Res 27: 252-255, 1990) FHM prepared daily by adding pasteurized, lyophilized mature donor milk to fresh maternal milk as previously described (12,Abbreviations 13 (12,13). Stools and urine were collected continuously during 96-h balance periods at 2.5 and 5 wk of age and the specimens were stored at -20°C until analyzed.…”

“…The molecular forms of lactoferrin (LF) were of the infant (3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Recent studies demonstrate that the urinary examined in stools and urine collected at 2.5 or 5 wk of excretion of IgA (1 1, 12), total secretory component (12), and age from very low birth wt infants fed either a cow's milk LF (12) was greater in human milk as compared to cow's milkformula or a fortified human milk preparation.…”

Session 1: Feeding and infant development Breast-feeding and immune function

“…Lactoferrin and fragments of lactoferrin are taken up by a receptor in the gut and appear in the urine of breast-fed infants (Goldblum et al 1989). This process may explain why human lactoferrin and certain active fragments of lactoferrin given perorally to mice can protect against experimental urinary tract infections (Haversen et al 2000).…”