Abstract
Objective: Our previous studies suggested that human milk proteases begin to hydrolyze proteins in the mammary gland and continue within the term infant' stomach. No research has measured milk protease and pepsin activity in the gastric aspirates of preterm infants after human milk feeding. This study investigated how the concentrations of human milk proteases and protease inhibitors changed in the premature infant stomach. Methods: Human milk and infant gastric samples were collected from 18 preterm-delivering mother-infant pairs (24-32 week gestational age). Paired human milk and gastric samples were collected across postnatal age (2-47 days). Protease concentrations were determined by spectrophotometric or fluorometric assays, and the concentrations of protease inhibitors and bioactive proteins were determined by enzyme-linked immunosorbent assay. Paired t tests were applied to compare enzymes, antiproteases, and bioactive proteins between human milk and gastric samples. Results: Our study reveals that although human milk proteases, including carboxypeptidase B2, kallikrein, plasmin, cathepsin D, elastase, thrombin, and cytosol aminopeptidase, are present in the preterm infant stomach, only plasmin and cathepsin D can actively hydrolyze proteins at gastric pH. Enzyme-linked immunosorbent assay and peptidomic evidence suggest that all milk antiproteases as well as lactoferrin and immunoglobulin A are partially digested in the preterm stomach. Conclusions: Most human milk proteases are active in milk but not at preterm infant gastric pH. Only cathepsin D and plasmin have potential to continue degrading milk proteins within the preterm infant stomach.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 318-324 |
| Number of pages | 7 |
| Journal | Journal of Pediatric Gastroenterology and Nutrition |
| Volume | 66 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 1 2018 |
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Keywords
- fluorometric assays
- peptidomics
- preterm milk
- spectrophotometric assay
- α-antitrypsin
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health
- Gastroenterology
Cite this
Changes in Proteases, Antiproteases, and Bioactive Proteins From Mother's Breast Milk to the Premature Infant Stomach. / Demers-Mathieu, Veronique; Nielsen, Søren Drud; Underwood, Mark; Borghese, Robyn; Dallas, David C.
In: Journal of Pediatric Gastroenterology and Nutrition, Vol. 66, No. 2, 01.02.2018, p. 318-324.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Changes in Proteases, Antiproteases, and Bioactive Proteins From Mother's Breast Milk to the Premature Infant Stomach
AU - Demers-Mathieu, Veronique
AU - Nielsen, Søren Drud
AU - Underwood, Mark
AU - Borghese, Robyn
AU - Dallas, David C.
PY - 2018/2/1
Y1 - 2018/2/1
N2 - Objective: Our previous studies suggested that human milk proteases begin to hydrolyze proteins in the mammary gland and continue within the term infant' stomach. No research has measured milk protease and pepsin activity in the gastric aspirates of preterm infants after human milk feeding. This study investigated how the concentrations of human milk proteases and protease inhibitors changed in the premature infant stomach. Methods: Human milk and infant gastric samples were collected from 18 preterm-delivering mother-infant pairs (24-32 week gestational age). Paired human milk and gastric samples were collected across postnatal age (2-47 days). Protease concentrations were determined by spectrophotometric or fluorometric assays, and the concentrations of protease inhibitors and bioactive proteins were determined by enzyme-linked immunosorbent assay. Paired t tests were applied to compare enzymes, antiproteases, and bioactive proteins between human milk and gastric samples. Results: Our study reveals that although human milk proteases, including carboxypeptidase B2, kallikrein, plasmin, cathepsin D, elastase, thrombin, and cytosol aminopeptidase, are present in the preterm infant stomach, only plasmin and cathepsin D can actively hydrolyze proteins at gastric pH. Enzyme-linked immunosorbent assay and peptidomic evidence suggest that all milk antiproteases as well as lactoferrin and immunoglobulin A are partially digested in the preterm stomach. Conclusions: Most human milk proteases are active in milk but not at preterm infant gastric pH. Only cathepsin D and plasmin have potential to continue degrading milk proteins within the preterm infant stomach.
AB - Objective: Our previous studies suggested that human milk proteases begin to hydrolyze proteins in the mammary gland and continue within the term infant' stomach. No research has measured milk protease and pepsin activity in the gastric aspirates of preterm infants after human milk feeding. This study investigated how the concentrations of human milk proteases and protease inhibitors changed in the premature infant stomach. Methods: Human milk and infant gastric samples were collected from 18 preterm-delivering mother-infant pairs (24-32 week gestational age). Paired human milk and gastric samples were collected across postnatal age (2-47 days). Protease concentrations were determined by spectrophotometric or fluorometric assays, and the concentrations of protease inhibitors and bioactive proteins were determined by enzyme-linked immunosorbent assay. Paired t tests were applied to compare enzymes, antiproteases, and bioactive proteins between human milk and gastric samples. Results: Our study reveals that although human milk proteases, including carboxypeptidase B2, kallikrein, plasmin, cathepsin D, elastase, thrombin, and cytosol aminopeptidase, are present in the preterm infant stomach, only plasmin and cathepsin D can actively hydrolyze proteins at gastric pH. Enzyme-linked immunosorbent assay and peptidomic evidence suggest that all milk antiproteases as well as lactoferrin and immunoglobulin A are partially digested in the preterm stomach. Conclusions: Most human milk proteases are active in milk but not at preterm infant gastric pH. Only cathepsin D and plasmin have potential to continue degrading milk proteins within the preterm infant stomach.
KW - fluorometric assays
KW - peptidomics
KW - preterm milk
KW - spectrophotometric assay
KW - α-antitrypsin
UR - http://www.scopus.com/inward/record.url?scp=85041566406&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85041566406&partnerID=8YFLogxK
U2 - 10.1097/MPG.0000000000001719
DO - 10.1097/MPG.0000000000001719
M3 - Article
C2 - 28906320
AN - SCOPUS:85041566406
VL - 66
SP - 318
EP - 324
JO - Journal of Pediatric Gastroenterology and Nutrition
JF - Journal of Pediatric Gastroenterology and Nutrition
SN - 0277-2116
IS - 2
ER -