Infants born prematurely are a vulnerable population with diverse nutritional needs to
battle their increased risk of gastrointestinal (GI) diseases. Human milk is considered the
'gold standard' of infant nutrition. Human milk not only provides nutrition for newborn
growth, but contains bioactive components which contribute to GI maturation, immune
protection and neurological development. Among these bioactive components are
extracellular vesicles known as exosomes. Exosomes are double-lipid membrane vesicles
containing mRNA, microRNA and proteins, secreted by cells as a form of cell-to-cell
communication. Human milk exosomes contain immune-related microRNA and proteins
that withstand in vitro simulated human digestion, suggesting that signals are being
delivered to the cells residing in the GI tract of a newborn. In premature birth, disruption
of GI tract maturation predisposes the infant to increased susceptibility of GI
inflammatory diseases. To prevent inflammation, immune tolerance in the GI tract of
premature infants should be promoted and I hypothesized that exosomes differ between
preterm and term milk, and may contribute to the anti-inflammatory effects of human
milk. Human milk exosomes from mothers who gave birth to term or preterm infants
were characterized based on size, surface protein markers and total protein. Preterm milk
exosomes contained a more diverse protein profile. The effects of milk exosomes on
intestinal epithelial cells were observed in an in vitro model using Caco-2/15 cells. Milk
exosomes were able to attenuate the inflammatory response induced by heat-killed
bacteria as measured by the transcription of pro-inflammatory cytokines.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/39006 |
| Date | 29 March 2019 |
| Creators | Kraft, Jamie |
| Contributors | Altosaar, Illimar, Ioshikhes, Ilya |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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