We aim to investigate the effects of early life events on neonatal intestinal, microbial, and immune development. Our first aim was to investigate the effect of route of delivery on microbial development and intestinal structure and function. Neonatal piglets were delivered either vaginally (VD) or by cesarean (CD) sow-reared for 21 days and then moved to cages and fed a weaning diet until d28. Samples were collected at d3, d14, d21 and d28 to examine effects of time. Mode of delivery did not affect digestive enzyme activity. Lactase and sucrase enzyme activities were measured. Lactase activity was variable over time (P<0.05), and sucrase activity increased over time (p<0.05). Both of these results were not unusual and reflect normal development in the piglet. Intestinal permeability was measured using the Ussing chamber. Route of delivery affect some of these parameters. CD piglets had greater glucose and glutamine transport at d14 compared to VD piglets. VD piglets also had increased jejunal basal Isc compared to CD piglets at all time points. In both the ileum and duodenum, 28-d-old piglets showed significant electrophysiological changes when compared to other time points, which s may be related to weaning. Resistance was increased at d28 in the duodenum compared to all other days, signaling that tight junction permeability was decreased. Intestinal histomorphology, villus height and crypt depth were evaluated and both day and mode of delivery had an effect, with VD piglets having longer villi than CD piglets and villi being longer at d14 than any other time point. Although, there were no significant differences in weight gain over time between the two groups, a slight separation in growth started to occur at d14 with the CD piglets slowing their rate of weight gain compared to VD piglets. These two results, in addition to the increased glucose and glutamine transport at d14, may be connected.
The second aim of this dissertation focused on the effect of route of delivery and diet on intestinal function and immunity. Piglets were born either vaginally or through cesarean section and were fed one of three diets: formula, formula+prebiotic, or sow milk. The prebiotics chosen were polydextrose and scFOS (2g/L of each). The study duration was 14 days with a collection time point at d7 and d14. Dissacharidase and peptidase enzymes were examined in jejunal and ileal tissues. In the jejunum, neither day nor diet had an effect on lactase activity, but day had an effect on sucrase activity with d14 piglets having higher sucrase activity than d7. In the ileum, both day (p<0.0001) and diet (p<0.0001) had an effect on lactase activity with formula fed (FF) piglets having highest lactase activity followed by formula+prebiotic (FP) piglets, and then sow reared (SR). Lactase activity was also higher at d14 than d7. Ileal sucrase activity was also impacted by both day (p<0.0001) and diet (p<0.0001) with FF piglets having higher sucrase activity than both FP and SR piglets and activity was higher at d14 compared to d7. Aminopeptidase N (APN) was measured in both jejunum and ileum, and Dipeptidylpeptidase IV (DPPIV) was measured in jejunum and ileum, as well as serum. In the jejunum, both day (p=0.0023) and diet (p=0.0003) were significant, with d7 piglets having higher APN activity than d14. Both FF and FP piglets had higher APN activity compared to SR. In ileum, APN also had both day (p=0.047) and diet (p<0.0001) effects with FF piglets having significantly higher activity than FP and SR. Jejunal DPPIV showed effects of diet (p<0.0001) with FF piglets having higher activity than FP and SR. In ileum, both diet (p<0.0001) and day (p=0.0182) had effects with FF piglets having higher activity than FP and SR. There were no significant effects in blood.
The final aim of this dissertation focused on the effects of combined feeding and prebiotics on immune response and the colonic transcriptome. We developed a novel piglet model to investigate these effects. Newborn piglets were randomized into 5 groups: sow-reared (SR), formula fed (FF), formula+prebiotic (FP), combined fed (CF), and combined fed +prebiotic (CP) (n=6 per group). SR remained with the sow 24h/day and FF/FP were fed a sow milk replacer with or without prebiotics (GOS and Inulin; 2g/L each). CF/CP piglets were sow-reared for 5d and were then rotated between the sow and respective formula feeding group every 12h. On d21, piglets were intraperitoneally injected with 10ug/kg body weight of LPS. Four hours after infection, blood, mesenteric lymph node (MLN), spleen (SPL), and AC were collected and analysis performed.
(Abstract shortened by UMI.)
|Commitee:||Donovan, Sharon M., Johnson, Rodney, Miller, Michael|
|School:||University of Illinois at Urbana-Champaign|
|School Location:||United States -- Illinois|
|Source:||DAI-B 75/01(E), Dissertation Abstracts International|
|Subjects:||Nutrition, Developmental biology|
|Keywords:||Breast feeding, Infant formula, Intestinal development, Macrophage, Neonatal piglets, Prebiotics|
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