Enterally delivered dipeptides induce changes in small intestinal (SI) morphology and PepT1 mRNA in a Yucatan miniature piglet model of short bowel syndrome

Abstract

PepT1, a di/tripeptide transporter, is preferentially maintained over free amino acid transporters in situations of gut stress. Our objective was to determine the impact of enterally delivered dipeptide-containing diets on PepT1 transporter abundance and SI adaptation in neonatal piglets with an 80% jejuno-ileal resection. A residual 100 cm of ileum was left intact. Piglets (n = 25, 10 ± 1 d old) were randomized to either: 1) control diet containing free amino acids (C), or the same diet but with equimolar amounts of free amino acids replaced by 2) alanylalanine (AA), 3) alanylgutamine (AG), 4) cysteinylglycine (CG) or 5) both AG and CG (AGCG). All pigs received TPN after surgery followed by continuous gastric infusion of test diets from d 3 to 7 at 50% of total intake (50:50 TPN:EN). Animals were killed on d 7. Residual SI mucosal mass of AG and AGCG pigs was 40% less than in C pigs (p<0.05). The CG pigs had greater villus height compared to either AA or AGCG (p<0.05). Moreover, CG pigs had greater crypt depth and PepT1 expression than AG pigs (p<0.05). Enteral provision of dipeptides impacts intestinal adaptation, but the responses are dipeptide specific. It appears that CG confers beneficial effects on gut adaptation compared to AG, although more research is needed to assess how this affects functional capacity. (Ajinomoto, CIHR). Grant Funding Source: Ajinomoto, CIHR