Oral insulin-like growth factor-I (IGF-I) enhances the effect of limited enteral feeding on intestinal development of piglets on total parenteral nutrition (TPN)

Premature delivery results in immature intestinal function and the necessity for TPN in 81% of low birth weight (LBW) infants. However, TPN causes mucosal atrophy, which further compromises the intestine. During the transition to enteral support, LBW infants on TPN are often provided limited enteral stimulation. Herein, IGF-I supplementation of enteral formula was assessed. Newborn piglets (n=27) were assigned to five groups based on route of nutrition support: 100% kcals as enteral formula, 100% TPN, or 80% TPN/20% enteral formula containing 0, 200 or 1000 Hg/kg BW IGF-I for 7 d. Diets were nutritionally adequate and isocaloric. Wt gain, serum IGF-I and cortisol concentrations were comparable in all groups. Both jejunal wt and mucosal mass were reduced 50% in piglets receiving TPN alone compared to piglets on full enteral support. Provision of 20% of kcals enterally increased jejunal wt and mucosal mass 30% to 50% over TPN alone. In addition, oral IGF-I at 1000 μg IGF-I/kg may enhance absorptive capacity by increasing jejunal villus surface area and potently stimulating total mucosal disaccharidase activity. In summary, oral IGF-I combined with limited enteral feeding promotes intestinal growth and enzyme activity during the transition from TPN to full enteral support in the neonate. 100% TPN 80/20 80/20+200 80/20+1000 100% Enteral Jejunal Wt (g/kg) 2.5±c.05 ^c 3.0±.2 ^bc 3.1±.5 ^b 3.6±.5 ^b 4.9±.5 ^a Surface Area (mm ²) .04±.005 ^c .05±.01 ^bc .05±.001 ^bc .07±.008 ^b .09±.02 ^a Jejunal Lactase 205±150 ^d 475±130 ^c 508±112 ^c 1087±40 ^a 800±142 ^b Jejunal Sucrase 28±20 ^c 75±38 ^bc 60±19 ^bc 272±30 ^a 111±57 ^b.