A Digestive Cartridge Reduces Parenteral Nutrition Dependence and Increases Bowel Growth in a Piglet Short Bowel Model

Abstract

Objective: To determine whether the use of an immobilized lipase cartridge (ILC) to hydrolyze fats in enteral nutrition (EN) reduces parenteral nutrition (PN) dependence in a porcine model of short bowel syndrome with intestinal failure (SBS-IF).

Background: SBS-IF occurs after intestinal loss resulting in malabsorption and PN dependence. Limited therapeutic options are available for achieving enteral autonomy.

Methods: Eleven Yorkshire piglets underwent 75% jejunoileal resection and were randomized into control (n=6) and treatment (n = 5) groups. PN was initiated postoperatively and reduced as EN advanced if predefined clinical criteria were fulfilled. Animals were studied for 14 days and changes in PN/EN calories were assessed. Intestinal adaptation, absorption, and nutrition were evaluated at the end of the study (day 15). Comparisons between groups were performed using analysis of covariance adjusted for baseline.

Results: ILC animals demonstrated a 19% greater reduction in PN calories ( P < 0.0001) and higher mean EN advancement (66% vs 47% of total calories, P < 0.0001) during the 14-day experiment. Treatment animals had increased intestinal length (19.5 vs 0.7%, P =0.03) and 1.9-fold higher crypt cell proliferation ( P =0.02) compared with controls. By day 15, ILC treatment resulted in higher plasma concentrations of glucagon-like peptide-2 ( P = 0.02), eicosapentaenoic acid ( P < 0.0001), docosahexaenoic acid ( P = 0.004), vitamin A ( P = 0.02), low-density lipoprotein ( P = 0.02), and high-density lipoprotein ( P = 0.04). There were no differences in liver enzymes or total bilirubin between the two groups.

Conclusions: ILC use in conjunction with enteral feeding reduced PN dependence, improved nutrient absorption, and increased bowel growth in a porcine SBS-IF model. These results support a potential role for the ILC in clinical SBS-IF.

FIGURE 1

Delivery of PN and EN over the study period. Piglets that received EN with the ILC (treatment) had a 19% greater reduction in PN calories compared with controls at day 15. (A). Treatment animals also demonstrated higher average EN advancement (B) over the study period. Comparison of the experimental groups at day 15 was done using ANCOVA adjusted for baseline (study day 1) whereas analysis of the 2 groups over the study period was done using time-weighted AUC and Student t test for 2-group comparisons. Data are jittered left and right to prevent overlap. Results are expressed as mean ± SE. Δ indicates difference; ANCOVA, analysis of covariance.

FIGURE 2

Plasma fatty acid analysis. Plasma fatty acids were analyzed and quantified to compare fat absorption between the two groups. At day 15, treatment animals demonstrated significantly higher plasma concentrations of DHA (A), EPA (B), and total omega-3 fatty acids (C). There were no significant differences in the plasma concentrations of arachidonic (D), linoleic (E), or total omega-6 fatty acids (F). The fat component of the PN used in this study contained linoleic acid but did not have any (DHA), or arachidonic acid. DHA and EPA represented 4.8% and 2.0%, respectively, of all fatty acids in the EN used in this study. Arachidonic acid only represented 0.19% of the fatty acids in the EN. Comparison of the experimental groups at day 15 was done using ANCOVA adjusted for baseline values (study day 1). Results are expressed as mean ± SE. ANCOVA indicates analysis of covariance; DHA, docosahexaenoic acid; EPA, eicosapentaenoic acid.

FIGURE 3

Plasma nutritional markers. The plasma triglyceride concentration (A) was similar between the two groups across the study period. The plasma concentrations of HDL (B) and LDL (C) were significantly higher in treated animals compared with controls at study day 15. Treatment animals also demonstrated a significant increase in vitamin A (D) concentration at day 15. There were no significant differences in the plasma concentration of the fat-soluble vitamins D and E between the two groups (E and F). Comparison of the experimental groups at day 15 was done using ANCOVA adjusted for baseline values (study day 1). Results are expressed as mean ± SE. ANCOVA indicates analysis of covariance.

FIGURE 4

Intestinal morphometrics and adaptation. At the end of the study, the remnant intestine was measured and cross-sectional samples were collected for morphometric analysis. The average jejunal (A) and ileal (C) villus height were not significantly different between treatment animals compared with controls. There was also no difference in jejunal (B) or ileal (D) crypt depth between the two groups. Treatment animals had a significant increase in intestinal length as demonstrated by the absolute (E) and percentage (F) change in the remnant intestinal length. This was accompanied by a significantly higher plasma concentration of GLP-2 in treatment animals at day 15 (G). Two-group comparisons of intestinal morphometrics and length were done using the Student t test. Comparison of GLP-2 concentration at day 15 was done using ANCOVA adjusted for baseline values (study day 1). Results are expressed as mean ± SE. ANCOVA indicates analysis of covariance.

FIGure 5

Immunohistochemistry to assess proliferation. Representative micrographs at 200x magnification of jejunal tissue (A) costained for the proliferative marker Ki67 (green) and nuclear marker DAPI (blue) demonstrate a higher number of Ki67-positive cells in treated animals compared with controls. On quantification, there were 1.9-fold more Ki67-positive cells per intestinal crypt in the treatment group (B). Two-group comparisons were done using the Student t test. Results are expressed as mean ± SE.

FIGure 6

Intestinal tissue immunoblots. Apoptotic activity was assessed in intestinal tissue by immunostaining for cleaved and total caspase-3 (A). Cleaved caspase-3 was lower in treated animals compared with controls (B), although not reaching statistical significance. The expression of total caspase-3 (C) was significantly lower in treated animals, however, there was no difference in overall apoptotic activity (cleaved/total caspase-3) between the two groups (D). Western blots were performed 2 times for quality control and a representative image is shown. Each lane represents a sample from a different animal. Uncropped blots are provided in Supplemental Information File 1 (Supplemental Digital Content 1, http://links.lww.com/SLA/E475). The β-actin for each membrane is displayed below the corresponding antibodies and was used to normalize the expression patterns. Statistical analysis of protein expression was performed with a Student t test. Results are expressed as mean ± SE. *P < 0.05.