The effect of different luminal glutamine concentrations during the cold preservation of the rat small intestines

Background: This study reports the development of a long-term short bowel syndrome (SBS) model using the Microminipig (MMP), the smallest experimental pig in the world, with an adult weight of 30 kg.Unlike previous porcine SBS models, which required intensive nutritional support and had limited survival periods, this model demonstrated extended survival without the need for postoperative parenteral nutrition (PN).Methods: Animals: MMPs (6 months old, body weight: 5 kg). Surgical Procedure: Approximately two-thirds of the ileum was resected 2 cm proximal to the ileocecum, followed by endto-end anastomosis between the jejunal and ileal stumps. Assessment: General condition, body weight, blood biochemistry, and fecal fat were evaluated preoperatively, at 2 and 4 weeks postoperatively, and monthly thereafter.Untreated MMPs served as controls.Results: In Model 1 and Model 2, 67% and 75% of the small intestine were resected, respectively. Both models maintained stable general health.Weight gain was observed for two months postoperatively but plateaued thereafter. Model 2 exhibited transient loose stools at one week postoperatively, which subsequently resolved. Hemoglobin levels were elevated in both models but remained comparable to those of the controls. Fecal fat levels showed no significant differences between SBS models and controls. Conclusions:The MMP SBS model demonstrated prolonged survival, remaining healthy for over four months without PN-significantly longer than previous porcine models.Future research will refine this model for applications in transplantation studies involving large intestinal segments induced to undergo small intestinal differentiation via organoid engraftment, as well as pharmacological interventions aimed at promoting small intestine regeneration.