Objective To investigate the effects of permissive hypocaloric enteral nutrition on gastrointestinal function and clinical outcome in severe acute pancreatitis (SAP).

Methods The enteral nutrition and other data from 114 SAP patients were collected, all of them received nasojejunal nutrition tube implantation upon admission. According to the numerical method, patients were randomly divided into group A (reaching 50% of the target energy, 38 cases), group B (reaching 60% of the target energy, 36 cases), and group C (reaching 70% of the target energy, 40 cases). General clinical data such as age, body mass index (BMI), gender, and etiology of patients upon admission were collected. The acute physiological function and chronic health evaluation Ⅱ (APACHE Ⅱ), CT severity index (CTSI) scores, nutritional indicators (peripheral blood albumin, prealbumin), inflammatory status indicators (TNF-α and IL-6), and biological markers of intestinal mucosal barrier function diamine oxidase (DAO), D-lactate, and intestinal fatty acid binding protein (I-FABP) levels on the first, third, and seventh days after feeding were recorded.The patient's feeding intolerance within 7 days and the patient's survival status 28 days after admission was analyzed.

Results On the seventh day of feeding, there was a statistically significant difference in albumin and prealbumin levels among the three groups (P < 0.01), with both group B and group C being higher than group A (P < 0.05). On the seventh day of feeding, the levels of albumin and prealbumin in all three groups were higher than those on the first and third days (P < 0.05 to P < 0.01). On the seventh day of feeding, the levels of TNF-α and IL-6 in group B were lower than those in group A (P < 0.05). Compared with the first day of feeding, the levels of TNF-α and IL-6 in the three groups decreased on the seventh day of feeding (P < 0.01). Compared with the first day of feeding, APACHE Ⅱ and CTSI scores decreased in all three groups on the seventh day of feeding (P < 0.01). On the seventh day of feeding, there was a statistically significant difference in DAO, D-LA, and I-FABP levels among the three groups (P < 0.01), with group B having lower levels of DAO, D-LA, and I-FABP than group A (P < 0.05). Except for group A patients with I-FABP, there were statistically significant differences in intestinal barrier biomarkers among the three groups of patients on the first, third, and seventh days of feeding (P < 0.01). Compared with the first day of feeding, DAO, D-LA, and I-FABP all decreased on the seventh day of feeding (P < 0.01). The incidence of diarrhea in group C was higher than that in group A and group B (P < 0.05).

Conclusions For SAP patients, 60% target hypocaloric enteral nutrition is more suitable for improving feeding intolerance, intestinal mucosal barrier, nutritional and inflammatory status.