# The effects of high-protein vs conventional protein enteral nutrition on intestinal permeability, severity of disease, and mortality in critically ill intensive care unit Patients: Protocol for a randomized controlled trial

## TL;DR

This study investigates how high-protein enteral nutrition affects intestinal permeability and outcomes in critically ill ICU patients.

## Contribution

The study introduces a novel randomized controlled trial examining the impact of high-protein enteral nutrition on intestinal permeability and zonulin levels in ICU patients.

## Key findings

- The study will measure changes in serum zonulin levels over 10 days of high-protein enteral nutrition.
- Secondary outcomes include SOFA scores and 30- and 60-day mortality rates.
- The trial will compare high-protein and conventional-protein nutrition in ICU patients.

## Abstract

Intestinal permeability is an important determinant in intensive care unit patients. Enteral nutrition is vital for nutritional supplementation in critically ill ICU patients. The amount of Enteral nutrition protein and its impact on intestinal barrier permeability and function are challenging issues. Zonulin is a protein that regulates intestinal epithelial cell tight junction permeability and has the potential to be used as a biomarker for assessing the integrity of the intestinal barrier. However, there are few data from studies on intestinal permeability and the effects of enteral feeding of protein on zonulin levels in critically ill patients. This study was conducted to investigate the effect of high-protein enteral nutrition on intestinal permeability in ICU patients.

Participants were selected from 88 adult patients with critical illness aged 18-65 years who were admitted to the ICU of Hazrat Rasoul Akram Hospital in Tehran. In this randomized controlled clinical trial, patients will be allocated randomly into two groups of 44. The intervention group will receive high-protein (HP) enteral nutrition (1.6 g/kg/day), and the control group will receive conventional-protein (CP) enteral nutrition (1.2 g/kg/day) for 10 days. The primary outcome will be the change in serum Zonulin levels during the intervention period. Zonulin will be measured on days 0, 5, and 10. The SOFA, APACHE II, and mNUTRIC scores will also be assessed. Mortality will be calculated at 30 and 60 days after the intervention. The secondary outcomes will be SOFA score and 30- and 60-day mortality.

Our study aims to present new evidence about the role of protein in enteral nutrition on intestinal permeability in critically ill patients in the ICU.

The clinical trial was registered on December 11, 2024 in the Iranian Registry of Clinical Trials (IRCT) (IRCT20241129063891N1).