The goal of this clinical trial is to learn whether enteral nutrition enriched with fiber can influence gut microbiota and improve resistance to colonization with multidrug-resistant bacteria in critically ill patients. The study will also evaluate the safety and clinical outcomes associated with fiber-enriched enteral nutrition.

The main questions it aims to answer are:

• Does fiber-enriched enteral nutrition reduce the acquisition of colonization with multidrug-resistant bacteria during intensive care unit (ICU) hospitalization?
• Does fiber-enriched enteral nutrition modify the composition and diversity of the intestinal microbiota?
• Are there differences in clinical outcomes, including adverse events, between patients receiving fiber-enriched and non-fiber enteral nutrition?

Researchers will compare patients receiving fiber-enriched enteral nutrition with patients receiving standard enteral nutrition without added fiber to determine whether fiber supplementation influences gut microbiota and colonization resistance.

Participants will:

• Receive enteral nutrition through a feeding tube according to their clinical needs.
• Receive either a fiber-enriched enteral nutrition formula or a standard enteral nutrition formula.
• Have stool samples collected during ICU hospitalization for analysis of intestinal microbiota and detection of multidrug-resistant bacteria.
• Be monitored for clinical outcomes, infections, antibiotic exposure, and adverse events during their ICU stay and follow-up period.