Evaluation of the Variation of the Intestinal Microbiota and the Integrity of the Intestinal Barrier in Patients With M.D.R. Germ-induced Pneumonia Undergoing Enteral Nutrition

The M.D.R. it is defined as multiple resistance to antibiotics and its prevalence in intensive care units (ICU) is continuously increasing throughout the world, with great variability between continents, but also between the microorganisms themselves involved. It is estimated that global mortality attributable to antibiotic resistance is approximately 1.3 million deaths/year.

The study in question is a prospective observational study in which the effect of enteral nutrition in patients suffering from MDR on the intestinal microbiota will be evaluated. This study will enroll patients who will be hospitalized at the Resuscitation Center in the U.O.C. of Anesthesia and Resuscitation and Intensive Care of our institution, after having been admitted to other hospitals following a traumatic event which required mechanical ventilation.

Following tracheostomy, patients developed an infection detected by tracheobronchial aspirate The infection was subsequently treated with high doses of various antibiotics which led to the onset of pneumonia caused by M.D.R. germs.

Once the overall clinical picture has stabilized, i.e. the specialist needs have ceased, patients come to the U.O.C. of Anesthesia and Intensive Care Unit with a clinical picture compromised by the use of antibiotics, which caused a modification of the intestinal bacterial flora and microbiota. In fact, these patients present soft or liquid stools, as well as persistent diarrhea. Therefore they are hospitalized to proceed with nutritional rehabilitation using Enteral Nutrition, as they are very often dysphagic and therefore unable to feed themselves independently, and consequently "wash out" of antibiotics from the moment of transfer.

As per normal clinical practice, enteral nutrition is started for these patients to avoid the risk of malnutrition. For the purpose of standardizing the study, three different commercial formulations of enteral nutrition are used depending on the presence or absence of concomitant pathologies:

• Jevity Plus from the Abbot company for patients who do not have prevalent pathologies;
• Oxepa from the Abbot company for patients presenting with acute pneumonia;
• Novasource Gi Balance from the Nestlé company for diabetic patients in whom glycemic control is necessary due to diabetes mellitus.

Treatment with enteral nutrition lasts 10 days, at the end of which patients are discharged or, alternatively, leave the study.

For this study, the investigators will collect stool, urine, and serum samples for analysis of the fecal microbiota and metabolome and assessment of intestinal barrier integrity.

After signing the informed consent by the patient or by a close relative/legal representative (in the hypothesis that the patient is incapable of signing the consent), the investigator will proceed with the collection of the samples.

The samples will be collected at V0 upon admission, i.e. before starting artificial enteral nutrition, and at V1, i.e. after 10 days of enteral nutritional administration.