Synbiotic therapy for patients on long term mechanical ventilation support

INTERVENTION: Patients in the synbiotic group were administrated Lactobacillus casei strain Shirota, Bifidobacterium breve strain Yakult, and galactooligosaccharides as synbiotics for 8 weeks. Patients in control groups were not administered any of these synbiotics. CONDITION: patients on long term mechanical ventilation support PRIMARY OUTCOME: amount of the colonization of Pseudomonas aeruginosa, changese of fecal organic acids and gut flora. INCLUSION CRITERIA: The present study included patients who received mechanical ventilation support and administration of enteral tube feeding for more than one month