Probiotics to Actively Counter Ventilator Associated Pneumonia (PROACT)

Inclusion Criteria: * adults aged 18-80 years * at least one of the following conditions: a) recent trauma involving head injury and at least one more organ system; b) stroke or brain hemorrhage without any sign of aspiration and lung infection * intubation and start of mechanical ventilation. This needs to start immediately after the event described in the inclusion criteria (b). For cases of head trauma this is defined as start in the ambulance or the emergency department * likelihood that the duration of mechanical ventilation would be at least six days * written informed consent provided by the patient or legal representative Exclusion Criteria: * has received mechanical ventilation more than 72 hours from start of screening * pregnancy or Lactation * patients at risk of iatrogenic probiotic infection e.g. immunosuppression which includes * HIV \<200 CD4 cells/μL * those receiving chronic immunosuppressive medications (e.g., azathioprine, cyclosporine, cyclophosphamide, tacrolimus, methotrexate, mycofenolate, Anti-IL2) * previous transplantation at any time * malignancy requiring chemotherapy in the last 3 months * neutropenia \[absolute neutrophil count \< 500\]) * patients with a primary diagnosis of severe pancreatitis (Ranson score of 3 or more). Mild and moderate pancreatis is not excluded * ischemic bowel disease * oropharyngeal mucosal injury * inability to receive enteral medications * intent to withdraw advanced life support as per ICU doctor in charge * patients at risk of endovascular infection which includes 1. previously documented rheumatic heart disease, congenital valve disease, surgically repaired congenital heart disease, unrepaired cyanotic congenital heart disease, any intracardiac repair with prosthetic material \[mechanical or bioprosthetic cardiac valves\] 2. previous or current endocarditis 3. permanent endovascular devices (e.g., endovascular grafts \[e.g., aortic aneurysm repair, stents involving large arteries such as aorta, femorals and carotids\] inferior vena cava filters, dialysis vascular grafts 4. tunnelled (not short-term) hemodialysis catheters 5. pacemakers or defibrillators Patients with peripherally inserted central catheters (PICCs), temporary central venous catheters, central venous dialysis catheters, coronary artery stents, coronary artery bypass grafts (CABG), or neurovascular coils are not excluded, nor are patients with mitral valve prolapse or bicuspid aortic valve if they do not meet any other exclusion criteria. * patients with sepsis and/or septic shock