Giving a cocktail of antibiotics to intensive care patients may cut the number who die, say researchers.
Intensive care patients are vulnerable
Dutch researchers writing the Lancet journal suggest that wiping out gut microbes could prevent life-threatening infections from taking hold.
Their study found that hospital deaths were cut by a quarter after antibiotic treatments were given.
However, there are fears that the technique could foster new strains of dangerous "superbugs".
The practice of "selective decontamination" - as the drug treatment is called - has been around for decades, and still practiced in many hospitals around the world.
However, there is still fierce debate over the benefits of giving the cocktail of drugs to intensive care patients.
People in these units are unusually vulnerable to infection - not only are they physically weakened by their illness or injury, but they often have "wounds" - including intravenous lines for the delivery of fluids or drugs.
The human gut contains a wide variety of bacteria which could, in theory, cause serious infection if they got into these wounds.
The researchers, from the universities of Amsterdam and Utrecht wanted to test the theory that killing the majority of potentially harmful bacteria as soon as the patient arrived in the intensive care unit could reduce the risk of them dying in hospital, or at least reduce the amount of time spent there.
On a random basis, they gave 934 patients either normal treatment or a cocktail of three antibiotics and one anti-fungal drug over a period of four days.
In the "decontamination" group, 69 patients died, compared with 107 in the normally-treated group - 15% as opposed to 23%.
Hospital stays were shorter for the "decontamination" group, as were costs associated with drug treatment - perhaps reflecting that these patients did not need to be treated for so many infections.
However, there are fears that widespread use of antibiotics might be counterproductive - increasing the risk of drug-resistant strains emerging and causing even greater problems for individual patients, and entire intensive care units.
Dr Jonathan Cooke, a member of a Department of Health advisory committee on anti-microbial resistance, said he would be unsure about the merits of the practice becoming widespread in the UK.
In recent years, there has been a drive to cut the amount of antibiotics used in hospitals to restrict the emergence of resistant bacteria.
"This is something that has gone in and out of vogue over the years - and I am not sure about it.
"It might yield a benefit to start with - but ultimately make things worse."
Surprisingly, however, patients in the treated group were less likely to become "colonised" with resistant strains of bacteria such as enterococci and Pseudonomas aeruginosa than those given normal treatment.
The authors of the report say that unless the hospital has particular problems with "superbugs", then the approach could cut death rates in intensive care units.