Honey and water might be a useful weapon against urine infections in hospital patients, say UK researchers.
Patients often have a catheter fitted, either to drain urine stuck in the bladder or to monitor urine output.
But these flexible tubes can harbour nasty bugs and cause infection.
Scientists at University of Southampton have shown in the lab that diluted honey stops some common bacteria from forming sticky, hard-to-remove layers on surfaces such as plastic.
In theory, a honey solution might be useful for flushing urinary catheters to keep them clean while they remain in the bladder.
Many more trials would be needed to check it would be safe to use in humans, however.
Honey has been used for centuries as a natural antiseptic. People have used it to treat burns and wounds and many companies now sell a range of "medical grade" honey products that comply with regulatory standards.
The laboratory work, published in the Journal of Clinical Pathology, looked at two common bacteria that can cause urine and bladder infections - E. coli and Proteus mirabilis.
Even at low dilution - about 3.3% - the honey solution appeared to stop the bacteria from clustering together and creating layers of known biofilm.
Dr Bashir Lwaleed's team used Manuka honey (made by bees that feed on the nectar of the manuka tree) in their study because this dark-coloured honey from Australia and New Zealand is known to have bacterial-fighting properties.
They say other types of honey might work too, but they have not tested this.
Dr Lwaleed said: "Nobody knows exactly how or why honey works as an antibacterial. And we don't know how well honey would be tolerated in the bladder. We are the first to propose this."
Prof Dame Nicky Cullum is an expert in wound care and has looked at the evidence around honey as a treatment.
She said: "This work from Southampton is at a very early stage so we shouldn't get too excited. But it is an interesting avenue that is worth pursuing.
"Obviously, we'd need more studies to check that it wouldn't irritate the bladder or cause any other problems.
"People like things that are natural but they are not always more effective."