Coconut oil fights tooth decay and could find its way into toothpaste and mouthwash, research suggests.
Scientists found that when the oil was treated with digestive enzymes it became a powerful killer of mouth bugs.
The bacteria it attacked included Streptococcus mutans, an acid-producing microbe that is a major cause of tooth decay.
Researchers were following up earlier work which showed that partially digested milk made S. mutans less likely to stick to tooth enamel.
Further studies will look at how coconut oil interacts with the bacteria at the molecular level, and what other microbe strains and yeasts it may combat.
Tests already suggest that enzyme-treated coconut oil is harmful to the yeast Candida albicans, the cause of thrush.
The findings were presented at the Autumn meeting of the Society for General Microbiology at the University of Warwick.
Lead researcher Dr Damien Brady, from the Athlone Institute of Technology in the Republic of Ireland, said: "Dental caries is a commonly overlooked health problem affecting 60%-90% of children and the majority of adults in industrialised countries.
"Incorporating enzyme-modified coconut oil into dental hygiene products would be an attractive alternative to chemical additives, particularly as it works at relatively low concentrations. Also, with increasing antibiotic resistance, it is important that we turn our attention to new ways to combat microbial infection."
He added: "Our data suggests that products of human digestion show antimicrobial activity. This could have implications for how bacteria colonise the cells lining the digestive tract and for overall gut health."