They are better known for their associations with yoghurt, but probiotic bacteria are now being used in a new range of household cleaning products.

The Aggie's Probiotic range fronted by How Clean Is Your House? presenter Aggie MacKenzie uses friendly bacteria rather than standard antibacterial ingredients to compete with harmful ­bacteria.

The effects of the live bacteria in Aggie's Probiotics, which claim to help prevent E.coli and MRSA, last up to eight days. Independent tests carried out by Geneius Labs showed the cleaners were four times more effective than antibacterial cleaners at inhibiting harmful bacteria after two hours and 13,200 times more effective after 24 hours.

The range, to be rolled out to Tesco Extra stores, consists of a multi-surface cleaner, washing-up liquid, toilet cleaner and bathroom cleaner (rsp: £1.49-£2.99). "Antibacterial cleaners kill all bacteria good as well as bad which allows bad bacteria to jump back in for up to 24 hours," explained MacKenzie, who is the face of the brand and helped develop the probiotic formula with manufacturer Cleveland Biotech. "Bacteria develop resistance to things designed to kill them, such as antibiotics. That's how we've ended up with MRSA. Good bacteria provide us with better natural defences."

People living with more good bacteria were less prone to respiratory conditions such as asthma, she added, quoting microbiologist research.

Cleveland Biotech was now looking to run clinical trials to test the cleaners for use in hospitals, added MD Ben Hoskyns.