Scientists in the United States discovered the resistant superbugs in pills designed to populate the human gut with "healthy" bacteria. The superbugs proved to be resistant to the antibiotic vancomycin, which doctors hold in reserve to treat people who do not respond to conventional antibiotics.
Research commissioned by the The Independent has also found the same species of bacteria in health-food pills on sale in Britain. The packets do not state that the contents contain potentially harmful bacteria.
The findings have worried leading medical researchers because vancomycin is the "antibiotic of last resort". The presence of resistant superbugs in pills meant for human consumption can only increase the risk of spreading vancomycin resistance in the general population, causing a rise in untreatable diseases.
The discovery that some health-food pills on sale in Britain contain Enterococcus faecium - which can cause death from blood poisoning - has alarmed medical experts even though these particular samples were not vancomycin resistant.
Jeremy Hamilton-Miller, professor of microbiology at the Royal Free Hospital in London, said: "I don't see any reason for having these organisms in such pills. What you are doing is exposing the population to a very large number of Enterococcus faecium, which is a potentially nasty organism.''
This microbe has already caused serious outbreaks of infections in hospitals. If it becomes vancomycin resistant "you can't treat this microorganism with any currently available antibiotics. If a patient gets infected with it, there's nothing you can do'', he said.
Joseph John, professor of medicine at the University of Medicine and Dentistry in New Jersey, discovered vancomycin resistance in two health-food products sold in the US that are designed to populate the human gut with healthy bacteria.
Following the findings, which will be published in the new year, Professor John has asked the US Food and Drug Administration to investigate the sale of health food pills containing potentially dangerous superbugs.
The bacteria in the pills are supposed to colonise the human gut. Although there is usually a relatively small number of E. faecium in the gut of a healthy person, Professor John said he is concerned about it being sold in health-food supplements becauseit can cause serious infection if it enters the bloodstream.
Both professors have written to suppliers requesting samples of different batches for further testing. Professor John said the companies he has contacted have so far declined to co-operate. He refused to name them until further tests are done.
In Britain, Professor Hamilton-Miller tested 10 brands of bacterial pills at the The Independent's request. He found Enterococcus faecium in three pills where it was stated on the packet to contain the bacterium, and four others that claimed only to contain a harmless bacterium called Lactobacillus acidophilus.
The four brands found unwittingly to contain Enterococcus faecium were supplied by Lifeplan Products, of Lutterworth in Leicestershire, Blackmores of Colnbrook, Buckinghamshire, the Health and Diet Company in Manchester and Klaire Laboratories in San Marcos, California. None of the pills were made in the UK.
The three suppliers who had knowingly supplied the bacterium were Nature's Own of West Malvern, Hereford and Worcester, Quest Vitamins in Birmingham and Boehringer Ingelheim.Reuse content