Bacteria and yeasts to prevent food poisoning

Researchers at the Institute of Food Research in England are harnessing the powers of friendly bacteria and yeasts to help defend us against food poisoning, and fungal and yeast infections.

In their experiments, harmless bacteria that live in chicken intestines are being used to compete with, and eliminate, salmonella and strains of E.coli that cause food poisoning from chickens, so they cannot be passed on to humans in our food.

Substances produced by yeasts that kill other yeasts and fungi are being developed by the same team at the Institute of Food Research for use as new treatments for fungal and yeast infections of humans. Novel treatments for such conditions are badly needed, especially for people whose immune systems are weakened as a consequence of Aids or other reasons, for whom normally minor fungal and yeast infections may become serious and even life-threatening.

The team led by Professor Mike Gasson is working on so-called lactic acid bacteria that live naturally in the gastro-intestinal tracts of chickens. In in-vitro (laboratory culture) experiments the IFR scientists have shown that such lactobacilli will successfully compete with, and exclude, more than 80% of pathogenic bacteria with which the lactic acid bacilli are competing for resources.

A third way in which the IFR team is enhancing the ability of lactic acid bacteria to eliminate pathogenic bacteria from the gastro-intestinal tracts of chickens is to use them as vectors for orally delivered vaccines designed to stimulate specific immunity against one or more pathogenic bacteria. Vaccines made in this way stimulate immunity against micro-organisms that invade the host via the mucosa of the gut and other areas lined with mucus, including the reproductive tract.