BBC Health Science — Could the humble worm hold the key to wiping out allergies and a whole lot of disorders of the immune system? Researchers in Nottingham are investigating whether giving hook worms to asthma sufferers can cure their condition. Another group in the US is trying a pig worm on patients with ulcerative colitis or inflammation of the colon and bowel. And scientists in Cambridge have proved that giving an extract of the tropical worm which causes bilharzia to mice can stop them developing type 1 diabetes.

The theory behind all this is that worms and other organisms, through our evolutionary history, developed a role in driving our immune systems. Professor Danny Altman, professor of immunity at Imperial College, said: “There is compelling evidence that something in our immune systems has changed since our ancestors, in fact has changed since our great grandparents. …

The scientists, who have all written articles for the journal, Immunology, said the key compound in question are found in worms, in mud and in the tiny organisms (flora) in our guts. Professor Graham Rook, an expert of medical microbiology at University College London, said: “What we think is that the immune system has become dependent on signals from certain organisms.” He said a fascinating recent study had illustrated this.

Bacteria were introduced to a group of amoebae. The amoebae did not like the bacteria and tried to kill them - but could not. And five years later neither organism could live without the other. The amoebae had deleted certain genes in their own immune systems and the bacteria had done the same so they could coexist peacefully. As a result, the amoebae no longer had a complete genome unless the bacteria were present.

Professor Rook said: “It now looks more and more likely that the development of our regulatory immune system depends on molecules that are encoded not in the genome of the human but in the genome of some other organism we lived with throughout history.” …

Professor Jan Bradley, a parasitologist from the University of Nottingham, said some worms could live in the human body for 15 to 20 years. She said: “The question I’ve been asking is how does a worm modify the host so it can survive that long? If you dissect any free-living organism it has worms. It’s full of them, in its blood, guts, everywhere. It is only in the last 50 years in Britain that humans have been free of worms. If, for instance, you look at the faeces of the Vikings you can find evidence of them having worms.” (01/29/09)
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