The theory that bacteria hasten our death has been questioned by research suggesting living in a sterile world would not boost life expectancy. It has been thought that the immune system response provoked by even harmless bacteria speeds up the ageing process by using up vital energy, a private TV channel reported.
But a study of fruit flies kept in a bacteria-free environment showed they did not outlive their grubby siblings. The researchers admit their experiment cannot be replicated in higher organisms, which need bacteria for proper digestion and other functions.
But they said the result in flies still may be relevant to human ageing research, In both flies and humans, the number of bacteria living on the organism increases with age.
The innate immune response to bacteria is similar in flies and humans, and it loses strength with age in both species, But the study suggests these factors may have nothing to do with ageing.
The researchers compared normal fruit flies to specimens born from eggs washed in antibiotic, raised in an axenic (bacteria-free) environment, and given disinfected food throughout their lives.