The present invention concerns medicaments for slowing ageing. The medicaments can include an inhibitor of microbial folate biosynthesis as well as agents capable of reducing folate uptake by an animal. Examples of such medicaments include inhibitors that reduce the activity of an enzyme in the folate biosynthesis pathway, such as sulfonamides including sulfamethoxazole. The invention also concerns a food supplement, additive, functional food, or nutraceutial comprising the inhibitor or agent or composition as discussed above, as well as methods for screening for an agent for use as a medicament for slowing ageing comprising determining whether a test agent inhibits microbial folate biosynthesis, or whether the test agent reduces folate uptake by a non-human animal.
