This large study looked back at the computerised records of over a million British children for a minimum of two years to see who was given antibiotics and who then developed IBD. In total 748 children went on to develop IBD. Using this figure as a baseline, comparisons could be made to establish the risk of developing IBD if certain possibilities were considered. Of these, children not exposed to the group of antibiotics studied had roughly 4/5 of the standard risk (lower) than the total population, but those given antibiotics were roughly 1 1/2 times as likely to develop IBD (higher). The risk appeared to be highest when antibiotics were given to younger children, with an estimated risk in those given antibiotics under 1 year of age being roughly 5 1/2 times higher than the baseline risk. This risk decreased with increasing age. Risk also increased with additional courses of antibiotics with each course being associated with an increase in risk of about 6%.
This study raises many questions about the role of antibiotics on normal bacterial colonisation in childhood and on the development of IBD. It also adds to the considerable genetic studies of the last decade in pointing towards bacteria as critically important in IBD development. Studies such as this one are often difficult to interpret as “association is not the same as causation”; meaning that linking two things together statistically does not mean one caused the other. It may be for instance that children who go on to develop IBD are more prone to infections requiring antibiotics in early childhood. Look-back studies such as this give useful clues, but studies which attempt to answer scientific questions going forward generally give more reliable answers.
Click here for full article