Long-term antibiotic use might be linked to cognitive decline, according to a new study published in the journal PLOS One. Harvard researchers collected data on over 14,000 women who took antibiotics for at least two months in their fifties for medical issues such as respiratory infections, dental problems, and urinary tract infections. They found that antibiotic use in midlife was significantly associated with poorer scores for global cognition, learning, working memory, and psychomotor speed and attention several years later. These lower cognitive assessments in women who had taken antibiotics were the equivalent of about three or four years of aging. This study doesn’t mean that people should never take antibiotics, especially because the research doesn’t prove that antibiotics caused the cognitive changes. But the link does warrant further research. The scientists propose that if the link proves accurate, the effect of antibiotic use on the gut microbiome altering the gut-brain axis could likely be the explanation.