In 2018, 11,336 American Gut participants mailed samples from used toilet paper to scientists; the dataset characterized microbial diversity on an unprecedented scale

In an extensive research initiative, scientists collected toilet paper swabs from a diverse group of thousands worldwide, revealing a significant increase in bacterial diversity compared to earlier studies. Notably, participants who incorporated numerous plant varieties into their diets experienced a remarkable boost in gut microbiome diversity. The study also found that antibiotic consumption correlated with more complex chemical profiles within samples.