A2: Microbes in the News (#2)
Bacteria in probiotics can evolve in your gut and turn nasty, study shows (The Independent)
Summary: This article talks about a study performed at the University of Washington in Missouri where a probiotic evolved to attack the protective coating of the intestine in the mice they tested. Unhealthy mice with low gut microbial diversity were more likely to develop an evolved strain of the E. coli Nissle bacteria that was used in the probiotic they studied. According to the researchers, their findings have implications for the development of safer probiotics in the future.
Connections: This article is very relevant to the human microbiome section that we covered in class. It involves the gut microbiome and the ways it can be more or less healthy, and more or less diverse. I think the way microbes can change and evolve right under our noses is fascinating!
Critical analysis: This was certainly an interesting piece and the writing style flowed well. However, this study is only one of many and might mislead readers to think that all probiotics can “turn bad.’ It could also be confusing to the regular reader, because the wording of the article makes it seem like probiotics are drugs that can change inside your body. Of course we all know that probiotics are made up of living bacterial cells that are supposed to help enhance the diversity of your gut microbiome. It was also unclear whether the E. coli strain always evolved in a negative direction or if it was simply more prone to evolve in an unhealthy gut microbiome (toward good or bad characteristics, we don’t know). Overall, this was a well-written article, but I think the writer conveyed what he wanted the readers to believe and not necessarily the actual truth of the study.
Question: What were the exact parameters of the evolution of E. coli Nissle observed in this study?