Probing probiotics . . . and other storiesBMJ 2020; 370 doi: https://doi.org/10.1136/bmj.m2737 (Published 16 July 2020) Cite this as: BMJ 2020;370:m2737
Because they’re classified as dietary supplements, probiotics escape many of the requirements of safety and efficacy that regulatory agencies insist on for drugs. Guidelines from the American Gastroenterological Association flag up the weakness of the evidence for their use (Gastroenterology doi:10.1053/j.gastro.2020.05.059). With the exceptions of children with acute infectious gastroenteritis, where they recommend against the use of probiotics, and preterm infants with low birth weight, where they recommend probiotics for the prevention of necrotising enterocolitis, the guidelines support the use of probiotics only in the context of a clinical trial.
A misunderstood metric
The reproduction number, R, was originally invented by demographers to help quantify whether a population was growing or shrinking. An article in Nature discusses how R became a dominant metric in the current covid-19 …