Investors have been snubbing the microbiome. That may be changingThe field needed to find some basic tools before it had a chance of developing a drug successfully, she said, like better biomarkers to determine how and where a drug was working. For example, in one paper, Synlogic scientists showed that their drug was working by tracking an isotope markers through the bacteria’s metabolic pathway and by measuring levels of a chemical produced by their bacterial “drug,” SYNB1618. “One of the challenges that microbiome companies face is that you can tell what goes in the top end, you can tell what comes out the bottom end, but you can’t tell what happens in the middle,” Brennan said during a presentation earlier this month. “There’s a lot of groundwork that’s required. Papers don’t make good drugs,” she said in an interview afterward.