NPR recently reported on a study where the participants ate either a meat-based, fiber-free ketogenic diet or a vegetarian diet and had their gut microflora analyzed. The low carb diet was much higher in fat, and as such, increased the prevalence of a microbe involved in fat digestion. “Bilophila.” The article focused on this one and cited a 2012 study where Bilophila was associated with intestinal inflammation… however, the ketogenic diet increased the levels of Bacteroides and decreased Firmicutes. These are the two that brought the whole gut microbe-obesity connection into the spotlight. The microbiome in obese mice is characterized by low Bacteriodetes and high Firmicutes. Fecal transplants from obese mice to lean mice causes them to gain weight. Little is known about Bilophila relative to Bacteriodetes & Firmicutes, and I suspect the focus was on Bilophila because the authors wanted something negative to say about a meat-based, fiber-free ketogenic diet, and that 2012 mouse study suggested Bilophila could be their answer.