Microbes over time

Lawrence David, at Duke University, tracked two people’s microbes for a year, offering a rare peek into how the makeup of the gut changes over time. Similar experiments have been performed by other people (e.g. Larry Smarr, ) but this is the first time I’ve seen this much detail. Armed with the iPhone app Tap Forms, the two subjects kept track of 300+ variables daily, including diet/exercise/mood, etc.  (Yes, that’s pretty hard-core self-tracking, but they were chosen specifically because they were die-hard QSers).  The whole paper is worth studying, but here are a few highlights:

• Overall microbial gut ecology is pretty stable over time — it takes a lot to change the bugs inside you
• Eating fiber has the biggest, fastest effect on the microbial profile
• What doesn’t change your microbes: sleep, exercise, mood (surprisingly)
• Saliva has little effect on gut bacteria (even though you swallow more than 1 liter of the stuff per day!)

Especially interesting were the two times where there was a noticeable change in the ecology of the microbes.  The first was when the person moved to Southeast Asia for several weeks in the middle of the experiment:


and here's when one of the people got sick:

 A little scary how permanently his gut bacteria were changed because of one sickness.
Very interesting experiment, and I look forward to being able to do the same thing on myself someday.