Join us on a field trip to the gut! We can joke about going with our gut all day, but in the meantime a serious pile of evidence is accumulating in support of the idea that our guts play a larger role in shaping choices and behavior than we might have suspected.
Could your gut bacteria be making decisions for you–even when choosing a mate? It certainly seems that way for flies. In Gut Feeling, student host Sophie Hearn talks with Dr. Sharon Greenblum about fly sex, a multiple choice mating test, poop (you’ve been warned), and why we think the gut-brain connection is real.

And if you think it seems far-fetched that humans could be controlled by single-celled overlords, guess what. It’s a good thing I didn’t release this episode last Friday because on this very day in the news, there is evidence that this may be true for humans, too, by way of body odor.

Anyway, hope you enjoy a brief departure from the brain. Turns out your brain isn’t really 100% in charge, anyway. Back to the brain and its chemicals later this week with some talk about magic mushrooms and death acceptance!
Details & links:
Recorded: June 7, 2017
Released: August 14, 2017
Student Host: Sophie Hearn, a first-year student at Stanford University (soon to be second-year)
Guest: Dr. Sharon Greenblum, a postdoctoral researcher at Stanford, who studies how organisms evolve (and co-evolve). More about some of her work here.
Show & tell: Commensal bacteria play a role in mating preference of Drosophila melanogaster by Gil Sharon, Daniel Segal, John Ringo, Abraham Hefetz, Ilana Zilber-Rosenberg, & Eugene Rosenberg
Thanks to: Stanford Storytelling Project for much guidance (Will Rogers, Jonah Willihnganz, Jake Warga, Jenny March), Thinking Matters for all kinds of support (Tiffany Lieuw, Parna Sengupta, Ellen Woods), the Generation Anthropocene podcast for advice (Michael Osborne and Leslie Chang), and Sarah Houser and Jen Sloan for feedback on early versions of this episode
Further reading: Bacteria are everywhere! For starters, variations in the gut microbiome are associated with schizophrenia, autism, and other disorders like anxiety and depression. Take all of this with a HUGE grain of salt, because even where there’s evidence of a link, it’s difficult to determine if this is at all a causal link, and even where there’s a causal link, that doesn’t mean we can manipulate it. Some other questions you might have: Is this like a personality transplant? More on probiotics and fecal transplants (or are they just hype?). These guys studied their poop for a year. Cohabitating couples’ immune systems and gut bacteria are more similar. Finally: Michael Pollan is a superorganism and so are you.
Fact check: Here’s that study that found travel impacted someone’s microbiome–we’re betting he knew this, though, because of the diarrhea. Anyway this is a minor correction but we said India, it was in fact Southeast Asia, whatever, travel sometimes means a drastic change in diet and this ripples through your community of gut bacteria, is the point.
Theme music: Transmogrify, by Podington Bear