A Gut Feeling

The title, Campylobacter jejuni infection increases anxiety-like behavior
in the holeboard: Possible anatomical substrates for viscerosensory
modulation of exploratory behavior, is unpromising but the paper is fascinating.  The authors show that infection with certain bacteria can cause more anxious or cautious like behavior in mice, perhaps causing the infected agent to avoid predators.

The presence of certain bacteria in the gastrointestinal tract
influences behavior and brain function. For example, challenge with
live Campylobacter jejuni (C. jejuni), a common
food-born pathogen, reduces exploration of open arms of the plus maze,
consistent with anxiety-like behavior, and activates brain regions
associated with autonomic function, likely via a vagal pathway.

Could bacteria also influence our emotional state?  If verified in humans this could offer insights into conditions like Crohn’s disease, irritable bowel syndrome and perhaps into fears such as agoraphobia.  Long time readers will know that this study is not alone in suggesting that parasites can influence our emotions.  Ever wonder why you like cats?

Hat tip to Monique van Hoek and Faculty of 1000.