Abstract
Increasing evidence indicates that abnormalities in the composition of gut microbiota might play a role in stress-related disorders. In the learned helplessness (LH) paradigm, ~60–70% rats are susceptible to LH in the face of inescapable electric stress. The role of gut microbiota in susceptibility in the LH paradigm is unknown. In this study, male rats were exposed to inescapable electric stress under the LH paradigm. The compositions of gut microbiota and short-chain fatty acids were assessed in fecal samples from control rats, non-LH (resilient) rats, and LH (susceptible) rats. Members of the order Lactobacillales were present at significantly higher levels in the susceptible rats than in control and resilient rats. At the family level, the number of Lactobacillaceae in the susceptible rats was significantly higher than in control and resilient rats. At the genus level, the numbers of Lactobacillus, Clostridium cluster III, and Anaerofustis in susceptible rats were significantly higher than in control and resilient rats. Levels of acetic acid and propionic acid in the feces of susceptible rats were lower than in those of control and resilient rats; however, the levels of lactic acid in the susceptible rats were higher than those of control and resilient rats. There was a positive correlation between lactic acid and Lactobacillus levels among these three groups. These findings suggest that abnormal composition of the gut microbiota, including organisms such as Lactobacillus, contributes to susceptibility versus resilience to LH in rats subjected to inescapable electric foot shock. Therefore, it appears likely that brain–gut axis plays a role in stress susceptibility in the LH paradigm.
Highlights
Resilience is adaptation in the face of stress and adversity
We examined whether the levels of short-chain fatty acids—acetic acid, propionic acid, butyric acid, lactic acid, and succinic acid—in the fecal samples from susceptible and resilient rats were altered compared with control rats, since these short-chain fatty acids can produced by the gut microbiota[23]
Susceptibility to learned helplessness (LH) in rats exposed to inescapable shock might be associated with an increase of Lactobacillales and a decrease of Actinomycetales in the host gut
Summary
Resilience is adaptation in the face of stress and adversity. Increasing amounts of evidence show that resilience might be mediated by adaptive changes in several neural circuits, including numerous molecular and cellular pathways[1,2,3,4,5,6,7,8,9,10,11]. An understanding of the molecular and cellular mechanisms underlying resilience will facilitate the discovery of new therapeutic drugs for stress-related psychiatric disorders, but the detailed mechanisms underlying resilience and susceptibility remain unclear. It has been shown that ~30–40% of rats are resilient to inescapable electric stress in the learned helplessness (LH) paradigm[31,32,33,34]; the role of gut microbiota in the production of this resilience has not yet been investigated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
