The Therapeutic Effect of Exercise on Anxiety and Bowel Oxidative Stress in the Maternal Separation Animal Model

According to evidence, Early-Life Stress (ELS), mood disorders, and medical comorbidities, i.e.  Irritable Bowel Syndrome (IBS), are correlated; however, the direct contribution of ELS to IBS manifestations is less understood. The current study aimed at evaluating the effect of voluntary exercise on the mitochondrial dysfunction of the bowel fibroblasts, following the confirmation of anxiety behavior. 

In this study, Postnatal Day (PND) rats underwent Maternal Separation (MS), as a valid animal model of the brain-gut axis dysfunction, in the days 2-14; three hours daily. On day 21, the study animals were divided into 4 groups, as follows: control, Running Wheel (RW) exercise, MS, and MS+RW groups. The study groups were housed in separate cages (4 rats per cage) until the onset of intervention. On day 60, the elevated plus-maze was used to assess anxiety-like behaviors; the level of oxidative stress biomarkers, i.e.  Reactive Oxygen Species (ROS), Glutathione (GSH) , as well as Adenosine Triphosphate (ATP) was measured to determine the gut mitochondrial function. 

Findings revealed that ELS affected the gut energy metabolism in the studied rats; the negative effects of MS on anxiety and the gut mitochondrial dysfunction decreased via RW exercise during adolescence. 

Overall, anxiety behaviors and ROS production, leading to increased GSH and ATP levels, improved after RW exercise; this significantly impacts the function of colon secretory mitochondria. According to the positive effects of RW exercise on mitochondrial dysfunction in an ELS animal model, a potential relationship was found between the brain and gut in the study rats.