Fujihara, H. | bioRxiv Science

bioRxiv2026

Acute running improves mood via changes in interoceptive sensibility

PurposeInteroception is the sensing and interpretation of internal bodily signals and may be a key process linking exercise-induced bodily changes to mood. This study examined whether acute moderate-intensity treadmill running changes interoception and mood states and whether running-related changes in interoception statistically account for mood improvement. MethodsTwenty-seven healthy young adults completed a within-subject crossover experiment consisting of 15 min of moderate-intensity treadmill running at 50% estimated [V]O2peak and seated rest on separate days. Before and after each condition, cardiac interoceptive accuracy was assessed using heartbeat counting and heartbeat tapping tasks, present-moment interoceptive sensibility using a state-adapted Body Perception Questionnaire (BPQ), and mood using the Profile of Mood States. Running-related changes were calculated as {Delta}RUN - {Delta}CTL. ResultsCompared with seated rest, running reduced total mood disturbance (TMD) and tension-anxiety (TA) and increased vigor-activity (VA). Running did not significantly change task-based indices of cardiac interoceptive accuracy but increased BPQ scores. Greater running-related increases in BPQ scores were associated with greater reductions in TMD (r = -.61, p < .001), TA (r = -.45, p = .018), and depression-dejection (r = -.49, p = .009). Greater increases in heartbeat tapping task d' were associated with greater increases in VA (r = .56, p = .003). Mediation analysis indicated that BPQ changes were statistically consistent with an indirect pathway linking running to reduced TMD, with weaker exploratory evidence for TA. ConclusionsA single bout of moderate-intensity running improved mood and increased present-moment interoceptive sensibility, but not task-based cardiac interoceptive accuracy. Enhanced subjective awareness of bodily sensations may be one proximal process related to the mood benefits of acute running.

neuroscience↗

bioRxiv2023

Temperament in early childhood is associated with gut microbiota composition and diversity

Temperament is a key predictor of human mental health, and cognitive and emotional development. While human fear behavior is reportedly associated with gut microbiome in infancy, infant gut microbiota changes dramatically during the first five years, when the diversity and composition of gut microbiome are established. This period is crucial for developing human executive functioning, including emotion regulation. Therefore, this study investigated the relationship between temperament and gut microbiota in 284 preschool children aged 3-4 years. Child temperament was assessed by maternal reports of the Childrens Behavior Questionnaire. Gut microbiota (alpha/beta diversity and genera abundance) was evaluated using 16S rRNA sequencing of stool samples. A high abundance of anti-inflammatory bacteria (e.g., Faecalibacterium) and low abundance of inflammatory bacteria (e.g., Eggerthella, Flavonifractor) were associated with higher positive emotionality and reward-seeking (i.e., Surgency/Extraversion, {beta} =0.15, p = 0.013), and lower negative emotionality and behavioral inhibition (i.e., Negative Affectivity, {beta} = -0.17, p = 0.004). Additionally, gut microbiota diversity was associated with a more active approach and exploration (i.e., Impulsivity, a specific aspect of Surgency/Extraversion, {beta} = 0.16, p = 0.008). This study provides insight into the biological mechanisms of temperament and takes important steps toward identifying predictive markers of psychological/emotional risk.

microbiology↗