LINKS BETWEEN BOWEL MOVEMENTS AND GUT-BRAIN COUPLING: PRELIMINARY INSIGHTS FROM THE YOURGUTBRAIN PROJECT

The gut-brain axis links bowel function with mood, cognition, and mental health. Accordingly, decreased bowel movements is associated with poorer quality of life and cognition. The gastric rhythm modulates spontaneous cortical brain activity, which might be influenced by satiety, cognitive effort, and mental health. Yet, its relationship with bowel habits remains unknown. Within the YourGutBrain trial(NCT06311097), we investigate the links between bowel movements and cognition. Participants include 38 women experiencing few weekly bowel movements (mean age:54.4, BMI:25.5) and 37 women experiencing daily bowel movements (mean age:54.6, BMI:24.3). Various cognitive domains were assessed using the Cambridge neuropsychological test automated battery (CANTAB). Gut–brain coupling was examined using simultaneous EGG–EEG recordings and quantified between alpha power (8–12 Hz) and gastric peak (~0.05 Hz) using the Kullback–Leibler Modulation Index (MI). Additionally, blood, urine, and fecal samples were obtained to investigate metabolic and microbial differences between the groups. Preliminary results confirm a significant difference in defecation frequency (p<0.001) between groups. Women with daily bowel movements show significantly better global cognitive composite z-score (p<0.02), and higher MI (p<0.05) with a significant frontal-central-parietal-occipital cluster (p<0.05)(figure 1), while there is no significant difference in alpha power and peak gastric power (p=0.4) between groups. A positive correlation was observed between bowel movements and MI (Pearson’s r=0.28, q=0.02). Overall, preliminary findings suggest that bowel movements might influence gut-brain vagal signaling and cognition. Ongoing analyses will further elucidate the effects of dietary intervention with a fermented-dairy product on bowel movements, gut-brain coupling, cognitive and metabolic measures.