<b>Modulating Mind and Body: Effects of tDCS and Probiotics on Cognitive-Behavioral and Autonomic Outcomes in Overweight Adults</b>

This study investigates the comparative effects of transcranial direct current stimulation (tDCS) targeting the ventromedial prefrontal cortex (vmPFC) and dorsolateral prefrontal cortex (dlPFC), alongside probiotic supplementation, on cognitive-behavioral and autonomic outcomes in 58 overweight adults (BMI ≥ 25 kg/m²). Conducted over a controlled intervention period, participants were randomized into four groups: vmPFC tDCS (n = 14), dlPFC tDCS (n = 14), probiotics (n = 15), and sham control (n = 15). Primary outcomes included impulsivity (UPPS-P), nutritional attitudes (EAT-26), self-control (Tanji), general health (GHQ-28), food choice, risky decision-making (BART), and heart rate variability (HRV) components (e.g., HF_power, RMSSD). Results revealed that vmPFC tDCS significantly reduced impulsivity (p = 0.019, η² = 0.170) and improved nutritional attitudes (p = 0.031, η² = 0.152), while enhancing parasympathetic activity (HF_power, p = 0.010). Probiotic supplementation increased RMSSD (p = 0.013), indicating improved autonomic balance, but showed no cognitive-behavioral effects. In contrast, dlPFC tDCS and the control group exhibited no notable changes (p &gt; 0.05). These findings highlight vmPFC tDCS as a promising intervention for modulating reward-related behaviors and autonomic function in obesity, with probiotics offering potential physiological benefits. The study bridges neuromodulation and gut-brain axis research, suggesting tailored approaches for managing obesity’s cognitive and physiological underpinnings.