Disruption of the brain–esophagus axis in obese patients with heartburn

Abstract

Summary Obesity is a risk factor for gastroesophageal reflux disease. Studies addressing the brain–esophagus axis in obese are lacking. In obese with and without heartburn, we assessed: (i) the brain responses to esophageal acid perfusion during functional brain imaging; (ii) esophageal impedance baseline before and after acid perfusion; and (iii) abdominal fat distribution. In this exploratory study, 26 obese underwent functional magnetic resonance imaging (fMRI) of the brain combined with esophageal acid perfusion. Esophageal impedance baseline was determined before and after fMRI, followed by tomographic quantification of the abdominal fat. Among 26 obese (54% men, 39.7 years old, 33.5 kg/m2), there were 17 with heartburn and 9 without heartburn. Before fMRI, the esophageal impedance baseline was lower in obese with heartburn than without heartburn (median 1187 vs. 1890 Ω; P = 0.025). After acid perfusion, impedance baseline decreased in obese with heartburn (from 1187 to 899 Ω; P = 0.011) and was lower in this group than in obese without heartburn (899 vs. 1614 Ω; P = 0.001). fMRI task-residual analysis showed that obese with heartburn presented higher functional connectivity in several brain regions than obese without heartburn. Abdominal fat area did not differ between obese with and without heartburn either for total (72.8 ± 4.4% vs. 70.3 ± 6.0%; P = 0.280), subcutaneous (42.2 ± 9.0% vs. 37.4 ± 9.0%; P = 0.226), or visceral (30.6 ± 7.9% vs. 33.0 ± 7.8%; P = 0.484). In subjects with obesity, the brain–esophagus axis is disrupted centrally with higher functional brain connectivity and peripherally with decreased esophageal mucosa integrity in the presence of heartburn.

Causal relationship between gastroesophageal reflux disease, Barrett's esophagus, and epilepsy: A bidirectional Mendelian randomization study

“…A potential correlation has been demonstrated between brain electrical activity and gastric acid‐related stimulation in which paraesophageal sensory nerves mediate esophageal sensation in response to acid stimulation, leading to alterations in electroencephalogram (EEG) results (Kim et al., 2017 ). The activation of multiple brain regions recorded by functional magnetic resonance imaging and increased functional connectivity reflect the potential connection between GERD and epilepsy (Kern et al., 2004 ; Ribeiro et al., 2022 ). Further, GERD may be associated with epilepsy, and the two often occur concomitantly (Byard, 2006 ; Fiorentino et al., 2009 ; Nishiyama et al., 2020 ).…”

The brain–esophagus axis in subjects with and without obesity assessed by esophageal acid perfusion and functional brain imaging

“…The evaluation of the brain–esophageal axis was recently characterized in patients with obesity [ 20 , 21 ]. We aimed to assess heartburn perception and brain connectivity responses during esophageal acid stimulation in subjects with and without obesity, controlling for the presence of reflux symptoms.…”