Geetanjali Bora ¹, Samantha N Atkinson ^2 3, Amy Pan ^3 4, Manu Sood ⁵, Nita Salzman ^# 1 2 3, Katja Kovacic ^# 1

Author information

¹Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI.

²Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI.

³Center for Microbiome Research, Medical College of Wisconsin, Milwaukee, WI.

⁴Divison of Quantitative Health Sciences, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI.

⁵Division of Pediatric Gastroenterology, Department of Pediatrics, University of Illinois College of Medicine Peoria.

^#Contributed equally.

Abstract

Objective: Auricular percutaneous electrical nerve field stimulation (PENFS) has documented clinical efficacy for irritable bowel syndrome (IBS) via plausible vagal neuromodulation effects. The vagus nerve relays brain-gut-immune signals and may affect gut microbiome composition. We aimed to investigate gut microbiome alterations by PENFS therapy in adolescent IBS.

Methods: Prospective study of females ages 11-18 years with IBS receiving PENFS therapy x 4 weeks with pre and post intervention stool sampling. Outcome surveys were completed pre-, weekly and post-therapy: IBS Severity Scoring System (IBS-SSS), Visceral Sensitivity Index (VSI), Functional Disability Inventory (FDI) and global symptom response scale (SRS). Bacterial DNA was extracted from stool followed by16S rRNA amplification and sequencing. QIIME2 (v. 2022.2) was used for analyses of α and β diversity and differential abundance by group.

Results: Twenty females, mean ± SEM 15.6 ± 1.62 years were included. IBS-SSS, VSI and FDI scores decreased significantly pre vs. post therapy (p<0.0001, p=0.0003, p=0.0004 respectively). No intra- or inter-individual microbiome changes were noted pre vs. post therapy or between responders and non-responders. When response was defined by 50-points IBS-SSS score reduction, α diversity was higher in responders vs non-responders at week 4 (p=0.033). There was higher abundance of Blautia bacteria in excellent responders vs. non-responders.

Conclusions: There were no substantial changes in microbial diversity after PENFS therapy. Subjects with excellent therapeutic response showed an enrichment of relative abundance of Blautia bacteria, which may indicate that patients with specific microbial signature have a more favorable response to PENFS therapy. This article is protected by copyright. All rights reserved.