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Electrical nerve field stimulation can help pediatric patients with irritable bowel syndrome (IBS) better manage symptoms such as pain, disability, and catastrophizing and restore the gut microbiota.¹

A team, led by Daniel F. Castillo, Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children's Hospital Medical Center, compared the microbiome between pediatric patients with IBS and a healthy control group for symptom severity and percutaneous electrical nerve field stimulation (PENFS).

A lack of Treatments

There aren’t many microbial studies involving pediatric patients with IBS, particular for studies involving centrally mediated treatments.

“There are many contributory factors to the development of IBS including the gut microbiome and its interaction with the gut–brain axis, though results have been heterogeneous,” the authors wrote. “This lack of consistency may be partially attributed to differences in the populations studied or technical variability including differences in sample collection, processing, and analysis.”

There are currently very few treatments available for pediatric IBS that has shown consistency in improving outcomes.

PENFS is a non-invasive treatment that targets central pain pathways that has shown promise in treating pediatric patients with IBS. The treatment works by alternating frequencies of electrical stimulation to modulate central pain pathways through branches of the cranial nerves that innervate the ear.

The Data

In the study, the investigators collected stool samples, questionnaires, and a 1-2 week stool and pain diary from patients with IBS aged 11-18 years.

Each patient completed 4 weeks of PENFS and repeated data collection immediately after and/or 3 months after treatment. The investigators also collected stool samples from the healthy control group.

Each sample underwent metagenomic sequencing to evaluate diversity, composition, and abundance of species and MetaCyc pathways.

The final analysis included 27 cases, as well as 34 health controls.

The investigators sought primary outcomes of stool microbiome feature differences between the healthy control samples and pediatric patients with IBS. They also looked at various secondary outcomes including correlation of stool microbiome features with the measures of IBS severity, other IBS-related measures, and differences in fecal calprotectin levels between the 2 groups.

The median fecal calprotectin levels were higher (P < 0.001) in the IBS group (74.9, IQR 73.6–78) compared to the controls (29.2, IQR 20.4–36.2), while 23 participants with IBS had a documented esophagogastroduodenoscopy (EGD) and 7 had both an EGD and colonoscopy. 

Differences

For the patients with IBS, the investigators identified 12 species including Firmicutes spp., and carbohydrate degradation/long-chain fatty acid (LCFA) synthesis pathways that were increased compared to the healthy control group. However, this was deemed to not be statistically significantly to symptom severity.

In addition, 17 female patients who completed PENFS showed improvements in various symptoms, such as pain (P = 0.012), disability (P = 0.007), and catastrophizing (P = 0.003).

Also, carbohydrate degradation and LCFA synthesis pathways decreased in the post-treatment and follow-up (FDR P <0.1).

“Firmicutes, including Clostridiaceae spp., and LCFA synthesis pathways were increased in IBS patients suggesting pain-potentiating effects,” the authors wrote. “PENFS led to marked improvements in abdominal pain, functioning, and catastrophizing, while Clostridial species and LCFA microbial pathways decreased with treatment, suggesting these as potential targets for IBS centrally mediated treatments.”

References:

1. Castillo, D. F., Denson, L. A., Haslam, D. B., Hommel, K. A., Ollberding, N. J., Sahay, R., & Santucci, N. R. (2023). The microbiome in adolescents with irritable bowel syndrome and changes with percutaneous electrical nerve field stimulation. Neurogastroenterology & Motility. https://doi.org/10.1111/nmo.14573