WASHINGTON — The presence of certain kinds of bacteria in a patient’s gut microbiome helped predict their responsiveness to cognitive behavioral therapy for the treatment of irritable bowel syndrome, according to research presented at Digestive Disease Week.
Jonathan Patrick Jacobs, MD, of the Oppenheimer Center for Neurobiology of Stress and Resilience, and the Vatche and Tamar Manoukian Division of Digestive Disease at UCLA, said previous studies have shown that cognitive behavioral therapy (CBT) reduces IBS symptom severity score.
“The aims of this study were to investigate whether baseline state of the gut microbiome modified response to CBT,” Jacobs said, “and to assess whether CBT alters the microbiome’s composition and function.”
Jacobs and colleagues collected stool samples from 49 patients with IBS at baseline and after 12 weeks (80% women; 37% IBS-C; 47% IBS-D). Then they randomly assigned patients to clinic-based CBT (n = 19), home-based CBT (n = 15) or patient education (n = 15). The researchers performed 16S rRNA sequencing and metabolomics analysis, and defined responders as having an IBS-SSS decrease of greater than 50 points at the end of treatment.
The investigators found that baseline microbiota composition was significantly associated with IBD-SSS response in CBT-treated patients both at the end of treatment (P = .016) and at three months after treatment (P = .029). Specifically, the researchers found that responders had increased levels of Roseburia, Lachnobacterium and unclassified Lachnospiraceae (all Clostridiales), as well as lower levels of Bacteroides, Parabacteroides and Prevotella, which are all Bacteroidales.
Jacobs said that CBT responders experienced an induction of five bacterial genera, while non-responders showed genus-level changes in bacteria.
Additionally, responders had higher levels of fecal serotonin compared with non-responders (P = .03). Jacobs said that previous studies have shown that some kinds of spore-forming bacteria can induce luminal serotonin release, and serotonin has been suggested as a possible mechanism that can link the microbiome to responsiveness of the brain to CBT. These spore-forming bacteria are often found within the order Clostridiales, according to Jacobs.
Jacobs and his colleagues presented several explanations for why gut microbiota can predict response to CBT.
“There’s two possibilities,” he said. “Peripheral signals from the microbiota may modulate central processes, which are influenced by CBT, that generate symptoms of IBS. Or the alternative is, perturbed top-down signals from the brain, which is again influenced by CBT, alter GI function and thereby affect the microbiome.” – by Alex Young
Jacobs JP, et al. Abstract 915. Presented at: Digestive Disease Week; June 2-5, 2018; Washington, D.C.
Jacobs reports financial ties to Prolacta Bioscience. Please see the DDW faculty disclosure index for a list of all other authors’ relevant financial disclosures.