Electroacupuncture and Tongbian decoction ameliorate CUMS-induced depression and constipation in mice via TPH2/5-HT pathway of the gut-brain axis.

If you've ever noticed that your mood and your digestion seem to affect each other, you're not imagining it. Scientists call this connection the "gut-brain axis," and a new study published in Brain Research Bulletin shows that a combination of electroacupuncture and a traditional herbal formula called Tongbian decoction may help treat both depression and constipation at the same time.

Researchers used a mouse model of depression and constipation triggered by chronic unpredictable mild stress (CUMS) — a well-established method of mimicking the kind of ongoing stress that contributes to depression in humans. The mice were then treated with either electroacupuncture alone, electroacupuncture combined with Tongbian decoction, or fluoxetine (Prozac), a common antidepressant.

The results were encouraging. Mice treated with the combination of electroacupuncture and Tongbian decoction showed significant improvements in mood, anxiety, and memory. They also showed better digestive function and less intestinal inflammation. Researchers found that the treatment worked by boosting levels of tryptophan hydroxylase 2 (TPH2), an enzyme involved in producing serotonin — the "feel-good" chemical that plays a key role in both brain function and gut health. The combination therapy increased serotonin levels in both the brain and the digestive tract simultaneously.

Importantly, fluoxetine helped with depression symptoms but did little to relieve constipation, suggesting that conventional medication may only address part of the problem for people dealing with both conditions.

This research highlights the potential of combining electroacupuncture with herbal medicine to treat interconnected conditions that conventional treatments often struggle to address together. For patients living with both depression and digestive issues, this integrated approach offers a promising new direction.

If you're interested in exploring electroacupuncture or traditional herbal medicine, seek out a licensed and qualified acupuncture practitioner with training in both acupuncture and Traditional Chinese Medicine.

This preclinical study (Brain Research Bulletin) investigated electroacupuncture (EA) combined with Tongbian decoction (TB) for comorbid depression and constipation using a chronic unpredictable mild stress (CUMS) mouse model. Treatment groups included EA alone, EA + TB, and fluoxetine (FLX) as a comparator. EA + TB produced superior antidepressant and anxiolytic outcomes compared to EA monotherapy, with restored cognitive function and significantly enhanced gastrointestinal motility. Mechanistically, EA + TB upregulated tryptophan hydroxylase 2 (TPH2) expression in both the prefrontal cortex and colon, elevated serum 5-HTP levels, and increased 5-HT synthesis across the gut-brain axis. Intestinal inflammation was also attenuated and neuronal morphology restored. FLX demonstrated limited prokinetic efficacy. The findings suggest that EA + TB exerts synergistic regulation of the central nervous and gastrointestinal systems via the TPH2/5-HT pathway. Clinically, this supports an integrative protocol for patients presenting with depression-GI comorbidity where standard pharmacotherapy shows incomplete response.