Mechanism of acupuncture on neuromodulation in the gut--a review.

INTRODUCTION: Acupuncture has been used for treating various gastrointestinal (GI) diseases. However, the mechanism of acupuncture remains unclear.
METHODS: The aim of this article is to review the published literature on the mechanism of acupuncture on neuromodulation in the gut.
RESULTS: Acupuncture treatment involves the insertion of thin needles into the skin and underlying muscle and the subsequent stimulation of the needles manually or electrically. Thus, acupuncture stimulates the somatic afferent nerves of the skin and muscles. The somatic sensory information from the body is carried to the cortex area of the brain. Somatic sensory fibers also project to the various nuclei at the brain stem and hypothalamus. Via somato-autonomic reflex, acupuncture modulates various biomechanical responses, such as prokinetic, antiemetic, and anti-nociceptive effects.
CONCLUSION: According to traditional Chinese medicine, "Acupuncture is believed to restore the balance of Yin and Yang." This can be translated into the Western medicine terminology that "Acupuncture modulates the imbalance between the parasympathetic and sympathetic activity." Acupuncture may be effective in patients with functional GI disorders because of its effects on GI motility and visceral pain.