Acupuncture and Digestive Health

Acupuncture therapy involves the use of thin, smooth needles that are inserted into specific locations, called acupoints, to help treat diseases. According to Traditional Chinese Medicine (TCM), when qi, an inner energy of human beings that is vital to health, is imbalanced, illness and disease occur.₁ The theory of acupuncture suggests that the flow of Qi can be rebalanced by activating acupoints, thus allowing more harmoniously flow throughout the body._1,2 Acupuncture provides a different approach from modern, Western medicine for treating many ailments because it has unique effects depending on the condition, helping to return the body to homeostasis._2,3

Acupuncture began as a practice where practitioners inserted the tips of needles into the skin which could then be manipulated manually by lifting, thrusting, twisting, twirling, or other complex combinations.₂ A modern method utilizes concepts of neuromodulation to modify traditional acupuncture by using an electrical pulse to stimulate acupoints._2,4 This approach is called electroacupuncture. There is also transcutaneous electrical acustimulation, which does not involve needles but rather applies low-intensity electrical current to acupoints on the skin via electrodes.₅

Acupuncture is thought to have originated in ancient China, where it has been practiced for thousands of years._1,2 It spread throughout the world, into Japan and slowly into East Asia, often being incorporated with Chinese herbs.₁ Since the 1950s, it has become more utilized in the West; however, the effectiveness of acupuncture is not always appreciated or recognized.₁ Collecting clinical evidence illustrating the efficacy of acupuncture can be difficult due to the highly personalized nature of this approach to health and disease; it is very difficult to study in a real-world clinical setting._1,3 Additionally, much of the literature related to acupuncture was conducted and reported in Chinese and thus remains inaccessible to the West due to the language barrier.₃

Acupuncture for Digestive Disorders

Many gastrointestinal (GI) disorders do not have clear causes or treatments, often leading patients to seek complementary and alternative medicine, with as many as 42 percent of adults with GI conditions in the United States seeking out integrative therapies in any given year._4,6 Both pre-clinical and clinical evidence indicates that acupuncture can benefit individuals with various GI disorders. While there are many different approaches to acupuncture for GI health, some of the most common primary acupoints for treatment of GI disorders include ST-36, PC-6, CV-12, and ST-25.₂

Nausea and vomiting

Acupuncture can help with nausea, bloating, and vomiting, even when the symptoms seem resistant to other treatments.₇ Additionally, acupuncture may help reduce nausea and vomiting due to pregnancy, post-operative complications, and chemotherapy._3,6 The specific acupoint PC-6 has strong evidence to support its use for reducing nausea, including nausea resulting from different conditions.₆

Regulation of gastric motility

Acupuncture may be able to regulate GI motility, which utilizes the contraction and expansion of smooth muscle throughout the GI tract to keep digestion moving.₂ In patients with low gastric motility, acupuncture promoted gastric peristalsis; however, in those with very active motility, it suppressed peristalsis.₂ One large randomized, controlled study found that eight weeks of electroacupuncture was effective at relieving constipation compared to a high quality control (“sham procedure”), and this effect lasted for about 20 weeks.₁ For individuals with diarrhea from an infection, acupuncture was able to speed recovery.₃

Functional dyspepsia

Functional dyspepsia is a GI disorder which can significantly impact psychological health and quality of life.₄ Several underlying factors contributing to functional dyspepsia include gastric dysmotility, delayed gastric emptying, and visceral hypersensitivity.₄ A meta-analysis revealed that acupuncture had a significant positive effect on patients with functional dyspepsia compared to sham acupuncture as the control.₄ Acupuncture was able to improve both symptoms of dyspepsia as well as quality of life.₄

Irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional GI disorder with complex causes and includes a wide range of symptoms.₅ Acupuncture can help decrease visceral hypersensitivity and regulate gastric motility, both of which are mechanisms that, when dysregulated, contribute to forms of IBS._2,5 A systematic review of randomized, controlled trials found that acupuncture was more effective than pharmacotherapy in relieving IBS symptoms.₆ Assessing the effects of acupuncture in IBS is also particularly challenging due to the unknown cause of the condition as well as the subjective rating of symptoms and a high placebo response rate.₃

How Does Acupuncture Work?

During acupuncture, the motion of the needle being inserted and manipulated sends a signal through various neural pathways including neurochemical signals and nerve fibers.₈ These signals work at multiple levels including the parasympathetic and sympathetic nervous systems, the enteric nervous system, and the central nervous system. Together, these control GI motility, pain and hypersensitivity, immune function, blood flow, gut barrier integrity, brain function, and many other important physiological and neurological pathways._2-4,8 Acupuncture can also activate signaling molecules, including gut peptides, neurotransmitters, and hormones._2,3

Neurotransmitters

Acupuncture can modify levels of neurotransmitters that are involved in digestion and GI health in part through the signaling of the vagal nerve fibers which transmit important mechanical and chemical information to the brain from the GI tract._2,8 These cellular messages can be transmitted via neurotransmitters, including GABA, glutamate, norepinephrine, and acetylcholine, which help regulate gastric function._2,8 Acupuncture has also been shown to upregulate expression of oxytocin, a neuropeptide that can induce anti-stress effects involved in GI function.₂

Gut-brain axis

Acupuncture activates the gut-brain axis, modulating neural activity and regulating levels of gut peptides that are involved in GI health._2,4 These peptides have a significant effect on many functions of the GI tract including gastric emptying and visceral hypersensitivity.₄ Gut peptides influenced by acupuncture include:_1-4

• Substance P (SP)- participates in smooth muscle contraction, and modulates epithelial cell secretions and pain perception
• Vasoactive intestinal polypeptide (VIP) – inhibits GI motility
• Somatostatin- inhibits GI secretions and decreases GI motility
• Motilin- stimulates GI motility
• Cholecystokinin (CCK)- regulates GI motility and induces satiety
• Ghrelin- increases the drive to eat
• Neuropeptide Y (NPY)- stimulates food intake and inhibits gastric motility and emptying
• Gastrin- stimulates acid secretion from stomach

Other mechanisms

Scientists are working to uncover precise mechanisms through which acupuncture benefits the GI tract. It may be able to modulate gut microbiota, with an effect similar to that of probiotics in one pre-clinical trial._9,10 It can also decrease pain and hypersensitivity via opioid, adrenal, and serotonin pathways throughout the nervous system.₂ Additionally, a pre-clinical study demonstrated the ability of electroacupuncture to promote the survival and proliferation of interstitial cells of Cajal (ICC), the pacemaker cells of the GI tract.₂ Finally, acupuncture may be able to regulate inflammatory pathways through multiple mechanisms including microRNAs and the cholinergic pathway._2,9

Together, acupuncture and other integrative therapies such as mind-body therapy, dietary intervention, and dietary supplements and herbs, may provide significant relief from a variety of GI symptoms.₆ Although research on acupuncture is increasing, barriers still exist that could help prove the efficacy of this approach in a more objective way.

Reviewed by Marisa Marciano, ND, RH

References

1. Zhu, J., Li, J., Yang, L., Liu, S. (2021). Acupuncture, from the ancient to the current. Anat Rec, 304(11):2365.
2. Li, H., He, T., Xu, Q., Li, Z., Liu, Y., Li, F., Yang, B.-F., Liu, C.-Z. (2015). Acupuncture and regulation of gastrointestinal function. World J Gastroenterol, 21(27):8304.
3. Diehl, D.L. (1999). Acupuncture for Gastrointestinal and Hepatobiliary Disorders. J Altern Complement Med, 5(1):27.
4. Guo, Y., Wei, W., Chen, J.D.Z. (2020). Effects and mechanisms of acupuncture and electroacupuncture for functional dyspepsia: A systematic review. World J Gastroenterol, 26(19):2440.
5. Huang, Z., Lin, Z., Lin, C., Chu, H., Zheng, X., Chen, B., Du, L., Chen, J.D.Z., Dai, N. (2022). Transcutaneous Electrical Acustimulation Improves Irritable Bowel Syndrome With Constipation by Accelerating Colon Transit and Reducing Rectal Sensation Using Autonomic Mechanisms. Am J Gastroenterol, 117(9):1491.
6. Dossett, M.L., Cohen, E.M., Cohen, J. (2017). Integrative Medicine for Gastrointestinal Disease. Prim Care, 44(2):265.
7. Ouyang, A., Xu, L. (2007). Holistic Acupuncture approach to idiopathic refractory nausea, abdominal pain and bloating. World J Gastroenterol, 13(40):5360.
8. Yu, Z. (2020). Neuromechanism of acupuncture regulating gastrointestinal motility. World J Gastroenterol, 26(23):3182.
9. Zhang, Y., Ding, N., Hao, X., Zhao, J., Zhao, Y., Li, Y., Li, Z. (2022). Manual acupuncture benignly regulates blood-brain barrier disruption and reduces lipopolysaccharide loading and systemic inflammation, possibly by adjusting the gut microbiota. Front Aging Neurosci, 14:1018371.
10. Mengzhu, S., Yujie, Z., Yafang, S., Jing, G., Tingting, Z., Yuhang, W., Lixia, P., Jianhua, S. (2022). Electroacupuncture at Tianshu (ST25) and Zusanli (ST36) alleviates stress-induced irritable bowel syndrome in mice by modulating gut microbiota and corticotropin-releasing factor. J Tradit Chin Med, 42(5):732.