Considering traditional Chinese medicine as adjunct therapy in the management of chronic constipation by regulating intestinal flora

Chronic constipation is one of the most common gastrointestinal disorders worldwide. Due to changes in diet, lifestyle, and the aging population, the incidence of chronic constipation has increased year by year. It has had an impact on daily life and poses a considerable economic burden. Nowadays, many patients with chronic constipation try to seek help from complementary and alternative therapies, and traditional Chinese medicine (TCM) is often their choice. The intestinal flora play an important role in the pathogenesis of constipation by affecting the body's metabolism, secretion, and immunity. Regulating the intestinal flora and optimizing its composition might become an important prevention and treatment for chronic constipation. TCM has unique advantages in regulating the imbalance of intestinal flora, and its curative effect is precise. Therefore, we reviewed the relationship between intestinal flora and chronic constipation as well as advances in research on TCM as adjunct therapy in the management of chronic constipation by regulating intestinal flora. Some single Chinese herbs and their active ingredients (e.g., Rheum palmatum, Radix Astragalus, and Cistanche deserticola), some traditional herbal formulations (e.g., Jichuan decoction, Zengye decoction, and Zhizhu decoction) and some Chinese patent medicines (e.g., Maren pills and Shouhui Tongbian capsules) that are commonly used to treat chronic constipation by regulating intestinal flora are highlighted and summarized. Moreover, some external forms of TCM, and especially acupuncture, have also been found to improve intestinal movement and alleviate constipation symptoms by regulating intestinal flora. We hope this review can contribute to an understanding of TCM as an adjunct therapy for chronic constipation and that it can provide useful information for the development of more effective constipation therapies.