Hindawi Evidence-Based Complementary and Alternative Medicine Volume 2021, Article ID 6652017, 13 pages https://doi.org/10.1155/2021/6652017 Research Article PositiveEffectof ElectroacupunctureTreatmentonGutMotility in Constipated Mice Is Related to Rebalancing the Gut Microbiota Mingmin Xu ,1 Lu Wang ,1 Yu Guo ,2 Wei Zhang ,3 Ying Chen ,1 and Ying Li 4 1School of Acupuncture–Moxibustion and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China 2Teaching and Research Section of Acupuncture, School of Traditional Chinese Medicine, Jinan University, Guangzhou 510632, China 3Office of Educational Administration, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China 4Graduate School, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China Correspondence should be addressed to Ying Li; [email protected] Received 23 December 2020; Revised 13 February 2021; Accepted 23 February 2021; Published 3 March 2021 Academic Editor: Jing Hua Wang Copyright © 2021 Mingmin Xu et al. *is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Functional constipation (FC) is a common and often recurrent functional bowel disorder that seriously affects the quality of life of affected individuals and incurs a significant economic burden on both the individual and society. *ere is accumulating evidence that intestinal dysbiosis contributes to constipation and that rebalancing the gut microbiota may be a novel therapeutic modality for FC. Electroacupuncture (EA) has been shown to restore the gut microbiota to normal levels in a variety of diseases. Ad- ditionally, several high-quality clinical studies have confirmed that EA is an effective, sustained, and safe treatment for FC. However, whether the effects of EA are secondary to changes in the gut microbiota and how EA modulates intestinal dysbiosis induced by constipation are unknown. *erefore, here, we focused on the potential regulatory mechanisms of EA on diphe- noxylate-induced constipation in mice by analyzing structural changes in the gut microbiota. Our results showed that EA treatment effectively rebalanced the gut microbiota of constipated mice, mainly by decreasing the Firmicutes/Bacteroidetes ratio, which may represent one way in which EA promotes gastrointestinal motility and alleviates constipation. Our findings lay the foundation for further mechanistic and clinical research into the application of EA in patients with FC. 1. Introduction in abdominal distension, nausea, anorectal lesions, psychi- atric symptoms, cardiovascular events, and even an increased Functional constipation (FC) is a common functional bowel risk of colorectal cancer [2, 5, 6]. Due to dietary and lifestyle disorder without identifiable structural or biochemical ab- changes, FC is affecting a growing number of people normalities [1]. According to the Rome IV criteria for worldwide and incurring a consequent substantial economic functional gastrointestinal disorders, FC is defined as defe- burden on individuals and society [4, 7]. For example, in the catory straining, hard or lumpy stools, a feeling of incomplete USA, FC accounts for over two million hospital visits and evacuation, defecatory obstruction, manual maneuvers to about 90 thousand hospitalizations annually, costing ∼7 facilitate defecation, and fewer than three complete sponta- billion USD in diagnostic assessments [4, 7]. Hence, prompt neous bowel movements (CSBM) per week [2]. A 2020 ep- and aggressive treatment of constipation is an important idemiological survey showed that the average prevalence of strategy to prevent other diseases and reduce healthcare FC was 7.8% in three English-speaking Western countries expenditures. Conventional treatments include medical (6.9% in the United States, 7.9% in Canada, and 8.6% in the therapies such as fiber, osmotic and stimulant laxatives, and United Kingdom) [3]. In some patients, FC can be recurrent selective 5-hydroxytryptamine receptor 4 (5-HT4) agonists to and refractory to treatment, resulting in significant pain and relieve constipation when lifestyle modifications are inef- an impaired quality of life [2, 4]. Clinically, FC can also result fective [8]. However, nearly half of patients with FC are 2 Evidence-Based Complementary and Alternative Medicine dissatisfied with current medical approaches due to a lack of 2.2. Experimental Design. Twenty-four mice were randomly response, drug dependence, and unpleasant side-effects [9]. separated into a normal control (NC) group, slow transit As a result, patients are urgently seeking effective, safe, and constipation (STC) group, and STC treated with EA nontoxic treatment alternatives. (STC.EA) group, with n � 8 mice in each group. After one Acupuncture, which originated in traditional Chinese week of acclimation, STC was induced in the STC and medicine (TCM), has attracted considerable interest due to STC.EA groups by intragastric administration of 10 mg/kg overwhelming clinical evidence that it is an effective and body weight diphenoxylate solution once a day for four safe treatment for FC. TCM theory and practice propose consecutive weeks [26–28]; the NC group was administered that acupuncture, which is performed by inserting needles an equivalent amount of saline. After four weeks of mod- into specific points in the body and then stimulating the eling, fecal parameters (the first black stool defecation time needles manually or electrically to elicit the Qi [10], can and feces number, weight, and water content) were mea- promote the intestinal function recovery [11]. Electro- sured to assess whether the STC models were successfully acupuncture (EA) is a modern acupuncture method that established. When every fecal parameter in STC and STC.EA uses weak electrical stimulation of acupuncture needles mice showed significant differences compared with those in instead of manual manipulation to enhance the acu- the NC group, the STC model was deemed successful. *en, puncture effect. As awareness of EA treatment grows, mice in STC.EA group were treated daily with EA for two clinical studies have confirmed positive outcomes from EA weeks, with two days of rest after five EA treatments. After therapy in the management of intestinal diseases such as the final treatment, fresh feces were collected from all mice irritable bowel syndrome [12] and quiescent inflammatory in sterile tubes and then immediately frozen at −80°C for 16S bowel disease [13] as well as other diseases such as stress rRNA sequencing. *e day after fecal collection, fecal pa- urinary incontinence [14], migraine prophylaxis [15], in- rameters were measured, and the day after that, intestinal somnia [16], and postprandial distress syndrome [17]. transit rate was measured. Colons were excised and fixed in Specifically related to bowel dysfunction, since 2019, sev- 4% paraformaldehyde for hematoxylin and eosin (HE) eral high-quality RCTs have confirmed that acupuncture staining. *e experimental protocol is shown in Figure 1. can increase CSBM, soften stool hardness, alleviate defe- cation straining, reduce frequent rescue medicine use, reduce adverse events, and improve the quality of life of 2.3. EA Treatment. Mice were restrained in home-made constipated patients [18, 19]. mouse pockets before treatment to ease restraint stress, and However, the mechanisms underlying EA for FC remain mice in the NC and STC groups were also fixed in mouse largely unknown. Intestinal dysbiosis contributes to con- pockets. *en, sterile acupuncture needles (0.25 ×13 mm) stipation via several mechanisms, and accumulating evi- were inserted vertically into the “Tianshu” (ST25) and dence from fecal bacterial transplantation and “Shangjuxu” (ST37) unilaterally to a depth of 4-5 mm, and microecological therapy indicates that chronic constipation the left or right acupuncture points were alternately stim- can potentially be ameliorated by rebalancing the gut ulated each time. *e stainless steel acupuncture needles microbiota composition [20–22]. However, in a systematic were connected to the Hwato SDZ-V electropulse acu- review, the effects of probiotics on constipation remained puncture therapeutic apparatus (Hwato, Jiangsu, China) at a uncertain [23]. Nevertheless, the curative effect of acu- frequency of 3/15 Hz and an intensity of 1 mA for 30 puncture on obesity and osteosarcoma has been shown to be minutes. related to restoring intestinal microflora to normal levels [24, 25], suggesting that intestinal dysbiosis disorders can be 2.4. Measurement of Fecal Parameters. Mice were given treated with acupuncture. 0.1 ml of 5% activated carbon suspension after fasting for It is currently unknown whether acupuncture can 12 h and then moved into individual empty cages lined with modulate intestinal dysbiosis induced by constipation. white blotting paper, where they received normal water and We therefore hypothesized that the purgative effect of food. *e length of time from activated carbon gavage to the acupuncture is mediated by regulation of the gut first black stool defecation was recorded as the first black microbiota. To test this hypothesis, we analyzed the effect stool defecation time. *e total fecal number and wet weight of electroacupuncture (EA) on changes in the gut during a 6 h period were calculated. Each sample was dried microbiota in diphenoxylate-induced constipation in in an oven at 90°C for 12 h and weighed. Fecal water content mice