Noninvasive electrical neuromodulation for gastrointestinal motility disorders

INTRODUCTION

Gastrointestinal motility disorders are highly prevalent without satisfactory treatment. noninvasive electrical neuromodulation is an emerging therapy for treating various gastrointestinal motility disorders.

AREAS COVERED

In this review, several emerging noninvasive neuromodulation methods are introduced, including transcutaneous auricular vagal nerve stimulation, percutaneous auricular vagal nerve stimulation, transcutaneous cervical vagal nerve stimulation, transcutaneous electrical acustimulation, transabdominal interference stimulation, tibial nerve stimulation, and translumbosacral neuromodulation therapy. Their clinical applications in the most common gastrointestinal motility are discussed, including gastroesophageal reflux disease, functional dyspepsia, gastroparesis, functional constipation, irritable bowel syndrome, and fecal incontinence. PubMed database was searched from 1995 to June 2023 for relevant articles in English.

EXPERT OPINION

Noninvasive neuromodulation is effective and safe in improving both gastrointestinal symptoms and dysmotility; it can be used when pharmacotherapy is ineffective. Future directions include refining the methodology, improving device development and understanding mechanisms of action.

Gastrointestinal Myoelectric Measurements via Simultaneous External and Internal Electrodes in Pigs

INTRODUCTION

Currently, there is no accurate noninvasive measurement system to diagnose gastrointestinal (GI) motility disorders. Wireless skin patches have been introduced to provide an accurate noninvasive measurement of GI myoelectric activity which is essential for developing neuro-stimulation devices to treat GI motility disorders. The aim of this study is to compare the external and internal electrical signal measurements in ambulatory pigs.

METHODS

Yucatan pigs underwent placement of internal electrodes on the stomach, small intestine, and colon. Wires were brought through the abdominal wall. Signals were collected by a wireless receptor. Four external patches were placed on the abdominal skin to record the signals simultaneously. Pigs were kept for 6 d while the sensors were continuously recording the data from both systems.

RESULTS

Internal sensors detected rich signals from each organ. The stomach had a dominant frequency that ranged from 4 to 4.5 cpm, with occasional higher frequencies at 2, 3 and 4 times that. Small intestine signals had their primary energy in the 12-15 cpm range. Colon signals primarily displayed a dominant broad peak in the 4-6 cpm region. External skin patches detected a substantial fraction of the activities measured by the internal electrodes. A clear congruence in the frequency spectrum was observed between the internal and external readings.

CONCLUSIONS

Internally measured myoelectrical signals confirmed different patterns of rhythmic activity of the stomach, small intestine, and colon. Skin patches provided GI myoelectric measurement with a range of frequencies that could be useful in the diagnosis and treatment of motility disorders.

miR-222 regulates cell growth, apoptosis, and autophagy of interstitial cells of Cajal isolated from slow transit constipation rats by targeting c-kit

BACKGROUND

Excessive autophagy and apoptosis of the interstitial cells of Cajal (ICC) have been identified in gastrointestinal (GI) motility disorders including slow transit constipation (STC). MicroRNA 222 (miR-222) has been shown to affect GI motility. This study aimed to explore whether miR-222 influences apoptosis and excessive autophagy of isolated ICC.

METHODS

miR-222, c-kit, and stem cell factor (SCF) were evaluated in colon tissues in STC rats compared with normal control by qRT-PCR and western blot analysis. The condition of autophagy of colon tissue was observed by transmission electron microscope. ICC were isolated from the colon of STC rats. Cell Counting Kit-8 (CCK-8) assay and wound healing assay were carried out to examine the cell viability and migration rate. Cell apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) and Annexin V-Flourescein Isothiocyanate/Propidine Iodide (FITC/PI) apoptosis detection kit. Western blot analysis was performed to detect the c-kit and SCF expression; apoptosis-related proteins Bcl-2, Bax, caspase-3, and pro-caspase-3; and autophagy-related proteins LC3B and Beclin-1. The connection between miR-222 and c-kit was detected by bioinformatics and luciferase activity analysis.

RESULTS

miR-222 expression was significantly higher, whereas c-kit and SCF expressions were markedly lower in STC rats' colon tissue compared with normal control. Meanwhile, STC rats exhibited excessive autophagy in colon tissue than normal control. Inhibition of miR-222 expression promoted cell proliferation as well as migration and inhibited autophagy, whereas upregulation of miR-222 had the opposite effect. In addition, miR-222 upregulation induced apoptosis and excessive autophagy compared with normal controls (NC). Western blot analysis showed that miR-222 overexpression caused decreased c-kit and SCF protein levels compared with NC. Bioinformatics and luciferase activity analysis revealed that miR-222 could be a predictive regulator of c-kit.

CONCLUSION

miR-222 induces apoptosis and excessive autophagy of ICC and may serve as potential biomarker for ICC loss in STC.

Nutritional status of protein intake in severe pneumonia patients based on dietary nutrition information system

In order to explore the effect of protein intake on the nutritional status of patients with severe pneumonia (SP) based on a dietary nutrition information system, 108 cases of SP patients of The First people's Hospital of Fuyang were selected as the research objects. Nutrition score of these patients was made by using dietary nutrition information system and then the patients were randomly divided into experimental group and control group. Both groups were treated with basic treatment combined nutrition treatment. At the same time, the experimental group was added with donkey milk, Badanmu, Chamagu compound containing a variety of protein nutritional preparations 20g/d. The changes of intestinal mucosal barrier function in two groups were observed before treatment and 7-14 days after treatment. The results showed that the enteral nutrition (EN) of the experimental group rich in multiple proteins could reduce the levels of blood diamine oxidase (DAO), D-Lactic ac (D-LC) and bacterial endotoxin (BT), protect the intestinal mucosal barrier function of SP patients, improve the gastrointestinal function of SP patients and reduce the incidence of gastrointestinal motility disorder. That is to say, SP patients need not only high protein nutrition supplement but also a variety of protein supply. The nutritional status of protein intake in patients with SP was studied based on dietary nutrition information system. The results provided experimental data for nutritional treatment of patients with SP.

Intestinal Electrical Stimulation to Increase the Rate of Peristalsis

BACKGROUND

Pediatric gastrointestinal motility disorders are a large and broad group. Some of these disorders have been effectively treated with electrical stimulation. The goal of our present study is to determine whether the rate of intestinal peristalsis can be increased with electrical stimulation.

METHODS

Juvenile mini-Yucatan pigs were placed under general anesthesia and a short segment of the jejunum was transected. Ultrasound gel was placed inside the segment. The segment of the jejunum was first monitored for 20 min under no stimulation, followed by direct electrical stimulation using a planar electrode. The gel extruded out of the intestine via peristalsis was collected and weighed for each 20-min time interval.

RESULTS

Effective delivery of the current to the intestine was confirmed via direct measurements. When there was no direct intestinal electrical stimulation, an average of 0.40 g of gel was expelled in 20 min, compared to 1.57 g of gel expelled during direct electrical stimulation (P < 0.01).

CONCLUSIONS

Direct intestinal electrical stimulation accelerates the transit of gastrointestinal contents. This approach may be useful in the treatment of a range of pediatric motility disorders.

Saturated long-chain fatty acid-producing bacteria contribute to enhanced colonic motility in rats

BACKGROUND

The gut microbiota is closely associated with gastrointestinal (GI) motility disorder, but the mechanism(s) by which bacteria interact with and affect host GI motility remains unclear. In this study, through using metabolomic and metagenomic analyses, an animal model of neonatal maternal separation (NMS) characterized by accelerated colonic motility and gut dysbiosis was used to investigate the mechanism underlying microbiota-driven motility dysfunction.

RESULTS

An excess of intracolonic saturated long-chain fatty acids (SLCFAs) was associated with enhanced bowel motility in NMS rats. Heptadecanoic acid (C17:0) and stearic acid (C18:0), as the most abundant odd- and even-numbered carbon SLCFAs in the colon lumen, can promote rat colonic muscle contraction and increase stool frequency. Increase of SLCFAs was positively correlated with elevated abundances of Prevotella, Lactobacillus, and Alistipes. Functional annotation found that the level of bacterial LCFA biosynthesis was highly enriched in NMS group. Essential synthetic genes Fabs were largely identified from the genera Prevotella, Lactobacillus, and Alistipes. Pseudo germ-free (GF) rats receiving fecal microbiota from NMS donors exhibited increased defecation frequency and upregulated bacterial production of intracolonic SLCFAs. Modulation of gut dysbiosis by neomycin effectively attenuated GI motility and reduced bacterial SLCFA generation in the colon lumen of NMS rats.

CONCLUSIONS

These findings reveal a previously unknown relationship between gut bacteria, intracolonic SLCFAs, and host GI motility, suggesting the importance of SLCFA-producing bacteria in GI motility disorders. Further exploration of this relationship could lead to a precise medication targeting the gut microbiota for treating GI motility disorders.

Primary presentation of Jeune's syndrome as gastric motility disorder in an infant: A case report

We report a case of a 4-week-old female neonate with Jeune's asphyxiating thoracic dystrophy (JATD) and coexistent situs anomaly, primarily presenting as gastric motility disorder. The child presented with abdominal distension and nonbilious vomiting since birth with failure to thrive. However, skeletal survey revealed JATD. Upper gastrointestinal contrast study showed situs inversus with delayed gastric emptying. Pyloric biopsy and intraoperative antro-duodenal manometry confirmed association of gastric motility disorder. Awareness of the unusual possibility of primary presentation of Jeune syndrome as gastric motility disorder will improve the management approach in such infants.

Validation of Ultrasonography for Assessment of Gastric Emptying Time in Healthy Cats by Radionuclide Scintigraphy

Background

The prevalence of gastric emptying (GE) disorders in cats is unknown due to lack of clinically applicable diagnostic tests.

Objectives

The principal aim of this study was to assess correlation between scintigraphic and ultrasonographic measurements of GE time (GET) in healthy cats. Additionally, variability of ultrasonographic GET, and correlation between scintigraphy and ultrasonographic parameters of gastric motility were evaluated.

Animals

Eight healthy domestic shorthair cats.

Methods

Prospective study. Scintigraphic GET was determined using a solid test meal containing 4 mCi ^99mTc‐mebrofenin. Each cat had 3 separate ultrasonographic assessments of GE, performed independent of scintigraphic assessment, after solid test meal consumption. The motility index (MI) of antral contractions was plotted against time and time for each fraction of the area under the MI curve determined. Ultrasonographic GET and MI were correlated to scintigraphic GET.

Results

Scintigraphic GET (mean ± SD) for 25, 50, and 75% GE was 103 ± 32 minutes, 196 ± 45 minutes, and 288 ± 62 minutes, whereas sonographic GET for 25, 50, and 75% GE was 106 ± 13 minutes, 203 ± 19 minutes, and 305 ± 27 minutes. There was good correlation between scintigraphic and sonographic GET (r = 0.72–0.82) at 45–90% fractional GE and between scintigraphic GET and time of corresponding MI curve fraction (r = 0.78–0.86) at 40–90% fraction of the MI curve. There was moderate intraindividual variability for sonographic GET and MI curve fraction times as well as significant variation among individuals.

Conclusions and clinical importance

Ultrasonography is a valid alternative to scintigraphy for assessment of solid‐phase GE and allows assessment of postprandial gastric motility in healthy cats.

Research progress on functional dyspepsia

Functional dyspepsia (FD) is considered to be a series of integrated responses to dysfunction of the brain-gut axis caused by a combination of biological factors and socio-psychological factors. Gastrointestinal motility disorder and mental emotional disorder are important factors leading to the development of FD, and abnormal function of the brain-gut axis is the core mechanism of FD pathogenesis. The high incidence of FD has caused a high degree of attention. In this paper, we will review the latest advances in the understanding of the pathogenesis of FD and in its treatment.

Role of itopride hydrochloride in gastrointestinal function recovery of postoperative patients with compound trauma

AIM: To observe the efficacy of itopride hydrochloride in recovering the gastrointestinal function of postoperative patients with compound trauma.

METHODS: Forty-four postoperative patients with compound trauma were randomly divided into groups A (n = 24) and B (n = 20), treated with IHC (50 mg, 3 times per day) and domperidone (10 mg, 3 times per day) for 1 wk. The efficacy and adverse reaction were observed and the data were processed by chi-square test.

RESULTS: Symptoms of the digestive system were improved in both groups, and there was no significant difference between them (χ² = 0.761, P > 0.05). Compared with group B, the gastric emptying rate of patients in group A significantly increased (χ² = 6.704, P < 0.05). The incidence rate of adverse reaction was 17% in group A and 10% in group B, and there was also no marked difference between the two groups (P > 0.05).

CONCLUSION: Itopride hydrochloride can effectively and safely improve the gastrointestinal function in postoperative patients with compound trauma.