Evaluation of regional and whole gut motility using the wireless motility capsule: relevance in clinical practice

Feasibility and accuracy of continuous intraabdominal pressure monitoring with a capsular device in human pilot trial

BACKGROUND

Intrabdominal pressure (IAP) is an important parameter. Elevated IAP can reduce visceral perfusion, lead to intraabdominal hypertension, and result in life-threatening abdominal compartment syndrome. While ingestible capsular devices have been used for various abdominal diagnoses, their application in continuous IAP monitoring remains unproven.

METHOD

We conducted a prospective clinical trial to evaluate the feasibility of IAP measurement using a digital capsule PressureDOT, an ingestible capsule equipped with wireless transmission capability and a pressure sensor, then compared its reliability with conventional intravesical method. Patients undergoing laparoscopic or robotic surgeries were recruited. During surgery, we created pneumoperitoneum by inflating CO2 into the peritoneal cavity and IAP was simultaneously monitored using both the ingestible capsules and intravesical measurements from Foley catheter. We assessed the feasibility of signal transmission and the accuracy of pressure measurements.

RESULTS

Six patients were enrolled in this pilot study. No adverse events were reported, and the average first-intake time was within 24 h. All capsules were successfully expelled, with an average excretion time of 81 h. In the summarized data, the mean IAPdot is 0.6 mmHg lower than the IAPivp, with a standard deviation of 1.68 mmHg. However, capsule measurements showed excellent correlation with intravesical IAP measurements, with an intraclass correlation coefficient of 0.916 (95% CI: 0.8821-0.9320).

CONCLUSION

Our study demonstrates the feasibility and safety of using digital capsules for continuous IAP monitoring, providing the agreement between IAP measurements from digital capsules and conventional intravesical measurement within a near-normal pressure.

Tracking the journey: Gastrointestinal transit and intraluminal pH dynamics in aging populations using wireless motility capsule

INTRODUCTION

Gastrointestinal (GI) changes may alter drug absorption, potentially impacting both efficacy and safety of oral pharmacotherapy. However, the GI physiology is rarely studied in the aging population. This study aimed to explore GI transit time and pH in geriatric inpatients and older adults, and compare these findings with those from young volunteers.

METHODS

A prospective study was performed in geriatric inpatients and community-dwelling adults aged ≥ 75 years. GI transit and intraluminal pH were assessed by using a wireless motility capsule system. Participants' data were pooled with those from a previous study in healthy young volunteers (n = 11). Multivariable linear regression models were developed to identify explanatory variables for GI transit time and pH value.

RESULTS

We recruited 30 subjects (median age 80 [interquartile range (IQR) = 77-83] years). When compared to young volunteers (median age 21 [20-33]) years), geriatric inpatients (N = 8) exhibited prolonged gastric emptying times (median = 0.63 h [IQR = 0.32-0.86 h] vs median = 2.98 h [IQR = 1.50-20.35 h], p < 0.01). Community-dwelling older adults (N = 22) did not demonstrate delayed gastric emptying (median = 0.42 h [IQR = 0.36-0.53 h]; p = 0.85. Proton pump inhibitors (PPI) use was associated with increased gastric pH (median pH = 3.75 [IQR = 1.69-4.96] vs. non-PPI median pH = 1.28[IQR = 1.01-1.70]; p < 0.01) in the pooled analysis. The total older cohort had significantly lower small intestine pH compared to young group (median pH = 6.8 vs. 7.2; p < 0.01).

CONCLUSION

Older age did not necessarily alter GI physiology with respect to gastric emptying time and luminal pH values. Only geriatric inpatients exhibited delayed gastric emptying of the motility capsule as compared to young volunteers, while community-dwelling older adults did not. Prevalent PPI use in the aging population led to higher gastric pH levels, with substantial intersubject variability.

Smooth Muscle Mechanosensitivity Generates and Maintains Pressure Gradients Across the Intestine

BACKGROUND

The gut, the ureter, or the Fallopian tube all transport biological fluids by generating trains of propagating smooth muscle constrictions collectively known as peristalsis. These tubes connect body compartments at different pressures. We extend here Poiseuille's experiments on liquid flow in inert tubes to an active, mechanosensitive tube: the intestine.

METHODS

We use as a miniature myogenic peristaltic pump model, the fetal chicken gut, and measured the flow and contractile wave propagation as a function of the initially applied pressures and pressure gradients. We dissect the molecular pathways of smooth muscle mechanosensitivity by measuring the force generated by gut rings in different pharmacological conditions.

RESULTS

We demonstrate that smooth muscle contractions in response to stretch or pressure is mediated by L-type Ca2+ channels and IP3 receptors. We show that this positive-feedback mechanosensitive behavior can spontaneously generate pressure gradients across gut segments initially subject to equal pressure; this same mechanism tends to stabilize initially applied pressure gradients; it can act jointly or compete with the pressure gradient induced by directional peristaltic waves. We demonstrate that high pressure differentials can reverse the physiological propagation direction of contractile waves imparted by interstitial cell of Cajal pacemaker activity. We find that flow rate increases with tube length, but that the maximum pressure differential generated depends solely on smooth muscle contractile force and on the initial resting pressure applied inside the organ.

CONCLUSIONS

We provide fundamental mechanical and hydrodynamic insight into the myogenic mechanisms of transport in the gastrointestinal tract. We scale up our results to other human peristaltic organs and discuss their implications for pathophysiology of intestinal obstruction, vesicoureteral reflux and endometriosis.

Gut physiology and environment explain variations in human gut microbiome composition and metabolism

The human gut microbiome is highly personal. However, the contribution of gut physiology and environment to variations in the gut microbiome remains understudied. Here we performed an observational trial using multi-omics to profile microbiome composition and metabolism in 61 healthy adults for 9 consecutive days. We assessed day-to-day changes in gut environmental factors and measured whole-gut and segmental intestinal transit time and pH using a wireless motility capsule in a subset of 50 individuals. We observed substantial daily fluctuations, with intra-individual variations in gut microbiome and metabolism associated with changes in stool moisture and faecal pH, and inter-individual variations accounted for by whole-gut and segmental transit times and pH. Metabolites derived from microbial carbohydrate fermentation correlated negatively with the gut passage time and pH, while proteolytic metabolites and breath methane showed a positive correlation. Finally, we identified associations between segmental transit time/pH and coffee-, diet-, host- and microbial-derived metabolites. Our work suggests that gut physiology and environment are key to understanding the individuality of the human gut microbial composition and metabolism.

State-of-the-art and future perspectives in ingestible remotely controlled smart capsules for drug delivery: A GENEGUT review

An emerging concern globally, particularly in developed countries, is the rising prevalence of Inflammatory Bowel Disease (IBD), such as Crohn's disease. Oral delivery technologies that can release the active therapeutic cargo specifically at selected sites of inflammation offer great promise to maximise treatment outcomes and minimise off-target effects. Therapeutic strategies for IBD have expanded in recent years, with an increasing focus on biologic and nucleic acid-based therapies. Reliable site-specific delivery in the gastrointestinal (GI) tract is particularly crucial for these therapeutics to ensure sufficient concentrations in the targeted cells. Ingestible smart capsules hold great potential for precise drug delivery. Despite previous unsuccessful endeavours to commercialise drug delivery smart capsules, the current rise in demand and recent advancements in component development, manufacturing, and miniaturisation have reignited interest in ingestible devices. Consequently, this review analyses the advancements in various mechanical and electrical components associated with ingestible smart drug delivery capsules. These components include modules for device localisation, actuation and retention within the GI tract, signal transmission, drug release, power supply, and payload storage. Challenges and constraints associated with previous capsule design functionality are presented, followed by a critical outlook on future design considerations to ensure efficient and reliable site-specific delivery for the local treatment of GI disorders.

The effect of fiber supplementation with agave fructans or psyllium plantago in symptoms of constipation and its relation with whole and regional transit time and pH

BACKGROUND

Supplementation with the Agave tequilana Weber blue variety fructans is a feasible treatment option for functional constipation (FC). However, its effects on colonic function have not yet been studied. This study assessed whole gut transit time (WGTT) and regional transit time using a wireless motility capsule (WMC) before and after supplementation with different fiber treatments in patients with FC.

METHODS

A secondary analysis was performed on data collected from a randomized, double-blind clinical trial comparing agave fructans with psyllium plantago. WGTT, regional transit time, contractility, and pH were measured using WMC before and after fiber supplementation. Comparisons were performed using nonparametric tests.

KEY RESULTS

Twenty patients with FC were evaluated, with a median age of 39 (25-54 years), and 18 (90%) were women. Five patients were included in each intervention group. There were no changes in WGTT or regional transit times between the groups (p > 0.05). Similarly, there were no differences in the changes experienced by regional or general contractility among the groups (p > 0.05). The cecal pH profile did not differ between the groups before and after fiber supplementation (p > 0.05). The percentages of clinical responses and consistency of bowel movements between the groups were similar.

CONCLUSIONS & INFERENCES

FC presents a clinical response to a fiber challenge, regardless of the administered intervention. However, this response was not associated with improvement in contractility or regional transit time. We speculate that there are other mechanisms by which fiber consumption may improve FC.

Intestinal Methanogen Overgrowth (IMO) Is Associated with Delayed Small Bowel and Colonic Transit Time (TT) on the Wireless Motility Capsule (WMC)

BACKGROUND

Methanogens are associated with gut dysmotility in animal models but have not been robustly studied in humans. The WMC assesses regional transit time (TT) and pH in the GI tract.

AIMS

To study the segmental TT and pH among patients with SIBO or IMO utilizing WMC.

METHODS

We conducted a retrospective study of 207 patients who underwent a glucose or lactulose breath test (BT) and WMC from 2010 to 2022. Diagnosis of SIBO and IMO were based on the 2017 North American consensus criteria. TT and pH were extracted from WMC recordings. We tested for differences in means of continuous variables and frequencies of categorical variables using two-sample t tests, Wilcoxon Rank Sum test, Chi-square, and Fisher exact tests. We used R version 3.3.1 (2016-06-21) for all statistical analyses.

RESULTS

A total of 196 patients met criteria, mean age 47.4 years and 155 (79.1%) females. Of the 86 (43.9%) patients with a positive BT, 42 (58.3%) had IMO only (meeting only CH4 criteria) and 30 (34.9%) met both H2 and CH4 criteria. Colonic TT was longer in patients with a positive BT compared to negative patients (40 h:29 min vs 28 h:51 min, p = 0.028). Small bowel TT and colonic TT were longer in patients with IMO compared to negative patients (SBTT: 5 h:15 min vs 4 h:32 min, p = 0.021; CTT: 44 h:23 min vs 28 h:51 min, p = 0.030). There were no significant differences in segmental pH compared to negative patients.

CONCLUSION

To our knowledge, this is the largest study of patients who have undergone both BT and WMC. A positive BT was associated with delayed CTT, while having IMO only was associated with both delayed CTT and SBTT, but neither with pH. Future investigation is needed to elucidate whether changes in intestinal microbiota affect gut transit.

Neuromodulation and Functional Gastrointestinal Disease

INTRODUCTION

Functional gastrointestinal disorders (FGIDs) are common, and they severely impair an individual's quality of life. The mechanism of pathogenesis and the effective treatments for FGIDs remain elusive. Neuromodulation-a relatively new treatment-has exhibited a good therapeutic effect on FGIDs, although there are different methods for different symptoms of FGIDs.

MATERIALS AND METHODS

We used PubMed to review the history of neuromodulation for the treatment of FGIDs and to review several recently proposed neuromodulation approaches with improved effects on FGIDs.

CONCLUSION

Electroacupuncture, transcutaneous electroacupuncture, transcutaneous auricular vagal nerve stimulation, sacral nerve stimulation (SNS) (which relies on vagal nerve stimulation), and gastric electrical stimulation (which works through the modulation of slow waves generated by the interstitial cells of Cajal), in addition to the noninvasive neurostimulation alternative approach method of SNS-tibial nerve stimulation and transcutaneous electrical stimulation (which is still in its infancy), are some of the proposed neuromodulation approaches with improved effects on FGIDs. This review has discussed some critical issues related to the selection of stimulation parameters and the underlying mechanism and attempts to outline future research directions backed by the existing literature.

A global bibliometric and visualized analysis of the status and trends of gastroparesis research

BACKGROUND

Gastroparesis has a substantial impact on the quality of life but has limited treatment options, which makes it a public health concern. No bibliometric studies on gastroparesis have been published thus far. Thus, this article aims to summarize and analyze research hotspots to provide a reference for clinical researchers.

MATERIALS AND METHODS

Gastroparesis-related research articles were searched in the Web of Science Core Collection (WOSCC), and relevant information was extracted after screening. A total of 1033 documents were analyzed with the bibliometric method using Microsoft Excel, Citespace, and VOSviewer.

RESULTS

Overall, our search retrieved 1033 papers contributed by 966 research institutions from 53 countries. Since 1980, publications in this field have increased rapidly. United States (n = 645) and Temple University (n = 122) were the most productive country and institution, respectively. Parkman, with 96 publications, was the most prominent author.

CONCLUSIONS

Research hotspots in gastroparesis can be summarized into four domains: innovation in diagnostic modalities, change of oral therapeutic agents, choice of surgical interventions, and pathological mechanisms. Future research on gastroparesis should focus on the quality of life of patients, diagnostic techniques, pyloromyotomy, and transpyloric stent placement.

Pan-alimentary assessment of motility, luminal content, and structures: an MRI-based framework

BACKGROUND

Gastrointestinal symptoms originating from different segments overlap and complicate diagnosis and treatment. In this study, we aimed to develop and test a pan-alimentary framework for the evaluation of gastrointestinal (GI) motility and different static endpoints based on magnetic resonance imaging (MRI) without contrast agents or bowel preparation.

METHODS

Twenty healthy volunteers (55.6 ± 10.9 years, BMI 30.8 ± 9.2 kg/m2) underwent baseline and post-meal MRI scans at multiple time points. From the scans, the following were obtained: Gastric segmental volumes and motility, emptying half time (T50), small bowel volume and motility, colonic segmental volumes, and fecal water content. Questionnaires to assess GI symptoms were collected between and after MRI scans.

KEY RESULTS

We observed an increase in stomach and small bowel volume immediately after meal intake from baseline values (p<.001 for the stomach and p=.05 for the small bowel). The volume increase of the stomach primarily involved the fundus (p<.001) in the earliest phase of digestion with a T50 of 92.1 ± 35.3 min. The intake of the meal immediately elicited a motility increase in the small bowel (p<.001). No differences in colonic fecal water content between baseline and 105 min were observed.

CONCLUSION & INFERENCES

We developed a framework for a pan-alimentary assessment of GI endpoints and observed how different dynamic and static physiological endpoints responded to meal intake. All endpoints aligned with the current literature for individual gut segments, showing that a comprehensive model may unravel complex and incoherent gastrointestinal symptoms in patients.

Host-diet-gut microbiome interactions influence human energy balance: a randomized clinical trial

The gut microbiome is emerging as a key modulator of human energy balance. Prior studies in humans lacked the environmental and dietary controls and precision required to quantitatively evaluate the contributions of the gut microbiome. Using a Microbiome Enhancer Diet (MBD) designed to deliver more dietary substrates to the colon and therefore modulate the gut microbiome, we quantified microbial and host contributions to human energy balance in a controlled feeding study with a randomized crossover design in young, healthy, weight stable males and females (NCT02939703). In a metabolic ward where the environment was strictly controlled, we measured energy intake, energy expenditure, and energy output (fecal and urinary). The primary endpoint was the within-participant difference in host metabolizable energy between experimental conditions [Control, Western Diet (WD) vs. MBD]. The secondary endpoints were enteroendocrine hormones, hunger/satiety, and food intake. Here we show that, compared to the WD, the MBD leads to an additional 116 ± 56 kcals (P < 0.0001) lost in feces daily and thus, lower metabolizable energy for the host (89.5 ± 0.73%; range 84.2-96.1% on the MBD vs. 95.4 ± 0.21%; range 94.1-97.0% on the WD; P < 0.0001) without changes in energy expenditure, hunger/satiety or food intake (P > 0.05). Microbial 16S rRNA gene copy number (a surrogate of biomass) increases (P < 0.0001), beta-diversity changes (whole genome shotgun sequencing; P = 0.02), and fermentation products increase (P < 0.01) on an MBD as compared to a WD along with significant changes in the host enteroendocrine system (P < 0.0001). The substantial interindividual variability in metabolizable energy on the MBD is explained in part by fecal SCFAs and biomass. Our results reveal the complex host-diet-microbiome interplay that modulates energy balance.

Evaluation of the Appropriate LigaSure™ Device to Transect the Appendix-A Comparison between 5 mm and 10 mm Laparoscopic Devices in an Ex Vivo Trial

Background and Objectives: A topic of greatinterest in the surgical field comprises cost and time reduction operative techniques with high efficiency rates. Thus, the aim of this paper is to evaluate whether a transection of the appendix using only a laparoscopic LigaSure™ device is feasible and, if so, which size of the laparoscopic device is optimal. Materials and Methods: Appendectomy specimens were sealed and cut using LigaSure^TM V (5 mm) and LigaSure Atlas^TM (10 mm) devices ex vivo. Analysis criteria included handling, resistance to bursting pressure of the appendicular stump (adequacy), eligibility, durability and airtightness. Results: Twenty sealed areas were measured. While the 5 mm instrument was not able to transect the appendix in one attempt in any of the cases, the 10 mm device could be applied successfully without any handling difficulties. The adequacy of the sealed area was rated as complete and dry in all 10 cases using the 10 mm device and as oozing in 8 of the cases using the 5 mm device. There was no leakage in terms of air and liquid tightness using the 10 mm device, in contrast to six sealed segments with air and liquid leakage when using the 5 mm device. The resistance to bursting pressure was on average 285 mmHg and 60.5 mmHg with the 10 mm and 5 mm devices, respectively. The durability and eligibility of the 10 mm device were rated as very sufficient in 9 of 10 cases (1 perforation) in contrast to the 5 mm device, where the sealing in 9 of 10 cases was not sufficient (9 perforations). Conclusions: Using the 10 mm laparoscopic LigaSure™ device for the transection of the appendix seems to be feasible, safe and resistant to 300 mmHg bursting pressure. The 5 mm LigaSure™ instrument is inadequate to seal the appendix in humans.

Fecal microbiota transplantation in Parkinson's disease-A randomized repeat-dose, placebo-controlled clinical pilot study

Background and purpose

The intestinal microbiome plays a primary role in the pathogenesis of neurodegenerative disorders and may provide an opportunity for disease modification. We performed a pilot clinical study looking at the safety of fecal microbiota transplantation (FMT), its effect on the microbiome, and improvement of symptoms in Parkinson's disease.

Methods

This was a randomized, double-blind placebo-controlled pilot study, wherein orally administered lyophilized FMT product or matching placebo was given to 12 subjects with mild to moderate Parkinson's disease with constipation twice weekly for 12 weeks. Subjects were followed for safety and clinical improvement for 9 additional months (total study duration 12 months).

Results

Fecal microbiota transplantation caused non-severe transient upper gastrointestinal symptoms. One subject receiving FMT was diagnosed with unrelated metastatic cancer and was removed from the trial. Beta diversity (taxa) of the microbiome, was similar comparing placebo and FMT groups at baseline, however, for subjects randomized to FMT, it increased significantly at 6 weeks (p = 0.008) and 13 weeks (p = 0.0008). After treatment with FMT, proportions of selective families within the phylum Firmicutes increased significantly, while proportion of microbiota belonging to Proteobacteria were significantly reduced. Objective motor findings showed only temporary improvement while subjective symptom improvements were reported compared to baseline in the group receiving FMT. Constipation, gut transient times (NS), and gut motility index (p = 0.0374) were improved in the FMT group.

Conclusions

Subjects with Parkinson's disease tolerated multi-dose-FMT, and experienced increased diversity of the intestinal microbiome that was associated with reduction in constipation and improved gut transit and intestinal motility. Fecal microbiota transplantation administration improved subjective motor and non-motor symptoms.

Clinical trial registration

ClinicalTrial.gov, identifier: NCT03671785.

Effect of sleeve gastrectomy and Roux-en-Y gastric bypass on gastrointestinal physiology

BACKGROUND

Knowledge regarding the gastrointestinal physiology after sleeve gastrectomy and Roux-en-Y gastric bypass is urgently needed to understand, prevent and treat the nutritional and pharmacological complications of bariatric surgery.

AIM

To investigate the effect of sleeve gastrectomy and Roux-en-Y gastric bypass on gastrointestinal motility (e.g., transit and pressure), pH, and intestinal bile acid concentration.

MATERIAL AND METHODS

An exploratory cross-sectional study was performed in six participants living with obesity, six participants who underwent sleeve gastrectomy, and six participants who underwent Roux-en-Y gastric bypass. During the first visit, a wireless motility capsule (SmartPill©) was ingested after an overnight fast to measure gastrointestinal transit, pH, and pressure. During the second visit, a gastric emptying scintigraphy test of a nutritional drink labeled with ^99mTc-colloid by a dual-head SPECT gamma camera was performed to measure gastric emptying half-time (GET_1/2). During the third visit, two customized multiple lumen aspiration catheters were positioned to collect fasting and postprandial intestinal fluids to measure bile acid concentration.

RESULTS

Immediate pouch emptying (P = 0.0007) and a trend for faster GET_1/2 (P = 0.09) were observed in both bariatric groups. There was a tendency for a shorter orocecal transit in participants with sleeve gastrectomy and Roux-en-Y gastric bypass (P = 0.08). The orocecal segment was characterized by a higher 25th percentile pH (P = 0.004) and a trend for a higher median pH in both bariatric groups (P = 0.07). Fasting total bile acid concentration was 7.5-fold higher in the common limb after Roux-en-Y gastric bypass (P < 0.0001) and 3.5-fold higher in the jejunum after sleeve gastrectomy (P = 0.009) compared to obesity. Postprandial bile acid concentration was 3-fold higher in the jejunum after sleeve gastrectomy (P = 0.0004) and 6.5-fold higher in the common limb after Roux-en-Y gastric bypass (P < 0.0001) compared to obesity.

CONCLUSION

The anatomical alterations of sleeve gastrectomy and Roux-en-Y gastric bypass have an important impact on gastrointestinal physiology. This data confirms changes in transit and pH and provides the first evidence for altered intraluminal bile acid concentration.

Impact of Objective Colonic and Whole Gut Motility Data as Measured by Wireless Motility Capsule on Outcomes of Antireflux Surgery

BACKGROUND

Studies show higher rates of dissatisfaction with antireflux surgery (ARS) outcomes in patients with chronic constipation. This suggests a relationship between colonic dysmotility and suboptimal surgical outcome. However, due to limitations in technology, there is no objective data available examining this relationship. The wireless motility capsule (WMC) is a novel technology consisting of an ingestible capsule equipped with pH, temperature, and pressure sensors, which provide information regarding regional and whole gut transit times, pH and motility. The aim of this study was to assess the impact of objective regional and whole gut motility data on the outcomes of ARS.

STUDY DESIGN

This was a retrospective review of patients who underwent WMC testing before ARS. Transit times, motility, and pH data obtained from different gastrointestinal tract regions were used in analysis to determine factors that impact surgical outcome. A favorable outcome was defined as complete resolution of the predominant reflux symptom and freedom from antisecretory medications.

RESULTS

The final study population consisted of 48 patients (fundoplication [n = 29] and magnetic sphincter augmentation [n = 19]). Of those patients, 87.5% were females and the mean age ± SD was 51.8 ± 14.5 years. At follow-up (mean ± SD, 16.8 ± 13.2 months), 87.5% of all patients achieved favorable outcomes. Patients with unfavorable outcomes had longer mean whole gut transit times (92.0 hours vs 55.7 hours; p = 0.024) and colonic transit times (78.6 hours vs 47.3 hours; p = 0.028), higher mean peak colonic pH (8.8 vs 8.15; p = 0.009), and higher mean antral motility indexes (310 vs 90.1; p = 0.050).

CONCLUSIONS

This is the first study to demonstrate that objective colonic dysmotility leads to suboptimal outcomes after ARS. WMC testing can assist with preoperative risk assessment and counseling for patients seeking ARS.

State of the Art in Smart Portable, Wearable, Ingestible and Implantable Devices for Health Status Monitoring and Disease Management

Several illnesses that are chronic and acute are becoming more relevant as the world's aging population expands, and the medical sector is transforming rapidly, as a consequence of which the need for "point-of-care" (POC), identification/detection, and real time management of health issues that have been required for a long time are increasing. Biomarkers are biological markers that help to detect status of health or disease. Biosensors' applications are for screening for early detection, chronic disease treatment, health management, and well-being surveillance. Smart devices that allow continual monitoring of vital biomarkers for physiological health monitoring, medical diagnosis, and assessment are becoming increasingly widespread in a variety of applications, ranging from biomedical to healthcare systems of surveillance and monitoring. The term "smart" is used due to the ability of these devices to extract data with intelligence and in real time. Wearable, implantable, ingestible, and portable devices can all be considered smart devices; this is due to their ability of smart interpretation of data, through their smart sensors or biosensors and indicators. Wearable and portable devices have progressed more and more in the shape of various accessories, integrated clothes, and body attachments and inserts. Moreover, implantable and ingestible devices allow for the medical diagnosis and treatment of patients using tiny sensors and biomedical gadgets or devices have become available, thus increasing the quality and efficacy of medical treatments by a significant margin. This article summarizes the state of the art in portable, wearable, ingestible, and implantable devices for health status monitoring and disease management and their possible applications. It also identifies some new technologies that have the potential to contribute to the development of personalized care. Further, these devices are non-invasive in nature, providing information with accuracy and in given time, thus making these devices important for the future use of humanity.

Randomised trial: Peppermint oil (menthol) pharmacokinetics in children and effects on gut motility in children with functional abdominal pain

AIMS

Little is known regarding the pharmacokinetics and pharmacodynamics of menthol, the active ingredient in peppermint oil (PMO). Our aim was to investigate the pharmacokinetics of menthol at 3 dose levels in children and determine their effects on gut motility and transit.

METHODS

Thirty children ages 7-12 years with functional abdominal pain underwent wireless motility capsule (WMC) testing. Approximately 1 week later they were randomized to 180, 360 or 540 mg of enteric coated PMO (10 participants per dose). Menthol pharmacokinetics were determined via blood sampling over 24 hours. They then took their respective dose of PMO (180 mg once, 180 mg twice or 180 mg thrice daily) for 1 week during which time the WMC test was repeated.

RESULTS

Evaluable area under the plasma concentration vs. time curve (AUC_last ) data were available in 29 of 30 participants. A direct linear relationship (apparent dose-proportionality for systemic menthol exposure) was observed between PMO dose and menthol systemic exposure with mean elimination half-life 2.1, 3.5 and 4.6 hours for the 180, 360 and 540 mg doses, respectively. WMC technical issues precluded complete motility data in all participants. Colonic transit time was inversely related to AUC_last (P = .003); transit time in other regions was not affected. In contrast, stomach, small bowel and whole gut (but not colonic) contractility positively correlated with menthol AUC_last (P < .05).

CONCLUSION

Pharmacokinetics and pharmacodynamics of menthol derived from PMO demonstrated apparent dose-proportionality. A higher dose of PMO may be needed to achieve maximal gut response. www.clinicaltrials.gov NCT03295747.

Ingestible devices for studying the gastrointestinal physiology and their application in oral biopharmaceutics

Ingestible sensor systems are unique tools for obtaining physiological data from an undisturbed gastrointestinal tract. Since their dimensions correspond to monolithic oral dosage forms, such as enteric coated tablets or hydrogel matrix tablets, they also allow insights into the physiological conditions experienced by non-disintegrating dosage forms on their way through the gastrointestinal tract. In this work, the different ingestible sensor systems which can be used for this purpose are described and their potential applications as well as difficulties and pitfalls with respect to their use are presented. It is also highlighted how the data on transit times, pH, temperature and pressure as well as the data from different animal models commonly used in drug product development such as dogs and pigs have contributed to a deeper mechanistic understanding of oral drug delivery.

Effect of obesity on gastrointestinal transit, pressure and pH using a wireless motility capsule

BACKGROUND

Despite the increasing prevalence and medical burden of obesity, the understanding of gastrointestinal physiology in obesity is scarce, which hampers drug development.

AIM

To investigate the effect of obesity and food intake on gastrointestinal transit, pressure and pH.

MATERIAL AND METHODS

An exploratory cross-sectional study using a wireless motility capsule (SmartPill©) was performed in 11 participants with obesity and 11 age- and gender-matched participants with normal weight (group) in fasted and fed state (visit). During the first visit, the capsule was ingested after an overnight fast. During a second visit, the capsule was ingested after a nutritional drink to simulate fed state. Linear mixed models were constructed to compare segmental gastrointestinal transit, pressure and pH between groups (obesity or control) and within every group (fasted or fed).

RESULTS

Food intake slowed gastric emptying in both groups (both P < 0.0001), though food-induced gastric contractility was higher in participants with obesity compared to controls (P = 0.02). In the small intestine, a higher contractility (P = 0.001), shorter transit (P = 0.04) and lower median pH (P = 0.002) was observed in participants with obesity compared to controls. No differences were observed for colonic measurements.

CONCLUSION

Obesity has a profound impact on gastrointestinal physiology, which should be taken into account for drug development.

Gastrointestinal Physiology Before and After Duodenal Switch with Comparisons to Unoperated Lean Controls: Novel Use of the SmartPill Wireless Motility Capsule

Purpose

Bariatric surgery alters gastrointestinal anatomy. In this exploratory study, the SmartPill® wireless motility capsule (WMC) was used to study changes in gastrointestinal physiology following biliopancreatic diversion with duodenal switch (BPD/DS).

Material and Methods

Twenty-eight BPD/DS patients (35 ± 11 years, 50% females, body mass index [BMI] 56 ± 5) were to be examined preoperatively and postoperatively. In addition to transit time, appetite control and gastrointestinal symptoms were studied by patient-scored questionnaires (visual analogue scale and Gastrointestinal Symptom Rating Scale (GSRS)). Data was compared to 41 lean unoperated controls.

Results

About 1.8 years postoperatively, 18 patients (BMI 35.8 ± 8.3) returned for a second WMC test. As expected, small bowel transit time was reduced, from 3.9 ± 1.6 h to 2.8 ± 2.0, p = 0.02, and at both these time points, it was shorter than in lean controls (5.4 ± 1.9 h, p = 0.001). Postoperatively, a trend towards reduced colon and whole gut transit times was seen in BPD/DS-patients, thus approaching those of lean controls. Surprisingly, BPD/DS patients scored higher satiety than controls preoperatively as well as increased hunger and desire to eat postoperatively. Compared to lean, BPD/DS patients reported a higher total GSRS score at both time points (1.2 ± 0.2 vs 1.7 ± 0.6 and 2.3 ± 0.5, p < 0.001). Postoperatively, the scores for diarrhea and indigestion increased.

Conclusions

The novel use of the SmartPill system in BPD/DS patients gave the expected readouts. Although small bowel transit time was further shortened after BPD/DS, whole gut transit time did not differ from controls. Typical gastrointestinal symptoms were reported postoperatively.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11695-021-05452-4.

Safety and Suitability of the SmartPill® after Abdominal Surgery: Results of the Prospective, Two-Armed, Open-Label PIDuSA Trial

INTRODUCTION

Postoperative ileus (POI) is a common complication after abdominal surgery. Until today, an evidence-based treatment of prolonged POI is still lacking, which can be attributed to the poor quality of clinical trials. Various different surrogate markers used to define POI severity are considered to be the cause of low-quality trials making it impossible to derive treatment recommendation. The SmartPill®, which is able to record pH values, temperature and pressure after ingestion, could be an ideal tool to measure transit times and peristalsis and therefore analyze POI severity. Unfortunately, the device has no approval for postoperative use due to safety concerns. The primary objective of the study is to determine safety of the SmartPill® in patients undergoing surgery. Secondary objectives were the quality of the recorded data and the suitability of the SmartPill® for analyzing intestinal motility after different surgical procedures.

METHODS

The PIDuSA Study is a prospective, 2-arm, open-label trial. At the end of surgery, the SmartPill® was applied to 49 patients undergoing abdominal surgery having a high risk for impaired intestinal motility and 15 patients undergoing extra-abdominal surgery. Patients were visited daily to access safety data of the SmartPill® on the basis of adverse and serious adverse events (AEs/SAEs). Suitability and data quality were investigated by analyzing data completeness and feasibility to determine transit times and peristalsis for all sections of the gastrointestinal tract.

RESULTS

In total, 179 AEs and 8 SAEs were recorded throughout the study affecting 42 patients in the abdominal (158 AEs) and 9 patients in the extra-abdominal surgery group (21 AEs, p = 0.061); none of them were device related. Primary capsule failure was observed in 5 patients, ultimately resulting in an impossibility of data analysis in only 3 patients (4.4%). 9% of the recorded data were incomplete due to the patient's incompliance in keeping the receiver close to the body. In 3 patients (4.4%), isolated small bowel transit could not be determined due to pH alterations as a result of prolonged POI.

DISCUSSION

Our study demonstrates that the use of the SmartPill® is safe after surgery but requires a reasonable patient compliance to deliver meaningful data. An objective analysis of transit times and peristalsis was possible irrespective of type and site of surgery in over 95% indicating that the SmartPill® has the potential to deliver objective parameters for POI severity in future clinical trials. However, in some patients with prolonged POI, analysis of small bowel transit could be challenging.

Severe gastroparesis is associated with an increased incidence of slow-transit constipation as measured by wireless motility capsule

BACKGROUND

Dysmotility in one region of the gastrointestinal tract has been found to predispose patients to developing motility disorders in other gastrointestinal segments. However, few studies have evaluated the relationship between gastroparesis and constipation.

METHODS

Retrospective review of 224 patients who completed 4-hour, solid-phase gastric emptying scintigraphy (GES), and wireless motility capsule (WMC) testing to evaluate for gastroparesis and slow-transit constipation, respectively. When available, anorectal manometry data were reviewed to evaluate for dyssynergic defecation. Patients were divided into two groups based on the results of the GES: 101 patients with normal gastric emptying and 123 patients with gastroparesis (stratified by severity). Differences in constipation rates were compared between the groups.

KEY RESULTS

Slow-transit constipation was more common in the gastroparesis group, but statistical significance was not reached (42.3% vs 34.7%, p = 0.304). Univariate logistical regression analysis found no association between slow-transit constipation and gastroparesis (OR 1.38, 95% CI 0.80-2.38, p = 0.245) nor dyssynergic defecation and gastroparesis (OR 0.88, 95% CI 0.29-2.70, p = 0.822). However, when stratifying gastroparesis based on severity, slow-transit constipation was found to be associated with severe gastroparesis (OR 2.45, 95% CI 1.20-5.00, p = 0.014). This association was strengthened with the exclusion of patients with diabetes mellitus (OR 3.5, 95% CI 1.39-8.83, p = 0.008) - a potential confounder.

CONCLUSIONS & INFERENCES

Patients with severe gastroparesis (>35% gastric retention at the 4-hour mark on solid-phase GES) have an increased likelihood of having underlying slow-transit constipation. Dyssynergic defecation does not appear to be associated with gastroparesis (of any severity).

Acupoint catgut embedding therapy for functional constipation: A protocol for systematic review and meta-analysis

BACKGROUND

This review will assess current evidence related to the effectiveness and safety of acupoint catgut embedding therapy for functional constipation (FC) and provide efficacy assessments for clinical applications.

METHODS

We will search the following databases for relevant trials: PubMed, EMBASE OVID, Cumulative Index of Nursing and Allied Health Literature, OVID MEDLINE, Web of Science, the Cochrane Central Register of Controlled Trials, Cochrane library, and Scopus. We will also search the following Chinese databases for trials published in the Chinese literature: China National Knowledge Infrastructure Database (CNKI), Chinese Scientific Journals Database, Wan Fang Database, Chinese Biomedicine and other resources from inception to December 2020. Only randomized controlled trials comparing acupoint catgut embedding versus acupuncture or sham acupuncture or placebo or other therapies will be included. The outcomes involved mean spontaneous bowel movements, complete spontaneous bowel movements, the Bristol Stool Form Scale, the Cleveland Clinic Score, Patient Assessment of Constipation symptom and so on. The risk of bias assessment and quality of evidence for outcomes will be appraised using the Cochrane Risk of Bias Tool and the Grading of Recommendations, Assessment, Development and Evaluation guidelines. RevMan 5.3 software will be employed for the meta-analysis.

RESULTS

This work will compare and arrange the comparative efficacy of acupoint catgut embedding with different treatments for FC by summarizing the current evidences.

CONCLUSION

The results of this meta-analysis may help doctors determine the best treatments for patients to manage FC.

ETHICS AND DISSEMINATION

This is a protocol with no patient recruitment and personal information collection, approval by the ethics committee is not required.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/XTKE2.

Effects of energy balance on appetite and physiological mediators of appetite during strenuous physical activity: secondary analysis of a randomised crossover trial

Energy deficit is common during prolonged periods of strenuous physical activity and limited sleep, but the extent to which appetite suppression contributes is unclear. The aim of this randomised crossover study was to determine the effects of energy balance on appetite and physiological mediators of appetite during a 72-h period of high physical activity energy expenditure (about 9·6 MJ/d (2300 kcal/d)) and limited sleep designed to simulate military operations (SUSOPS). Ten men consumed an energy-balanced diet while sedentary for 1 d (REST) followed by energy-balanced (BAL) and energy-deficient (DEF) controlled diets during SUSOPS. Appetite ratings, gastric emptying time (GET) and appetite-mediating hormone concentrations were measured. Energy balance was positive during BAL (18 (sd 20) %) and negative during DEF (–43 (sd 9) %). Relative to REST, hunger, desire to eat and prospective consumption ratings were all higher during DEF (26 (sd 40) %, 56 (sd 71) %, 28 (sd 34) %, respectively) and lower during BAL (–55 (sd 25) %, −52 (sd 27) %, −54 (sd 21) %, respectively; Pcondition < 0·05). Fullness ratings did not differ from REST during DEF, but were 65 (sd 61) % higher during BAL (Pcondition < 0·05). Regression analyses predicted hunger and prospective consumption would be reduced and fullness increased if energy balance was maintained during SUSOPS, and energy deficits of ≥25 % would be required to elicit increases in appetite. Between-condition differences in GET and appetite-mediating hormones identified slowed gastric emptying, increased anorexigenic hormone concentrations and decreased fasting acylated ghrelin concentrations as potential mechanisms of appetite suppression. Findings suggest that physiological responses that suppress appetite may deter energy balance from being achieved during prolonged periods of strenuous activity and limited sleep.

Gastrointestinal symptoms and cardiac vagal tone in type 1 diabetes correlates with gut transit times and motility index

BACKGROUND

Although gastrointestinal (GI) symptoms are common in diabetes, they frequently do not correlate with measurable sensorimotor abnormalities. The wireless motility capsule (WMC) measures pressure, temperature, and pH as it traverses the GI tract wherefrom transit times and motility indices are derived. The aim was to investigate whether GI symptoms correlate with changes in (a) segmental transit times, (b) segmental motility index, (c) cardiac vagal tone, or (d) presence/absence of peripheral neuropathy in type 1 diabetes.

METHODS

Gastrointestinal symptoms in 104 participants with type 1 diabetes were measured using Gastroparesis Cardinal Symptoms Index and Gastrointestinal Symptom Rating Scale. All underwent standardized WMC investigation measuring segmental transit time and motility. Cardiac vagal tone and presence of peripheral neuropathy were measured using electrocardiographic and nerve conduction velocity testing.

KEY RESULTS

Colonic transit time was correlated with postprandial fullness (P = .01) and constipation (P = .03), while decreased colonic motility index was correlated with diarrhea (P = .01) and decreased bloating (P < .05). Symptoms were not correlated with gastric or small bowel transit time or motility index. In participants with low cardiac vagal tone, gastric motility index (P < .01) and colonic transit time (P < .05) were increased, but not in those with peripheral neuropathy. Abdominal pain was decreased with both peripheral neuropathy (P = .04) and decreased cardiac vagal tone (P = .02).

CONCLUSIONS AND INFERENCES

This study supports the rationale for whole gut investigation, using not only transit times but incorporating contractility indices as well. Furthermore, a decreased parasympathetic modulation and an increased hyposensate state appear to be present in type 1 diabetes.

Video Capsule Endoscopy and Ingestible Electronics: Emerging Trends in Sensors, Circuits, Materials, Telemetry, Optics, and Rapid Reading Software

Real-time monitoring of the gastrointestinal tract in a safe and comfortable manner is valuable for the diagnosis and therapy of many diseases. Within this realm, our review captures the trends in ingestible capsule systems with a focus on hardware and software technologies used for capsule endoscopy and remote patient monitoring. We introduce the structure and functions of the gastrointestinal tract, and the FDA guidelines for ingestible wireless telemetric medical devices. We survey the advanced features incorporated in ingestible capsule systems, such as microrobotics, closed-loop feedback, physiological sensing, nerve stimulation, sampling and delivery, panoramic imaging with adaptive frame rates, and rapid reading software. Examples of experimental and commercialized capsule systems are presented with descriptions of their sensors, devices, and circuits for gastrointestinal health monitoring. We also show the recent research in biocompatible materials and batteries, edible electronics, and alternative energy sources for ingestible capsule systems. The results from clinical studies are discussed for the assessment of key performance indicators related to the safety and effectiveness of ingestible capsule procedures. Lastly, the present challenges and outlook are summarized with respect to the risks to health, clinical testing and approval process, and technology adoption by patients and clinicians.

Gastroparesis in the Hospital Setting

Gastroparesis (GP) is commonly seen in hospitalized patients. Refractory vomiting and related dehydration, electrolyte abnormalities, and malnutrition are indications for hospital admission. In addition, tube feeding intolerance is a common sign of gastric dysmotility in critically ill patients. The diagnosis and management of GP in the hospital setting can be quite challenging. Diagnostic tests are often deferred because of patient intolerance of the oral meal for standard scintigraphy or severity of the primary disease. The diagnosis of GP is often established on the basis of clinical scenario and risk factors for gastric motor dysfunction. Medical therapy in GP is directed toward controlling nausea and vomiting by prokinetic and antinausea medications and correcting nutrition risks or treating malnutrition with nutrition therapy. Enteral nutrition is the preferred nutrition intervention for patients with GP. Delayed gastric emptying in critically ill patients has a negative impact on the timely delivery of enteral feeding and meeting the energy and protein goals. Measures to improve gastric tolerance or provide feeding beyond the stomach are often needed, since early enteral nutrition has been an important target of therapy for critically ill patients. This review will address the current understanding of the mechanisms of GP and feeding intolerance in critical illness, diagnostic workup, drug therapies, and interventions to improve the provision of enteral nutrition in hospital settings when gastric dysmotility is present or suspected.

Neuroimmunogastroenterology: At the Interface of Neuroimmunology and Gastroenterology

The central nervous system (CNS) is an important regulator of the gastrointestinal tract, and CNS dysfunction can result in significant and disabling gastrointestinal symptom manifestation. For patients with neuroimmunologic and neuroinflammatory conditions, the recognition of gastrointestinal symptoms is under-appreciated, yet the gastrointestinal manifestations have a dramatic impact on quality of life. The current treatment strategies, often employed independently by the neurologist and gastroenterologist, raise the question of whether such patients are being treated optimally when siloed in one specialty. Neuroimmunogastroenterology lies at the borderlands of medical specialties, and there are few resources to guide neurologists in this area. Here, we provide an overview highlighting the potential mechanisms of crosstalk between immune-mediated neurological disorders and gastrointestinal dysfunction.

Constipation screening in people taking clozapine: A diagnostic accuracy study

OBJECTIVE

Clozapine is the favoured antipsychotic for treatment-refractory schizophrenia but its safe use requires careful adverse-effect management. Clozapine-induced gastrointestinal hypomotility (CIGH or 'slow-gut') is one of the most common and serious of clozapine's adverse effects. CIGH can lead to paralytic ileus, bowel obstruction, gastrointestinal ischaemia, toxic megacolon, and death. Enquiring about constipation is a simple and commonly used screening method for CIGH but its diagnostic accuracy has not previously been assessed.

METHODS

First, we examined the reliability of asking about constipation compared with asking about Rome constipation criteria in inpatients treated with clozapine (n = 69). Second, we examined the diagnostic accuracy of (1) self-reported constipation and (2) the Rome criteria, compared with the reference standard of gastrointestinal motility studies.

RESULTS

After 30 motility tests, it was clear constipation screening had very poor diagnostic properties in this inpatient group and the study was terminated. Although 73% of participants had objective CIGH on motility testing, only 26% of participants self-reported constipation, with sensitivity of 18% (95% CI: 5-40%). Specificity and positive predictive values were higher (95% CI: 63-100% and 40-100%, respectively). Adding in Rome criteria improved sensitivity to 50% (95% CI: 28.2-71.8%), but half the cases were still missed, making this no more accurate than tossing a coin.

CONCLUSIONS

CIGH is often silent, with self-reported constipation having low sensitivity in its diagnosis. Treating CIGH based on self-reported symptoms questions will miss most cases. However, universal bowel motility studies are impractical. In the interests of patient safety, prophylactic laxatives are suggested for people taking clozapine.

Normative values for gastric motility assessed with the 3D-transit electromagnetic tracking system

BACKGROUND

The Motilis 3D-Transit system allows ambulatory description of transit patterns throughout the gastrointestinal tract and offers an alternative method for studying gastric motility. We aimed to establish normative values for gastric motility assessed with the method.

METHOD

A total of 132 healthy volunteers ingested the 3D-Transit capsule for assessment of gastrointestinal transit times. Recordings from 125 subjects were used for definition of normative values. Forty-six subjects were studied on two consecutive days. Recordings were reanalyzed using newly developed software providing information on gastric emptying (GE) as well as contraction frequency and movement during gastric contractions.

RESULTS

The median GE time was 2.7 hours (range 0.1-21.2). In 89% of subjects, the capsule passed the pylorus within a postingestion period of 6 hours. The median frequency of gastric contractions was 3.1 per minute (range 2.6-3.8). The frequency was higher in women (3.2, range 2.7-3.8) than in men (3.0, range 2.6-3.5) and increased with age (0.004 per year) (P < .05). The median amplitudes were 35° (range 4-85) when based on rotation of the capsule and 11 mm (range 6-31) when based on capsule change in position. The rotation amplitude was higher in women and decreased with increasing BMI (P < .05). The position amplitude was also higher in women and increased with the amount of calories in the test meal, but decreased with increasing BMI and age (P < .05). Day-to-day variation (P > .05) was considerable while inter-rater variability was small.

CONCLUSION AND INFERENCES

We have established normative values for gastric motility assessed with the 3D-Transit system.

Ingestible Sensors and Sensing Systems for Minimally Invasive Diagnosis and Monitoring: The Next Frontier in Minimally Invasive Screening

Ingestible electronic systems that are capable of embedded sensing, particularly within the gastrointestinal (GI) tract and its accessory organs, have the potential to screen for diseases that are difficult if not impossible to detect at an early stage using other means. Furthermore, these devices have the potential to (1) reduce labor and facility costs for a variety of procedures, (2) promote research for discovering new biomarker targets for associated pathologies, (3) promote the development of autonomous or semiautonomous diagnostic aids for consumers, and (4) provide a foundation for epithelially targeted therapeutic interventions. These technological advances have the potential to make disease surveillance and treatment far more effective for a variety of conditions, allowing patients to lead longer and more productive lives. This review will examine the conventional techniques, as well as ingestible sensors and sensing systems that are currently under development for use in disease screening and diagnosis for GI disorders. Design considerations, fabrication, and applications will be discussed.

Wireless motility capsule compared with scintigraphy in the assessment of diabetic gastroparesis

BACKGROUND

Gastroparesis is a potentially severe late complication of diabetes mellitus. Today, delayed gastric emptying (GE) is mandatory for establishing the diagnosis. In this study, we compared wireless motility capsule (WMC) with gastric emptying scintigraphy (GES).

METHODS

Seventy-two patients (49 women) with diabetes mellitus (59 type 1) and symptoms compatible with gastroparesis were prospectively included between 2014 and 2018. Patients were simultaneously examined with GES and WMC. Symptoms were assessed with the Patient Assessment of Upper Gastrointestinal Symptom Severity Index (PAGI-SYM) questionnaire. All patients were on intravenous glucose-insulin infusion during testing.

KEY RESULTS

WMC and GES correlated r = .74, P < .001. Compared to GES, WMC at ordinary cutoff for delayed GE (300 minutes) had a sensitivity of 0.92, specificity 0.73, accuracy 0.80, and Cohen's kappa κ = 0.61 (P < .001). By receiver operating characteristics (ROC), the area under the curve was 0.95 (P < .001). A cutoff value for delayed GE of 385 minutes produced sensitivity 0.92, specificity 0.83, accuracy 0.86, and Cohen's kappa κ = 0.72 (P < .001). Inter-rater reliability for GE time with WMC was r = .996, κ = 0.97, both P < .001. There was no difference in symptom severity between patients with normal and delayed GE.

CONCLUSIONS & INFERENCES

Our findings demonstrate the applicability of WMC as a reliable test to assess gastric emptying in diabetic gastroparesis showing very high inter-observer correlation. By elevating the cutoff value for delayed emptying from 300 to 385 minutes, we found higher specificity without reducing sensitivity.

Determination of gastrointestinal passage rate using three different markers in laying hens

The titanium dioxide (TiO₂ ) marker technique is currently widely practiced as a method to evaluate gastrointestinal (GI) passage rate in poultry. However, this method requires sacrificing the animal to obtain digesta samples, is labour-intensive and eliminates the possibility of follow-up studies with the same individual. The aim of this study was to evaluate whether the radiographic methods barium-impregnated polyethylene spheres (BIPS) and barium sulphate (BaSO₄ ) suspension are in agreement with the TiO₂ technique and can be used as an alternative method for GI passage rate determination in laying hens. Whole-body radiographs were taken at different time points. Hens of group 3 (n = 55) were orally inoculated with 5 g of feed mixed with 0.15 g TiO₂ , 5 hens per time point sacrificed, and whole gastrointestinal organs (crop, proventriculus, gizzard, small intestine and large intestine) were collected and analysed for TiO₂ content. The average marker passage rate of hens administered BaSO₄ was significantly faster than those administered BIPS (gizzard: 15.2 hr vs. 43.2 hr; small intestine: 15.2 hr vs. 38.4 hr, respectively). A greater percentage of BIPS remained in the crop at 0, 0.5, 2, 3 and 8 hr post-inoculation (p.i.) and in the gizzard at 2, 24, 36 and 48 hr p.i. (all p < 0.05) compared to TiO₂ . In conclusion, the evaluation of the GI transit time is feasible using BIPS, TiO₂ and BaSO₄ . The evaluation of the GI transit time using BIPS and BaSO₄ needs further investigation.

Gastrointestinal diagnosis using non-white light imaging capsule endoscopy

Capsule endoscopy (CE) has proved to be a powerful tool in the diagnosis and management of small bowel disorders since its introduction in 2001. However, white light imaging (WLI) is the principal technology used in clinical CE at present, and therefore, CE is limited to mucosal inspection, with diagnosis remaining reliant on visible manifestations of disease. The introduction of WLI CE has motivated a wide range of research to improve its diagnostic capabilities through integration with other sensing modalities. These developments have the potential to overcome the limitations of WLI through enhanced detection of subtle mucosal microlesions and submucosal and/or transmural pathology, providing novel diagnostic avenues. Other research aims to utilize a range of sensors to measure physiological parameters or to discover new biomarkers to improve the sensitivity, specificity and thus the clinical utility of CE. This multidisciplinary Review summarizes research into non-WLI CE devices by organizing them into a taxonomic structure on the basis of their sensing modality. The potential of these capsules to realize clinically useful virtual biopsy and computer-aided diagnosis (CADx) is also reported.

Mechanically induced development and maturation of human intestinal organoids in vivo

The natural ability of stem cells to self-organize into functional tissue has been harnessed for the production of functional human intestinal organoids. Although dynamic mechanical forces play a central role in intestinal development and morphogenesis, conventional methods for the generation of intestinal organoids have relied solely on biological factors. Here, we show that the incorporation of uniaxial strain, by using compressed nitinol springs, in human intestinal organoids transplanted into the mesentery of mice induces growth and maturation of the organoids. Assessment of morphometric parameters, transcriptome profiling, and functional assays of the strain-exposed tissue revealed higher similarities to native human intestine, with regards to tissue size and complexity, and muscle tone. Our findings suggest that the incorporation of physiologically relevant mechanical cues during the development of human intestinal tissue enhances its maturation and enterogenesis.

Colonic transit time and pressure based on Bernoulli's principle

PURPOSE

Variations in the caliber of human large intestinal tract causes changes in pressure and the velocity of its contents, depending on flow volume, gravity, and density, which are all variables of Bernoulli's principle. Therefore, it was hypothesized that constipation and diarrhea can occur due to changes in the colonic transit time (CTT), according to Bernoulli's principle. In addition, it was hypothesized that high amplitude peristaltic contractions (HAPC), which are considered to be involved in defecation in healthy subjects, occur because of cecum pressure based on Bernoulli's principle.

METHODS

A virtual healthy model (VHM), a virtual constipation model and a virtual diarrhea model were set up. For each model, the CTT was decided according to the length of each part of the colon, and then calculating the velocity due to the cecum inflow volume. In the VHM, the pressure change was calculated, then its consistency with HAPC was verified.

RESULTS

The CTT changed according to the difference between the cecum inflow volume and the caliber of the intestinal tract, and was inversely proportional to the cecum inflow volume. Compared with VHM, the CTT was prolonged in the virtual constipation model, and shortened in the virtual diarrhea model. The calculated pressure of the VHM and the gradient of the interlocked graph were similar to that of HAPC.

CONCLUSION

The CTT and HAPC can be explained by Bernoulli's principle, and constipation and diarrhea may be fundamentally influenced by flow dynamics.

A Prospective Evaluation of Ileocecal Valve Dysfunction and Intestinal Motility Derangements in Small Intestinal Bacterial Overgrowth

BACKGROUND

Small intestinal bacterial overgrowth (SIBO) is an increasingly recognized clinical syndrome; however, its etiophathogenesis is poorly understood. We hypothesized that loss of gastric acid, a delayed intestinal transit, and ileocecal valve dysfunction may contribute to the genesis of this syndrome.

AIMS

Our primary aim was to assess these parameters using wireless motility capsule (WMC) testing and to correlate them with the presence or absence of SIBO.

METHODS

We prospectively evaluated 30 consecutive patients at a tertiary care center with suspected SIBO, diagnosed by lactulose hydrogen breath testing (LBT), and small bowel aspirate microbiology. Patients underwent WMC testing to assess ileocecal junction pressure (ICJP), small bowel transit time (SBTT), and regional gastrointestinal pH.

RESULTS

Thirty patients completed testing; 15 had a positive LBT, and 11 had a positive aspirate culture. As compared with LBT-negative patients, ICJP was lower (27.8 vs. 72.7 mmHg, p = 0.027), SBTT was longer (10.0 vs. 1.1 h, p = 0.004), gastric pH was higher (3.63 vs. 2.42, p < 0.01), and small bowel pH was higher (6.96 vs. 6.61, p = 0.05). A hypotensive ICJP (<46.61 mmHg) was more prevalent in LBT-positive patients as compared with LBT-negative patients (73.3 vs. 14.29%, p = 0.003). Logistic regression models were used to assess the magnitude of each measured WMC parameter and the presence of SIBO. p values ≤0.05 were considered statistically significant.

CONCLUSIONS

Patients with SIBO have significantly lower ICJP, prolonged SBTT, and a higher gastrointestinal pH as compared to those without SIBO. These abnormalities may play different roles in the pathogenesis of SIBO, facilitating more targeted treatment to prevent recurrences of SIBO.

Detecting the Non-physiological, Surgically Tailored Ileocolic Anastomosis Using the Wireless Motility Capsule. A Pre- and Post-operative, Prospective, Within Subject Trial

Background/Aims

Wireless motility capsule (WMC) detects the ileocolic junction (ICJ) in most non-operated patients. We find no data concerning this examination in patients where the ileocolic valve is replaced by a per definition incompetent, surgically created ICJ. We wanted to see if WMC could detect the ICJ after a right colectomy and assess the competency.

Methods

Prospective cohort study using a within-subject design to eliminate subject-subject variability. Selected patients operated with right colectomy underwent 3 WMC examinations (pre-operatively, 3 weeks, and 6 months after surgery).

Results

Twenty patients (8 men) included, 7 (4 men) excluded due to poor recordings (4) and unforeseen events (3). Thirteen patients (4 men), median age 63 years completed 3 tests. Median bowel lengths removed were 11 cm for ileum and 21 cm for colon. Thirty-nine examinations analyzed by 2 physicians who found all 13 ICJs at 3 examinations with high inter-rater reliability (intra-class correlation coefficient: 0.99, 0.91, and 0.99 respectively), whereas the computer found 9, 8, and 10 out of the 13 ICJs, respectively. Computed values significantly more often deviated from the 2 raters. Mean magnitude and duration of pH-drop at the ICJ (3 examinations) was 1.16-1.02-1.13 pH units and 3.15-4.78-3.75 minutes, respectively. pH-drop was smaller and duration longer at 3 weeks. We found no differences between the pre-operative (competent ICJ) and post-operative 6-month examinations (incompetent ICJ). Highest pressure immediately prior to ICJ was equal before and after surgery.

Conclusion

WMC can identify the non-physiological ICJ after right colectomy. Ileocolic competence cannot be assessed.

From clinical uncertainties to precision medicine: the emerging role of the gut barrier and microbiome in small bowel functional diseases

Over the last decade, remarkable progress has been made in the understanding of disease pathophysiology. Many new theories expound on the importance of emerging factors such as microbiome influences, genomics/omics, stem cells, innate intestinal immunity or mucosal barrier complexities. This has introduced a further dimension of uncertainty into clinical decision-making, but equally, may shed some light on less well-understood and difficult to manage conditions. Areas covered: Comprehensive review of the literature on gut barrier and microbiome relevant to small bowel pathology. A PubMed/Medline search from 1990 to April 2017 was undertaken and papers from this range were included. Expert commentary: The scenario of clinical uncertainty is well-illustrated by functional gastrointestinal disorders (FGIDs). The movement towards achieving a better understanding of FGIDs is expressed in the Rome IV guidelines. Novel diagnostic and therapeutic protocols focused on the GB and SB microbiome can facilitate diagnosis, management and improve our understanding of the underlying pathological mechanisms in FGIDs.

Two center experience of capsule endoscopy in Iran: Report on 101 cases

Background: Capsule endoscopy (CE) is a minimally invasive method for the visual examination of the small intestine, which may be for the evaluation and follow-up of patients with Crohn's disease. It can also be used to look at mucosal inflammation. Methods: This cross sectional study was used to determine the diagnostic efficacy of the CE system by performing a cross-sectional study of cases from 2011-2014. This study involved a total of 101 Iranian patients who were referred to the gastrointestinal and liver diseases outpatient clinics in Guilan (northern Iran) and in Isfahan (central Iran) for complaints of gastrointestinal problems. For all patients, definitive diagnosis had failed with the use of other diagnostic tools and CE was performed. Descriptive analysis was used. The patient population was represented by men and women equally, and the mean age of the patients was 42.3 ± 17.2 years (range: 16-89 years). Results: The final diagnoses were: non-specific enteritis (30.6%), Crohn's disease (20.7%), ulcers caused by aspirin or non-steroidal anti-inflammatory drugs (8.9%), mucosal erosion (5.9%) and angioectasia (4.9%); nearly 10% of the patients had normal findings. Analysis of the distribution of chief presenting complaints with patients stratified by the final diagnosis of Crohn's disease showed that the most frequently presented chief complaint was abdominal pain 42.9% and the least frequently presented chief complaint was diarrhea (4.8%). Conclusions: Small bowel evaluation by CE was well tolerated and capable of diagnosing Crohn's disease and gastrointestinal bleeding in patients who failed other diagnostic tests.

Two center experience of capsule endoscopy in Iran: Report on 101 cases

Background: Capsule endoscopy (CE) is a minimally invasive method for the visual examination of the small intestine, which may be for the evaluation and follow-up of patients with Crohn's disease. It can also be used to look at mucosal inflammation. Methods: This cross sectional study was used to determine the diagnostic efficacy of the CE system by performing a cross-sectional study of cases from 2011-2014. This study involved a total of 101 Iranian patients who were referred to the gastrointestinal and liver diseases outpatient clinics in Guilan (northern Iran) and in Isfahan (central Iran) for complaints of gastrointestinal problems. For all patients, definitive diagnosis had failed with the use of other diagnostic tools and CE was performed. Descriptive analysis was used. The patient population was represented by men and women equally, and the mean age of the patients was 42.3 ± 17.2 years (range: 16-89 years). Results: The final diagnoses were: non-specific enteritis (30.6%), Crohn's disease (20.7%), ulcers caused by aspirin or non-steroidal anti-inflammatory drugs (8.9%), mucosal erosion (5.9%) and angioectasia (4.9%); nearly 10% of the patients had normal findings. Analysis of the distribution of chief presenting complaints with patients stratified by the final diagnosis of Crohn's disease showed that the most frequently presented chief complaint was abdominal pain 42.9% and the least frequently presented chief complaint was diarrhea (4.8%). Conclusions: Small bowel evaluation by CE was well tolerated and capable of diagnosing Crohn's disease and gastrointestinal bleeding in patients who failed other diagnostic tests.

Patients with symptoms of delayed gastric emptying have a high prevalence of oesophageal dysmotility, irrespective of scintigraphic evidence of gastroparesis

Background

Patients with symptoms suggestive of gastroparesis exhibit several symptoms, such as epigastric pain, postprandial fullness, bloating and regurgitation. It is uncertain if such symptoms reflect underlying oesophageal motor disorder.

Aims

To examine whether patients with epigastric pain and postprandial distress syndrome suggestive of functional dyspepsia and/or gastroparesis also have concomitant oesophageal motility abnormalities and, if so, whether there are any associations between these disturbances.

Methods

In this retrospective cohort study, consecutive patients with functional gastrointestinal symptoms suggestive of gastric neuromuscular dysfunction (gastroparesis or functional dyspepsia) underwent clinical assessment, gastric scintigraphy, oesophageal high-resolution manometry and ambulatory pH monitoring using standard protocols.

Results

We studied 61 patients with various functional upper gastrointestinal symptoms who underwent gastric scintigraphy, oesophageal high-resolution manometry and ambulatory pH monitoring. Forty-four patients exhibited gastroparesis by gastric scintigraphy. Oesophageal motility disorders were found in 68% and 42% of patients with or without scintigraphic evidence of gastroparesis respectively, suggesting of overlapping gastric and oesophageal neuromuscular disorder. Forty-three per cent of patients with gastroparesis had abnormal oesophageal acid exposure with mean % pH <4.0 of 7.5 in contrast to 38% of those symptomatic controls with normal gastric emptying, with mean %pH <4.0 of 5.4 (NS). Symptoms of epigastric pain, heartburn/regurgitation, bloating, nausea, vomiting, dysphagia, belching and weight loss could not distinguish patients with or without gastroparesis, although weight loss was significantly more prevalent and severe (p<0.002) in patients with gastroparesis. There was no relationship between oesophageal symptoms and motor or pH abnormalities in either groups.

Conclusions

Irrespective of gastric emptying delay by scintigraphy, patients with symptoms suggestive of gastric neuromuscular dysfunction have a high prevalence of oesophageal motor disorder and pathological oesophageal acid exposure that may contribute to their symptoms and may require therapy. High-resolution oesophageal manometry and pH monitoring are non-invasive and potentially useful in the assessment and management of these patients.

Minimally invasive wireless motility capsule to study canine gastrointestinal motility and pH

The aim of this study was to describe the feasibility of using a gastrointestinal tract wireless motility capsule (WMC) that measured intraluminal pressure, pH and transit time through the gastrointestinal tract, in dogs in their home environment. Forty-four adult healthy dogs, eating a standard diet, were prospectively enrolled. The WMC was well tolerated by all dogs and provided data from the different sections of the gastrointestinal tract. Median gastric emptying time was 20h (range, 6.3-119h), demonstrating a large range. The gastric pressure pattern and pH depended on the phase of food consumption. The small bowel transit time was 3.1h (range, 1.6-5.4h) with average contraction pressures of 6.5mmHg (range, 1.1-21.4mmHg) and pH 7.8 (range, 7-8.9). The large bowel transit time was 21h (range, 1-69h) with average contractions pressures of 0.9mmHg (range, 0.3-2.7mmHg) and pH 6.4 (range, 5.3-8.2). There was considerable individual variation in motility patterns and transit times between dogs. No difference was observed between the sexes. No relationships between any transit time, bowel pH or pressure pattern and bodyweights were identified. The WMC likely represents movement of a large non-digestible particle rather than normal ingesta. Due to its large size, the WMC should not be use in smaller dogs. The WMC is a promising minimally invasive tool to assess GIT solid phase transit times, pressures and pH. However, further studies are necessary due to the current limitations observed.

Ingestible Sensors

Ingestible sensing capsules are fast emerging as a critical technology that has the ability to greatly impact health, nutrition, and clinical areas. These ingestible devices are noninvasive and hence are very attractive for customers. With widespread access to smart phones connected to the Internet, the data produced by this technology can be readily seen and reviewed online, and accessed by both users and physicians. The outputs provide invaluable information to reveal the state of gut health and disorders as well as the impact of food, medical supplements, and environmental changes on the gastrointestinal tract. One unique feature of such ingestible sensors is that their passage through the gut lumen gives them access to each individual organ of the gastrointestinal tract. Therefore, ingestible sensors offer the ability to gather images and monitor luminal fluid and the contents of each gut segment including electrolytes, enzymes, metabolites, hormones, and the microbial communities. As such, an incredible wealth of knowledge regarding the functionality and state of health of individuals through key gut biomarkers can be obtained. This Review presents an overview of the gut structure and discusses current and emerging digestible technologies. The text is an effort to provide a comprehensive overview of ingestible sensing capsules, from both a body physiology point of view as well as a technological view, and to detail the potential information that they can generate.

Assessment of the cardiovascular and gastrointestinal autonomic complications of diabetes

The global prevalence of diabetes mellitus is increasing; arguably as a consequence of changes in diet, lifestyle and the trend towards urbanization. Unsurprisingly, the incidence of both micro and macrovascular complications of diabetes mirrors this increasing prevalence. Amongst the complications with the highest symptom burden, yet frequently under-diagnosed and sub-optimally treated, is diabetic autonomic neuropathy, itself potentially resulting in cardiovascular autonomic neuropathy and gastrointestinal (GI) tract dysmotility. The aims of this review are fourfold. Firstly to provide an overview of the pathophysiological processes that cause diabetic autonomic neuropathy. Secondly, to discuss both the established and emerging cardiometric methods for evaluating autonomic nervous system function in vivo. Thirdly, to examine the tools for assessing pan-GI and segmental motility and finally, we will provide the reader with a summary of putative non-invasive biomarkers that provide a pathophysiological link between low-grade neuro inflammation and diabetes, which may allow earlier diagnosis and intervention, which in future may improve patient outcomes.