New developments in the treatment of gastroparesis and functional dyspepsia

The causality between gut microbiota and functional dyspepsia: A two-sample Mendelian randomization analysis

To investigate the potential link between gut microbiota and functional dyspepsia (FD). Genome-wide association studies (GWAS) of gut microbiota and FD were used in Mendelian randomization (MR) research. Using the GWAS of 18,340 people, instrumental variables related to gut microbiota as an exposure factor were identified. In a GWAS investigation, 189,695 control individuals and 4376 FD patients were included as outcome variables. The primary analysis technique was inverse variance weighted analysis. The reliability of MR analysis results is tested using sensitivity analysis. Two-sample Mendelian randomization analysis revealed the presence of 7 gut microbiota associated to FD. In the inverse variance weighted analysis method, Order Erysipelotrichales (odds ratio (OR): 1.301; 95% confidence interval (CI): 1.016, 1.665; P = .037), Family Erysipelotrichales (OR: 1.301; 95% CI: 1.016, 1.665; P = .037), Genus Haemophilus (OR: 1.236; 95% CI 1.059, 1.442; P = .007), Genus Ruminiclostridium 9 (OR: 1.422; 95% CI: 1.078, 1.877; P = .013), Genus Lachnospiraceae NK4A 136 group (OR: 1.297; 95% CI: 1.059, 1.589; P = .012) was positively associated with FD. Class Gammaproteobacteria (OR: 0.705; 95% CI: 0.522, 0.952; P = .022) and Genus Erysipelatoclostridium (OR: 0.747; 95% CI: 0.628, 0.888; P = .001) were found to be inversely related to FD. There was no evidence of pleiotropy or heterogeneity in the sensitivity analysis. Our research provides evidence for a possible link between FD and a number of gut microbiota. The role that gut microbiota plays in the development of FD requires more investigation.

Prognostic value of preoperative intragastric meal distribution in gastric emptying scintigraphy for long-term success of gastric peroral endoscopic myotomy in gastroparesis

BACKGROUND AND AIMS

Gastric emptying scintigraphy (GES) is the criterion standard for the diagnosis of gastroparesis. However, data are lacking regarding the prognostic value of preoperative intragastric meal distribution during GES in patients undergoing gastric peroral endoscopic myotomy (G-POEM) for gastroparesis. This study investigated the association of GES morphologic parameters and the long-term clinical success of G-POEM.

METHODS

This retrospective study included patients who underwent G-POEM for refractory gastroparesis in a tertiary center with preoperative GES data. Intragastric meal distribution was measured using the proximal to distal count ratio (PDCR) at 0, 1, 2 and 4 hours, and the retention index was calculated. Clinical success was defined as a decrease of at least 50% in the Gastroparesis Cardinal Symptom Index total score after G-POEM.

RESULTS

In total, 77 patients were included with a mean follow-up of 40.14 months. Clinical success was observed in 54.55% of patients. The retention index was not associated with clinical success. Only PDCR at 0 hours (PDCR0) was associated with clinical success. In univariate analysis, the median PDCR0 was 6.0 (interquartile range, 5.59) in patients with clinical success and 4.29 (interquartile range, 4.51) in patients with clinical failure (P = .019). In multivariate analysis, PDCR0 >5.25 was associated with clinical success (odds ratio, 4.36; 95% confidence interval, 1.55-12.26; P = .00524).

CONCLUSIONS

This study suggests that in patients with gastroparesis, a high PDCR0 value (suggestive for a preferential fundic meal distribution) during preoperative GES is associated with long-term clinical response to G-POEM.

Therapeutic effect of Wendan Decoction combined with mosapride on gastroesophageal reflux disease after esophageal cancer surgery

BACKGROUND

Gastroesophageal reflux disease (GERD) is a common complication of esophageal cancer surgery that can affect quality of life and increase the risk of esophageal stricture and anastomotic leakage. Wendan Decoction (WDD) is a traditional Chinese herbal formula used to treat various gastrointestinal disorders, such as gastritis, functional dyspepsia, and irritable bowel syndrome. Mosapride, a prokinetic agent, functions as a selective 5-hydroxytryptamine 4 agonist, enhancing gastrointestinal motility.

AIM

To evaluate the therapeutic effects of WDD combined with mosapride on GERD after esophageal cancer surgery.

METHODS

Eighty patients with GERD were randomly divided into treatment (receiving WDD combined with mosapride) and control (receiving mosapride alone) groups. The treatment was conducted from January 2021 to January 2023. The primary outcome was improved GERD symptoms as measured using the reflux disease questionnaire (RDQ). The secondary outcomes were improved esophageal motility (measured using esophageal manometry), gastric emptying (measured using gastric scintigraphy), and quality of life [measured via the Short Form-36 (SF-36) Health Survey].

RESULTS

The treatment group showed a notably reduced RDQ score and improved esophageal motility parameters, such as lower esophageal sphincter pressure, peristaltic amplitude, and peristaltic velocity compared to the control group. The treatment group showed significantly higher gastric emptying rates and SF-36 scores (in both physical and mental domains) compared to the control group. No serious adverse effects were observed in either group.

CONCLUSION

WDD combined with mosapride is an effective and safe therapy for GERD after esophageal cancer surgery. It can improve GERD symptoms, esophageal motility, gastric emptying, and the quality of life of patients. Further studies with larger sample sizes and longer follow-up periods are required to confirm these findings.

Cholecystokinin-Induced Duodenogastric Bile Reflux Increases the Severity of Indomethacin-Induced Gastric Antral Ulcers in Re-fed Mice

BACKGROUND/AIMS

We examined the involvement of cholecystokinin (CCK) in the exacerbation of indomethacin (IND)-induced gastric antral ulcers by gastroparesis caused by atropine or dopamine in mice.

METHODS

Male mice were fed for 2 h (re-feeding) following a 22-h fast. Indomethacin (IND; 10 mg/kg, s.c.) was administered after re-feeding; gastric lesions were examined 24 h after IND treatment. In another experiment, mice were fed for 2 h after a 22-h fast, after which the stomachs were removed 1.5 h after the end of the feeding period. Antral lesions, the amount of gastric contents, and the gastric luminal bile acids concentration were measured with or without the administration of the pro- and antimotility drugs CCK-octapeptide (CCK-8), atropine, dopamine, SR57227 (5-HT3 receptor agonist), apomorphine, lorglumide (CCK1 receptor antagonist), ondansetron, and haloperidol alone and in combination.

RESULTS

IND produced severe lesions only in the gastric antrum in re-fed mice. CCK-8, atropine, dopamine, SR57227 and apomorphine administered just after re-feeding increased bile reflux and worsened IND-induced antral lesions. These effects were significantly prevented by pretreatment with lorglumide. Although atropine and dopamine also increased the amount of gastric content, lorglumide had no effect on the delayed gastric emptying provoked by atropine and dopamine. Both ondansetron and haloperidol significantly inhibited the increase of bile reflux and the exacerbation of antral lesions induced by atropine and dopamine, respectively, but did not affect the effects of CCK-8.

CONCLUSIONS

These results suggest that CCK-CCK1 receptor signal increases bile reflux during gastroparesis induced by atropine and dopamine, exacerbating IND-induced antral ulcers.

Prevalence and disease burden of gastroparesis in Asia

Gastroparesis is a gastrointestinal disorder characterized by significant prolongation of gastric emptying time caused by impaired motility of the stomach. Its estimated prevalence is 24.2 per 100 000 people. However, the prevalence of gastroparesis in Asian countries is unknown due to a limited number of epidemiological studies and significant phenotypic variability of the Asian population in these studies. Analysis of previous research on gastroparesis and functional bowel disorders reveals the possibility of an increased prevalence among Asian individuals. A comparison of ethnic constituents between the recent United Kingdom gastroparesis study and its mother database has demonstrated a higher prevalence of gastroparesis among British Asian patients when compared with British Caucasian patients. An estimated gastroparesis prevalence in the Asian population can be calculated by identifying the individuals who are likely to demonstrate a delayed gastric emptying from all diagnosed functional dyspepsia patients. We suggest that gastroparesis tends to be underdiagnosed in Asians due to a lack of studies on gastroparesis in the Asian continent, a lack of knowledge among practitioners, and poor availability of scintigraphy testing as well as limited therapeutic options for this disease. Given the high probability of Asian predominance in gastroparesis and its disease impact on quality of life, epidemiological research focusing on the Asian population is required.

Gastric volumetry for the assessment of fundic compliance and visceral hypersensitivity in patients with gastroparesis: a retrospective comparative study

BACKGROUND/AIMS

The evaluation of visceral hypersensitivity and gastric accommodation in patients with gastroparesis (GP) is difficult. CT-scan gastric volumetry allows to test the distension of different regions of the stomach. We aimed to study gastric volumes and patient's sensitivity to gastric distension between in patients with GP compared to patients with GERD.

METHOD

Retrospective study including patients who had CT-scan volumetry for GP or GERD. Two CT-scan series were made after gastric distension: left lateral decubitus 30° (LLD30) for antrum and right lateral decubitus (RLD) for body. Pain and discomfort were assessed using visual analogue scale (VAS). Gastric volumes were measured for LLD30 and RLD.

RESULTS

13 patients (7 GP and 6 GERD) were included. Mean age was 35.6+/-7.3 years. Median gastric volume in the RLD was lower in GP vs GERD (927+/-208 ml vs. 1115+/-163 ml; p = 0.046) while it was similar for LLD30 (1053+/-228 ml vs. 1054+/-193 ml; p = 0.603). GP patients had significantly more pain and discomfort during the procedure: pain VAS for GP was 6[0-9] versus 0[0-2] for GERD, p = 0.004, discomfort VAS for GP was 7[4-10] versus 4[0-5] for GERD, p = 0.007. 66.7% of GERD patients felt no pain vs. 14.3% in GP, p = 0.053.

CONCLUSION

This pilot study suggests that GP could be associated with a reduced gastric volume compared to GERD in RLD after gaseous distension. In contrast, patient self-assessment of pain related to gastric distension was greater int GP patients. A lack of fundus accommodation and visceral hypersensitivity could explain some mechanisms in the genesis of GP symptoms.

The Disease Spectrum and Natural History of Patients With Abdominal Bloating or Distension: A Longitudinal Study

Background/Aims

Abdominal bloating or distension (AB/D) is a common complaint in the outpatient of gastroenterology department. Since the potential contributors are numerous and complex, a longitudinal study on the disease spectrum and natural history of patients was performed to better understand the key factors of AB/D.

Methods

Consecutive patients with the chief complaint of AB/D referred to the outpatient clinic were screened. Functional gastrointestinal disorders (FGIDs) were diagnosed according to Rome IV criteria. A 3-year follow-up was performed to seek for the changes in symptoms as well as disease spectrum.

Results

A total of 261 participants were enrolled and 139 completed the follow-up. Most patients suffered from moderate to severe symptoms more than 1 day per week. Common causes of AB/D were FGIDs (51.7%) and organic diseases (17.2%). The latter group was older with lower body mass index (BMI). Functional dyspepsia was the most common type of FGIDs in AB/D. The symptoms of 18.0% of participants failed to improve at the end of the 3-year follow-up, and those diagnosed with FGIDs were most likely to continue to suffer. Abdominal pain was a positive predictive factor for good prognosis in the FGIDs group. Besides, only 22.7% of participants had a consistent diagnosis of FGIDs during follow-up.

Conclusions

FGIDs are the most common diagnosis in patients with AB/D. Symptoms were especially hard to be improved. Classification diagnoses of FGIDs in AB/D patients fluctuated significantly over time.

Research Progress for Probiotics Regulating Intestinal Flora to Improve Functional Dyspepsia: A Review

Functional dyspepsia (FD) is a common functional gastrointestinal disorder. The pathophysiology remains poorly understood; however, alterations in the small intestinal microbiome have been observed. Current treatments for FD with drugs are limited, and there are certain safety problems. A class of active probiotic bacteria can control gastrointestinal homeostasis, nutritional digestion and absorption, and the energy balance when taken in certain dosages. Probiotics play many roles in maintaining intestinal microecological balance, improving the intestinal barrier function, and regulating the immune response. The presence and composition of intestinal microorganisms play a vital role in the onset and progression of FD and serve as a critical factor for both regulation and potential intervention regarding the management of this condition. Thus, there are potential advantages to alleviating FD by regulating the intestinal flora using probiotics, targeting intestinal microorganisms. This review summarizes the research progress of probiotics regarding improving FD by regulating intestinal flora and provides a reference basis for probiotics to improve FD.

Liquid and solid gastric emptying and correlation with clinical characteristics in pediatric patients with dyspepsia

BACKGROUND

There is limited data on gastric emptying in dyspeptic children. We aimed to determine solid and liquid emptying rates in dyspeptic children and correlate with clinical characteristics.

METHODS

Charts of dyspeptic children undergoing 4-hour dual-phase gastric scintigraphy were reviewed for demographics, symptoms, and comorbidities.

KEY RESULTS

In 1078 dyspeptic patients (65% females, median age 13 years) vomiting (55%), nausea (53%), and abdominal pain (52%) were the most common symptoms. The most common comorbidities were mental health (32%), neurologic (27%), and hypermobility spectrum disorders (20%). Solid and liquid emptying rates were aligned in 61.23%. Delayed solid with normal liquid emptying were noted in 2.5%, compared to delayed liquid with normal solid emptying in 26.16%. Abdominal pain had a trend for association with delayed or normal solid emptying (p = 0.06). Nausea was mostly reported with normal solid emptying (p < 0.0001) and underreported in patients <12 years with vomiting (29%). Abnormal solid emptying (rapid and delayed) was noted more frequently in children with mental health disorders (p = 0.027). Rapid liquid emptying was more common in children with genetic disorders (p = 0.032).

CONCLUSION AND INFERENCES

Over half of children with dyspepsia had delayed liquid gastric emptying, and one quarter had delayed liquid with normal solid emptying. Dual-phase gastric emptying studies may help target therapy in dyspeptic children. Nausea is not a reliable symptom for dyspepsia in younger children. Given the significant association of abnormal gastric emptying in children with mental health disorders, we recommend screening and treating children with dyspepsia.

Effects of electroacupuncture combined with acupoint catgut embedding on gastrointestinal motility and gastrointestinal hormones in rats with functional dyspepsia

Electroacupuncture (EA) or acupoint catgut embedding (ACE) plays a therapeutic role in functional dyspepsia (FD). Herein, we aimed to elucidate the influences of EA combined with ACE on gastrointestinal motility and gastrointestinal hormones in rats with FD. Sprague-Dawley rats were randomized into the control group, model group, EA group, ACE group, and EA + ACE group (n = 10). Except for the control group, the rats in all groups were modeled by combining neonatal iodoacetamide gastrogavage and modified tail-clamping stimulation. The rats were treated with different treatments according to their groups. The rats were observed for changes in general behavior, body weight, food intake, and paw mechanical pain threshold. Gastric emptying rate (GER) and intestinal propulsive ratio (IPR) were measured in each group, and serum gastrointestinal hormone (motilin [MTL], leptin, gastrin [GAS], vasoactive intestinal peptide [VIP], calcitonin gene-related peptide [CGRP], and somatostatin [SS]) levels, oxidative stress factors (superoxide dismutase [SOD] and malondialdehyde [MDA]) and 5-hydroxytryptamine (5-HT) levels were also measured. Decreased mean body weight, paw mechanical pain thresholds, food intake, and GER and IPR were found in rats of the model group in comparison to the control group. Serum MTL, GAS, SS, and SOD levels were reduced, and serum leptin, VIP, CGRP, MDA, and 5-HT levels were increased in rats of the model group in comparison to the control group. Elevated mean body weight, paw mechanical pain threshold, food intake, GER and IPR, and serum MTL, GAS, SS, and SOD levels, and reduced serum leptin, VIP, CGRP, MDA, and 5-HT levels were observed in rats of the EA, ACE, and EA + ACE groups relative to the model group. EA combined with ACE treatment was more effective than the EA or ACE treatment alone. EA combined with ACE treatment improves gastrointestinal motility and gastrointestinal hormone levels, promotes food intake, and reduces visceral hypersensitivity in FD rats.

Gastroparesis Worsens Indomethacin-Induced Gastric Antral Ulcers by Bile Reflux via Activation of 5-HT3 and Dopamine D2 Receptors in Mice

BACKGROUND/AIMS

We examined the contributions of gastric emptying and duodenogastric bile reflux in the formation of gastric antral ulcers induced by NSAIDs in mice.

METHODS

We used the murine re-fed indomethacin (IND) experimental ulcer model. Outcome measures included the appearance of gastric lesions 24 h after IND treatment and the assessment of gastric contents and the concentration of bile acids 1.5 h after re-feeding. The effects of atropine, dopamine, SR57227 (5-HT3 receptor agonist), apomorphine, ondansetron, haloperidol, and dietary taurocholate and cholestyramine were also examined.

RESULTS

IND (10 mg/kg, s.c.) induced severe lesions only in the gastric antrum in the re-fed model. The antral lesion index and the amount of food intake during the 2-h refeeding period were positively correlated. Atropine and dopamine delayed gastric emptying, increased bile reflux, and worsened IND-induced antral lesions. SR57227 and apomorphine worsened antral lesions with increased bile reflux. These effects were prevented by the anti-emetic drugs ondansetron and haloperidol, respectively. The anti-emetic drugs markedly decreased the severity of antral lesions and the increase of bile reflux induced by atropine or dopamine without affecting delayed gastric emptying. Antral lesions induced by IND were increased by dietary taurocholate but decreased by the addition of the bile acid sequestrant cholestyramine.

CONCLUSIONS

These results suggest that gastroparesis induced by atropine or dopamine worsens NSAID-induced gastric antral ulcers by increasing duodenogastric bile reflux via activation of 5-HT3 and dopamine D2 receptors.

It's a helluva journey: a qualitative study of patient and clinician experiences of nausea and vomiting syndromes

Background

Chronic gastroduodenal disorders including, chronic nausea and vomiting syndrome, gastroparesis, and functional dyspepsia, are challenging to diagnose and manage. The diagnostic and treatment pathways for these disorders are complex, costly and overlap substantially; however, experiences of this pathway have not been thoroughly investigated. This study therefore aimed to explore clinician and patient perspectives on the current clinical pathway.

Methods

Semi-structured interviews were conducted between June 2020 and June 2022 with 11 patients with chronic nausea and vomiting syndrome alone (based on Rome IV criteria) and nine gastroenterologists who treat these conditions. Interviews were recorded, transcribed, and thematically analyzed using a reflexive, iterative, inductive approach. Five key patient themes were identified: (1) the impacts of their chronic gastroduodenal symptoms, (2) the complexity of the clinical journey, (3) their interactions with healthcare providers, (4) the need for advocacy, and (5) their experience of treatments. Five key clinician themes were also identified: (1) these conditions were seen as clinically complex, (2) there is an uncertain and variable clinical pathway, (3) the nuance of investigations, (4) these conditions were difficult to therapeutically manage, and (5) there are barriers to developing a therapeutic relationship.

Conclusion

Findings indicate that both patients and clinicians are dissatisfied with the current clinical care pathways for nausea and vomiting syndromes. Recommendations included the development of more clinically relevant and discriminant tests, standardization of the diagnostic journey, and the adoption of a multidisciplinary approach to diagnosis and treatment.

Gastroparesis: The Complex Interplay with Microbiota and the Role of Exogenous Infections in the Pathogenesis of the Disease

Gastroparesis (GP) is a disorder of gastric functions that is defined by objective delayed gastric emptying in the absence of mechanical obstruction. This disease is characterized by symptoms such as nausea, post-prandial fullness, and early satiety. GP significantly impacts patients' quality of life and contributes to substantial healthcare expenses for families and society. However, the epidemiological burden of GP is difficult to evaluate, mainly due its significant overlap with functional dyspepsia (FD). GP and FD represent two similar diseases. The pathophysiology of both disorders involves abnormal gastric motility, visceral hypersensitivity, and mucosal inflammation. Moreover, both conditions share similar symptoms, such as epigastric pain, bloating, and early satiety. The latest evidence reveals that dysbiosis is directly or indirectly connected to gut-brain axis alterations, which are the basis of pathogenesis in both FD and GP. Furthermore, the role of microbiota in the development of gastroparesis was demonstrated by some clinical studies, which found that the use of probiotics is correlated with improvements in the gastric emptying time (GET). Infections (with viruses, bacteria, and protozoa) represent a proven etiology for GP but have not been sufficiently considered in current clinical practice. Previous viral infections can be found in about 20% of idiopathic GP cases. Moreover, delayed gastric emptying during systemic protozoal infections represents a huge concern for compromised patients, and few data exist on the topic. This comprehensive narrative review analyzes the relationship between microorganisms and GP. We explore, on the one hand, the correlation between gut microbiota dysbiosis and GP pathogenesis, including treatment implications, and, on the other hand, the association between exogenous infections and the etiology of the disease.

Targeting the altered duodenal microenvironment in functional dyspepsia

Duodenal micro-inflammation and microbial dysregulation are increasingly recognized to play an important role in functional dyspepsia (FD) pathophysiology, previously regarded as a purely functional disorder. With current therapeutic options contested through insufficient efficacy or unfavorable adverse effects profiles, novel treatments directed to duodenal alterations could result in superior symptom control in at least a subset of patients. Indeed, recent advances in FD research provided evidence for anti-inflammatory therapies to relieve gastroduodenal symptoms by reducing duodenal eosinophils or mast cells. In addition, restoring microbial homeostasis by probiotics proved to be successful in FD. As the exact mechanisms by which these novel pharmacological approaches result in clinical benefit often remain to be elucidated, future research should focus on how immune activation and dysbiosis translate into typical FD symptomatology.

Do prokinetic agents provide symptom relief through acceleration of gastric emptying? An update and revision of the existing evidence

BACKGROUND

Gastroparesis and functional dyspepsia are disorders characterized by upper gastrointestinal symptoms and multifaceted etiologies. One of the main therapeutic approaches is accelerating gastric emptying (GE) by means of prokinetic agents. Their efficacy has been demonstrated, although the association between symptom improvement and acceleration of emptying is less clear. Meta-analyses have found contradictory results. Differences in applied methodology and included trials might drive these contradictions.

OBJECTIVE

To provide a transparent meta-analysis update to elucidate the association between symptom improvement and acceleration of GE due to gastroprokinetic agents available for long-term use in patients with gastroparesis.

DESIGN

Two approaches from earlier meta-analyses were executed and compared. One analyzed the relative changes on active treatment versus baseline, the other compared the change from baseline on active treatment versus the change from baseline on placebo. Papers that reported sufficient numerical data for both analyses were selected. Both analyses included the same trials.

RESULTS

Overall, both approaches yield the same positive direction of association between symptom improvement and acceleration of emptying (0.291 (-0.391, 0.972), p = 0.4 and 0.453 (0.123, 0.782), p = 0.007 for the active-only and placebo-controlled analysis respectively). The association between symptom improvement and GE acceleration for studies using optimal GE tests was either 0.028 (p > 0.9) or 0.463 (p = 0.007), and for sub-optimal GE tests was either 0.370 (p = 0.4) or 0.052 (p > 0.9) depending on the used meta-analysis methodology.

CONCLUSIONS

The applied methodology for GE testing, and the meta-analysis substantially impacts the conclusion. When considering the clinically relevant outcome of improvement from baseline, symptoms and emptying improve with prokinetics, but no correlation is found between both aspects. When the change over placebo is considered, limiting the analysis to scientifically more rigorous study approaches, changes in emptying rate and symptom improvement are positively associated.

Reduced mastication is a risk factor for Rome IV postprandial distress syndrome in patients investigated with upper endoscopy

BACKGROUND AND AIMS

Reduced mastication could force the stomach to do extra work on crushing food and contribute to dyspeptic symptoms. This study aimed to assess the relationship between mastication and dyspepsia.

METHODS

This cross-sectional study involved 209 consecutive patients referred for elective upper endoscopy. Before endoscopy, an expert dentist performed an oral examination and scored chewing function in three levels (normal, regular, and reduced), and applied questionnaires for assessment of dyspepsia (Rome IV), xerostomia, and mastication (normal, regular, and reduced). A reduced masticatory function was defined when an oral examination or mastication questionnaire rated the chewing as poor. Associations between mastication, confounders, and dyspepsia were estimated by prevalence ratio [PR (95% Confidence Interval)] using Poisson regression.

RESULTS

Thirty-four patients showed relevant organic conditions in the upper gastrointestinal tract (moderate to severe reflux oesophagitis, peptic ulcer, neoplasia, and surgical modification) and were excluded. Among 175 patients with non-organic diseases (aging 51.3 ± 15.7 years; 61.7% women), 50 (28.6%) had reduced mastication, and 125 (71.4%) had normal/regular mastication. After adjusting for age and xerostomia, reduced mastication was associated with postprandial distress syndrome [PR = 1.93 (95%CI 1.27 - 2.91)] but not with epigastric pain syndrome [PR = 1.09 (95%CI 0.75 - 1.60)].

CONCLUSIONS

In patients referred for upper digestive endoscopy, reduced mastication was associated with postprandial distress syndrome but not with epigastric pain syndrome. An interdisciplinary approach with dentists and physicians might benefit dyspeptic patients with postprandial distress syndrome.

Investigation of the improving effect of raw and charred hawthorn on functional dyspepsia based on interstitial cells of Cajal

Background

Raw hawthorn (RH) is a traditional Chinese medicine commonly used to treat indigestion. Charred hawthorn (CH) is obtained from RH by charring. It is reported that the effect of CH treatment on dyspepsia is stronger than RH. However, this has not been fully proven. The purpose of this study was to compare the effects of RH and CH on functional dyspepsia (FD) model rats. And contribute to the development of dietary therapy for dyspepsia.

Methods

SPF-grade male SD rats were divided into 5 groups: the control group, the model group, the Mos group, the RH group, and the CH group. The FD rat model was established by using the methods of water restriction, fasting, tilting cage restraint, day and night upside down, swimming, and tail damping. The body weight of rats in each group was recorded. And the gastric emptying rate, intestinal propulsive rate, and the levels of motilin (MTL), gastrin (GAS), and 5-HT in serum were compared in each group. The expression of C-kit in the stomach and small intestine of each group was compared by immunofluorescence and PCR.

Results

RH and CH could increase weight, improve the gastric emptying rate and intestinal propulsive rate, and promote the secretion of motilin (MTL), gastrin (GAS), and 5-HT in the serum of FD rats. RH and CH can upregulate the expression of the characteristic protein c-kit of ICC in the stomach and small intestine of FD model rats, and the effect of CH is stronger than RH.

Conclusion

RH and CH may increase the number of interstitial cells of Cajal (ICC) in the gastrointestinal tract by upregulating c-kit expression, thus improving gastrointestinal motility in FD model rats. And compared with RH, CH has certain advantages.

Gastric peroral endoscopic myotomy outcomes after 4 years of follow-up in a large cohort of patients with refractory gastroparesis (with video)

BACKGROUND AND AIMS

Gastric peroral endoscopic myotomy (G-POEM) is used for refractory gastroparesis (RG) with good early-term but variable mid- and long-term outcomes. Limited data exist about candidates and long-term clinical and predictive factors. Our aim was to evaluate the 4-year follow-up efficacy and predictive factors in patients with RG.

METHODS

Confirmed RG patients were included and evaluated between April 2017 and December 2021. Gastroparesis Cardinal Symptom Index (GCSI) score, retention percentage at 4 hours (RP4H), mean half-emptying time (MHET), and the 36-item short-form survey (SF-36) were performed at 1, 6, 12, 18, 24, 30, 36, 42, and 48 months.

RESULTS

After G-POEM, 374 patients with RG were included: 141 patients (37.7%) had diabetic gastroparesis (DG), 115 (30.7%) had idiopathic gastroparesis (IG), 102 (27.3%) had postsurgical gastroparesis (PSG), and 16 (4.3%) had other etiologies. After the 48-month evaluation, 102 patients completed follow-up (DG, 58; IG, 22; PSG, 18; other, 4). Before G-POEM, GCSI score, RP4H, and MHET were 3.84 ± .53, 44% (interquartile range [IQR], 11-68), and 246 minutes (IQR, 150-368), respectively, and after the 48-month evaluation improved to 2.1 ± .70 (P < .001), 15.5% (IQR, 0-36; P = .021), and 135 minutes (IQR, 67-290; P = .045), respectively. At the 48-month evaluation, clinical success was 77.5%. DG showed the best outcomes (DG vs IG vs PSG vs other: 86.5% vs 72.5% [P = .001] vs 72.1% [P = .003] vs 68.8% [P < .001]). Long-term success predictors were DG (odds ratio [OR], 5.113; 95% confidence interval [CI], 1.643-5.981; P = .035), early diagnosis (OR, 2.455; 95% CI, 1.129-3.522; P = .042), nausea/vomiting (OR, 3.541; 95% CI, 1.881-5.511; P = .012), GCSI score at 6 months (1.5-2) (OR, 3.612; 95% CI, 2.122-5.317; P = .022), and RP4H <10% at 6 months (OR, 2.188; 95% CI, 1.435-4.233; P = .039).

CONCLUSIONS

G-POEM is an effective 4-year treatment in patients with RG, especially in DG, establishing a potential first-line therapy in these patients. However, randomized controlled clinical trials are needed to confirm these results. (Clinical trial registration number: NTC03126513.).

The efficacy of cognitive behavior stress management on functional dyspepsia: A protocol for systematic review and meta-analysis

BACKGROUND

Functional dyspepsia and digestive disorders are common, debilitating and costly. Little information is available about the role of stress management in terms of cognitive-behavioral treatment of dyspepsia. We performed a protocol for systematic review and meta-analysis to evaluate the effectiveness of cognitive behavior stress management for the treatment of functional dyspepsia.

METHODS

A comprehensive search of several databases from 1966 to March 2022 will be conducted. The databases include Ovid Medline In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid EMBASE, Ovid PsycINFO, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus. The primary outcome for this study was the rate of successful treatment (presence of no more than mild pain or discomfort after treatment). The secondary outcomes were improvement of dyspepsia at short-term (<1 year) and long-term (≥1 year) follow up, improvement in quality of life, and development of treatment-related adverse events. The risk of bias in each included study will be assessed utilizing the Cochrane Collaboration's risk of bias tool. The Review Manager 5.3 (Cochrane Collaboration, Oxford, UK) will be used to analyze the data.

RESULTS

We will synthesize the current studies to evaluate the effectiveness and safety of cognitive behavior stress management on functional dyspepsia.

CONCLUSION

The result of this review will provide more reliable references to help clinicians make decisions when dealing with functional dyspepsia.

Neural Responses of Acupuncture for Treating Functional Dyspepsia: An fMRI Study

Different acupoints exhibiting similar therapeutic effects are a common phenomenon in acupuncture clinical practice. However, the mechanism underlying this phenomenon remains unclear. This study aimed to investigate the similarities and differences in cerebral activities elicited through stimulation of CV12 and ST36, the two most commonly used acupoints, in the treatment of gastrointestinal diseases, so as to partly explore the mechanism of the different acupoints with similar effects. Thirty-eight eligible functional dyspepsia (FD) patients were randomly assigned into either group A (CV12 group) or group B (ST36 group). Each patient received five acupuncture treatments per week for 4 weeks. The Symptom Index of Dyspepsia (SID), Nepean Dyspepsia Symptom Index (NDSI), and Nepean Dyspepsia Life Quality Index (NDLQI) were used to assess treatment efficacy. Functional MRI (fMRI) scans were performed to detect cerebral activity changes at baseline and at the end of the treatment. The results demonstrated that (1) improvements in NDSI, SID, and NDLQI were found in both group A and group B (p < 0.05). However, there were no significant differences in the improvements of the SID, NDSI, and NDLQI scores between group A and group B (p > 0.05); (2) all FD patients showed significantly increased amplitude of low-frequency fluctuation (ALFF) in the left postcentral gyrus after acupuncture treatment, and the changes of ALFF in the left postcentral gyrus were significantly related to the improvements of SID scores (r = 0.358, p = 0.041); and (3) needling at CV12 significantly decreased the resting-state functional connectivity (rsFC) between the left postcentral gyrus and angular gyrus, caudate, middle frontal gyrus (MFG), and cerebellum, while needling at ST36 significantly increased the rsFC between the left postcentral gyrus with the precuneus, superior frontal gyrus (SFG), and MFG. The results indicated that CV12 and ST36 shared similar therapeutic effects for dyspepsia, with common modulation on the activity of the postcentral gyrus in FD patients. However, the modulatory pattern on the functional connectivity of the postcentral gyrus was different. Namely, stimulation of CV12 primarily involved the postcentral gyrus–reward network, while stimulation of ST36 primarily involved the postcentral gyrus–default mode network circuitry.

Evaluation of the pharmacokinetics of trazpiroben (TAK-906) in the presence and absence of the proton pump inhibitor esomeprazole

Trazpiroben, a dopamine D2 /D3 receptor antagonist under development to treat gastroparesis, displays decreasing solubility with increasing pH. This single-sequence, open-label, two-period, crossover study evaluated the effect of esomeprazole, a proton pump inhibitor that raises gastric pH, on the single-dose pharmacokinetics, safety, and tolerability of trazpiroben in healthy adults (NCT03849690). In total, 12 participants were enrolled and entered period 1 (days 1-3), receiving a single oral dose of trazpiroben 25 mg on day 1. After a 4-day washout, participants then entered period 2 (days 8-13) and received esomeprazole 40 mg once daily on days 8-12, with a single oral dose of trazpiroben 25 mg co-administered 1 h post esomeprazole dosing on day 11. Geometric mean area under the curve from time 0 extrapolated to infinity (AUC∞ ) and maximum plasma concentration (Cmax ) values were generally similar when trazpiroben was administered alone versus alongside esomeprazole (AUC∞ , 44.03 vs. 38.85 ng h/ml; Cmax , 19.76 vs. 17.24 ng/ml). Additionally, the associated geometric mean ratio (GMR; co-administration: administration alone) 90% confidence intervals (CIs) suggested no clinically meaningful difference between treatment groups (AUC∞ , GMR 0.88, 90% CI 0.78-1.00; Cmax , 0.87, 90% CI 0.70-1.09). Mean apparent first-order terminal elimination half-life values were similar between treatments, illustrating co-administration with esomeprazole had minimal effect on trazpiroben elimination. Trazpiroben was well-tolerated in healthy adults following administration alone and alongside esomeprazole, with no clinically relevant adverse events reported. The lack of evidence of any clinically meaningful drug-drug interaction supports the co-administration of esomeprazole with trazpiroben.

Gastrointestinal hormones and regulation of gastric emptying

PURPOSE OF REVIEW

In this review, we evaluate recent findings related to the association between gastrointestinal hormones and regulation of gastric emptying.

RECENT FINDINGS

Motilin and ghrelin, which act during fasting, promote gastric motility, whereas most of the hormones secreted after a meal inhibit gastric motility. Serotonin has different progastric or antigastric motility effects depending on the receptor subtype. Serotonin receptor agonists have been used clinically to treat dyspepsia symptoms but other hormone receptor agonists or antagonists are still under development. Glucagon-like peptide 1 agonists, which have gastric motility and appetite-suppressing effects are used as a treatment for obesity and diabetes.

SUMMARY

Gastrointestinal hormones play an important role in the regulation of gastric motility. Various drugs have been developed to treat delayed gastric emptying by targeting gastrointestinal hormones or their receptors but few have been commercialized.

Diabetic visceral neuropathy of gastroparesis: gastric mucosal innervation and clinical significance

BACKGROUND

The pathogenesis of diabetic gastroparesis due to visceral neuropathy involves multi-dimensional mechanisms with limited exploration of gastric mucosal innervation. This study aimed to quantitatively examine this topic and its relationship with gastroparesis symptoms and gastric emptying in diabetes.

METHODS

We prospectively enrolled 22 patients with type 2 diabetes and gastroparesis symptoms and 25 age- and gender-matched healthy controls for comparison. The assessments include (1) neuropathology with quantification of gastric mucosal innervation density (MID) on endoscopic biopsy, (2) clinical manifestations with questionnaire of gastroparesis cardinal symptom index (GCSI), and (3) functional tests of gastric emptying scintigraphy (GES).

RESULTS

In diabetic patients, stomach fullness, bloating, and feeling excessively full after meals constituted the most common GCSI symptoms. Seven (32%) diabetic patients had prolonged gastric emptying patterns. In diabetes, gastric MID was significantly lower in all examined parts compared with the controls: antrum (294.8±237.0 vs. 644.0±222.0mm/mm³ , p<0.001), body (292.2±239.0 vs. 652.6±260.9mm/mm³ , p<0.001), and fundus (238.0±109.1 vs. 657.2±332.8mm/mm³ , p<0.001). Gastric MID was negatively correlated with gastroparesis symptoms and total scores of GCSI (p<0.001). Furthermore, gastric MID in the fundus was negatively correlated with fasting glucose and HbA1c levels. Gastric emptying parameters, including T_1/2 and gastric retention, were prolonged in diabetes and gastric retention at 3h was correlated with fasting glucose level.

CONCLUSION

In diabetes, gastric MID was reduced and GES parameters were prolonged. Both were correlated with gastroparesis symptoms and glycemic control. These findings provide pathology and functional biomarkers for diabetic visceral neuropathy of gastroparesis and underlying pathophysiology.

Non-pharmacological management of pediatric functional abdominal pain disorders: Current evidence and future perspectives

Functional abdominal pain disorders (FAPDs) are an important and prevalent cause of functional gastrointestinal disorders among children, encompassing the diagnoses of functional dyspepsia, irritable bowel syndrome, abdominal migraine, and the one not previously present in Rome III, functional abdominal pain not otherwise specified. In the absence of sufficiently effective and safe pharmacological treatments for this public problem, non-pharmacological therapies emerge as a viable means of treating these patients, avoiding not only possible side effects, but also unnecessary prescription, since many of the pharmacological treatments prescribed do not have good efficacy when compared to placebo. Thus, the present study provides a review of current and relevant evidence on non-pharmacological management of FAPDs, covering the most commonly indicated treatments, from cognitive behavioral therapy to meditation, acupuncture, yoga, massage, spinal manipulation, moxibustion, and physical activities. In addition, this article also analyzes the quality of publications in the area, assessing whether it is possible to state if non-pharmacological therapies are viable, safe, and sufficiently well-based for an appropriate and effective prescription of these treatments. Finally, it is possible to observe an increase not only in the number of publications on the non-pharmacological treatments for FAPDs in recent years, but also an increase in the quality of these publications. Finally, the sample selection of satisfactory age groups in these studies enables the formulation of specific guidelines for this age group, thus avoiding the need for adaptation of prescriptions initially made for adults, but for children use.

Relationship Between Gastric Emptying Rate and Simultaneously Assessed Symptoms in Functional Dyspepsia

METHODS

During a GE test (breath test with ¹³C-octanoic acid labelled 250 kcal solid meal), the severity of 6 symptoms (postprandial fullness, epigastric pain and burning, bloating, nausea and belching) was assessed, every 15 min, before meal-intake and 4h postprandially. The sum of individual symptom scores generated the meal-related symptoms score; the sum of all symptoms generated overall meal-related symptom severity (OSS). Data were compared in patients with normal and delayed GE (cut-off T_1/2≥ 109 min). Data are shown as mean±SEM.

RESULTS

504 patients were included, of which 382 patients (67% female, age 43.8±0.8 years, BMI 23.3±0.2 kg/m²) had normal and 122 patients (77% female, age 42.7±1.5 years, BMI 23.2±0.6 kg/m²) had delayed GE. OSS tended to be higher in patients with delayed GE (81.8±3.4 vs. 99.5±7.1, p=.05). Only nausea was significantly higher in patients with delayed GE (11±0.8 vs. 16±1.6, p=.01). No correlations were observed between GE rate and any of the symptoms (OSS: r=0.06, p=.2; nausea: r=0.06, p=.1). The symptom severity time course showed a significant difference only for nausea, with increased severity ratings 90 min after the meal (p<.01) in delayed GE compared to normal GE patients.

CONCLUSION

The severity of symptoms in functional dyspepsia and idiopathic gastroparesis, even when assessed during the GE test meal, is not correlated to gastric emptying rate. (Ethics committee University Hospital of Leuven study number S55426).

Effect of Mirtazapine on Nausea in Children with Functional Nausea and Functional Dyspepsia Postprandial Distress Syndrome

OBJECTIVE

The objective of this study was to assess the clinical response and safety of mirtazapine in the pediatric population with a diagnosis of functional nausea and nausea associated with functional dyspepsia postprandial distress syndrome.

METHODS

This was a retrospective chart review to evaluate the safety and efficacy of mirtazapine for pediatric nausea and nausea associated with functional dyspepsia postprandial distress syndrome. Clinical response was classified as complete response, partial response, and no response. We also identified the prescribed doses, side effects, and weight changes during mirtazapine therapy.

RESULTS

Among the 57 total patients, 67% were females and ages ranged from 7 to 19 years with a mean of 14 ± 3 years. Clinical (complete and partial) response was reported in 82% of patients. Nausea resolved in 82% and insomnia in 77% of the patients. Eighty-four percent gained weight with a mean of 4 ± 7 kg. Sixty-five percent did not report adverse effects. The most common adverse effects were undesired weight gain (16%) and dysphoria (9%). Two patients discontinued the medicine after the first dose because of adverse effects. There was a significant correlation between the initial dose and weight (r_s = 0.478; p = 0.0002). The median initial and final doses were 15 mg, respectively.

CONCLUSIONS

Mirtazapine is an option for treating children and adolescents with functional nausea and nausea associated with functional dyspepsia post-prandial distress syndrome, especially for a select group of patients with concurrent weight loss, anxiety, and insomnia.

Gastroparesis: A Multidisciplinary Approach to Management

Gastroparesis is a neuromuscular disorder whose hallmark is delayed gastric emptying. It is a global challenge to the healthcare system because of poor treatment satisfaction for both the patients and clinicians, eventually leading to a reduction in the quality of life, with antecedent anxiety and depression. Although it is multifactorial in origin, diabetic, idiopathic, and drug-induced gastroparesis are the major risk factors. Disrupted interstitial cells of Cajal (ICC) and gastric dysrhythmia are pivotal to the pathogenesis, with most of the investigations targeted toward assessing gastric emptying and accommodation usually affected by distorted ICC and other neural networks. The treatment challenges can be overcome by a multidisciplinary approach involving gastroenterologists, gastrointestinal surgeons, biomedical engineers, nutritionists, psychologists, nurses, radionuclide radiologists, pharmacists, and family physicians. The exploration of the fundamental physiological processes underlying gastroparesis with the use of biomechanical materials should be given more attention by biomedical engineers to integrate innovative engineering with medicine for solving complex medical issues.

Evaluating the Safety, Tolerability, and Disposition of Trazpiroben, a D2 /D3 Receptor Antagonist: Phase I Single- and Multiple-Ascending Dose Studies in Healthy Japanese Participants

Trazpiroben (TAK‐906) is a peripherally selective dopamine D₂/D₃ receptor antagonist being developed to treat chronic gastroparesis. This phase I, randomized, double‐blind, placebo‐controlled, single‐ and multiple‐ascending dose, parallel‐group study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of trazpiroben in healthy Japanese men. Findings were compared with those from a prior US trial in healthy individuals. Overall, 24 participants were enrolled into 3 cohorts (each n = 8). Per cohort, 6 participants received trazpiroben (cohort 1, 50 mg; 2, 100 mg; 3, 10 mg) once on day 1 and twice daily on days 3 through 7, and two received placebo. Trazpiroben was well tolerated, with no clinically meaningful adverse events observed. Following single‐ and multiple‐dose administration, trazpiroben was rapidly absorbed and eliminated (mean elimination half‐life, 1.89‐6.45 hours; median time to maximum serum concentration [steady state], 1.00‐1.25 hours). Serum prolactin increased with trazpiroben treatment (mean maximum serum concentration 93.32 ng/mL [10 mg] vs. 10.83 ng/mL [placebo]), illustrating receptor target engagement. Results reflected those from healthy US participants, indicating a lack of differences between these ethnic populations in trazpiroben disposition and safety profile. Trazpiroben may represent a promising therapy for chronic gastroparesis across different populations, with further evaluation ongoing in a phase IIb study (NCT03544229).

Gastric accommodation: Physiology, diagnostic modalities, clinical relevance, and therapies

BACKGROUND

Gastric accommodation is an essential gastric motor function which occurs following ingestion of a meal. Impaired gastric fundic accommodation (IFA) is associated with dyspeptic symptoms. Gastric accommodation is mediated by the vagal pathway with several important physiologic factors such as duodenal nutrient feedback playing a significant role. IFA has been described as a pathophysiologic factor in several gastrointestinal disorders including functional dyspepsia, diabetic gastropathy, post-Nissen fundoplication, postsurgical gastrectomy, and rumination syndrome. Modalities for gastric accommodation assessment include gastric barostat, intragastric meal distribution via scintigraphy, drinking tests (eg, water load), SPECT, MRI, 2D and 3D ultrasound, and intragastric high-resolution manometry. Several treatment options including sumatriptan, buspirone, tandospirone, ondansetron, and acotiamide may improve symptoms by increasing post-meal gastric volume.

PURPOSE

Our aim is to provide an overview of the physiology, diagnostic modalities, and therapies for IFA. A literature search was conducted on PubMed, Google Scholar, and other sources to identify relevant studies available until December 2020. Gastric accommodation is an important gastric motor function which if impaired, is associated with several upper gastrointestinal disorders. There are an increasing number of gastric accommodation testing modalities; however, each has facets which warrant consideration. Evidence regarding potentially effective therapies for IFA is growing.

Protective effect of mirtazapine against acetic acid-induced ulcerative colitis in rats: Role of NLRP3 inflammasome pathway

AIMS

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that causes long-lasting inflammation on the innermost lining of the colon and rectum. Mirtazapine (MRT) is a well-known antidepressant that was proven to have anti-inflammatory activity; however, to date, its role has not been investigated in UC. The current study aimed to investigate the role and mechanism of MRT in UC.

MAIN METHOD

Acetic acid (AA) was used for UC induction, and sulfasalazine (SLZ) was used as a positive control. Rats were divided into five equal groups; as follows; normal control, AA, SLZ (received SLZ in a dose of 250 mg/kg for 14 days), MRT10 (received MRT in a dose of 10 mg/kg/day for 14 days), and MRT30 (received MRT in a dose of 30 mg/kg/day for 14 days) groups. Macroscopic and microscopic examinations together with oxidative stress parameters evaluation were done. NOD-like receptors-3 (NLRP3), caspase-1, TNF-α, and nuclear factor kappa B (NF-κB) expression together with interleukin (IL)-1β and IL-18 levels were examined.

KEY FINDING

MRT, in a dose-dependent manner, prevented the macroscopic and microscopic colonic damage and corrected the oxidative stress induced by AA. Moreover, MRT decreased the colonic tissue NLRP3 inflammasome, caspase-1, NF-κB, TNF-α expressions, IL-1β, and IL-18 levels that were elevated in colonic tissue by the AA.

SIGNIFICANCE

MRT has a dose-dependent protective effect against UC that was mediated mainly by its anti-inflammatory activity with modulation of NLRP3/caspase-1 inflammatory pathway.

A Systematic Review of the Therapeutic Role of Gastric Pacemakers in Adults With Gastroparesis

Gastroparesis or gastric stasis is the delayed transit of the ingested contents through the stomach in the absence of mechanical obstruction. It can have multiple etiologies, most commonly idiopathic (ID) and diabetic (DM). Gastroparesis can cause significant distress to patients as it leads to symptoms like intractable nausea and vomiting, weight loss, abdominal bloating, early satiety, etc. The pathogenesis is mainly thought to be due to the dysfunction of the gastric pacemaker cells, i.e., interstitial cells of Cajal (ICC), and their interaction with the other gastric motor function regulatory components. There are several proposed treatment options for gastroparesis. Despite that, most patients remain refractory to medical treatment and require additional interventions for symptomatic relief. One such intervention is gastric electrical stimulation or gastric pacemaker, which aids in improving gastric motility. We have searched PubMed, PubMed Central (PMC), Medline, Science Direct, and Google Scholar for articles pertaining to the use of gastric electrical stimulation in gastroparesis published in the last 10 years. The keywords used include "gastroparesis", "gastric stasis", "gastric pacemaker'', "gastric electrical stimulation", "nausea", "vomiting", "abdominal bloating", "gastric neuromodulation". We have finally included twelve studies that were the most relevant to our research question and met the quality assessment criteria. Exclusion criteria consisted of pediatric population studies, studies conducted on animals, books, and grey literature. Overall, these twelve studies helped evaluate the impact of gastric pacemakers on symptoms of gastroparesis like nausea, vomiting, weight loss, abdominal bloating, and quality of life. We found that most studies favored gastric pacemakers, improving the incidence of nausea and vomiting in patients with gastroparesis. There was a marked improvement in the BMI as well. On the other hand, most open-labeled studies showed improved quality of life and Gastroparesis Cardinal Symptom Index (GCSI) scores, while randomized controlled trials and meta-analyses did not reflect the same result. In addition, some other parameters improved with gastric pacemakers, Inflammatory markers, insulin levels (especially in diabetics), and the number of hospitalizations. In conclusion, gastric pacemaker is a potential treatment option for patients with medically refractory gastroparesis. As noted from the results of our study, nausea/vomiting, weight loss, and overall GCSI scores have shown marked improvement with gastric electrical stimulation (GES). Nevertheless, more extensive research is needed to understand better the full extent of this device's use as a viable treatment option for patients suffering from gastroparesis.

United European Gastroenterology (UEG) and European Society for Neurogastroenterology and Motility (ESNM) consensus on functional dyspepsia

BACKGROUND

Functional dyspepsia (FD) is one of the most common conditions in clinical practice. In spite of its prevalence, FD is associated with major uncertainties in terms of its definition, underlying pathophysiology, diagnosis, treatment, and prognosis.

METHODS

A Delphi consensus was initiated with 41 experts from 22 European countries who conducted a literature summary and voting process on 87 statements. Quality of evidence was evaluated using the grading of recommendations, assessment, development, and evaluation (GRADE) criteria. Consensus (defined as >80% agreement) was reached for 36 statements.

RESULTS

The panel agreed with the definition in terms of its cardinal symptoms (early satiation, postprandial fullness, epigastric pain, and epigastric burning), its subdivision into epigastric pain syndrome and postprandial distress syndrome, and the presence of accessory symptoms (upper abdominal bloating, nausea, belching), and overlapping conditions. Also, well accepted are the female predominance of FD, its impact on quality of life and health costs, and acute gastrointestinal infections, and anxiety as risk factors. In terms of pathophysiological mechanisms, the consensus supports a role for impaired gastric accommodation, delayed gastric emptying, hypersensitivity to gastric distention, Helicobacter pylori infection, and altered central processing of signals from the gastroduodenal region. There is consensus that endoscopy is mandatory for establishing a firm diagnosis of FD, but that in primary care, patients without alarm symptoms or risk factors can be managed without endoscopy. There is consensus that H. pylori status should be determined in every patient with dyspeptic symptoms and H. pylori positive patients should receive eradication therapy. Also, proton pump inhibitor therapy is considered an effective therapy for FD, but no other treatment approach reached a consensus. The long-term prognosis and life expectancy are favorable.

CONCLUSIONS AND INFERENCES

A multinational group of European experts summarized the current state of consensus on the definition, diagnosis and management of FD.

United European Gastroenterology (UEG) and European Society for Neurogastroenterology and Motility (ESNM) consensus on gastroparesis

BACKGROUND

Gastroparesis is a condition characterized by epigastric symptoms and delayed gastric emptying (GE) rate in the absence of any mechanical obstruction. The condition is challenging in clinical practice by the lack of guidance concerning diagnosis and management of gastroparesis.

METHODS

A Delphi consensus was undertaken by 40 experts from 19 European countries who conducted a literature summary and voting process on 89 statements. Quality of evidence was evaluated using grading of recommendations assessment, development, and evaluation criteria. Consensus (defined as ≥80% agreement) was reached for 25 statements.

RESULTS

The European consensus defined gastroparesis as the presence of symptoms associated with delayed GE in the absence of mechanical obstruction. Nausea and vomiting were identified as cardinal symptoms, with often coexisting postprandial distress syndrome symptoms of dyspepsia. The true epidemiology of gastroparesis is not known in detail, but diabetes, gastric surgery, certain neurological and connective tissue diseases, and the use of certain drugs recognized as risk factors. While the panel agreed that severely impaired gastric motor function is present in these patients, there was no consensus on underlying pathophysiology. The panel agreed that an upper endoscopy and a GE test are required for diagnosis. Only dietary therapy, dopamine-2 antagonists and 5-HT₄ receptor agonists were considered appropriate therapies, in addition to nutritional support in case of severe weight loss. No consensus was reached on the use of proton pump inhibitors, other classes of antiemetics or prokinetics, neuromodulators, complimentary, psychological, or more invasive therapies. Finally, there was consensus that gastroparesis adversely impacts on quality of life and healthcare costs and that the long-term prognosis of gastroparesis depends on the cause.

CONCLUSIONS AND INFERENCES

A multinational group of European experts summarized the current state of consensus on definition, symptom characteristics, pathophysiology, diagnosis, and management of gastroparesis.

Safety, Pharmacokinetics, and Pharmacodynamics of Trazpiroben (TAK-906), a Novel Selective D2 /D3 Receptor Antagonist: A Phase 1 Randomized, Placebo-Controlled Single- and Multiple-Dose Escalation Study in Healthy Participants

Gastroparesis is a chronic neuromuscular disorder of the upper gastrointestinal tract in which episodic exacerbation can lead to frequent hospitalizations and severe disability. Dopamine D2 /D3 receptor antagonists have been used to treat patients with gastroparesis with some efficacy; however, their chronic use is limited owing to associated central nervous system (CNS) or cardiovascular safety concerns. Trazpiroben (TAK-906) is a dopamine D2 /D3 receptor antagonist under development for the long-term treatment of gastroparesis. Preclinical studies in rat and dog have shown trazpiroben to have minimal brain penetration and low affinity for the human ether-à-go-go-related gene (hERG) potassium channel (IC50 ,  15.6 µM), thereby reducing the risk of the CNS and cardiovascular adverse effects seen with other dopamine D2 /D3 receptor antagonists. This phase 1 trial evaluated the safety, pharmacokinetics, and pharmacodynamics of trazpiroben in healthy participants. Trazpiroben was rapidly absorbed and eliminated (Tmax , ∼1.1 hours; t1/2 , 4-11 hours) after administration of single (5-300 mg) and multiple (50 or 100 mg) doses. Receptor target engagement was confirmed for all doses, as indicated by an increase in serum prolactin levels compared with placebo (mean prolactin Cmax , 134.3 ng/mL after administration of trazpiroben 10 mg vs 16.1 ng/mL with placebo). Therapeutically relevant single and multiple doses of trazpiroben were well tolerated in healthy participants, and no clinically meaningful cardiovascular adverse effects were observed across the whole dose range. These data support the further development of trazpiroben for the treatment of gastroparesis.

Preclinical Evaluation of the Effects of Trazpiroben (TAK-906), a Novel, Potent Dopamine D2/D3 Receptor Antagonist for the Management of Gastroparesis

Current therapies for gastroparesis, metoclopramide and domperidone, carry risks of extrapyramidal symptoms and life-threatening cardiac arrhythmias. Trazpiroben, a novel, potent dopamine D₂/D₃ receptor antagonist, has low brain permeation and very low affinity for human ether-à-go-go-related gene (hERG) channel inhibition, potentially improving on safety profiles of existing therapies. Trazpiroben demonstrated the following receptor affinities: high for D₂ and D_3, moderate for D₄ and minimal for D₁ and D₅ It demonstrated moderate affinity for adrenergic alpha 1B (α_1B) and 5-hydroxytryptamine 2A (5HT_2A) receptors and low potential for off-target adverse events (AEs). Trazpiroben potently inhibited dopamine-activated D_2L receptor activation of cognate G-proteins in human embryonic kidney 293 cell membranes and was a neutral D_2L receptor antagonist. In vivo, trazpiroben dose-dependently increased prolactin release in orally dosed rat (0.1-1mg/kg). Additionally, multiple oral doses in the rat (100mg/kg) and dog (50mg/kg) for 3 days produced robust plasma exposures and prolactin increases in both species. Trazpiroben inhibited retching/vomiting in the dog with apomorphine-induced emesis with a potency (0.1-1mg/kg) like that of trazpiroben-mediated prolactin increases in rat. Oral trazpiroben (1, 10, and 30mg/kg) did not affect rat rotarod performance, suggesting low brain penetration. Trazpiroben concentrations were low in cerebrospinal fluid versus plasma following multiple oral doses for 4 days in rat and dog. Trazpiroben weakly inhibited the hERG channel current (concentration causing half-maximal inhibition of control-specific binding of 15.6µM), indicating little potential for disrupting cardiac rhythm. Overall, trazpiroben is a potent D₂/D₃ receptor antagonist designed to avoid serious potential AEs associated with current gastroparesis therapies. Significance Statement Trazpiroben is a novel, potent dopamine D₂/D₃ selective receptor antagonist designed to avoid adverse effects associated with the current pharmacological therapies, metoclopramide and domperidone. Pre-clinical studies have demonstrated low brain penetration and weak affinity for the hERG channel, indicating that trazpiroben is not expected to be associated with central nervous system or cardiovascular safety issues. With these pharmacological properties, trazpiroben may represent a viable new treatment option for gastroparesis due to a potentially improved safety profile relative to existing therapies.

Nutrient Drinking Test as Biomarker in Functional Dyspepsia

INTRODUCTION

Functional dyspepsia (FD) is a prevalent condition with multifactorial pathophysiology, including impaired gastric accommodation (GA), hypersensitivity to gastric distention, and delayed gastric emptying. Drink tests (DT) have been proposed as a potential biomarker for the presence and severity of gastric sensorimotor dysfunction. Thus, we aimed to summarize the state of knowledge on different DT and their potential as a biomarker for FD.

METHODS

A PubMed and MEDLINE search was conducted for English language articles, reviews, meta-analyses, case series, and randomized controlled trials, including also published meeting abstracts.

RESULTS

Several DT have been described in literature (e.g., different type of liquid, number of calories used, pace of drinking, and subject's awareness of the amount of liquid drunk). FD patients ingest significantly less volume in the different variants of the tests. The slow nutrient ("satiety drinking") test (SDT) studies show the most consistent separation between health and FD and correlation with GA. However, sensitivity to distention may be correlated with rapid DT. SDTs were used to evaluate the effect of several pharmacological agents, often showing concordance between their effects on GA and tolerated nutrient volume. This correlation was not found mainly for agents with central actions.

DISCUSSION

An SDT is a potential diagnostic biomarker in FD, reflecting GA. Additional studies are required to confirm its role as a predictive biomarker for treatment outcome in FD.

Functional Dyspepsia: Diagnostic and Therapeutic Approaches

Functional dyspepsia is a common functional gastrointestinal (GI) disorder of gastroduodenal origin, diagnosed clinically in the presence of prototypical symptoms of epigastric pain and meal-related symptoms, and without structural explanation. The most recent diagnostic criteria provide for two functional dyspepsia subtypes, epigastric pain syndrome (EPS) and post-prandial distress syndrome (PDS) based on the predominant symptom pattern. The evaluation of dyspepsia should keep laboratory, imaging, and invasive testing to a minimum, as extensive or repetitive investigations are of rather low diagnostic yield in the absence of localizing symptoms or alarm features. Factors with etiopathologic relationships to functional dyspepsia include micro-inflammation, GI infections, abnormalities of gastroduodenal motility, visceral hypersensitivity, disturbances along the brain-gut axis, and psychological factors; all of these causative mechanisms have potential to partially explain symptoms in some functional dyspepsia patients, thus providing a rationale for the efficacy of a diversity of therapeutic approaches to functional dyspepsia. Management of dyspepsia symptoms relies upon both pharmacologic treatments and non-pharmacologic approaches, including psychological and complementary interventions. The evidence in support of established functional dyspepsia therapies is reviewed, and forms the basis for an effective functional dyspepsia treatment strategy emphasizing the patient's current symptom severity, pattern, and impact on the function and quality of life of the individual.

Rikkunshito as a Therapeautic Agent for Functional Dyspepsia and its Prokinetic and Non-Prokinetic Effects

Prokinetics is one of the therapeutic agents for functional and motility disorders of the stomach. However, its efficacy is limited. Kampo medicine is a unique medical system that was developed in Japan. In Kampo medicine, herbal medicine is prescribed based on the patient’s condition. Therefore, even for functional and motility disorders of the stomach, some herbal medicines are considered as a therapeutic option. Recently, there has been an increase in evidence for the efficacy or the mechanism of herbal medicine for functional and motility disorders of the stomach. Among these, rikkunshito is a well-studied herbal medicine that could be used as an alternative to prokinetics. In this review, we discuss the possibilities of rikkunshito for functional dyspepsia with its prokinetic and non-prokinetic effects and provide an overview of their current use with a focus on their therapeutic mechanism.

Risk factors associated with functional dyspepsia in Chinese children: a cross-sectional study

Background

There is no study assessing the risk factors associated with functional dyspepsia (FD) in Chinese children based on the Rome IV criteria.

Methods

In this cross-sectional study, we analyzed data from eight representative primary and secondary schools to assess the risk factors associated with FD in Chinese children based on the Rome IV criteria.

Results

A total of 6976 Chinese children were enrolled. The mean age was 14.3 ± 2.5 years, with a range from 7 to 17 years, and 3497 (50.1%) participants were female. FD was prevalent in 209 (3.0%) of the Chinese child population studied. Age (OR = 1.112, P = 0.006), living independent of parents (OR = 1.677, P < 0.001), prolonged school meals (OR = 2.107, P < 0.001), never eat breakfast (OR = 2.192, P = 0.003), often/daily eat cold foods (OR = 2.296, P = 0.002; OR = 2.736, P = 0.011), and often eat pickled foods (OR = 2.390, P = 0.001) were found to be independent risk factors for FD. A nomogram with these risk factors had good discrimination (AUC = 0.727) and calibration (Hosmer–Lemeshow test was 0.851).

Conclusions

Age, living independent of parents, prolonged school meals, never eat breakfast, often/daily eat cold foods and often eat pickled foods were independent risk factors for FD. The nomogram could be used as a quick screening tool to assess FD in Chinese children.

United European Gastroenterology (UEG) and European Society for Neurogastroenterology and Motility (ESNM) consensus on functional dyspepsia

Background

Functional dyspepsia (FD) is one of the most common conditions in clinical practice. In spite of its prevalence, FD is associated with major uncertainties in terms of its definition, underlying pathophysiology, diagnosis, treatment, and prognosis.

Methods

A Delphi consensus was initiated with 41 experts from 22 European countries who conducted a literature summary and voting process on 87 statements. Quality of evidence was evaluated using the grading of recommendations, assessment, development, and evaluation (GRADE) criteria. Consensus (defined as >80% agreement) was reached for 36 statements.

Results

The panel agreed with the definition in terms of its cardinal symptoms (early satiation, postprandial fullness, epigastric pain, and epigastric burning), its subdivision into epigastric pain syndrome and postprandial distress syndrome, and the presence of accessory symptoms (upper abdominal bloating, nausea, belching), and overlapping conditions. Also, well accepted are the female predominance of FD, its impact on quality of life and health costs, and acute gastrointestinal infections, and anxiety as risk factors. In terms of pathophysiological mechanisms, the consensus supports a role for impaired gastric accommodation, delayed gastric emptying, hypersensitivity to gastric distention, Helicobacter pylori infection, and altered central processing of signals from the gastroduodenal region. There is consensus that endoscopy is mandatory for establishing a firm diagnosis of FD, but that in primary care, patients without alarm symptoms or risk factors can be managed without endoscopy. There is consensus that H. pylori status should be determined in every patient with dyspeptic symptoms and H. pylori positive patients should receive eradication therapy. Also, proton pump inhibitor therapy is considered an effective therapy for FD, but no other treatment approach reached a consensus. The long‐term prognosis and life expectancy are favorable.

Conclusions and Inferences

A multinational group of European experts summarized the current state of consensus on the definition, diagnosis and management of FD.

Current knowledge

Functional dyspepsia is one of the most common conditions encountered in clinical practice.

There is a lack of guidance for clinicians in guiding diagnosis and treatment of this prevalent condition.

No treatments are currently approved for the treatment of functional dyspepsia in Europe.

What is new here

A Delphi panel consisting of 41 experts from 22 European countries established the level of consensus on 87 statements regarding functional dyspepsia.

The statements reaching consensus serve to guide clinicians in recognizing, diagnosing and treating FD in clinical practice.

Endoscopy is mandatory for establishing a firm diagnosis of functional dyspepsia D, but in primary care patients without alarm symptoms or risk factors can be managed without endoscopy.

Helicobacter pylori status should be determined in every patient with dyspeptic symptoms and H. Pylori positive patients should receive eradication therapy.

Proton pump inhibitor‐therapy is considered an effective therapy for FD, but no other treatment approach reached consensus support.

Practical management approach to gastroparesis

Gastroparesis is a syndrome characterised by delayed gastric emptying in the absence of mechanical obstruction. Symptoms can include early satiety, abdominal pain, bloating, vomiting and regurgitation which cause significant morbidity in addition to nutritional deficits. There is a higher prevalence in diabetics and females, but the incidence in the Australian population has not been well studied. Management of gastroparesis involves investigating and correcting nutritional deficits, optimising glycaemic control and improving gastrointestinal motility. Symptom control in gastroparesis can be challenging. Nutritional deficits should be addressed initially through dietary modification. Enteral feeding is a second-line option when oral intake is insufficient. Home parenteral nutrition is rarely used, and only accessible through specialised clinics in the outpatient setting. Prokinetic medication classes that have been used include dopamine receptor antagonists, motilin receptor agonists, 5-HT₄ receptor agonists and ghrelin receptor agonists. Anti-emetic agents are often used for symptom control. Interventional treatments include gastric electrical stimulation, gastric per-oral endoscopic myotomy, feeding jejunostomy and gastrostomy/jejunstomy for gastric venting and enteral feeding. In this article we propose a framework to manage gastroparesis in Australia based on current evidence and available therapies.

United European Gastroenterology (UEG) and European Society for Neurogastroenterology and Motility (ESNM) consensus on gastroparesis

BACKGROUND

Gastroparesis is a condition characterized by epigastric symptoms and delayed gastric emptying (GE) rate in the absence of any mechanical obstruction. The condition is challenging in clinical practice by the lack of guidance concerning diagnosis and management of gastroparesis.

METHODS

A Delphi consensus was undertaken by 40 experts from 19 European countries who conducted a literature summary and voting process on 89 statements. Quality of evidence was evaluated using grading of recommendations assessment, development, and evaluation criteria. Consensus (defined as ≥80% agreement) was reached for 25 statements.

RESULTS

The European consensus defined gastroparesis as the presence of symptoms associated with delayed GE in the absence of mechanical obstruction. Nausea and vomiting were identified as cardinal symptoms, with often coexisting postprandial distress syndrome symptoms of dyspepsia. The true epidemiology of gastroparesis is not known in detail, but diabetes, gastric surgery, certain neurological and connective tissue diseases, and the use of certain drugs recognized as risk factors. While the panel agreed that severely impaired gastric motor function is present in these patients, there was no consensus on underlying pathophysiology. The panel agreed that an upper endoscopy and a GE test are required for diagnosis. Only dietary therapy, dopamine-2 antagonists and 5-HT4 receptor agonists were considered appropriate therapies, in addition to nutritional support in case of severe weight loss. No consensus was reached on the use of proton pump inhibitors, other classes of antiemetics or prokinetics, neuromodulators, complimentary, psychological, or more invasive therapies. Finally, there was consensus that gastroparesis adversely impacts on quality of life and healthcare costs and that the long-term prognosis of gastroparesis depends on the cause.

CONCLUSIONS AND INFERENCES

A multinational group of European experts summarized the current state of consensus on definition, symptom characteristics, pathophysiology, diagnosis, and management of gastroparesis.

Complete resection of the gastric antrum decreased incidence and severity of delayed gastric emptying after pancreaticoduodenectomy

BACKGROUND

Delayed gastric emptying (DGE) is the main complication after pancreaticoduodenectomy (PD), but the mechanism is still unclear. The aim of this study was to elucidate the role of complete resection of the gastric antrum in decreasing incidence and severity of DGE after PD.

METHODS

Sprague-Dawley rats were divided into three groups: expanded resection (ER group), complete resection (CR group), and incomplete resection (IR group) of the gastric antrum. The tension (g) of remnant stomach contraction was observed. We analyzed the histological morphology of the gastric wall by different excisional methods after distal gastrectomy. Moreover, patients underwent PD at our department between January 2012 and May 2016 were included in the study. These cases were divided into IR group and CR group of the gastric antrum, and the clinical data were retrospectively analyzed.

RESULTS

The ex vivo remnant stomachs of CR group exhibited much greater contraction tension than others (P < 0.05). The contraction tension of the remnant stomach increased with increasing acetylcholine concentration, while remained stable at the concentration of 10 × 10^-5 mol/L. Furthermore, 174 consecutive patients were included and retrospectively analyzed in the study. The incidence of DGE was significantly lower (3.5% vs. 21.3%, P < 0.01) in CR group than in IR group. In addition, hematoxylin-eosin staining analyses of the gastric wall confirmed that the number of transected circular smooth muscle bundles were higher in IR group than in CR group (8.24 ± 0.65 vs. 3.76 ± 0.70, P < 0.05).

CONCLUSIONS

The complete resection of the gastric antrum is associated with decreased incidence and severity of DGE after PD. Gastric electrophysiological and physiopathological disorders caused by damage to gastric smooth muscles might be the mechanism underlying DGE.

Recent Advances in the Definition and Management of Functional Dyspepsia

In 2016, the Rome criteria were updated as Rome IV, and only minor changes were introduced for functional dyspepsia (FD). The major symptoms of FD now include not only postprandial fullness, but also epigastric pain and burning, and early satiation at above the "bothersome" level. Investigations into the effect of meal ingestion on symptom generation have indicated that not only postprandial fullness and early satiety but also epigastric pain and burning sensation and nausea (not vomiting) may increase after meals. Helicobacter pylori infection is considered to be the cause of dyspepsia if successful eradication leads to sustained resolution of symptoms for more than 6 months, and such a condition has been termed H. pylori-associated dyspepsia. Prompt esophagogastroduodenoscopy and H. pylori "test and treat" may be beneficial, especially in regions with a high prevalence of gastric cancer, such as east Asia. In terms of treatment, acotiamide, tandospirone, and rikkunshito are newly listed in Rome IV as treatment options for FD. Clinical studies in the field of FD should be strictly based on the Rome IV criteria until the next Rome V is published in 2026.

Gastric Motor Functions in Patients With Mood Disorders and Functional Gastroduodenal Symptoms

OBJECTIVE

Functional gastroduodenal symptoms (FGDSs) may result from perturbations in gastric emptying (GE) and gastric accommodation (GA), which are variably affected by acute stress. This study aimed to examine whether individuals who have both mood disorder and FGDS exhibit differences in GE and GA using standardized, validated, and reproducible noninvasive methods.

METHODS

Using a data retrieval program, 1554 individuals at a single center were identified after having undergone measurements of GE by scintigraphy of a 99mTc-radiolabeled egg (320 kcal, 30% fat meal) and GA by single-photon emission computed tomography to assess the underlying pathophysiology in FGDS. An extensive medical record review identified 267 of these individuals as having diagnoses of depression, anxiety, or comorbid anxiety/depression (CAD). Differences in GE and GA as related to the presence of anxiety or depressive disorders were analyzed using one-way analysis of variance on ranks and Mann-Whitney tests for the two-group comparisons.

RESULTS

Sixty-three patients with anxiety, 134 with depression, and 70 with CAD were identified. GE at 1 hour was slower (p = .04) and GE at 2 hours numerically decreased (p = .07) for depression compared with anxiety. GA was diminished for CAD compared with anxiety (p = .04) and depression (p = .009). There were no differences in fasting gastric volume or GE at 4 hours.

CONCLUSIONS

In this study examining GE and GA in anxiety and depressive disorders among patients with FGDS, the combined presence of anxiety and depression was associated with impaired GA compared with patients with depression or anxiety alone, and early GE seemed to be slower in those with depression compared with patients with anxiety.

Erythromycin stimulates phasic gastric contractility as assessed with an isovolumetric intragastric balloon pressure measurement

BACKGROUND

A novel technique to assess gastric motility by measuring the pressure in a low-volume intragastric balloon was developed to monitor (disordered) motility. We previously showed that this technique allows measuring pharmacologically induced inhibition of motility. In this study, we assessed whether it is possible to measure pharmacologically induced stimulation of gastric motility using 200 mg erythromycin. Erythromycin is a highly effective stimulator of gastric emptying and contractility.

METHODS

After an overnight fast, a nasogastric balloon catheter was introduced in healthy subjects. After inflation with 120 ml of air, the catheter was connected to a pressure sensor. Intraballoon pressure was continuously recorded for 4 h. After a baseline recording of 2 h, 200 mg erythromycin was infused intravenously over 20 min while the recording continued for 2 h. Epigastric symptoms were surveyed on 100-mm visual analogue scales. Motility was quantified from the pressure recording as a gastric balloon motility index. Wilcoxon signed-rank tests were performed. Data are shown as median (interquartile range).

KEY RESULTS

Six subjects were enrolled and five completed the procedures (age: 28 (25-29) years, body mass index: 24.0 (23.8-24.5) kg m^-2 ). One subject could not tolerate tube placement. Bloating, nausea, and epigastric sensation scores were 0 (0-3), 0 (0-1), and 1 (0-1) mm, respectively. Erythromycin significantly increased the motility index from 0.48 (0.41-0.51) to 0.79 (0.70-0.82) (p = 0.03).

CONCLUSIONS AND INFERENCES

Gastric motility assessed via pressure measurement in a low-volume intragastric balloon is able to detect pharmacologically stimulated motility in healthy subjects, which further validates this technique.