Epidemiology of functional dyspepsia and gastroparesis as diagnosed in Flemish-Belgian primary care: A registry-based study from the Intego database.

BACKGROUND: Dyspepsia is a prevalent condition in the general population. Besides organic causes, the differential diagnosis of dyspepsia includes functional dyspepsia (FD) and gastroparesis (GP) which share similar pathophysiological mechanisms and clinical presentation. So far, no study investigated the prevalence of FD and GP in a primary care in Belgium. METHODS: Data were obtained from Intego, a Flemish-Belgian general practice-based morbidity registration network. From 586,164 patients between 2000 and 2021, we selected patients with ICD-10 code for FD and GP. Patients with organic gastrointestinal diseases were excluded. We determined demographics and comorbidities of FD/GP. For prevalence and incidence calculation, we included those who consulted their general practitioners at least once in the given year. Pair-wise comparison was conducted to access the impact of comorbidities on risk of FD/GP. KEY RESULTS: Between 2011 and 2021, the prevalence of FD/GP ranged from 1.03% to 1.21%. The incidence of FD/GP ranged from 109 to 142 per 100,000 adults. In total 5242 cases of FD/GP were identified. These cases shared commonly coexisting diagnoses of gastroesophageal reflux disease (18.8%), irritable bowel syndrome (17.1%), and chronic constipation (18.7%). Patients with somatization/anxiety/depression had significantly higher risk of FD/GP, compared to the control (OR 1.38, 95% CI 1.19-1.61, p < 0.01). CONCLUSIONS AND INFERENCES: The prevalence (1.03%-1.21%) and incidence (109-142/100,000) of FD/GP in primary care over last decade appear to conflict with epidemiological research in the general population. The discrepancies suggest a potential lack of awareness of FD and GP among physicians and/or patients in Flemish-Belgium.

Prokinetics-safety and efficacy: The European Society of Neurogastroenterology and Motility/The American Neurogastroenterology and Motility Society expert review.

BACKGROUND: Prokinetics are a class of pharmacological drugs designed to improve gastrointestinal (GI) motility, either regionally or across the whole gut. Each drug has its merits and drawbacks, and based on current evidence as high-quality studies are limited, we have no clear recommendation on one class or other. However, there remains a large unmet need for both regionally selective and/or globally acting prokinetic drugs that work primarily intraluminally and are safe and without systemic side effects. PURPOSE: Here, we describe the strengths and weaknesses of six classes of prokinetic drugs, including their pharmacokinetic properties, efficacy, safety and tolerability and potential indications.

The Effects of Corticotropin-Releasing Hormone on Gastric Electrical Activity and Sensorimotor Function in Healthy Volunteers: A Double-blinded Crossover Study.

Biopsychosocial factors are associated with disorders of gut brain interaction and exacerbate gastrointestinal symptoms. The mechanisms underlying pathophysiological alterations of stress remain unclear. Corticotropin-releasing hormone (CRH) is a central regulator of the hormonal stress response and has diverse impact on different organ systems. The aim of the present study was to investigate the effects of peripheral CRH infusion on meal-related gastrointestinal symptoms, gastric electrical activity and gastric sensorimotor function in healthy volunteers (HVs). In a randomized, double-blinded, placebo-controlled, crossover study, we evaluated the effects of CRH on gastric motility and sensitivity. HVs were randomized to receive either peripheral administered CRH (100 µg bolus + 1 µg/kg/hr) or placebo (saline), followed by at least a 7-day washout period and assignment to the opposite treatment. Tests encompassed saliva samples, gastric emptying (GE) testing, body surface gastric mapping (BSGM, Gastric Alimetry®; Alimetry) to assess gastric myoelectrical activity with real-time symptom profiling, and a gastric barostat study to assess gastric sensitivity to distention and accommodation. 20 HVs (13 women, mean age 29.2±5.3 years, BMI 23.3±3.8 kg/m2) completed GE tests, of which 18 also underwent BSGM measurements during the GE tests. The GE half time decreased significantly after CRH exposure (65.2±17.4 vs 78.8±24.5 minutes, p=0.02) with significantly increased gastric amplitude (49.7 (34.7-55.6) vs 31.7 (25.7-51.0) µV, p<0.01), saliva cortisol levels and postprandial symptom severity. Eleven HVs also underwent gastric barostat studies on a separate day. However, the thresholds for discomfort during isobaric distensions, gastric compliance, and accommodation did not differ between CRH and placebo.

The Use of Peppermint Oil in Gastroenterology.

BACKGROUND: For decades, mint has been used worldwide for its relieving effects against gastrointestinal disturbances. Peppermint is a perennial herb common in Europe and North America. The active ingredient of peppermint oil is menthol and has various gastroenterological and non-gastroenterological uses, especially in the context of functional gastrointestinal disorders (FGIDs). METHODS: We conducted a literature search on the main medical databases for original articles, reviews, meta-analyses, randomized clinical trials, and case series using the following keywords and acronyms and their associations: peppermint oil, gastro-intestinal motility, irritable bowel syndrome, functional dyspepsia, gastrointestinal sensitivity and gastrointestinal endoscopy. RESULTS: Peppermint oil and its constituents exert smooth muscle relaxant and anti-spasmodic effects on the lower esophageal sphincter, stomach, duodenum, and large bowel. Moreover, peppermint oil can modulate visceral and central nervous system sensitivity. Taken together, these effects suggest using peppermint oil both for improved endoscopic performance and for treating functional dyspepsia and irritable bowel syndrome. Importantly, peppermint oil has an attractive safety profile compared to classical pharmacological treatments, especially in FGIDs. CONCLUSION: Peppermint oil is a safe herbal medicine therapy for application in gastroenterology, with promising scientific perspectives and rapidly expanding use in clinical practice.

Prevalence of delayed gastric emptying in patients with gastroparesis-like symptoms.

BACKGROUND: The European consensus defined gastroparesis as a condition characterised by delayed gastric emptying (GE) in the absence of mechanical obstruction, with a symptom pattern of predominant nausea and/or vomiting and overlapping postprandial distress syndrome (PDS). The distinction between patients with gastroparesis and those with functional dyspepsia (FD), another gastrointestinal condition characterised by predominant PDS or epigastric pain syndrome symptoms, is ongoing. AIM: To investigate the extent that symptom patterns may differentiate gastroparesis from FD. METHODS: This retrospective study included 637 patients from Leuven University Hospital in 2006-2021 who had upper gastrointestinal symptoms, underwent a GE test, and completed the Dyspepsia Symptom Severity (DSS) questionnaire. Patients were identified as with gastroparesis-like symptoms (GPLS; i.e., moderate to severe nausea with moderate to severe PDS) or FD symptoms (not fitting GPLS). We excluded patients aged <18 years, and those with diabetes, organic gastrointestinal disease or a history of abdominal surgeries. Demographic and clinical variables were compared. RESULTS: Among 545 patients, 238 reported GPLS and 307 reported FD symptoms. Those with GPLS had a significantly higher prevalence of delayed GE (half emptying time (T1/2) ≥109 min) and lower body mass index than those with FD (33.2% vs 17.6%, p < 0.01; 19.9 vs 21.2, p < 0.01, respectively). Among GPLS patients, those with delayed GE had higher DSS than those without (13.0 vs 12.0, p < 0.01). CONCLUSIONS: In tertiary care patients who reported gastroparesis or FD symptoms, the presence of delayed GE was associated with GPLS. In patients with GPLS, delayed GE was associated with higher symptom severity.

Worldwide prevalence and burden of gastroparesis-like symptoms as defined by the United European Gastroenterology (UEG) and European Society for Neurogastroenterology and Motility (ESNM) consensus on gastroparesis.

BACKGROUND/OBJECTIVES: The global epidemiology of gastroparesis is unknown. The European UEG and European Society for Neurogastroenterology and motility consensus defines Gastroparesis as a condition characterized by delayed gastric emptying in the absence of mechanical obstruction, with a symptom pattern of nausea and/or vomiting and overlapping postprandial distress syndrome (PDS). Real-world evidence of this gastroparesis-like symptom pattern is a crucial step in understanding the epidemiology of gastroparesis. METHODS: In the Rome Foundation Global Epidemiology Study, 54,127 respondents from 26 countries completed the Rome IV Diagnostic Questionnaire and variables associated with disorders of gut-brain interaction via Internet. We selected subjects with gastroparesis-like symptoms (GPLS) (nausea and/or vomiting ≥1 day/week and simultaneous PDS). Patients reporting organic gastrointestinal disease, or fulfilling criteria for self-induced vomiting, cyclic vomiting or cannabinoid hyperemesis syndrome were excluded. We determined prevalence, associated comorbidities, quality of life (QoL) (PROMIS Global-10), symptoms of anxiety and depression (PHQ-4), somatic symptoms (PHQ-12), and healthcare utilization. RESULTS: The global prevalence of GPLS was 0.9% overall and 1.3% among diabetic individuals. Subjects with GPLS showed frequent overlapping of epigastric pain syndrome and irritable bowel syndrome. Subjects with GPLS had significantly lower body mass index, QoL, more non-gastrointestinal somatic complaints, symptoms of anxiety and depression, higher medication usage and doctor visits in the overall and diabetic population, compared to subjects without these symptoms. CONCLUSIONS: GPLS are common worldwide and more common in diabetic patients. The symptom complex is associated with multiple aspects of illness and an increased healthcare consumption.

The Role of Leaky Gut in Functional Dyspepsia.

Patients with functional dyspepsia (FD) complain of epigastric symptoms with no identifiable cause. Increased intestinal permeability has been described in these patients, especially in the proximal small bowel or duodenum, and was associated with mucosal immune activation and symptoms. In this review, we discuss duodenal barrier function, including techniques currently applied in FD research. We summarize the available data on duodenal permeability in FD and factors associated to increased permeability, including mucosal eosinophils, mast cells, luminal and systemic factors. While the increased influx of antigens into the duodenal mucosa could result in local immune activation, clinical evidence for a causal role of permeability is lacking in the absence of specific barrier-protective treatments. As both existing and novel treatments, including proton pump inhibitors (PPI) and pre- or probiotics may impact duodenal barrier function, it is important to recognize and study these alterations to improve the knowledge and management of FD.

Postinfectious onset in functional dyspepsia is a risk factor for weight loss.

BACKGROUND: Functional dyspepsia (FD) is differentiated into two subgroups: the postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS). Acute gastroenteritis and Helicobacter pylori (HP) infection have been identified as risk factors for FD. It is unclear how these risk factors relate to Rome IV subgroups and their clinical impact. We aimed to study the association of postinfectious FD (PI-FD) and HP status with clinical profiles and weight loss. METHODS: Consecutive FD patients were assessed for symptom frequency and severity. Patients were identified as PDS, EPS or the overlap group according to severity scores. Additionally, PI history and HP status were determined. RESULTS: In a cohort of 459 FD-patients, 36% were characterized as having PDS, 9% as having EPS and 55% showed overlap. PI onset and positive HP status were reported by, respectively, 20% and 14% of patients, not significantly differing between subgroups (respectively, p = 0.31 and p = 0.40). Weight loss was reported by 63% in PDS, 36% in EPS and 56% in overlap patients (p = 0.011). Only early satiety severity correlated with more severe weight loss in the PDS (r 0.31, p < 0.0001) and overlap group (r 0.38, p < 0.0001). PI-FD patients were more likely to experience weight loss (OR 2.27, p = 0.0013). HP status was not significantly associated with weight loss (p = 0.90). CONCLUSION: In this cohort, PI onset of FD symptoms emerged as a risk factor for weight loss, but was not associated with the symptom patterns of PDS, EPS or overlap subgroups. Patients with HP infection were not more likely to experience important weight loss.

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.

The effect of an air purifier on aerosol generation measurements during clinical motility testing.

BACKGROUND: Aerosol spread is key to interpret the risk of viral contamination during clinical procedures such as esophageal high-resolution manometry (HRM). Installing an air purifier seems a legitimate strategy, but this has recently been questioned. METHODS: Patients undergoing an HRM procedure at the Leuven University Hospital were included in this clinical study. All subjects had to wear a surgical mask which was only lowered beneath the nose during the placement and removal of the nasogastric catheter. The number of aerosol particles was measured by a Lasair® II Particle Counter to obtain data about different particles sizes: 0.3; 0.5; 1.0; 3.0; 5.0; and 10.0 µm. Measurements were done immediately before the placement and the removal of the HRM catheter, and one and 5 min after. A portable air purifier with high-efficiency particle air filters was installed in the hospital room. KEY RESULTS: Thirteen patients underwent a manometry examination. The amount of 0.3 µm-sized particles was unaffected during the whole procedure. The larger particle sizes (1.0; 3.0; 5.0; and 10.0 µm) decreased when the catheter was positioned, but not 0.5 µm. During the HRM measurements itself, these numbers decreased further. Yet, 1 min after catheter removal a significant elevation of particles was seen, which did not recover within 5 min. CONCLUSIONS & INTERFERENCES: Based on this study, there is no evidence that filtration systems reduce aerosol particles properly during a clinical investigation.

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 T1/2≥ 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).

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.

The gastrointestinal tract in hunger and satiety signalling.

BACKGROUND: Different peripheral pathways are implicated in the regulation of the food ingestion-digestion cycle. METHODS: Narrative review on gastrointestinal mechanisms involved in satiety and hunger signalling. RESULTS: Combined mechano- and chemoreceptors, peripherally released peptide hormones and neural pathways provide feedback to the brain to determine sensations of hunger (increase energy intake) or satiation (cessation of energy intake) and regulate the human metabolism. The gastric accommodation reflex, which consists of a transient relaxation of the proximal stomach during food intake, has been identified as a major determinant of meal volume, through activation of tension-sensitive gastric mechanoreceptors. Motilin, whose release is the trigger of gastric Phase 3, has been identified as the major determinant of return of hunger after a meal. In addition, the release of several peptide hormones such as glucagon-like peptide 1 (GLP-1), cholecystokinin as well as motilin and ghrelin contributes to gut-brain signalling with relevance to control of hunger and satiety. A number of nutrients, such as bitter tastants, as well as pharmacological agents, such as endocannabinoid receptor antagonists and GLP-1 analogues act on these pathways to influence hunger, satiation and food intake. CONCLUSION: Gastrointestinal mechanisms such as gastric accommodation and motilin release are key determinants of satiety and hunger.

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.

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.

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.

Probiotics and gut health.

Gut microbiota is a complex ecosystem of bacteria, viruses, archea, protozoa and yeasts in our intestine. It has several functions which maintain human body equilibrium. Microbial "dysbiosis" can be responsible for several gastrointestinal diseases. To build a narrative review we performed a Pubmed, Medline, Embase search for English language papers, reviews, meta-analyses, case series, and randomized controlled trials (RCTs) by keywords and their associations. Gut microbiota is altered in several gastrointestinal diseases with very different pathophysiology. They range from multifactorial diseases such as irritable bowel syndrome (IBS), nonalcoholic fatty liver disease (NAFLD) and gastric and colorectal cancers, immune-mediated such as celiac disease, inflammatory bowel diseases (IBD), and antibiotic-related such as clostridium difficile infection (CDI). Microbial dysbiosis remodulation by probiotics is feasible and safe in some of them. Gut microbial dysbiosis is statistically associated with several gastrointestinal diseases, affecting their pathophysiology. Its reverse by probiotics has some promising evidence of efficacy.