Mechanisms of Food-Induced Symptom Induction and Dietary Management in Functional Dyspepsia

Functional dyspepsia (FD) is a common disorder of gut-brain interaction, characterised by upper gastrointestinal symptom profiles that differentiate FD from the irritable bowel syndrome (IBS), although the two conditions often co-exist. Despite food and eating being implicated in FD symptom induction, evidence-based guidance for dietetic management of FD is limited. The aim of this narrative review is to collate the possible mechanisms for eating-induced and food-related symptoms of FD for stratification of dietetic management. Specific carbohydrates, proteins and fats, or foods high in these macronutrients have all been reported as influencing FD symptom induction, with removal of 'trigger' foods or nutrients shown to alleviate symptoms. Food additives and natural food chemicals have also been implicated, but there is a lack of convincing evidence. Emerging evidence suggests the gastrointestinal microbiota is the primary interface between food and symptom induction in FD, and is therefore a research direction that warrants substantial attention. Objective markers of FD, along with more sensitive and specific dietary assessment tools will contribute to progressing towards evidence-based dietetic management of FD.

Wheat Sensitivity and Functional Dyspepsia: A Pilot, Double-Blind, Randomized, Placebo-Controlled Dietary Crossover Trial with Novel Challenge Protocol

Introduction: Functional dyspepsia (FD), characterised by symptoms of epigastric pain or early satiety and post prandial distress, has been associated with duodenal eosinophilia, raising the possibility that it is driven by an environmental allergen. Non-coeliac gluten or wheat sensitivity (NCG/WS) has also been associated with both dyspeptic symptoms and duodenal eosinophilia, suggesting an overlap between these two conditions. The aim of this study was to evaluate the role of wheat (specifically gluten and fructans) in symptom reduction in participants with FD in a pilot randomized double-blind, placebo controlled, dietary crossover trial. Methods: Patients with Rome III criteria FD were recruited from a single tertiary centre in Newcastle, Australia. All were individually counselled on a diet low in both gluten and fermentable oligo-, di-, mono-saccharides, and polyols (FODMAPs) by a clinical dietitian, which was followed for four weeks (elimination diet phase). Those who had a ≥30% response to the run-in diet, as measured by the Nepean Dyspepsia Index, were then re-challenged with ‘muesli’ bars containing either gluten, fructan, or placebo in randomised order. Those with symptoms which significantly reduced during the elimination diet, but reliably reappeared (a mean change in overall dyspeptic symptoms of ≥30%) with gluten or fructan re-challenge were deemed to have wheat induced FD. Results: Eleven participants were enrolled in the study (75% female, mean age 43 years). Of the initial cohort, nine participants completed the elimination diet phase of whom four qualified for the rechallenge phase. The gluten-free, low FODMAP diet led to an overall (albeit non-significant) improvement in symptoms of functional dyspepsia in the diet elimination phase (mean NDI symptom score 71.2 vs. 47.1, p = 0.087). A specific food trigger could not be reliably demonstrated. Conclusions: Although a gluten-free, low-FODMAP diet led to a modest overall reduction in symptoms in this cohort of FD patients, a specific trigger could not be identified. The modified Salerno criteria for NCG/WS identification trialled in this dietary rechallenge protocol was fit-for-purpose. However, larger trials are required to determine whether particular components of wheat induce symptoms in functional dyspepsia.

Diet and functional dyspepsia: Clinical correlates and therapeutic perspectives

Hypervigilance and symptoms anticipation, visceral hypersensitivity and gastroduodenal sensorimotor abnormalities account for the varied clinical presentation of functional dyspepsia (FD) patients. Many patients recognize meals as the main triggering factor; thus, dietary manipulations often represent the first-line management strategy in this cohort of patients. Nonetheless, scarce quality evidence has been produced regarding the relationship between specific foods and/or macronutrients and the onset of FD symptoms, resulting in non-standardized nutritional approaches. Most dietary advises are indeed empirical and often lead to exclusion diets, reinforcing in patients the perception of “being intolerant” to food and self-perpetuating some of the very mechanisms underlying dyspepsia physiopathology (i.e., hypervigilance and symptom anticipation). Clinicians are often uncertain regarding the contribution of specific foods to dyspepsia physiopathology and dedicated professionals (i.e., dietitians) are only available in tertiary referral settings. This in turn, can result in nutritionally unbalanced diets and could even encourage restrictive eating behaviors in severe dyspepsia. In this review, we aim at evaluating the relationship between dietary habits, macronutrients and specific foods in determining FD symptoms. We will provide an overview of the evidence-based nutritional approach that should be pursued in these patients, providing clinicians with a valuable tool in standardizing nutritional advises and discouraging patients from engaging into indiscriminate food exclusions.

Certain Dietary Habits Contribute to the Functional Dyspepsia in South China Rural Area

BACKGROUND Functional dyspepsia (FD) refers to a group of upper gastrointestinal syndromes, subdivided into two types: postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS). The etiology of FD remains unclear; however, unhealthy dietary habit is one potential underlying cause. We aim to explore the association of poor dietary habits with FD and its subtypes. MATERIAL AND METHODS A validated epidemiological questionnaire was designed to investigate dietary habits and gastrointestinal syndromes. Citizens in the Baotun community of Dongguan were invited to complete the study questionnaire. All participants were asked to undergo a physical examination and a blinded physician interview. The study was conducted from June 2015 to June 2016. FD was diagnosed using ROME III criteria. The association between investigated dietary habits and dyspeptic symptoms were explored. RESULTS There were 1,304 adult residents recruited for the study survey; 165 residents had existing organic dyspepsia (OD), 203 residents were diagnosed with FD, and the other 936 participants, who were without dyspeptic symptoms or functional gastrointestinal diseases, were regarded as the control group. Subtype diagnosis indicated 61 participants had EPS, 66 participants had PDS, and 76 participants had coexisting EPS and PDS. Unhealthy dietary habits were more prevalent in the FD group than in the control groups (75.86% versus 37.50%; p<0.001). FD was found to be associated with irregular mealtime, dining out, fatty food, sweet food, and coffee (p<0.05). The impact of each dietary factor varied with FD subtypes. CONCLUSIONS Certain types of dietary habits were positively correlated with the prevalence of FD. FD subtypes showed relatively different associations with dietary factors.

Effect of an extra-virgin olive oil enriched with probiotics or antioxidants on functional dyspepsia: a pilot study

BACKGROUND

While antioxidants and probiotics have been proposed for the treatment of functional dyspepsia, current data are still heterogeneous and studies are poorly designed. Extra-virgin olive oil, a common ingredient of Mediterranean diet, has shown antioxidant properties.

AIMS

To evaluate the effect of extra-virgin olive oil enriched with antioxidants or probiotics on functional dyspepsia.

PATIENTS AND METHODS

This study has been designed as a "proof of concept". Extra-virgin olive oil enriched with antioxidants or probiotics was blindly added to the common diet of 8 subjects with functional dyspepsia for 7 days. Dyspeptic symptoms were then evaluated in all patients.

RESULTS AND CONCLUSIONS

A significant improvement of dyspeptic symptoms was observed in subjects receiving the antioxidant or probiotic enriched oil diet, with a greater effect observed for the latter. Larger studies are now needed to confirm these data.

Laboratory parameters and nutritional status in patients with functional dyspepsia

BACKGROUND

To investigate differences in laboratory markers, nutritional status parameters and eating patterns among newly diagnosed patients with functional dyspepsia.

METHOD

The investigation was performed on 180 newly diagnosed patients with functional dyspepsia, aged 20-79, which were referred to the gastroenterology unit of the Clinical and Hospital Center "Bezanijska Kosa" from April to October 2009. Rome II criteria were used for further classification.

RESULTS

ANOVA Bonferroni post hoc correction outlined that concentrations of serum magnesium and calcium were significantly lower in subjects with ulcer-like dyspepsia, while vitamin B12, glucose and immunoglobulin G level was significantly higher in group with dismotility-like dyspepsia. Statistical analysis revealed that the numbers of meal taken per day were significantly different. There was a statistical trend to skipping meals and to eat fast in patients with ulcer-like and dismotility-like functional dyspepsia when compared with non-specific dyspeptic subjects.

CONCLUSION

Patients with ulcer-like functional dyspepsia suffered from epigastric pain and burning and from heartburn, while persons with dismotility-like dyspepsia were complaining about postprandial fullness, bloating and early satiety. They skipped meals more frequently and avoided intake of certain supplies which, together with eating habits, provoked or emphasized the annoying symptoms.

Effectiveness of a "cold dessert", with or without the addition of a mixture of digestive herbs, in subjects with "functional dyspepsia"

"Functional dyspepsia" represents a clinical condition of pain and/or persistent or recurrent discomfort that concerns a large portion of the healthy population. It has already been shown that some herbs (Melissa Officinalis, Cynara scolymus) can have favorable effects on digestion. The principal aim of this study is to determine whether the ingestion of "Gran Soleil" dessert, with or without herbs, after meals can be beneficial to health in subjects suffering from functional dyspepsia. For this purpose, thirty subjects with functional dyspepsia were enrolled and were asked to consume "Gran Soleil" with or without herbs; these subjects reported the course of their symptoms on VAS scale, during the basal period and after the ingestion "Gran Soleil" with and without herbs. It has been shown that the ingestion of "Gran Soleil" without herbs can induce a reduction both in the number of events connected to a dyspeptic syndrome and in their intensity; moreover the assumption of "Gran Soleil" with the addition of herbs helped to intensify this effect.

A randomized double-blind placebo-controlled trial of Lactobacillus GG for abdominal pain disorders in children

BACKGROUND

Functional abdominal pain disorders (FAPD) are common in school-aged children; however, there is no reliable treatment.

AIM

To determine the efficacy of Lactobacillus rhamnosus GG (LGG) for treating FAPD in children.

METHODS

A total of 104 children who fulfilled the Rome II criteria for functional dyspepsia (FD), or irritable bowel syndrome (IBS), or functional abdominal pain (FAP) were enrolled in a double-blind, randomized controlled trial in which they received LGG (n = 52), or placebo (n = 52) for 4 weeks.

RESULTS

For the overall study population, those in the LGG group were more likely to have treatment success (no pain) than those in the placebo group (25% vs. 9.6%, relative benefit (RB) 2.6, 95% confidence interval (CI): 1.05-6.6, number needed to treat (NNT) 7, 95% CI: 4-123). For children with IBS (n = 37), those in the LGG group were more likely to have treatment success than those in the placebo group (33% vs. 5%, RB 6.3, 95% CI: 1.2-38, NNT 4, 95% CI: 2-36) and reduced frequency of pain (P = 0.02), but not pain severity (P = 0.10). For the FD group (n = 20) and FAP group (n = 47), no differences were found.

CONCLUSION

The LGG appears to moderately increase treatment success, particularly among children with IBS.

[Naturopathic dietary treatment in functional disorders]

When applied to functional disorders, dietary treatment- the most important measure in natural medicine - has its greatest effect when these disorders affect the gastrointestinal tract, in particular epigastric dyspepsia and irritable bowel syndrome. On the basis of a comprehensive dietary anamnesis, it is often possible to identify foodstuffs and eating behavior capable of aggravating the patient's symptoms. The underlying basic principle of treatment is that the gastrointestinal tract first undergo a temporary period of rest before being gradually re-accustomed to a biologically high-quality diet. A central approach includes various forms of fasting therapy, in particular in the case of severe conditions, which can usefully be supported by additional relaxation techniques, psychotherapy, hydrotherapy, massage and special manual techniques.

Efficacy and tolerability of potato juice in dyspeptic patients: a pilot study

In Europe, use of potatoes (Solani tuberosi tuberecens) is a traditional remedy for stomach complaints. We performed a pilot study on the effectiveness and tolerability of freshly squeezed potato juice in patients suffering from dyspeptic symptoms. After informed written consent, 44 patients with various dyspeptic symptoms were enrolled, to drink for 1 week twice daily 100ml or more of potato juice (Biotta, if complaints persisted, a further 100ml was recommended. Validated outcome measures included the gastrointestinal symptom (GIS) profile, a disease-specific health assessment questionnaire (QOLRAD) and self-rated treatment success (efficacy, a 5-point Likert Scale). The study was completed by 42 patients. The GIS and QOLRAD scores improved significantly by 41.9+/-40.8% (p=0.001) and 50.7+/-36.1% (p<0.001), respectively (ITT); the absolute values changed from 11.5+/-5.1 to 6.3+/-5.3 (GIS) and 62.0+/-25.7 to 32.0+/-28.8 (QORAD). Sixteen, 18 and 26 patients, respectively, rated the effectiveness of the treatment as very good or good on the GIS, QOLRAD (improvements >60%) and on efficacy, respectively. Poor treatment success was achieved in 13 (GIS), 11 (QOLRAD) and 10 (Efficacy), not necessarily by the same patients. Since about two-thirds of the patients benefited to some extent from the treatment, potato juice in its present formulation may be useful for self-treatment. However, placebo-controlled studies with a longer treatment period are needed to confirm this.

[Effects of biologically active pectin-containing dietary supplement on gastroduodenal motility in patients with a functional dyspepsia]

For 21 patients with a functional dyspepsia the influencing biologically active additives to nutrition "Pekcecom" on dynamics of clinical symptoms and parameters gastroduodenal motility under the data gastroduodenoscintigraphy was studied. The usage of biologically active additives during 4 weeks was accompanied by deboosting of accelerated gastric emptying for want of statistically significant influencing on a normal and delayed gastric emptying and parameters of duodenal transit.

[Experience of nutritional support in late period of traumatic disease of wounded patients]

There are no standards of nutritional support of wounded patients in different periods of disease. Influence of supplementation with Nutrition on dynamic of anthropometric indexes, some biochemical and laboratory parameters in wounded malnourished patients in the last period of disease was examined. The results of investigation indicated that supplementation with Nutrizon increased all tianthropometric indexes, normalized albumin blood level, nitrogen balance, decreased nitrogen of urine.

[Diet and drugs in the therapy of nonorganic dyspepsia: the hypothesis and factual data]

Non-organic dyspepsia, although not frequently reported, is still a disorder which is difficult to classify in nosographic and physiopathological terms, a fact which inevitably influences the indications for its treatment. Non-pharmacological treatment of non-organic dyspepsia includes changes in dietary and behavioural habits which, even if established on empirical grounds, play a far from ancillary role. When considered appropriate, pharmacological treatment must be formulated solely on the basis of controlled clinical trials vs placebo given the well-known significance of the placebo effect in this and other so-called "functional" diseases. The therapeutic strategies which are most subject to verification are based on the one hand on the neutralisation or inhibition of gastric acid secretion and, on the other, on the improvement of gastrointestinal motility. Surprisingly, the widely used antacid drugs are among those which have been less well studied and show the lowest efficacy. Among the anti-secretory drugs, pirenzepine is approximately 25% more effective than placebo. H2-antagonists, the drugs which have been most closely studied both in terms of the number of trials and the size of the sample populations studied, produce contradictory results. However, a meta-analysis of the trials shows an overall 18% improvement in efficacy compared to placebo. The overall results of studies on prokinetic compounds are "good" in meta-analytical terms, with an improved efficacy of 50% compared to placebo. This is not necessarily due to the superiority of prokinetic compared to anti-secretory drugs and can be explained by the reduced placebo effect in trials using prokinetic drugs or a greater presence in the latter of dyspepsia which is physiopathologically correlated to motor discord. Among the future drugs still being studied, it is particularly worth mentioning fedotozine, a specific K opioid receptor agonist which appears to have provided extremely interesting results in preliminary studies. The role of barrier drugs, such as sucralfate and colloidal bismuth, continues to remain unclear and in particular the latter might be of increased use if evidence of a relationship between Helicobacter pylori and non-organic dyspepsia were reinforced; this relationship may in fact not exist in all dyspeptic patients but only in a subgroup. Lastly, the problem of the duration of pharmacological treatment still remains unsolved, as do the questions of whether longterm treatment should be conceived once acute symptoms have disappeared and whether it is possible to hypothesise differentiated pharmacological treatment depending on the clinical variants of functional dyspepsia which have been defined with greater attention over the course of the past decade.

[Non-pharmacological therapeutic possibilities in gastroesophageal reflux dyspepsia]

New knowledge concerning the pathophysiology of gastroesophageal reflux gives an opportunity for updating measures of conservative antireflux treatment. There are only few controlled trials, and it is uncertain whether the requirement for pharmacological treatment may hereby be diminished. General advice such as eating small meals, reducing the fat intake, avoiding food intake for three hours before bedtime are recommended to all, while advice on more specific foods should be individualized according to actual food related symptoms. Patients with annoying symptoms of reflux are advised not to consume alcohol every day, while the consumption of tobacco seems to be of minor importance. Advising weight loss isn't well founded, but ought to be given to obese patients. Elevation of the head of the bed is suggested to patients with nocturnal symptoms of reflux, which usually coincide with the presence of a hiatal hernia. If possible, revision of other current pharmacotherapy should be done. Theophylline, calcium channel blockers, benzodiazepines and nonsteroidal antiinflammatory drugs, seem in particular to be able to provoke or aggravate reflux. Patient support groups with medical supervision might be useful and reduce the number of consultations. The non-pharmacological measures should still be the basis of treatment and it might be sufficient in mild cases. It is recommended that the advise be individualized to each patient in such a way that no unfounded changes of life style are recommended that impair the quality of life. Gastroesophageal reflux, nonpharmacological treatment, food advices, alcohol, tobacco, overweight, hiatal hernia, drugs, patient education.

ABC of nutrition. Therapeutic diets

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[Bile-dependent gastrointestinal dyspepsia]

"Indigestion" caused by organic and functional alterations in the biliary ways was examined. The difficulty of accurately identifying this form of dyspepsia, whose frequency explains the interest it arouses, is emphasised. Dyspepsia attributable to dyskinesia of the biliary ways and post-cholecystectomy syndrome is specifically analysed. After a review of the results obtained by the medical and surgical treatment of biliary dyspepsia, a more accurate nosologic and pathogenetic classification of the disease is recommended, together with a more detailed definition of the action mechanism of the biliary acids.