Francesco Paolo Zito

Irritable bowel syndrome and food interaction

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders in Western countries. Despite the high prevalence of this disorders, the therapeutic management of these patients is often unsatisfactory. A number of factors have been suggested to be involved in the pathogenesis of IBS, including impaired motility and sensitivity, increased permeability, changes in the gut microbiome and alterations in the brain-gut axis. Also food seems to play a critical role: the most of IBS patients report the onset or the exacerbation of their symptoms after the meals. Recently, an increasing attention has been paid to the role of food in IBS. In this review we summarize the most recent evidences about the role of diet on IBS symptoms. A diet restricted in fermentable, poorly absorbed carbohydrates and sugar alcohols has beneficial effects on IBS symptoms. More studies are needed to improve our knowledge about the relationship between food and IBS. However, in the foreseeable future, dietary strategies will represent one of the key tools in the therapeutic management of patients with IBS.

The role of a pre-load beverage on gastric volume and food intake: comparison between non-caloric carbonated and non-carbonated beverage

BackgroundThere is conflicting data on the effects of carbon dioxide contained in beverages on stomach functions. We aimed to verify the effect of a pre-meal administration of a 300 ml non-caloric carbonated beverage (B+CO2) compared to water or a beverage without CO2 (B-CO2), during a solid (SM) and a liquid meal (LM) on: a) gastric volume, b) caloric intake, c) ghrelin and cholecystokinin (CCK) release in healthy subjects.MethodsAfter drinking the beverages (Water, B-CO2, B+CO2), ten healthy subjects (4 women, aged 22-30 years; BMI 23 ± 1) were asked to consume either an SM or an LM, at a constant rate (110 kcal/5 min). Total gastric volumes (TGV) were evaluated by Magnetic Resonance Imaging after drinking the beverage and at maximum satiety (MS). Total kcal intake at MS was evaluated. Ghrelin and CCK were measured by enzyme immunoassay until 120 min after the meal. Statistical calculations were carried out by paired T-test and analysis of variance (ANOVA). The data is expressed as mean ± SEM.ResultsTGV after B+CO2 consumption was significantly higher than after B-CO2 or water (p < 0.05), but at MS, it was no different either during the SM or the LM. Total kcal intake did not differ at MS after any of the beverages tested, with either the SM (Water: 783 ± 77 kcals; B-CO2: 837 ± 66; B+CO2: 774 ± 66) or the LM (630 ± 111; 585 ± 88; 588 ± 95). Area under curve of ghrelin was significantly (p < 0.05) lower (13.8 ± 3.3 ng/ml/min) during SM following B-CO2 compared to B+CO2 and water (26.2 ± 4.5; 27.1 ± 5.1). No significant differences were found for ghrelin during LM, and for CCK during both SM and LM after all beverages.ConclusionsThe increase in gastric volume following a 300 ml pre-meal carbonated beverage did not affect food intake whether a solid or liquid meal was given. The consistency of the meal and the carbonated beverage seemed to influence ghrelin release, but were unable, under our experimental conditions, to modify food intake in terms of quantity. Further studies are needed to verify if other food and beverage combinations are able to modify satiation.

The Bitter Taste Receptor Agonist Quinine Reduces Calorie Intake and Increases the Postprandial Release of Cholecystokinin in Healthy Subjects.

Background/Aims Bitter taste receptors are expressed throughout the digestive tract. Data on animals have suggested these receptors are involved in the gut hormone release, but no data are available in humans. Our aim is to assess whether bitter agonists influence food intake and gut hormone release in healthy subjects. Methods Twenty healthy volunteers were enrolled in a double-blind cross-over study. On 2 different days, each subject randomly received an acid-resistant capsule containing either placebo or 18 mg of hydrochloride (HCl) quinine. After 60 minutes, all subjects were allowed to eat an ad libitum meal until satiated. Plasma samples were obtained during the experiment in order to evaluate cholecystokinin (CCK) and ghrelin levels. Each subject was screened to determine phenylthiocarbamide (PTC) tasting status. Results Calorie intake was significantly lower when subjects received HCl quinine than placebo (514 ± 248 vs 596 ± 286 kcal; P = 0.007). Significantly higher CCK ΔT90 vs T0 and ΔT90 vs T60 were found when subjects received HCl quinine than placebo (0.70 ± 0.69 vs 0.10 ± 0.86 ng/mL, P = 0.026; 0.92 ± 0.75 vs 0.50 ± 0.55 ng/mL, P = 0.033, respectively). PTC tasters ingested a significantly lower amount of calories when they received HCl quinine compared to placebo (526 ± 275 vs 659 ± 320 kcal; P = 0.005), whereas no significant differences were found for PTC non-tasters (499 ± 227 vs 519 ± 231 kcal; P = 0.525). Conclusions This study showed that intra-duodenal release of a bitter compound is able to significantly affect calorie intake and CCK release after a standardized meal. Our results suggest that bitter taste receptor signaling may have a crucial role in the control of food intake.

Good adherence to mediterranean diet can prevent gastrointestinal symptoms: A survey from Southern Italy

AIM To evaluate how different levels of adherence to a mediterranean diet (MD) correlate with the onset of functional gastrointestinal disorders. METHODS As many as 1134 subjects (598 M and 536 F; age range 17-83 years) were prospectively investigated in relation to their dietary habits and the presence of functional gastrointestinal symptoms. Patients with relevant chronic organic disease were excluded from the study. The Mediterranean Diet Quality index for children and adolescents (KIDMED) and the Short Mediterranean Diet Questionnaire were administered. All subjects were grouped into five categories according to their ages: 17-24 years; 25-34; 35-49; 50-64; above 64. RESULTS On the basis of the Rome III criteria, our population consisted of 719 (63.4%) individuals who did not meet the criteria for any functional disorder and were classified as controls (CNT), 172 (13.3%) patients meeting criteria for prevalent irritable bowel syndrome (IBS), and 243 (23.3%) meeting criteria for prevalent functional dyspepsia (FD). A significantly lower adherence score in IBS (0.57 ± 0.23, P < 0.001) and FD (0.56 ± 0.24, P < 0.05) was found compared to CNT (0.62 ± 0.21). Females with FD and IBS exhibited significantly lower adherence scores (respectively 0.58 ± 0.24, P < 0.05 and 0.56 ± 0.22, P < 0.05) whereas males were significantly lower only for FD (0.53 ± 0.25, P < 0.05). Age cluster analyses showed a significantly lower score in the 17-24 years and 25-34 year categories for FD (17-24 years: 0.44 ± 0.21, P < 0.001; 25-34 years: 0.48 ± 0.22, P < 0.05) and IBS (17-24 years: 0.45 ± 0.20, P < 0.05; 24-34 years: 0.44 ± 0.21, P < 0.001) compared to CNT (17-24 years: 0.56 ± 0.21; 25-34 years: 0.69 ± 0.20). CONCLUSION Low adherence to MD may trigger functional gastrointestinal symptoms, mainly in younger subjects. Moreover, with increasing age, patients tend to adopt dietary regimens closer to MD.

Alcoholic Beverages and Carbonated Soft Drinks: Consumption and Gastrointestinal Cancer Risks

Alcoholic beverages (ABs) and carbonated soft drinks (CSDs) are widely consumed worldwide. Given the high consumption of these beverages, the scientific community has increased its focus on their health impact. There is epidemiological evidence of a causal association between AB intake and digestive cancer, but the role of alcohol in determining cancer is not fully defined. Experimental studies have so far identified multiple mechanisms involved in carcinogenesis; ethanol itself is not carcinogenic but available data suggest that acetaldehyde (AA) and reactive oxygen species-both products of ethanol metabolism-have a genotoxic effect promoting carcinogenesis. Other carcinogenetic mechanisms include nutritional deficits, changes in DNA methylation, and impaired immune surveillance. As CSDs are often suspected to cause certain gastrointestinal disorders, consequently, some researchers have hypothesized their involvement in gastrointestinal cancers. Of all the ingredients, carbon dioxide is prevalently involved in the alteration of gastrointestinal physiology by a direct mucosal effect and indirect effects mediated by the mechanical pressure determined by gas. The role of sugar or artificial sweeteners is also debated as factors involved in the carcinogenic processes. However, several surveys have failed to show any associations between CSDs and esophageal, gastric, or colon cancers. On the other hand, a slight correlation between risk of pancreatic cancer and CSD consumption has been found.

Partially hydrolyzed guar gum in the treatment of irritable bowel syndrome with constipation: Effects of gender, age, and body mass index

Background/Aims: Partially hydrolyzed guar gum (PHGG) relieves symptoms in constipation-predominant irritable bowel syndrome (IBS) and may have prebiotic properties. However, the correlation between the effectiveness of PHGG and patient characteristics has not been examined. We aimed to investigate the effect of PHGG in symptom relief on constipation-predominant IBS according to gender, age, and body mass index (BMI). Patients and Methods: Sixty-eight patients with IBS entered a 2-week run-in period, followed by a 4-week study period with PHGG. Patients completed a daily questionnaire to assess the presence of abdominal pain/discomfort, swelling, and the sensation of incomplete evacuation. The number of evacuations/day, the daily need for laxatives/enemas and stool consistency-form were also evaluated. All patients also underwent a colonic transit time (CTT) evaluation. Results: PHGG administration was associated with a significant improvement in symptom scores, use of laxatives/enemas, stool form/consistency and CTT. At the end of the study period and compared with baseline, the number of evacuations improved in women, patients aged ≥ 45 years and those with BMI ≥ 25 (P < 0.05 for all comparisons); abdominal bloating improved in males (P < 0.05), patients < 45 years (P < 0.01) and those with BMI < 25 (P < 0.05). A decrease in the number of perceived incomplete evacuations/day was reported in patients with a BMI ≥ 25 (P < 0.05). Reductions in laxative/enema use were recorded in females (P < 0.05), patients < 45 years (P < 0.01), and patients with BMI < 25 (P < 0.05). Conclusions: Gender, age, and BMI seem to influence the effect of PHGG supplementation in constipated IBS patients. Further studies are needed to clarify the interaction of such parameters with a fiber-enriched diet.

Bacterial stimuli activate nitric oxide colonic mucosal production in diverticular disease. Protective effects of L. casei DG® (Lactobacillus paracasei CNCM I-1572)

Background Micro-inflammation and changes in gut microbiota may play a role in the pathogenesis of diverticular disease (DD). Objective The objective of this article is to evaluate the expression of nitric oxide (NO)-related mediators and S100B in colonic mucosa of patients with DD in an ex vivo model of bacterial infection. Methods Intestinal biopsies obtained from patients with diverticulosis, symptomatic uncomplicated diverticular disease (SUDD) and SUDD with previous acute diverticulitis (SUDD+AD) were stimulated with the probiotic L. casei DG® (LCDG) and/or the pathogen enteroinvasive Escherichia coli (EIEC). S100B, NO release and iNOS expression were then evaluated. Results Basal iNOS expression was significantly increased in SUDD and SUDD+AD patients. Basal NO expression was significantly increased in SUDD+AD. No differences in S100B release were found. In all groups, iNOS expression was significantly increased by EIEC and reduced by LCDG. In all groups, except for SUDD+AD, EIEC significantly increased NO release, whereas no increase was observed when LCDG was added to biopsies. EIEC did not induce significant changes in S100B release. Conclusions Colonic mucosa of patients with DD is characterized by a different reactivity toward pathogenic stimuli. LCDG plays a role in counteracting the pro-inflammatory effects exerted by EIEC, suggesting a beneficial role of this probiotic in DD.

Specific dyspeptic symptoms are associated with poor response to therapy in patients with gastroesophageal reflux disease

Introduction In patients with gastroesophageal reflux disease (GORD), co-existence of functional dyspepsia (FD) is known to be associated with poor response to proton pump inhibitors (PPIs), but the contribution of specific dyspepsia symptoms has not yet been systematically investigated. Objective We aimed to characterize the impact of dyspepsia symptoms on response to PPIs in patients with GORD. Methods The enrolled subjects were consecutive patients with a diagnosis of GORD. All patients underwent a 24 hour pH–impedance test, while on PPI therapy. Patients were divided into two groups, refractory and responders, according to the persistence of GORD symptoms. A standardized questionnaire for FD was also administered to assess presence of dyspepsia symptoms. Results In the subgroup of refractory patients FD was more prevalent than in responders, with post-prandial fullness, nausea, vomiting, early satiation and epigastric pain being significantly prevalent in refractory GORD patients. In the multivariate analysis only early satiation and vomiting were significantly associated with poor response to PPIs. Conclusion Co-existence of FD is associated with refractory GORD. We showed that only early satiation and vomiting are risk factors for poor response to therapy with PPIs. Our findings suggest that symptoms of early satiation and vomiting would help to identify the subset of PPI-refractory GORD patients.