The Brain-Gut Team.

Background: Interactions between brain and gut have been suspected for centuries but our understanding of the neural centers and neurohormonal links that establish bidirectional regulatory communication between these 2 body systems has advanced significantly in the last decades. The label "brain-gut axis" designates a useful but deceivingly simple concept, since the mechanistic complexity of brain-gut interaction is enormous.

Summary: The significance of the brain-gut axis is perhaps best conceived as "a team" since both systems are physiologically coordinated to ensure a healthy status.

Enteric neuron density correlates with clinical features of severe gut dysmotility.

Gastrointestinal (GI) symptoms can originate from severe dysmotility due to enteric neuropathies. Current methods used to demonstrate enteric neuropathies are based mainly on classic qualitative histopathological/immunohistochemical evaluation. This study was designed to identify an objective morphometric method for paraffin-embedded tissue samples to quantify the interganglionic distance between neighboring myenteric ganglia immunoreactive for neuron-specific enolase, as well as the number of myenteric and submucosal neuronal cell bodies/ganglion in jejunal specimens of patients with severe GI dysmotility.

Gut epithelial and vascular barrier abnormalities in patients with chronic intestinal pseudo-obstruction.

Background: Chronic intestinal pseudo-obstruction (CIPO) is a rare condition due to severe impairment of gut motility responsible for recurrent subocclusive episodes. Although neuromuscular-glial-ICC abnormalities represent the main pathogenetic mechanism, the pathophysiology of CIPO remains poorly understood. Intestinal epithelial and vascular endothelial barrier (IEVB) abnormalities can contribute to neuroepithelial changes by allowing passage of harmful substances.

Functional neuromuscular impairment in severe intestinal dysmotility.

Background: Chronic intestinal pseudo-obstruction (CIPO) and enteric dysmotility (ED) are severe intestinal motility disorders usually associated with underlying neuromuscular abnormalities.

Objective: To evaluate the in vitro neuromuscular function of patients with severe intestinal motility disorders.

Methods: Full-thickness intestinal biopsies (16 jejunum and 3 ileum) obtained from patients with CIPO (n = 10) and ED (n = 9) were studied using muscle bath and microelectrode techniques.

Bloating and Abdominal Distension: Old Misconceptions and Current Knowledge.

Bloating, as a symptom and abdominal distension, as a sign, are both common functional-type complaints and challenging to manage effectively. Individual patients may weight differently the impact of bloating and distension on their well-being. Complaints may range from chronic highly distressing pain to simply annoying and unfashionable protrusion of the abdomen.

Small Bowel Motility.

Purpose Of Review: Small bowel motility disorders constitute a relatively small but important segment of clinical gastroenterology. Presenting features encompass a broad range of symptom manifestations and severity: from chronic functional-type complaints to life-threatening nutritional impairment. Diagnostic assessment of patients with suspected intestinal motility disorders is often hampered by the complexity of measuring intestinal contractile activity in humans.

Effect of prucalopride on intestinal gas tolerance in patients with functional bowel disorders and constipation.

Background And Aim: Patients with functional bowel disorders develop gas retention and symptoms in response to intestinal gas loads that are well tolerated by healthy subjects. Stimulation of 5HT-4 receptors in the gut has both prokinetic and antinociceptive effects. The aim of this study is to determine the effect of prucalopride, a highly selective 5HT-4 agonist, on gas transit and tolerance in women with functional bowel disorders complaining of constipation.

Randomized, Placebo-Controlled Trial of Biofeedback for the Treatment of Rumination.

Objectives: We previously demonstrated that rumination is produced by an unperceived, somatic response to food ingestion, and we developed an original biofeedback technique based on electromyography (EMG)-guided control of abdomino-thoracic muscular activity. Our aim was to demonstrate the superiority of biofeedback vs. placebo for the treatment of rumination.

Gastroduodenal Disorders.

Symptoms that can be attributed to the gastroduodenal region represent one of the main subgroups among functional gastrointestinal disorders. A slightly modified classification into the following 4 categories is proposed: (1) functional dyspepsia, characterized by 1 or more of the following: postprandial fullness, early satiation, epigastric pain, and epigastric burning, which are unexplained after a routine clinical evaluation; and includes 2 subcategories: postprandial distress syndrome that is characterized by meal-induced dyspeptic symptoms and epigastric pain syndrome that does not occur exclusively postprandially; the 2 subgroups can overlap; (2) belching disorders, defined as audible escapes of air from the esophagus or the stomach, are classified into 2 subcategories, depending on the origin of the refluxed gas as detected by intraluminal impedance measurement belching: gastric and supragastric belch; (3) nausea and vomiting disorders, which include 3 subcategories: chronic nausea and vomiting syndrome; cyclic vomiting syndrome; and cannabinoid hyperemesis syndrome; and (4) rumination syndrome.

Mechanism-Oriented Therapy of Irritable Bowel Syndrome.

Irritable bowel syndrome (IBS) is a common and well-accepted diagnosis but often imprecisely applied to patients in usual clinical practice. Diagnosis is entirely based on symptom criteria that tend to include broad strata of abdominal complainers. Established criteria for diagnosis are strictly followed in controlled clinical trials for new therapeutic agents, but physicians are more lax in the clinic.

Effect of selective CCK1 receptor antagonism on accommodation and tolerance of intestinal gas in functional gut disorders.

Background: Participants with functional gut disorders develop gas retention and symptoms in response to intestinal gas loads that are well tolerated by healthy subjects. To determine the role of cholecystokinin (CCK1 ) receptors on gas transit and tolerance in women with functional gut disorders.

Methods: In 12 healthy women, and 24 women with functional gut disorders (12 dyspepsia and 12 constipation-predominant irritable bowel syndrome) gas was infused into the jejunum at 12 mL/min for 3 h with simultaneous duodenal lipid infusion (intralipid 1 kcal/min), while measuring anal gas evacuation and abdominal symptoms on a 0-6 score scale.

Classification of functional bowel disorders by objective physiological criteria based on endoluminal image analysis.

We have previously developed an original method to evaluate small bowel motor function based on computer vision analysis of endoluminal images obtained by capsule endoscopy. Our aim was to demonstrate intestinal motor abnormalities in patients with functional bowel disorders by endoluminal vision analysis. Patients with functional bowel disorders (n = 205) and healthy subjects (n = 136) ingested the endoscopic capsule (Pillcam-SB2, Given-Imaging) after overnight fast and 45 min after gastric exit of the capsule a liquid meal (300 ml, 1 kcal/ml) was administered.

Abdominothoracic mechanisms of functional abdominal distension and correction by biofeedback.

Background & Aims: In patients with functional gut disorders, abdominal distension has been associated with descent of the diaphragm and protrusion of the anterior abdominal wall. We investigated mechanisms of abdominal distension in these patients.

Methods: We performed a prospective study of 45 patients (42 women, 24-71 years old) with functional intestinal disorders (27 with irritable bowel syndrome with constipation, 15 with functional bloating, and 3 with irritable bowel syndrome with alternating bowel habits) and discrete episodes of visible abdominal distension.

Vitamin E and vitamin E acetate absorption from self-assembly systems under pancreas insufficiency conditions.

We determined the bioavailability of vitamin E from self-assembly structures in patients with diagnosed chronic pancreas insufficiency. Vitamin E solubilized in dispersed inverted bicontinuous cubic phase and in micellar formulation was delivered directly to the small intestine by tube-feeding. A cross-over study with randomization of 6 subjects and 2 treatments including a combined dose of 18 mg (27 IU) of vitamin E (RRR-[5,7-methyl-((2)H6)]-α-tocopherol) and 27 mg (27 IU) vitamin E acetate (RRR-[5-methyl-(2)H3]-α-tocopheryl acetate) was applied over a time period of 1 h.

Biofeedback-guided control of abdominothoracic muscular activity reduces regurgitation episodes in patients with rumination.

Background & Aims: Rumination syndrome is characterized by effortless recurrent regurgitation of recently ingested food into the mouth, with consequent expulsion or re-chewing and swallowing. We investigated whether rumination is under volitional control and can be reversed by behavioral treatment.

Methods: We performed a prospective study of 28 patients who fulfilled the Rome criteria for rumination and had no organic disorders on the basis of a thorough evaluation.

Anal gas evacuation and colonic microbiota in patients with flatulence: effect of diet.

Objective: To characterise the influence of diet on abdominal symptoms, anal gas evacuation, intestinal gas distribution and colonic microbiota in patients complaining of flatulence.

Design: Patients complaining of flatulence (n=30) and healthy subjects (n=20) were instructed to follow their usual diet for 3 days (basal phase) and to consume a high-flatulogenic diet for another 3 days (challenge phase).

Results: During basal phase, patients recorded more abdominal symptoms than healthy subjects in daily questionnaires (5.

Mechanisms of postprandial abdominal bloating and distension in functional dyspepsia.

Objective: Patients with irritable bowel syndrome and abdominal bloating exhibit abnormal responses of the abdominal wall to colonic gas loads. We hypothesised that in patients with postprandial bloating, ingestion of a meal triggers comparable abdominal wall dyssynergia. Our aim was to characterise abdominal accommodation to a meal in patients with postprandial bloating.

Impact of orocecal transit time on patient´s perception of lactose intolerance.

Background: symptoms attributed to the lactose intolerance are an important public health issue because of their prevalence and social relevance. Also because they may cause undue rejection of dairy products consume with potential health consequences. Transit time is a putative factor implied in the severity of symptoms associated with lactose.

Diseases of the digestive tract: is prevention possible and feasible?

Prevention is and will remain a major goal of medicine and gastroenterology. Economics will have a major influence. Preventive approaches will need to prove a favorable cost-benefit ratio before they are authorized for broad implementation.

Chronic psychosocial stress induces reversible mitochondrial damage and corticotropin-releasing factor receptor type-1 upregulation in the rat intestine and IBS-like gut dysfunction.

The association between psychological and environmental stress with functional gastrointestinal disorders, especially irritable bowel syndrome (IBS), is well established. However, the underlying pathogenic mechanisms remain unknown. We aimed to probe chronic psychosocial stress as a primary inducer of intestinal dysfunction and investigate corticotropin-releasing factor (CRF) signaling and mitochondrial damage as key contributors to the stress-mediated effects.

Abdomino-phrenic dyssynergia in patients with abdominal bloating and distension.

Objectives: The abdomen normally accommodates intra-abdominal volume increments. Patients complaining of abdominal distension exhibit abnormal accommodation of colonic gas loads (defective contraction and excessive protrusion of the anterior wall). However, abdominal imaging demonstrated diaphragmatic descent during spontaneous episodes of bloating in patients with functional gut disorders.

The dysfunctional gut.

After many decades debating whether the clinical manifestations of patients with functional digestive symptoms originate "in their minds" or "in their guts," arguments remain strong on both sides of the controversy. However, advances in understanding of gut physiology and pathophysiology, and persuasive evidence on the bidirectionality of the regulatory traffic between the enteric and central nervous systems, are helping to characterize clinical situations in which we can legitimately speak of gut dysfunction, as opposed to others where symptoms are not associated with apparent or detectable gut disturbances and may truly represent somatization of an affective disorder. In this review, we describe available clinically applicable technology, albeit in specialized clinical research units, that may be used to discern whether or not challenging patients have gut sensory or motor disturbances.

Subjective perception of lactose intolerance does not always indicate lactose malabsorption.

Background & Aims: Symptomatic lactose intolerance is common; however, abdominal symptoms that patients experience after ingestion of lactose-containing foods can have causes beyond lactose malabsorption. We aimed to determine whether symptoms that patients usually attribute to lactose intolerance are comparable to symptoms provoked by a controlled lactose challenge and whether these symptoms are related to lactose absorption capacity.

Methods: We performed an observational, prospective, transverse study of 353 patients referred for a lactose hydrogen breath test (HBT).

Colonic responses to gas loads in subgroups of patients with abdominal bloating.

Objectives: We sought to evaluate colonic gas accommodation, ileocecal competence, and colonic clearance in subgroups patients with abdominal bloating.

Methods: Thirty-six patients complaining of abdominal bloating (12 constipation-predominant irritable bowel syndrome (IBS-C), 12 diarrhea-predominant irritable bowel syndrome (IBS-D), and 12 functional bloating) and 18 healthy controls were studied. Abdominal perception and girth were measured during: (i) 1 h continuous infusion of gas at 24 ml/min into the rectum (accommodation period) and (ii) 30 min free rectal gas evacuation (clearance period).