112,113 In a large retrospective tertiary center study, Tack et al.114 showed that a subset of presumed post-infectious dyspepsia patients had higher prevalence of impaired accommodation of the proximal stomach. There is evidence that post-infectious FD can occur in a subset of patients, and functional selleck inhibitor abnormalities and persistent inflammation of the gut are found. Statement 20. Genetic factors may be involved in pathogenesis in a subset of patients with functional dyspepsia. Grade of evidence: low. Level of agreement: a: 78.9%; b: 15.8%; c: 5.3%; d: 0%; e: 0%; f: 0%. The G-protein β3 subunit C825T polymorphism was reported to be associated with dyspepsia in studies from the United States (both

CC and TT genotypes with meal-unrelated dyspepsia)115 and Germany (CC genotype).116 In contrast, the 825 T allele was suggested to be related to dyspepsia in reports from Japan and the Netherlands.117–119 In Japanese groups, the following polymorphisms have been reported to be associated with the development of FD or dyspeptic symptoms: IL-17F 7488T, macrophage migration inhibitory factor G-173C,120 catechol-o-methyltransferase gene val158met,121 T779C

of CCK-1 intron 1,122 cyclooxygenase-1 T-1676C,123 p22 phagocyte oxidase component of nicotinamide adenine dinucleotide phosphate oxidase C242T,124 and transient receptor potential vanilloid 1 G315C.125 These data indicate that genetic factors are associated with the development of FD. However, the studies from Asia are limited and are only from Japan. Validation in other countries and in a large-scale study is warranted. Statement 21. Dietary factors and lifestyle may be involved in selleck chemicals llc the pathogenesis of functional dyspepsia. Grade of evidence: low. Level of agreement: a: 94.7%; b: 5.3%; c: 0%; d: 0%; e: 0%; f: 0%. The investigation of lifestyle factors in FD has been limited to a few studies. From Asia, Chen et al.79 and Mahadeva et al.44 reported that tea drinking was negatively associated with FD. Theophylline in tea acts as a competitive antagonist MCE to adenosine receptors, which induce epigastric pain

and chest pain.126,127 However, there is little Asian literature on the types and amounts of tea drunk by dyspeptic patients. More recently, the concept of visceral hypersensitivity to nutrient stimuli, especially hypersensitivity to fat,128,129 has been highlighted as an etiology of FD.130,131 Food ingestion is associated with stimulation of secretion of a range of GI hormones, including cholecystokinin and peptide YY, and suppression of ghrelin.132 It is conceivable that gut peptides play a role in the induction of dyspeptic symptoms in FD patients with nutrient hypersensitivity. In patients with FD, intolerance to specific foods is common and many foods are reported to induce symptoms.133 On the contrary, chili and rice134 and ginger135 are reported to be good for dyspepsia. Feinle-Bisset et al.