Here, we investigate the role of the gut-brain axis in gastric dysfunction during and after chronic H. pylori infection. Control and chronically H. pylori-infected Balb/c mice were studied before and 2 mo after bacterial eradication. Gastric motility and emptying were investigated using videofluoroscopy image analysis. Gastric mechanical viscerosensitivity was assessed by cardioautonomic responses to distension. Feeding patterns were recorded by a computer-assisted system. Plasma leptin, ghrelin, and CCK levels were measured using ELISA. IL-1, TNF-␣, proopiomelanocortin (POMC), and neuropeptide Y mRNAs were assessed by in situ hybridizations on frozen brain sections. Gastric inflammation was assessed by histology and immunohistochemistry. As shown previously, H. pylori-infected mice ate more frequently than controls but consumed less food per bout, maintaining normal body weight. Abnormal feeding behavior was accompanied by elevated plasma ghrelin and postprandial CCK, higher TNF-␣ (median eminence), and lower POMC (arcuate nucleus) mRNA. Infected mice displayed delayed gastric emptying and visceral hypersensitivity. Eradication therapy normalized gastric emptying and improved gastric sensitivity but had no effect on eating behavior. This was accompanied by persistently increased TNF-␣ in the brain and gastric CD3 ϩ T-cell counts. In conclusion, chronic H. pylori infection in mice alters gastric emptying and mechanosensitivity, which improve after bacterial eradication. A feeding pattern reminiscent of early satiety persists after H. pylori eradication and is accompanied by increased TNF-␣ in the brain. The results support a role for altered gut-brain pathways in the maintenance of postinfective gut dysfunction.inflammation; gut-brain axis; gastric emptying; visceral sensitivity FUNCTIONAL GI DISORDERS SUCH as irritable bowel disease (IBS) and functional dyspepsia (FD) have traditionally been viewed as psychosomatic. The concept that previous infection can trigger the development of functional GI disease is now accepted. A large cohort study identified bacterial gastroenteritis as the most significant risk factor identified to date for the development of IBS (24). IBS symptoms have been reported to develop in a significant proportion of subjects with documented Campylobacter, Salmonella, E. coli, or Shigella infection (12,32,37). A similar case has been also made for functional dyspepsia (18,33). These studies were restricted to acute enteric infections.Accumulating evidence suggests that changes in the bacterial content in the gut can affect the central nervous system (CNS) (10, 13). Most of these studies have dealt with the effect of acute infection and early CNS changes that occurred before the onset of the inflammatory response to the infection. The effect of chronic GI infection and inflammation on the CNS has not yet been investigated. Previous studies suggested that vagal sensory afferents are responsible for the rapid changes that occur in the brain within hours of a GI infection (13). However, multiple...