Impact of Lifestyle on Irritable Bowel Syndrome

Brain-gut interactions play a major role in the pathophysiology of irritable bowel syndrome (IBS). Several lifestyles greatly influence on the onset and/or exacerbation in IBS symptoms. There are two major lifestyles affecting on the manifestation of IBS. One is eating habit and the other is stress coping.　Foods are direct stimuli to the gut as well as nutrients for the gut microbiota. Composition, frequency, and chronological timing of taking meals influence on gastrointestinal function. Psychosocial stressors are stimuli to the brain and coping style is one of important elements which determine physiological stress response. In IBS patients, females ate less fish, fruit, milk, and green-yellow vegetables, and more processed food products than controls. The rates of missed meals and irregular mealtimes were higher in IBS women. Moreover, daily consumption of rice, bread, pasta, and buckwheat noodles were associated with higher prevalence of IBS. Composition of the gut microbiota in IBS patients differed from that of controls. Fecal concentration of acetic acid and propionic acid as products of gut microbiotra in IBS patients was higher than that in controls. Degree of increase in acetic acid and propionic acid was associated with severity of IBS and alexitymia as the emotional dysregulation. Evidence of low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet, soluble dietary fibers, probiotics, and psychobehavioral therapies on IBS is accumulated. Further research for impact of lifestyle on IBS is warranted.