Article

Digestive Diseases and Sciences

, Volume 39, Issue 5, pp 946-956

First online:

Intestinal microflora stimulates myoelectric activity of rat small intestine by promoting cyclic initiation and aboral propagation of migrating myoelectric complex

  • Einar HusebyeAffiliated withFrom the Department of Medical Microbial Ecology, Karolinska Institute, Karolinska HospitalDepartment of Medicine, Karolinska Hospital
  • , Per M. HellströmAffiliated withFrom the Department of Medical Microbial Ecology, Karolinska Institute, Karolinska HospitalDepartment of Medicine, Karolinska Hospital
  • , Tore MidtvedtAffiliated withFrom the Department of Medical Microbial Ecology, Karolinska Institute, Karolinska HospitalDepartment of Medicine, Karolinska Hospital

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Microbial modulation of myoelectric activity in small intestine was studied. Germ-free male Sprague-Dawley rats were equipped with bipolar electrodes from the duodenojejunal junction to the midpoint of small intestine. Prior to and one week after introduction of conventional intestinal microflora, 32±5% and 61±5% (mean±se), respectively, of activity fronts of the migrating myoelectric complex reached the midpoint (P<0.05), and the interval between activity fronts in proximal jejunum was reduced from 31.2±2.0 min to 17.5±0.8 min, respectively (P<0.01). The pattern of propagation was more regular after conventionalization. Slow-wave frequency in proximal jejunum was 38.5±1.2/min in germ-free rats and 43.0±0.8/min in conventional rats (P<0.01), but introduction of microflora failed to increase the frequency in germ-free rats. The frequency of spike potentials succeeding jejunal infusion of 5 ml of 12.5% glucose remained unchanged after conventionalization. Statistical analyses showed that the interval between activity fronts varied mainly within rats, whereas the propagation velocity showed statistically significant variability between rats (P<0.01), regardless of intestinal microflora. Luminal control by the resident microflora is important for physiological cycling and aboral propagation of the migrating myoelectric complex, but seems to be of no major consequence for postprandial myoelectric response.

Key words

gastrointestinal motility germ-free intestinal motility microbiology microflora migrating myoelectric complex myoelectric activity rat small intestine transit