The use of a wireless motility device (SmartPill^®) for the measurement of gastrointestinal transit time after a dietary fibre intervention

Historically, measurement of gastrointestinal transit time has required collection and X-raying of faecal samples for up to 7d after swallowing radio-opaque markers; a tedious, labour-intensive technique for both subjects and investigators. Recently, a wireless motility capsule (SmartPill), which uses gut pH, pressure and temperature to measure transit time, has been developed. This device, however, has not been validated with dietary interventions. Therefore, we conducted a controlled cross-over trial to determine whether the device could detect a significant difference in transit time after ten healthy subjects (five men and five women) consumed 9g of wheat bran (WB) or an equal volume, low-fibre control for 3d. A paired t test was used to determine differences in transit times. Colonic transit time decreased by 108 (sd 66)h (P=0006) on the WB treatment. Whole-gut transit time also decreased by 89 (sd 54)h (P=002) after the consumption of WB. Gastric emptying time and small-bowel transit time did not differ between treatments. Despite encouraging results, the present study had several limitations including short duration, lack of randomisation and unusable data due to delayed gastric emptying of the capsule. With minimal participant burden, the SmartPill technology appears to be a potentially useful tool for assessing transit time after a dietary intervention. This technology could be considered for digestive studies with novel fibres and other ingredients that are promoted for gut health.