Caecal pH is a biomarker of excessive colonic fermentation

AIM:To ascertain whether caecal pH is different in patients with irritable bowel syndrome(IBS),whose primary symptoms are bloating and distension,to healthy controls.METHODS:Motility and pH data were reviewed from16 patients with RomeⅢdefined IBS and 16 healthy controls,who had undergone a wireless motility capsule(WMC)study using a standardized protocol.Motility measures were anchored around known anatomical landmarks as identified by compartmental pH changes.Sixty-minute epochs were used to quantify antral,duodenal,ileal,caecal and distal colonic contractility.The maximum and minimum pH was measured either side of the ileo-caecal junction.RESULTS:No differences were seen in motility parameters,compartmental transit times or maximal ileal pH between the two groups.Caecal pH was significantly lower in patients compared to controls(5.12±0.05vs 6.16±0.15,P<0.0001).The ileal:caecalΔchange was greater in patients than controls(-2.63±0.08 vs-1.42±0.11,P<0.0001).There was a significant correlation between caecal pH and right colonic contractility(r=0.54,P=0.002).CONCLUSION:Patients with bloating and distension have a lower caecal pH compared to controls.The measurement of caecal pH using the WMC provides a quantifiable biomarker of fermentation potentially identifying those patients that may preferentially benefit from antibiotic or dietary interventions.     

Design,Development, and Evaluation of a Novel Microneedle Array-based Continuous Glucose Monitor

The development of accurate, minimally invasive continuous glucose monitoring (CGM) devices has been the subject of much work by several groups, as it is believed that a less invasive and more user-friendly device will result in greater adoption of CGM by persons with insulin-dependent diabetes. This article presents the results of preliminary clinical studies in subjects with diabetes of a novel prototype microneedle-based continuous glucose monitor. In this device, an array of tiny hollow microneedles is applied into the epidermis from where glucose in interstitial fluid (ISF) is transported via passive diffusion to an amperometric glucose sensor external to the body. Comparison of 1396 paired device glucose measurements and fingerstick blood glucose readings for up to 72-hour wear in 10 diabetic subjects shows the device to be accurate and well tolerated by the subjects. Overall mean absolute relative difference (MARD) is 15% with 98.4% of paired points in the A+B region of the Clarke error grid. The prototype device has demonstrated clinically accurate glucose readings over 72 hours, the first time a microneedle-based device has achieved such performance.