A standardised nutritional drink as a test meal for the ¹³ C mixed triglyceride breath test for pancreatic exocrine...

The ¹³ C mixed triglyceride breath test (¹³ C MTGT) is a diagnostic test for pancreatic exocrine insufficiency (PEI). It is poorly standardised with much heterogeneity of the test meal, the commonest being toast and butter. A standardised oral nutritional supplement that could be easily transported, stored and made up would be valuable for making this test accessible outside of specialist centres.

A prospective, randomised, two-arm crossover study of different test meals was carried out in 14 healthy controls. The ¹³ C MTGT was performed in identical conditions on two separate days. Two test meals were given in random order, either standard (toast and butter) or novel (oral nutritional supplement), with 250 mg of ¹³ C-labelled mixed triglyceride incorporated. Breath samples were taken postprandially to calculate cumulative percentage dose recovery (cPDR) of ¹³ C at 6 h.

All 14 participants completed both arms of the study with no protocol deviations. The mean cPDR was 39.39% (standard deviation [SD] 5.19) for the standard test meal and 39.93% (SD 5.20) for the novel test meal. A one-way repeated measures analysis of variance (ANOVA) found no significant difference in cPDR between the two meals, F(1, 13) = 0.18, p = 0.68 (minimum detectable difference of 0.81 at 80% power).

This study demonstrates that a standardised oral nutritional supplement can be used without compromising ¹³ C recovery. Using this test meal provides a standardised dietary stimulus to the pancreas, avoiding possible variation in quantity of dietary components with other test meals. Further, the ease of use of this method would help establish the ¹³ C MTGT test more widely.