Abstract
Background: Colored food substances may interfere with Bilitec system that uses bilirubin as a marker for the detection of duodeno-gastro-esophageal reflux, causing false positive results. Therefore, diets have been suggested for consumption during Bilitec studies that contain minimal amounts of pigments. Aim: To enrich the list of suitable foods for Bilitec measurements with dishes common in Mediterranean diets, and improve subject’s compliance. Methods: Ninety substances were in vivo tested for ‘bilirubin absorbance’. ‘Dry’ substances were blended after being diluted in water, while ‘floppy’ substances and cooked foods were blended undiluted. Blended mixtures and ‘liquids’ were tested for bilirubin without further dilution and after being mixed with hydrochloric acid. The procedure was repeated to assess reproducibility of the measurements. Results: Measurements are highly reproducible. Thirty five foods exhibited ‘bilirubin absorbance’ values safely below the threshold, and are considered to be suitable for Bilitec studies. On the contrary some vegetables and fruits, legumes, tomato sauce preparations, red wine, coffee, tea and jams showed high absorbance values, and are not recommended. Conclusion: Menus containing part of the variety of Mediterranean food preparations are safely recommended for consumption during Bilitec studies, enriching food lists available at present.