Ultrasound Assessment of Gallbladder Motility After Ingestion of a Bicarbonate-Rich Mineral Water (Aqua 3): A Randomized Crossover Study

Background: Bicarbonate mineral waters have been reported to modulate biliary dynamics. Prior symptom-based data with Aqua 3 suggested digestive benefits, but objective confirmation is still lacking. Aims: We sought to evaluate the effect of Aqua 3 on gallbladder motility in fasting healthy adults, compared with an oligomineral water. Methods: In this randomized, crossover study, twenty healthy volunteers underwent two ultrasound sessions after an overnight fast and the ingestion of 500 mL of either Aqua 3 (bicarbonate-rich mineral water) or oligomineral water. Gallbladder volume was measured at baseline and after 10, 20, 30, and 60 min. Primary endpoint was the maximum observed ejection fraction. Results: Bicarbonate-rich mineral water induced a rapid increase in ejection fraction: peaking at 10 min, persisting at 20 min and attenuating by 30 min. At 60 min, gallbladder refilling exceeded baseline. Oligomineral water produced only modest early emptying at 10 min, no significant change at 20 min, and progressive refilling thereafter. Throughout the observation period, ejection fraction was significantly higher after bicarbonate than oligomineral water. Maximum observed ejection fraction was significantly greater with bicarbonate than oligomineral water, occurring most frequently at 10 min for both waters. Conclusions: Because the study compared Aqua 3 with one selected oligomineral water and the two waters differed in several chemical–physical characteristics, including bicarbonate, free CO2, calcium, magnesium, and sodium, the observed response cannot be attributed exclusively to the bicarbonate content and should be interpreted as an effect of Aqua 3. This rapid and sustained effect is potentially useful in the clinical setting to improve early phases of postprandial digestion and providing a mechanistic rationale for the previously reported digestive benefits of bicarbonate-rich mineral water. These results describe an acute physiological effect and require confirmation in larger studies, including postprandial settings and clinical populations, before therapeutic implications can be drawn.