Enteric-coated sodium bicarbonate attenuates gastrointestinal side-effects

Enteric-formulated capsules can mitigate gastrointestinal (GI) side effects following sodium bicarbonate (NaHCO₃) ingestion; however, it remains unclear how encapsulation alters postingestion symptoms and acid–base balance. The current study aimed to identify the optimal ingestion form to mitigate GI distress following NaHCO₃ ingestion. Trained males (n = 14) ingested 300 mg/kg body mass of NaHCO₃ in gelatin (GEL), delayed-release (DEL), and enteric-coated (ENT) capsules or a placebo in a randomized cross-over design. Blood bicarbonate anion concentration, potential hydrogen, and GI symptoms were measured pre- and postingestion for 3 hr. Fewer GI symptoms were reported with ENT NaHCO₃ than with GEL (p = .012), but not with DEL (p = .106) in the postingestion phase. Symptom severity decreased with DEL (4.6 ± 2.8 arbitrary units) compared with GEL (7.0 ± 2.6 arbitrary units; p = .001) and was lower with ENT (2.8 ± 1.9 arbitrary units) compared with both GEL (p < .0005) and DEL (p = .044) NaHCO₃. Blood bicarbonate anion concentration increased in all NaHCO₃ conditions compared with the placebo (p < .0005), although this was lower with ENT than with GEL (p = .001) and DEL (p < .0005) NaHCO₃. Changes in blood potential hydrogen were reduced with ENT compared with GEL (p = .047) and DEL (p = .047) NaHCO₃, with no other differences between the conditions. Ingestion of ENT NaHCO₃ attenuates GI disturbances for up to 3 hr postingestion. Therefore, ENT ingestion forms may be favorable for those who report GI disturbances with NaHCO₃ supplementation or for those who have previously been deterred from its use altogether.