The treatment of acute diarrhoea in children utilizes Oral rehydration solutions (ORSs). They are important as they restore the electrolyte balance by stimulating the intestinal sodium/glucose transporter SGLT1 to induce fluid absorption. 

The compositions of the ORSs proposed by The World Health Organization (WHO) and The European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) are different. WHO and UNICEF proposed ORS composition specifies that glucose should at least equal that of sodium within the range of 60–90 mEq/L, while ESPGHAN recommends an ORS with a sodium concentration of 60 mEq/L and glucose concentration ranging 74–111 mmol/l.

Buccigrossi V. et al. explained that the concerning agent of childhood acute gastroenteritis remains rotavirus (RV), so it is important to evaluate the effects of ORS with different concentration of glucose and sodium on RV induced secretion. 

For comparing the efficacy of both the solutions, they conducted electrophysiology experiments with the Ussing chambers technique to evaluate ion fluid flux. They found that ESPGHAN ORS (sodium 60 mmol/L and glucose 111 mmol/L) induced a more potent proabsorptive effect in Caco-2 cells than WHO ORS, pertaining to its sodium/glucose ratio. 

They explained with Titration experiments that RV-induced fluid secretion can be reverted to a proabsorptive direction when sodium and glucose concentration fall in specific ranges, specifically 45–60 mEq/L and 80–110 mM respectively. They confirmed their results by testing commercial ORSs. 

Commercially available ORSs formulations also contain several functional factors, i.e., zinc and/or prebiotics to promote intestinal functions mainly ion absorption. Additionally, the commercial preparations also contain aromas and sweeteners to improve palatability. Optimal concentrations should consider both factors chemical composition and palatability to impart maximum benefit.

Thus, they concluded by saying that ORS absorptive potency depends on sodium and glucose concentrations. Optimal ORS composition is important to reduce RV-induced ion secretion by also considering palatability. They also necessitated confirmation of in vitro data by clinical trials.

Source: Buccigrossi V, Lo Vecchio A, Bruzzese E, et al. Potency of Oral Rehydration Solution in Inducing Fluid Absorption is related to Glucose Concentration. Sci Rep. 2020;10(1):7803. Published 2020 May 8. doi:10.1038/s41598-020-64818-3