Journal of the American College of Nutrition, Vol 13, Issue 4 364-368, Copyright © 1994 by American College of Nutrition

JOURNAL ARTICLE

Oral rehydration solutions (ORS): enhancement by a soluble fiber

J. T. Go, C. G. Sia, R. G. Harper and R. A. Wapnir
Department of Pediatrics, North Shore University Hospital-Cornell University Medical College, Manhasset 11030.

OBJECTIVE: This study was designed to test the hypothesis that, in an animal model of protein-energy malnutrition (PEM), carboxymethylcellulose (CMC), a viscous additive for the World Health Organization Oral Rehydration Solution (WHO-ORS), previously found to be effective in rats with osmotic diarrhea as an enhancer of water and sodium absorption, would also improve the performance of the WHO-ORS. This hypothesis was based on the changes in fluid and electrolyte transport that could be induced by an increase in the viscosity. METHODS: We evaluated CMC in young rats fed a low-protein, low-energy diet for 3 weeks to induce PEM. Control (CTL) rats were fed a nutritionally complete diet. The ORS were tested with an in vivo perfusion procedure under anesthesia. RESULTS: CMC addition (0, 2.5, 5.0 and 10.0 g/L) sharply increased the rates of net water and sodium absorption in both groups of rats, especially in the PEM animals. Net water absorption increased from (means +/- SEM) 0.75 +/- 0.06 to 2.21 +/- 0.18, 3.35 +/- 0.20 and 8.46 +/- 0.84 microL/min x cm in the PEM rats (0, 2.5, 5.0 and 10.0 g/L CMC, respectively). For the same CMC concentrations, sodium absorption improved from 178.8 +/- 20.3 to 402.4 +/- 18.4, 486.4 +/- 29.2 and 898.4 +/- 21.4 nmol/min x cm, respectively. CTL rats also showed marked increases. Rates of lumen-to-serosa water influx improved in both groups without major changes in water efflux. Net water and sodium absorption appeared related to the log of the ORS viscosity. CONCLUSIONS: The results further support the concept that increased viscosity induced by CMC enhances the effectiveness of ORS.