Elicit: Efficacy of SGLT Activators on Water Absorption (public)
How effective are sodium-glucose cotransport activators in improving water absorption?
Sodium-glucose cotransport activators effectively improve water absorption in both experimental models and human subjects, with amino acid-based and glucose-based formulations showing significant increases in water uptake rates.
Abstract
Sodium‐glucose cotransport activators improve water absorption in both experimental models and human subjects. Many studies report that amino acid–based activators—most notably L‑alanine and leucine—increase water uptake, with one study noting a rise from 17.4 to 43.9 μL/min/g (p < 0.001). Glucose‐based formulations administered in carefully balanced oral rehydration solutions yield similarly positive results; for example, one report documented an increase of 98.6 ± 16 μL/min/g (p < 0.01), and glucose polymers increased absorption rates from 221–240 to 291–332 μL/min/g (p < 0.02 to p < 0.005). In addition, interventions such as stevia extract yielded a 1.8‐fold boost in SGLT1‐mediated glucose transport (p < 0.05), an effect linked to improved water uptake. In diarrheal or secretory models, these activators also lower net fluid secretion and reduce stool water content. Overall, the studies indicate that activators targeting the sodium‐glucose cotransport mechanism effectively enhance water absorption as measured by both quantitative fluid uptake and associated transporter activity.
Methods
We analyzed 29 sources from an initial pool of 997, using 7 screening criteria. Each paper was reviewed for 5 key aspects that mattered most to the research question. More on methods
Papers identified with Elicit search
n = 997
Papers screened using: SGLT Activators/Enhancers, Water Absorption Outcome, In Vivo Studies, Appropriate Study Design, SGLT Activators vs Inhibitors, Beyond In Vitro Only, Publication Quality
n = 997
Papers screened out
n = 968
Papers included for extraction
n = 29
Results
Characteristics of Included Studies
| Study | Study Design | Clinical Condition | Intervention Type | Primary Outcome Measure |
|---|---|---|---|---|
| Wapnir et al., 1988 | Animal experimental study | Osmotic diarrhea (rats) | L-alanine, protein hydrolysate in oral hydration solution | Water and sodium absorption |
| Rongione et al., 2001 | Animal experimental; in vivo physiological | Normal dogs | Epidermal Growth Factor (EGF), Transforming Growth Factor (TGF) | Sodium, chloride, water, glucose absorption |
| Grahammer et al., 2006 | Animal experimental; in vivo physiological | Normal and dexamethasone-treated mice | Dexamethasone | SGLT1 / NHE3 activity, sodium absorption |
| Aguero et al., 1990 | Animal experimental; in vivo physiological | Normal and diarrheic Wistar rats | Glutamine in WHO-ORS | Sodium and water absorption |
| Wapnir et al., “Enhancement by Alanine” | Animal experimental; in vivo physiological | Chronic diarrhea (rats) | L-alanine, protein hydrolysate in oral hydration solution | Water and sodium absorption |
| Sundaram et al., “Corticosteroids Reverse Na-Glucose Cotransport” | Animal experimental; in vivo physiological | Chronic ileal inflammation (rabbits) | Methylprednisolone | SGLT1 activity |
| Wapnir et al., 1990 | Animal experimental; in vivo physiological | Secretory diarrhea (rats) | L-alanine in oral hydration solution | Water and sodium absorption |
| Elliott et al., 1986 | Animal experimental; in vivo physiological | Secretory diarrhea (rats) | Oral rehydration solution with varying glucose:sodium ratios | Water absorption |
| Laverty et al., 2001 | Animal experimental | High/low salt diet (hens) | Aldosterone | SGLT activity, short-circuit current (Isc) |
| Summers and Schedl, 1968 | In vivo physiological; animal experimental | Normal rats | Glucose, mannitol, varying tonicity | Sodium and water absorption |
Summary of water absorption effects:
- Activator types:
- 6 studies used amino acids (L-alanine, glutamine, leucine, phenylalanine, protein hydrolysate).
- 6 studies used glucose or glucose-based activators (including analogs, polymers, and oral rehydration solution).
- 3 studies used peptide or growth factors (Epidermal Growth Factor, Transforming Growth Factor, Teduglutide).
- 2 studies used steroids (dexamethasone, methylprednisolone).
- 2 studies used hormones (aldosterone, Angiotensin II).
- 2 studies used enzymes or kinases (Glycogen synthase kinase 3 beta, PDK-1).
- 2 studies used plant extracts (stevia, gum arabic).
- 2 studies used complex carbohydrates (cereal-based oral rehydration solution, dextrin).
- 1 study each used a transporter (SGLT1 transfection), an immunosuppressant (tacrolimus), sodium (with glucose), and a meal.
Statistical significance:
- 10 studies reported p<0.05 (including p<0.01, p<0.001, p≤0.028).
- 2 studies reported significant effects without a p-value.
- 1 study reported no significant effect (p>0.05).
Conclusion
Dextrin mediates an earlier hypervolemic response associated with ingestion of high-sodium solution in resting euhydrated young men.