Intestinal amino acid transporters

Intestinal amino acid transporters are a diverse group of membrane proteins, primarily belonging to the Solute Carrier (SLC) superfamily, that mediate the absorption of dietary amino acids and small peptides across the intestinal epithelium (Bröer, 2008; Bröer, 2023). These transporters are strategically localized on the apical (brush border) and basolateral membranes of enterocytes to facilitate the vectorial movement of nutrients from the gut lumen into the systemic circulation (Bröer, 2023; NIH, 2026). Key members include SLC6A19 (B0AT1), which handles neutral amino acids, and SLC15A1 (PEPT1), which transports di- and tripeptides (ACS, 2021; NIH, 2026). Beyond their role in nutrition, these transporters are increasingly recognized as therapeutic targets; for instance, inhibiting SLC6A19 is being explored to treat metabolic disorders like type 2 diabetes and obesity by inducing a state of "protein restriction" that triggers beneficial hormonal responses like increased GLP-1 and FGF21 (NIH, 2018; ResearchGate, 2026). Additionally, transporters like PEPT1 are exploited in prodrug design to enhance the oral bioavailability of poorly permeable drugs such as valacyclovir (NIH, 2020; NIH, 2026). Dysregulation or genetic mutations in these transporters are linked to various conditions, including Hartnup disease, cystinuria, and inflammatory bowel disease, making them critical focal points for both metabolic and rare disease research (Ace Therapeutics, 2023; NIH, 2024).

Other names

Gut amino acid transportersEpithelial amino acid transportersSLC amino acid transportersIntestinal solute carriers

Intestinal amino acid transporters are targeted through two primary strategies: pharmacological inhibition and prodrug hijacking. Inhibition of transporters like SLC6A19 (B0AT1) reduces the absorption of neutral amino acids, mimicking protein restriction to improve metabolic health (e.g., via GLP-1 and FGF21 induction). Alternatively, transporters like SLC15A1 (PEPT1) are utilized as vehicles for drug delivery, where therapeutic agents are conjugated to amino acids or peptides to facilitate their uptake via the transporter's natural mechanism.