title: Intestinal SGLT1 in metabolic health and disease.
abstract: The Na(+)-glucose cotransporter 1 (SGLT1/SLC5A1) is predominantly expressed in the small intestine. It transports glucose and galactose across the apical membrane in a process driven by a Na(+) gradient created by Na(+)-K(+)-ATPase. SGLT2 is the major form found in the kidney, and SGLT2-selective inhibitors are a new class of treatment for type 2 diabetes mellitus (T2DM). Recent data from patients treated with dual SGLT1/2 inhibitors or SGLT2-selective drugs such as canagliflozin (SGLT1 IC50 = 663 nM) warrant evaluation of SGLT1 inhibition for T2DM. SGLT1 activity is highly dynamic, with modulation by multiple mechanisms to ensure maximal uptake of carbohydrates (CHOs). Intestinal SGLT1 inhibition lowers and delays the glucose excursion following CHO ingestion and augments glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) secretion. The latter is likely due to increased glucose exposure of the colonic microbiota and formation of metabolites such as L cell secretagogues. GLP-1 and PYY secretion suppresses food intake, enhances the ileal brake, and has an incretin effect. An increase in colonic microbial production of propionate could contribute to intestinal gluconeogenesis and mediate positive metabolic effects. On the other hand, a threshold of SGLT1 inhibition that could lead to gastrointestinal intolerability is unclear. Altered Na(+) homeostasis and increased colonic CHO may result in diarrhea and adverse gastrointestinal effects. This review considers the potential mechanisms contributing to positive metabolic and negative intestinal effects. Compounds that inhibit SGLT1 must balance the modulation of these mechanisms to achieve therapeutic efficacy for metabolic diseases.
authors.affiliation: Division of Endocrinology, Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; and.
authors.forename: Anders
authors.initials: A
authors.lastname: Lehmann
authors.affiliation: Cardiovascular and Metabolic Disease, Janssen Research and Development, LLC, Spring House, Pennsylvania phornby@its.jnj.com.
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Hornby
mesh_terms: D000818:Animals; D019858:Enteroendocrine Cells / Q000378:metabolism; D005769:Gastrointestinal Motility; D006801:Humans; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism*; D008659:Metabolic Diseases / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D051269:Sodium-Glucose Transporter 1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: C495674:SLC5A1 protein, human; D051269:Sodium-Glucose Transporter 1
keywords: SLC5A1; diarrhea; gluconeogenesis; glucose tolerance; ileal brake; incretin; microbiome; monosaccharide; sodium/hydrogen exchanger isoform 3; taste receptors