Taste Receptors in the Rectum
The rectum does not contain taste buds, but it does contain sweet-taste receptors (chemosensory receptors) distributed along the intestinal mucosa, which are functionally distinct from the gustatory taste buds found in the oral cavity. 1
Key Distinction: Taste Buds vs. Taste Receptors
Taste buds are specialized peripheral chemosensory organs consisting of 50-100 elongated cells that extend from the basal lamina to the surface of the tongue, where their apical microvilli encounter taste stimuli in the oral cavity. 2, 3, 4
True taste buds are exclusively located in the oral cavity, specifically distributed in the epithelium of taste papillae of the palate, tongue, epiglottis, throat, and larynx—not in the rectum or lower gastrointestinal tract. 2, 5, 4
Sweet-taste receptors (T1R family and α-gustducin receptors) are present along the intestinal mucosa, including the rectum, but these are not organized into taste bud structures. 1
Functional Role of Intestinal Taste Receptors
These intestinal sweet-taste receptors activate in response to nutritive and non-nutritive sweeteners, triggering stimulus to pleasure-generating loci of the brain and influencing glucose uptake and appetite regulation. 1
The receptors in the intestinal mucosa are part of a broader chemosensory system that monitors nutrient content and regulates metabolic responses, rather than providing conscious taste perception. 1, 6
Recent evidence demonstrates that taste receptors are expressed "ectopically" in many non-gustatory organs, including airways, gastrointestinal tract, and other tissues, where they serve metabolic and regulatory functions distinct from taste perception. 6, 3
Clinical Relevance
The presence of these chemosensory receptors in the intestinal tract has implications for understanding how non-nutritive sweeteners affect appetite regulation and metabolic pathways, though the precise mechanisms remain incompletely understood. 1
This distinction is important when discussing rectal anatomy and physiology, as the rectum contains chemosensory receptors but not the specialized taste bud structures that enable conscious taste perception. 1, 2