Tuft cells were first spotted by electron microscopists in the 1950s and 1960s, when researchers noticed epithelial cells bearing an unusual tuft of long microvilli unlike the shorter, uniform bristles of ordinary absorptive cells. For decades they remained a morphological curiosity, described in the airways, stomach, intestine, gallbladder and pancreas but assigned no clear function. That began to change with the arrival of genetic tools. The discovery that tuft cells express the chemosensory signaling machinery more familiar from taste buds, including the G protein gustducin and components of the transient receptor potential ion channel cascade, suggested they were the epithelial equivalent of sensory neurons, sampling the chemical environment of the gut lumen and relaying what they find to the nervous and immune systems.

Modern single-cell technologies have transformed the field again. The review highlights how transcriptomic profiling has yielded a growing panel of tuft cell biomarkers, including DCLK1, POU2F3, Trpm5, Ascl2 and the interleukin-25 receptor, allowing researchers to identify, isolate and manipulate these cells with precision that earlier generations could only dream of. These markers have revealed that tuft cells are not a monolithic population. Subsets differ across organs and along the length of the gut, expressing distinct receptor repertoires and effector molecules, which likely underlies the diverse roles the cells play in chemoreception, immune modulation, neural regulation and epithelial regeneration.

The most celebrated chapter in tuft cell biology came from studies of intestinal parasitic infection. When helminth worms colonize the intestine, tuft cells expand dramatically in number and secrete the cytokine interleukin-25, which acts on group 2 innate lymphoid cells to launch a type 2 immune response. That response, in turn, feeds back through epithelial stem cells to generate still more tuft cells, creating a feed-forward loop that amplifies host defense. This tuft cell–ILC2 circuit, now regarded as a textbook example of epithelial immune surveillance, established tuft cells as the gut’s first line of sensory detection for parasites and positioned them at the interface between epithelium and immunity.

Chemoreception, however, is only part of the story. The review emphasizes that tuft cells express a remarkable repertoire of receptors tuned to detect microbial metabolites, nutrients and danger signals. Some subsets sense short-chain fatty acids and succinate, metabolites whose concentrations shift during infection or dysbiosis. Others carry taste receptors capable of detecting bitter compounds, allowing the epithelium to respond to bacterial products. By translating luminal chemistry into neural signals through their connections with enteric nerves and into immune signals through cytokine secretion, tuft cells function as a biological transducer, converting what happens inside the gut tube into coordinated responses by the body.

In inflammatory bowel disease, the picture is more complicated and, in some ways, more provocative. Studies summarized in the review show that tuft cell abundance changes in both Crohn’s disease and ulcerative colitis, and that the cells can either restrain or amplify inflammation depending on context. Interleukin-25 production by tuft cells has been linked to tissue-protective and anti-inflammatory programs, while loss of tuft cell function has been associated with worsened colitis in experimental models. At the same time, some tuft cell–derived signals can promote inflammatory pathways under certain conditions. This duality suggests that tuft cells act as regulators of epithelial immune tone, and that therapies aimed at modulating their activity could either calm chronic inflammation or, if misapplied, worsen it.

The role of tuft cells in cancer has attracted particular attention because of one specific marker: doublecortin-like kinase 1, or DCLK1, which labels a subset of tuft cells and has become one of the most intensively studied candidates for a tumor stem cell marker in gastrointestinal malignancies. DCLK1-positive cells expand in inflamed tissue and in tumors of the stomach, pancreas and colon, and their presence has been correlated with tumor initiation, progression, metastasis and resistance to therapy in experimental systems. The review cautions that the relationship between normal tuft cells and DCLK1-positive tumor-associated cells remains incompletely resolved, but the overlap has made tuft cell lineage a focal point for research into cancer stemness and targeted therapy.

Epithelial injury and repair represent another emerging frontier. The gut lining turns over rapidly and must regenerate after damage from infection, ischemia or chemical injury. Evidence assembled in the review indicates that tuft cells participate in regenerative responses, with their numbers changing after epithelial damage and their signaling contributing to the coordination of repair programs. Because tuft cells sit at the crossroads of sensory detection, immune signaling and stem cell regulation, they may serve as an early warning system that helps the epithelium decide when and how to rebuild, a hypothesis the authors flag as a priority for future investigation.

None of this means the field has solved the tuft cell puzzle. The review is candid about the gaps: the precise developmental origins of different tuft cell subsets, the full catalog of their receptors and ligands, their exact contributions to human disease as opposed to mouse models, and the mechanisms by which they communicate with nerves, immune cells and stem cells all remain open questions. Human tissue studies are still limited by the rarity of the cells and the fragility of their morphology, and much of what is known derives from genetically manipulated mice whose tuft cell biology may not map perfectly onto patients.

Even so, the trajectory is unmistakable. A cell type once dismissed as an anatomical footnote is now implicated in some of the most burdensome gastrointestinal conditions in medicine, from parasitic infection and inflammatory bowel disease to colorectal and pancreatic cancer. The authors argue that deeper understanding of tuft cell biology could open the door to targeted clinical interventions, whether by boosting tuft cell–driven immunity against parasites, tuning their cytokine output to dampen colitis, or exploiting DCLK1 to attack therapy-resistant tumor cells. For a cell that constitutes only a sliver of the gut’s epithelial population, the tuft cell is proving that rarity is no measure of importance, and the coming years of research promise to reveal just how much influence these tiny brush-tipped sentinels exert over human digestive health.

Subject of Research: Characteristics and roles of tuft cells in gastrointestinal diseases

Article Title: Characteristics of tuft cells and their role in gastrointestinal diseases: a comprehensive narrative review

Article References: Characteristics of tuft cells and their role in gastrointestinal diseases: a comprehensive narrative review. (n.d.). https://doi.org/10.1186/s12967-026-09078-x

Image Credits: AI Generated

DOI: 10.1186/s12967-026-09078-x

Keywords: tuft cells, gastrointestinal diseases, epithelial cells, chemoreception, interleukin-25, inflammatory bowel disease, DCLK1, gastrointestinal cancer, epithelial regeneration, immune modulation, biomarkers, enteric nervous system