Pectin, a soluble dietary fiber found in fruits like apples and citrus, has been studied for its potential to alleviate some side effects of chemotherapy, particularly gastrointestinal disturbances such as diarrhea and mucositis. The evidence supporting its use is based on its known prebiotic effects, its ability to form viscous solutions, and its role in modulating gut microbiota composition. Several preclinical studies and a limited number of clinical trials suggest that pectin may help maintain gut integrity and promote the growth of beneficial bacteria, which can be disrupted during chemotherapy. This, in turn, may reduce the severity of diarrhea—a common and sometimes dose-limiting side effect of certain chemotherapeutic agents.

For example, a 2014 randomized controlled trial in pediatric cancer patients found that adding pectin to the diet reduced the duration and severity of chemotherapy-induced diarrhea. Other studies, primarily in animal models, have demonstrated that pectin supplementation can reduce gut inflammation and support epithelial barrier function during cytotoxic treatments.

While these findings are promising, the overall clinical evidence remains moderate, as large-scale, high-quality human studies are still limited. Nevertheless, the use of pectin in this context is supported by a scientific rationale and some early clinical results, justifying its consideration as a supportive intervention during chemotherapy, particularly for gastrointestinal side effects.