A new study has identified a potential link between the artificial sweetener sucralose and reduced effectiveness of cancer immunotherapy treatments in patients with melanoma and non-small cell lung cancer. The research, conducted by the University of Pittsburgh in collaboration with the UPMC Hillman Cancer Centre, found that patients consuming higher levels of sucralose responded less effectively to immune checkpoint inhibitors and had poorer overall survival rates than those who consumed little or none.

The findings, published in Cancer Discovery, a journal of the American Association for Cancer Research, highlight how dietary choices may influence the outcome of cancer treatment. The study used both mouse models and clinical data to explore the mechanisms underlying the observed effects. In animal studies, sucralose was shown to disrupt the gut microbiome, resulting in reduced levels of arginine, a key amino acid required for T cell function.
Arginine plays a critical role in the efficacy of anti-PD1 therapies, a class of immunotherapy that works by activating T cells to attack cancer cells. In mice that were fed sucralose, the altered gut bacteria increased the degradation of arginine, leading to insufficient levels of the amino acid in blood, tumor tissues and stool. As a result, the immune system’s ability to respond to tumors was significantly diminished.
Sucralose disrupts gut microbiome and weakens T cell activity
Diwakar Davar, M.D., associate professor of medicine at the University of Pittsburgh and medical oncologist at UPMC Hillman Cancer Centre, explained that the study’s results suggest artificial sweeteners may interfere with critical metabolic pathways necessary for the success of immunotherapy. Lead author Abby Overacre, Ph.D., assistant professor in the Department of Immunology at the University of Pittsburgh and UPMC Hillman, added that supplementation with arginine or citrulline the latter of which is converted into arginine in the body reversed the effects of sucralose in mice and restored the efficacy of treatment.
To explore whether these results could apply to human patients, the team analyzed dietary data from 132 individuals with advanced melanoma or non-small cell lung cancer, all of whom were undergoing anti-PD1 therapy alone or in combination with chemotherapy. Patients completed dietary questionnaires assessing their consumption of artificial sweeteners in items such as tea, coffee and soft drinks.
Researchers explore targeted nutrition for cancer patients
The analysis found that higher sucralose intake was associated with reduced treatment response, regardless of cancer type or stage. While the findings are not yet conclusive for clinical practice, the research opens avenues for further investigation into the role of nutrition during cancer treatment. According to Davar, the results support exploring targeted dietary interventions or supplementation strategies, such as prebiotics or amino acid support, for patients regularly consuming artificial sweeteners.
Clinical trials may be warranted to test whether adjusting diet or providing metabolic support could improve immunotherapy outcomes. The researchers emphasized the importance of understanding the interaction between gut microbiota, diet and immune function in the development of effective cancer treatments. – By Content Syndication Services.
