Impact of Dietary Fiber Intake on the Immunological Response to Immunotherapy in Cancer Patients: A Scoping Review

Sep 22, 2026

Immunotherapy is a key cancer treatment strategy, yet gut microbiota is increasingly recognized as a determinant of its effectiveness, suggesting dietary fiber may be a modifiable factor. This scoping review evaluates scientific evidence linking dietary fiber intake with immune modulation and immunotherapy response in cancer patients. An integrative review searched MEDLINE, BVS, and EMBASE using Neoplasms, Dietary Fiber, and Immunomodulation terms. Among 325 records, three studies met criteria, showing higher fiber intake correlates with better therapeutic responses and gut microbiota changes, including melanoma patients on anti–PD-1 checkpoint inhibitors.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages4

Reading Time10 min

AccessFree to download

Introduction

Methodology

Study Design

Databases

Descriptors and Search Strategy

Eligibility Criteria

Results

Discussion

Conclusion

Cancer Medicine Impact of Dietary Fiber Intake on the Immunological Response to Immunotherapy in Cancer Patients: A Scoping Review Michele Edmila Silva Sousa 1 | Valéria Duarte de Almeida 2 | Roque Ribeiro da Silva Júnior 1,3 | Thales Allyrio Araújo Medeiros de Fernandes 1,3,4 | Micássio Fernandes de Andrade 1,5 1Postgraduate Program in Health and Society, University of the State of Rio Grande do Norte (UERN), Mossoró, Brazil | 2Department of Biosciences, Federal Rural University of the Semi-Arid Region, Mossoró, Brazil | 3Multicenter Postgraduate Program in Physiological Sciences, University of the State of Rio Grande Do Norte (UERN), Mossoró, Brazil | 4Multicenter Postgraduate Program in Biochemistry and Molecular Biology, University of the State of Rio Grande do Norte (UERN), Mossoró, Brazil | 5Department of Health Sciences, Federal Rural University of the Semi-Arid Region, Mossoró, Brazil Correspondence: Roque Ribeiro da Silva Júnior ([roque20231008923@alu.uern.br](roque20231008923@alu.uern.br)) Received: 12 March 2026 | Revised: 22 June 2026 | Accepted: 2 July 2026 Keywords: cancer | dietary fiber | gut microbiota | immune response | immunotherapy ABSTRACT Introduction: Immunotherapy has emerged as a major therapeutic strategy for cancer, and accumulating evidence indicates that the gut microbiota influences its effectiveness, highlighting the potential role of dietary fiber. Objective: To evaluate the scientific evidence regarding the relationship between dietary fiber intake, immune modulation, and the response to immunotherapy in patients with cancer. Methodology: An integrative review was conducted using the MEDLINE, BVS, and EMBASE databases with the descriptors“Neoplasms,” “Dietary Fiber,” and “Immunomodulation.” Original studies involving patients with cancer undergoing immunotherapy that evaluated dietary fiber intake through habitual diet, dietary intervention, or supplementation, as well as its association with immune response, gut microbiota, or clinical outcomes were included. Results: A total of 325 records were identified, of which three studies met the inclusion criteria. Discussion: Higher dietary fiber intake was associated with improved therapeutic responses and favorable changes in the gut microbiota. The included studies involved patients with melanoma receiving immune checkpoint inhibitors, predominantly antiPD-1 therapy. Conclusion: Dietary fiber plays a relevant role in gut microbiota modulation and may enhance the effectiveness of immunotherapy. 1 | Introduction Cancer remains one of the leading causes of morbidity and mortality worldwide, driving the continuous search for more effective therapeutic strategies. Among recent advances, immunotherapy has emerged as a major therapeutic approach by harnessing the patient's own immune system to combat tumor cells [1, 2] . Consequently, there is growing interest in understanding the factors that may influence therapeutic responses. Increasing evidence indicates that the gut microbiota plays a fundamental role in regulating the immune system, including its involvement in mechanisms of cancer control [3] . Diet plays a crucial role in modulating this ecosystem, particularly through dietary fiber intake. Dietary fibers serve as substrates for This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. © 2026 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd. Cancer Medicine, 2026; 15:e72108 1 of 4 [https://doi.org/10.1002/cam4.72108](https://doi.org/10.1002/cam4.72108) bacterial fermentation, leading to the production of short-chain fatty acids (SCFAs), which exert well-established immunomodulatory effects and promote an antitumor immune profile [4]. Despite recent advances, few reviews have compre

FAQs

What is the main objective of the scoping review?

To evaluate scientific evidence on how dietary fiber intake relates to immune modulation and the response to immunotherapy in cancer patients.

How were studies selected for inclusion?

Human studies were included if participants had cancer receiving immunotherapy, dietary fiber intake was evaluated via habitual diet or intervention/supplementation, and associations with immune response and/or clinical outcomes were assessed.

What did the review find about dietary fiber intake and immunotherapy response?

Higher dietary fiber intake was associated with improved therapeutic responses and favorable changes in gut microbiota, particularly in melanoma patients treated with immune checkpoint inhibitors, mainly anti–PD-1.

Sep 22, 2026

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