Feasibility of a Lifestyle Intervention for Women With Triple-negative Breast Cancer Under Neoadjuvant Immunotherapy (BallastImmun)

Feasibility of a Lifestyle Intervention to Switch to a High-fiber, Gut-healthy Diet in Women With Triple-negative Breast Cancer Undergoing Neoadjuvant Immunotherapy: a Randomized Controlled Trial

Triple-negative breast cancer (TNBC) is considered a tumor with a high risk of recurrence and metastasis and requires aggressive systemic therapy combining immunotherapy and chemotherapy. If the therapy leads to complete remission (pCR), this is prognostically beneficial for patients.

Studies demonstrating the influence of the microbiome on the development of cancer and on the efficacy and toxicity of immunotherapy and chemotherapy underscore the potential of targeted nutritional interventions. Current data from microbiome research indicate that a high-fiber, gut-healthy diet modulates the microbiota in such a way that the response to and toxicity of immunotherapy and chemotherapy could be improved.

The aim of this project is to translate these findings into clinical care. The study will investigate whether an online integrative oncology group training program with mind-body elements supports and is feasible for the implementation of a high-fiber diet in patients with TNBC undergoing neoadjuvant immunotherapy and chemotherapy. The program will be compared with a control group that receives a flyer with nutritional recommendations. If the feasibility of this complementary medicine approach can be demonstrated, a confirmatory study is planned to investigate the expected effect on the pathological complete remission of TNBC.

Study Overview

• Status: Recruiting
• Conditions: Microbiome
• Intervention / Treatment: Other: switching to a high-fibre diet; Other: official dietary recommendations

Detailed Description

This study examines a nutritional concept developed specifically for this study with regard to the implementation of a switch to a high-fibre diet in patients with TNBC undergoing neoadjuvant immunotherapy and chemotherapy. This nutritional concept is embedded in an online, integrative oncology group training programme with mind-body medicine elements to support the change in diet and its tolerability. This intervention is compared with a control group that receives standard care, i.e. a flyer and an educational training video with nutritional recommendations based on the guidelines of the German Nutrition Society (DGE).

The following criteria have been established to determine the feasibility of these two target levels:

• Recruitment
• Consent to participate and randomisation
• Dropout rate
• Implementation of the intervention (dietary change and acceptance/effect of mind-body elements)
• Completeness of data collected for at least 80% of patients who complete the study

If the study proves feasible and demonstrates the viability of this integrative medical approach in women with TNBC undergoing neoadjuvant immunotherapy, a confirmatory intervention study with a larger sample size is planned. This study aims to contribute to expanding the current knowledge base and improving existing treatment options. The follow-up study aims to investigate the effects of the nutritional concept and the group training programme on the pCR of TNBC. It will analyse whether the nutritional concept and the group training programme enhance the response to immunotherapy and improve its tolerability in the study participants. The findings from this study will therefore be incorporated into the follow-up study, which will investigate the potential for an improved immune response to therapy and, at the same time, identify possible positive effects of the nutritional intervention on the side effect profile of immunotherapy. Furthermore, the design of the nutritional concept and/or the group training programme could be adapted for the follow-up study if the results are appropriate. The findings from both studies will then be transferred to clinical care, thereby optimising the current treatment options for TNBC patients and increasing their chances of recovery in the long term.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Germany
  • North Rhine-Westphalia
    • Essen, North Rhine-Westphalia, Germany, 45276
      • Recruiting
      • Evang. Kliniken Essen-Mitte gGmbh
      • Contact: Petra Voiss, PD Dr.; Phone Number: 004920117439001; Email: p.voiss@kem-med.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Female patients aged 18-75
• Histologically confirmed diagnosis of non-metastatic triple-negative breast cancer (TNM stage I-III) with planned neoadjuvant chemotherapy and immunotherapy
• Willingness to participate in the study and signed consent form

Exclusion Criteria:

• Advanced stage of disease with metastases
• Severe physical or psychopharmacologically treated psychiatric comorbidity that prevents a patient from participating in the study
• Pregnancy
• Participation in other clinical studies involving behavioral, psychological, or complementary medical interventions
• A diet that is incompatible with a high-fiber diet, such as the ketogenic diet
• Abuse of drugs and/or alcohol
• Inability to complete the questionnaires independently
• Colectomy
• Gastrointestinal stenosis
• Fructose intolerance
• Histamine intolerance
• Gluten intolerance
• Ketogenic diet
• Unwillingness to refrain from taking probiotics for the duration of the study
• Eating disorders
• No laptop and/or camera available to participate in the online group training program

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Switching to a high-fibre diet in patients with TNBC undergoing neoadjuvant immunotherapy and chemot; Switching to a high-fibre diet is supported by multi-professional consultation hours, individual counselling and group sessions that combine mind-body medicine and nutritional therapy content.	Other: switching to a high-fibre diet; The aim of the intervention is to support patients in implementing a high-fibre diet (20-30 g of fibre per day) before and during systemic therapy. A multi-professional team consisting of a specialist doctor, a qualified nutritionist and an MBM therapist ensures comprehensive support during lifestyle modification. While the nutritional counselling provides recommendations for optimising diet, the MBM intervention addresses behavioural factors such as motivation, self-efficacy expectations and dealing with barriers to action. In addition, the specialist provides advice on symptom management.
Active Comparator: control group receives official dietary recommendations; Control group receives standard care, i.e. a leaflet and an educational training video with dietary recommendations of the Deutsche Gesellschaft fuer Ernaehrung (DGE)	Other: official dietary recommendations; providing official dietary recommendations and an educational training video based on these recommendations of the guidelines of the German Nutrition Society (DGE)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The primary target parameter is the feasibility of the planned study and the intervention.	The feasibility criteria are defined in the following categories: Recruitment: Recruitment is considered feasible if the required sample size of n = 60 patients can be recruited within 17 months.; Randomisation: Randomisation is considered feasible if at least 25% of potentially eligible patients agree to participate in the study; Dropout rate: A maximum dropout rate of 20% per group is considered proof of feasibility.; Intervention: The intervention is considered feasible if at least 80% of the patients who complete the study are able to implement the nutritional intervention according to protocol. Implementation according to protocol is defined as a fibre intake of at least 20 g/day and the consumption of fermented foods. Data collection: Data collection is considered feasible if complete data on the planned primary endpoint parameter of the planned confirmatory study, pCR, is available for at least 80% of the patients who complete the study.	from the enrolment to the end of treatment at 6.5 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Course of therapy (pCR)	Course of therapy in the sense of a complete response to systmatic therapy (= complete pathological remission)	6 months after baseline
Toxicity (CTCAE 6.0) including adverse events (AEs)	adverse events	6 months after baseline
Fatty acid profile (stool sample analysis)	Fatty acid profile	baseline and 6 months after baseline
α-diversity and β-diversity of the microbiome (stool sample analysis)	diversity of the microbiome	baseline and 6 months after baseline
Body weight	Body weight	baseline, 1 to 3 weeks after baseline (start of the chemotherapy), 3 months after baseline, 6 months after baseline
Self-reported quality of life (FACT-B = Functional Assessment of Cancer Therapy - Breast)	quality of life, ranges from 0 to 4, with lower scores indicating higher stress levels which means a lower quality of life	baseline, 1 to 3 weeks after baseline (start of the chemotherapy), 3 months after baseline, 6 months after baseline
Self-reported fatigue (FACIT fatigue = Functional Assessment of Chronic Illness Therapy Fatgigue)	Self-reported fatigue, scale from 0 to 4 with lower value indicating a greater fatigue. Two items are reversed.	baseline, 1 to 3 weeks after baseline (start of the chemotherapy), 3 months after baseline, 6 months after baseline
Self-reported fiber intake (dietary records)	Self-reported fiber intake	baseline, 1 to 3 weeks after baseline (start of the chemotherapy), 3 months after baseline, 6 months after baseline
Self-reported tolerance of increased fiber intake (IBS-SSS = irritable bowel syndrome severity scoring system)	Self-reported tolerance of increased fiber intake, symptoms are rated on a visual analog scale (VAS) from 0 to 100 points. 100 points indicate the most severe irritable bowel symptoms.	baseline, 1 to 3 weeks after baseline (start of the chemotherapy), 3 months after baseline, 6 months after baseline
Adverse Events and Serious Adverse Events	Adverse Events and Serious Adverse Events	baseline, 1 to 3 weeks after baseline (start of the chemotherapy), 3 months after baseline, 6 months after baseline

Collaborators and Investigators

• Sponsor: Kliniken Essen-Mitte
• Collaborators: Karl and Veronica Carstens Foundation

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2026
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 1, 2027

Study Registration Dates

• First Submitted: December 16, 2025
• First Submitted That Met QC Criteria: December 16, 2025
• First Posted (Actual): December 30, 2025

Study Record Updates

• Last Update Posted (Actual): May 8, 2026
• Last Update Submitted That Met QC Criteria: May 5, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 2024001-PV3

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No