Recruiting

Chia Seeds

Sponsor:

University of Chicago

Code:

NCT07553234

Conditions

Breast Cancer

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Stool Sampling

Chia Seeds

Study Details

Brief summary:

This study will be conducted in 2 sequential parts. The first part will be a prospective, observational study. This will be followed by a small interventional, pilot study involving use of fiber supplement (chia seeds). The study aims to evaluate the relationship between the gut microbiome (a diverse ecosystem of microorganisms that affects your health and well-being) and treatment-related gastrointestinal toxicities in patients with HR+/HER2- breast cancer receiving abemaciclib plus endocrine therapy.

Conditions

Breast Cancer

Study ID

NCT07553234

Start date

Sep 21, 2026

Status verified date

Sep, 2026

Completion date

May 3, 2030

Anticipated

Primary completion date

May 3, 2030

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Be willing and able to provide written informed consent for the trial
  • Be a male or female subject 18 years of age on day of signing informed consent.
  • Histologically proven infiltrating carcinoma of the breast on core needle biopsy that is:

HER2 negative in primary tumour pre-treatment by local pathology assessed according current American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines: In situ hybridization non-amplified (ratio of HER2 to CEP17 < 2.0 or single probe average HER2 gene copy number < 4 signals/cell), OR Immunohistochemistry (IHC) 0 or IHC 1+.

  • Estrogen receptor (ER) and progesterone receptors (PR) positive in primary tumour pre-treatment defined as >1% of cells expressing hormonal receptors via IHC analysis by local laboratory assessment.
  • Planned to undergo standard of care therapy with abemaciclib and endocrine therapy, in the adjuvant or metastatic setting (Part 1) or the adjuvant setting (Part 2).
  • Be willing to provide mandatory stool samples at baseline and on treatment.
  • The Eastern Cooperative Oncology Group (ECOG) 0-2

Exclusion Criteria:

  • Patients who are pregnant or breast-feeding
  • Current use of any investigational agents
  • Uncontrolled Ulcerative Colitis, Crohn's Disease, Malabsorption syndrome or any disease significantly affecting gastrointestinal function
  • History or current evidence of any condition, therapy, lab abnormality or other circumstance that in the opinion of the investigator might expose the subject to risk by participating in the trial, confound the results of the trial, or interfere with the subject's participation for the full duration of the trial.

Study Design

Enrollment

20 participants

Anticipated

Allocation

Non randomized

Intervention Model

Sequential

Primary purpose

Supportive Care

Interventions and Outcome Measures

Arms

experimental: Observational Cohort

Enrolled patients with early or advanced HR+/HER2- breast cancer starting abemaciclib as per standard of care to characterize the baseline composition and longitudinal dynamics of the gut microbiome before and during treatment. Stool samples will be collected continuously using the GutLab platform, alongside clinical toxicity assessments, with a focus on identifying microbial signatures associated with the development and severity of diarrhea. No intervention will be administered.

experimental: Dietary Intervention Cohort

Enrolled patients with early-stage HR+/HER2- breast cancer. A 2-week chia seed intervention will be administered prior to initiation of abemaciclib. The goal of this high fiber intervention is to favorably modulate the gut microbiome by supporting a more diverse microbiome and reducing the risk of inflammation and dysbiosis.

Interventions

Stool Sampling

Stool samples will be collected continuously (during as many bowel movements as possible) using the GutLab device (BiomeSense, Inc.).

Chia Seeds

In the Fiber Study cohort (Part 2), participants will be advised to consume a standardized daily serving of chia seeds (25g/day) and provided with guidance on how to integrate this into their usual diet.

Primary outcome measure

  • Stool Sampling Feasibility [ Time Frame: 2 years ]

Central Contacts and Locations

Central contacts

Clinical Trials Intake

855-702-8222cancerclinicaltrials@bsd.uchicago.edu

Rita Nanda

rnanda@bsd.uchicago.edu

Locations

The University of Chicago Medicine Comprehensive Cancer Center

Recruiting

Chicago, Illinois, United States, 60637

Contacts

Clinical Trials Intake

855-702-8222cancerclinicaltrials@bsd.uchicago.edu

Principal Investigator:

Rita Nanda

More Information

Sponsor

University of Chicago

Last update posted

Sep 28, 2026

Last verified

Sep, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-29. This information was provided to ClinicalTrials.gov by University of Chicago on 2026-09-28. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.