AB in Earth and Planetary Sciences and Biology, Harvard College, 2008
PhD in Microbiology, Immunology, and Cancer Biology, University of Minnesota, 2015
MD, University of Minnesota, 2017
Internal Medicine Residency, Stanford, 2017-2019
Gastroenterology Fellowship, Stanford, 2019 - Present

Clinical Focus

  • Gastroenterology

Academic Appointments

Professional Education

  • Fellowship: Stanford University Division of Gastroenterology and Hepatology (2023) CA
  • Board Certification: American Board of Internal Medicine, Gastroenterology (2023)
  • Board Certification: American Board of Internal Medicine, Internal Medicine (2020)
  • Residency: Stanford University Internal Medicine Residency (2019) CA
  • Medical Education: University of Minnesota Medical School Twin Cities (2017) MN


  • Sadowsky MJ, Khoruts A, Weingarden AR, Hamilton MJ. "United States Patent 2014/0147417 A1 Compositions and methods for transplantation of colon microbiota", University of Minnesota, May 29, 2014

Graduate and Fellowship Programs

  • Gastroenterology & Hepatology (Fellowship Program)

All Publications

  • Non-prescription Therapeutics. The American journal of gastroenterology Weingarden, A. R., Ko, C. W. 2024; 119 (1S): S7-S15

    View details for DOI 10.14309/ajg.0000000000002578

    View details for PubMedID 38153220

  • Delivery of Fecal Material to Terminal Ileum Is Associated with Long-Term Success of Fecal Microbiota Transplantation. Digestive diseases and sciences Weingarden, A. R., Treiger, O., Ulsh, L., Limketkai, B., Goldenberg, D., Okafor, P., Sonu, I., Stollman, N., Neshatian, L. 2022


    BACKGROUND: Fecal microbiota transplantation (FMT) is a highly effective treatment for recurrent Clostridioides difficile infection (CDI). However, 10-20% of patients still fail to recover following FMT. There is a need to understand why these failures occur and if there are modifiable factors that can be addressed by clinicians performing FMT.AIMS: We sought to identify factors related to the FMT procedure itself which could impact FMT outcomes. We also aimed to identify patient demographics which might be associated with FMT outcomes and whether any factors were associated with early FMT failure compared to late CDI recurrence.METHODS: We performed a retrospective multicenter cohort analysis of FMT procedures between October 2005 and November 2020. We collected data on patient demographics, details of the FMT procedure, and procedure outcomes. Using univariate and multivariate regression, we evaluated whether these factors were associated with long-term FMT success, early FMT failure (less than 60days following procedure), or late CDI recurrence (more than 60days following procedure).RESULTS: Long-term success of FMT was strongly correlated with any delivery of stool to the terminal ileum (Odds Ratio [OR] 4.83, 95% confidence interval [CI] 1.359-17.167) and underlying neurologic disease (OR 8.012, 95% CI 1.041-61.684). Lower bowel prep quality was significantly associated with both early FMT failure (p=0.034) and late CDI recurrence (p=0.050).CONCLUSIONS: Delivery of stool to the terminal ileum is significantly associated with long-term success following FMT. This is a relatively safe practice which could easily be incorporated into the standard of care for colonoscopic FMT.

    View details for DOI 10.1007/s10620-022-07761-9

    View details for PubMedID 36372864

  • Immune checkpoint inhibitor-mediated colitis is associated with cancer overall survival. World journal of gastroenterology Weingarden, A. R., Gubatan, J., Singh, S., Balabanis, T. C., Patel, A., Sharma, A., Habtezion, A. 2022; 28 (39): 5750-5763


    Immune checkpoint inhibitor-mediated colitis (IMC) is a common adverse event following immune checkpoint inhibitor (ICI) therapy for cancer. IMC has been associated with improved overall survival (OS) and progression-free survival (PFS), but data are limited to a single site and predominantly for melanoma patients.To determine the association of IMC with OS and PFS and identify clinical predictors of IMC.We performed a retrospective case-control study including 64 ICI users who developed IMC matched according to age, sex, ICI class, and malignancy to a cohort of ICI users without IMC, from May 2011 to May 2020. Using univariate and multivariate logistic regression, we determined association of presence of IMC on OS, PFS, and clinical predictors of IMC. Kaplan-Meier curves were generated to compare OS and PFS between ICI users with and without IMC.IMC was significantly associated with a higher OS (mean 24.3 mo vs 17.7 mo, P = 0.05) but not PFS (mean 13.7 mo vs 11.9 mo, P = 0.524). IMC was significantly associated with OS greater than 12 mo [Odds ratio (OR) 2.81, 95% confidence interval (CI) 1.17-6.77]. Vitamin D supplementation was significantly associated with increased risk of IMC (OR 2.48, 95%CI 1.01-6.07).IMC was significantly associated with OS greater than 12 mo. In contrast to prior work, we found that vitamin D use may be a risk factor for IMC.

    View details for DOI 10.3748/wjg.v28.i39.5750

    View details for PubMedID 36338892

    View details for PubMedCentralID PMC9627421

  • Immune Checkpoint Inhibitor-Mediated Colitis Is Associated With Improved Cancer Overall Survival Weingarden, A. R., Gubatan, J., Balabanis, T., Patel, A., Singh, S., Habtezion, A. LIPPINCOTT WILLIAMS & WILKINS. 2021: S1381
  • Immune checkpoint inhibitor-mediated colitis in gastrointestinal malignancies and inflammatory bowel disease. World journal of gastrointestinal oncology Weingarden, A. R., Rubin, S. J., Gubatan, J. 2021; 13 (8): 772-798


    Immune checkpoint inhibitors (ICI) have markedly changed the landscape of cancer therapy. By re-invigorating the immune system against tumors, ICI provide novel therapeutic options for a broad variety of malignancies, including many gastrointestinal (GI) cancers. However, these therapies can also induce autoimmune-like side effects in healthy tissue across the body. One of the most common of these side effects is ICI-mediated colitis and diarrhea (IMC). Here, we review the incidence and risk of IMC in ICI therapy, with a focus on what is known regarding IMC in patients with GI malignancies. We also discuss data available on the use of ICI and risk of IMC in patients with pre-existing inflammatory bowel disease, as these patients may have increased risk of IMC due to their underlying intestinal pathology.

    View details for DOI 10.4251/wjgo.v13.i8.772

    View details for PubMedID 34457186

    View details for PubMedCentralID PMC8371513

  • Not in the Same Vein: Inflammatory Bowel Disease, Malignancy, and Enterocolic Lymphocytic Phlebitis. Digestive diseases and sciences Farber, O. N., Weingarden, A., Lee, C., Braxton, D. R., Bingham, D., Scott, G., Fernandez-Becker, N., Goff, D., Shelton, A., Kin, C. 2020

    View details for DOI 10.1007/s10620-020-06425-w

    View details for PubMedID 32594463

  • A Failure to Communicate: Disentangling the Causes of Perianal Fistula in Crohn's Disease and Anal Squamous Cell Cancer. Digestive diseases and sciences Weingarden, A. R., Smith, P., Streett, S., Triadafilopoulos, G. 2020

    View details for DOI 10.1007/s10620-020-06130-8

    View details for PubMedID 32037474

  • Occam's Razor: An Unusual Shoulder Mass in a Patient with Achalasia. Digestive diseases and sciences Weingarden, A. R., Villescas, V. n., Clarke, J. n., Triadafilopoulos, G. n. 2020

    View details for DOI 10.1007/s10620-020-06558-y

    View details for PubMedID 32833155

  • Author Spotlight: Alexa R. Weingarden. Digestive diseases and sciences Weingarden, A. R. 2020

    View details for DOI 10.1007/s10620-020-06131-7

    View details for PubMedID 32040663