Clinical Focus

  • Gastroenterology

Academic Appointments

Professional Education

  • Fellowship: Stanford University Gastroenterology Fellowship (2022) CA
  • Board Certification: American Board of Internal Medicine, Internal Medicine (2019)
  • Residency: Stanford University Internal Medicine Residency (2019) CA
  • Medical Education: Harvard Medical School (2016) MA

All Publications

  • Paternal Medications in Inflammatory Bowel Disease and Male Fertility and Reproductive Outcomes: A Systematic Review and Meta-Analysis. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association Gubatan, J., Barber, G. E., Nielsen, O. H., Juhl, C. B., Maxwell, C., Eisenberg, M. L., Streett, S. E. 2022


    Studies evaluating reproductive outcomes among male patients with inflammatory bowel disease (IBD) are limited. We evaluated use of IBD medications and association with semen parameters, a proxy of male fertility, and adverse pregnancy outcomes [early pregnancy loss (EPL), preterm birth (PB), congenital malformations (CM)].We searched Medline, Embase, Scopus, and Web of Science (PROSPERO CRD42020197098) from inception to April 2022 for studies reporting semen parameters and adverse pregnancy outcomes among male patients exposed to biologics, thiopurine, or methotrexate. Standardized mean difference, prevalence, and odds ratios of outcomes were pooled and analysed using a random effects model.Ten studies reporting semen parameters (268 IBD patients) and 16 studies reporting adverse pregnancy outcomes (over 25,000 IBD patients) were included. Biologic, thiopurine, or methotrexate use were not associated with decreased sperm count, motility, or abnormal morphology compared to non-exposed patients. The prevalence of adverse pregnancy outcomes with paternal biologic (5%), thiopurine (6%), or methotrexate (6%) exposure was comparable to non-exposed patients (5%). Biologic use was not associated with risk of EPL (OR 1.26, I2= 0%, P=0.12), PB (OR 1.10, I2= 0%, P=0.17), or CM (OR 1.03, I2=0%, P=0.69). Thiopurine use was not associated with risk of EPL (OR 1.31, I2= 19%, P=0.17), PB (OR 1.05, I2= 0%, P=0.20), or CM (OR 1.07, I2=7%, P=0.34). Methotrexate use was not associated with risk of PB (OR 1.06, I2= 0%, P=0.62) or CM (OR 1.03, I2=0%, P=0.81).Biologic, thiopurine, or methotrexate use among male patients with IBD are not associated with impairments in fertility or with increased odds of adverse pregnancy outcomes.Biologic therapy, congenital malformations, early pregnancy loss, father, inflammatory bowel disease, male, pregnancy outcomes, preterm birth, reproductive health.

    View details for DOI 10.1016/j.cgh.2022.07.008

    View details for PubMedID 35870769

  • Paternal Biologic and Thiopurine Exposure in Inflammatory Bowel Disease and Association With Adverse Pregnancy Outcomes and Semen Parameters: A Systematic Review and Meta-Analysis Gubatan, J., Barber, G., Nielsen, O., Juhl, C., Maxwell, C., Eisenberg, M., Streett, S. LIPPINCOTT WILLIAMS & WILKINS. 2021: S353
  • Thiopurine Monotherapy Is Effective in Maintenance of Mild-Moderate Inflammatory Bowel Disease. Digestive diseases and sciences Barber, G. E., Hendler, S., Choe, M., Keyashian, K., Lechner, S., Limketkai, B. N., Limsui, D. 2021


    BACKGROUND: Crohn's disease (CD) and ulcerative colitis (UC) are complex, inflammatory bowel diseases (IBD) with debilitating complications. While severe IBD typically requires biologic agents, the optimal therapy for mild-moderate IBD is less clear.AIMS: To assess the efficacy of thiopurine monotherapy for maintenance of mild-moderate IBD and clinical variables associated with treatment outcome.METHODS: This retrospective study included adults with mild-moderate IBD who were started on thiopurines without biologic therapy. The primary outcome was therapy failure, defined by disease progression based on clinical, endoscopic, and radiologic criteria. Clinical variables were extracted at time of thiopurine initiation. Univariable and multivariable Cox proportional hazards models were used to examine the independent contribution of the clinical variables on treatment response.RESULTS: From 230 CD patients, 64 (72%) were free of treatment failure with mean follow-up of 3.3years. In our multivariable model, thiopurine failure was associated with concomitant systemic steroid administration (aHR 2.43, p=0.001), whereas protective factors included concomitant oral 5-aminosalicylic acid (5-ASA) therapy (aHR 0.54, p=0.02) and non-fistulizing, non-stricturing disease (aHR 0.57, p=0.047). From 173 UC patients, 50 (71%) were free from treatment failure with mean follow-up of 3.3years. On multivariable analysis, concomitant oral steroids were associated with thiopurine failure (aHR 2.71, p=0.001). Only 13 (4%) discontinued thiopurines from adverse effects.CONCLUSIONS: In mild-moderate uncomplicated IBD, thiopurine monotherapy was associated with longitudinal maintenance of remission and may represent a lower-cost, convenient, and effective alternative to biologics. Multiple clinical variables were predictive of treatment response.

    View details for DOI 10.1007/s10620-021-06947-x

    View details for PubMedID 33755823

  • Cytomegalovirus infection is associated with worse outcomes in inflammatory bowel disease hospitalizations nationwide. International journal of colorectal disease Hendler, S. A., Barber, G. E., Okafor, P. N., Chang, M. S., Limsui, D., Limketkai, B. N. 2020


    BACKGROUND: Cytomegalovirus (CMV) infection may complicate ulcerative colitis (UC) or Crohn's disease (CD) hospitalizations. Studies examining this relationship are often single-center examining short time periods.AIMS: To quantify the prevalence of CMV and its impact on outcomes among UC and CD hospitalizations over time using nationwide administrative databases.METHODS: The National Inpatient Sample and Nationwide Readmissions Database were analyzed to calculate CMV prevalence per 1000 UC and CD hospitalizations between 1998 and 2014. Univariable and multivariable logistic and linear regression were used to assess CMV's association with outcomes. Separate analyses examined effects from the introduction of anti-TNF therapy in UC in 2005, CD anatomic extent, and Clostridioides difficile infection.RESULTS: Among UC, from 1998 to 2014, the prevalence of CMV infection rose from 1.4 to 6.3 per 1000 UC hospitalizations (p<0.001), although this increase was not statistically significant for the years 2006 to 2014 (p=0.07). Among CD, prevalence rose from 0.3 to 1.8 per 1000 CD hospitalizations (p<0.001) from 1998 to 2014. CMV was independently associated with increased inpatient mortality (UC: odds ratio (OR) 2.3, 95% confidence interval (CI) 1.2-4.5; CD: OR 4.6, CI 1.5-13.7), colectomy in UC (OR 2.5, CI 1.9-3.3), and higher length of stay and costs.CONCLUSION: CMV infection's prevalence among UC and CD hospitalizations is rising over time, but may have slowed after 2005 in UC. CMV is independently associated with increased inpatient mortality, length of stay, and hospital charges in UC and CD and with colectomy in UC.

    View details for DOI 10.1007/s00384-020-03536-8

    View details for PubMedID 32124046

  • Rising Incidence of Intestinal Infections in Inflammatory Bowel Disease: A Nationwide Analysis INFLAMMATORY BOWEL DISEASES Barber, G. E., Hendler, S., Okafor, P., Limsui, D., Limketkai, B. N. 2018; 24 (8): 1849–56

    View details for DOI 10.1093/ibd/izy086

    View details for Web of Science ID 000449181900025

  • Rising Incidence of Intestinal Infections in Inflammatory Bowel Disease: A Nationwide Analysis. Inflammatory bowel diseases Barber, G. E., Hendler, S. n., Okafor, P. n., Limsui, D. n., Limketkai, B. N. 2018


    Intestinal infections are common in patients with inflammatory bowel disease (IBD) and may mimic IBD flares. In this study, we estimate the changing incidence of intestinal infections among IBD hospitalizations and assess the impact of intestinal infections on key hospitalization metrics.The National Inpatient Sample (NIS) was analyzed for hospitalizations from IBD between 1998 and 2014. Intestinal infections were identified using ICD-9-CM codes, and incidence for each infection was calculated for Crohn's disease (CD) and ulcerative colitis (UC). Linear and logistic regression analyses were used to assess the effects of intestinal infections on hospitalization duration, charges, and mortality.There were 4,030,620 hospitalizations for IBD between 1998 and 2014. The annual incidence of intestinal infections rose from 26.2 to 70.6 infections per 1000 IBD hospitalizations (Ptrend < 0.01). A main driver of this rising incidence was Clostridium difficile infections, which increased from 7.8 to 32.1 per 1000 CD hospitalizations and from 23.0 to 84.7 per 1000 UC hospitalizations (Ptrend < 0.01). The incidence of other intestinal infections increased from 10.2 to 15.3 per 1000 CD hospitalizations and 16.5 to 25.3 per 1000 UC hospitalizations. Intestinal infections and particularly C. difficile infections were associated with longer hospitalizations, greater hospital charges, and greater all-cause mortality.The incidence of intestinal infections among hospitalized IBD patients has increased over the past 15 years, primarily driven by C. difficile infections. Intestinal infections are associated with length of stay, hospital charges, and all-cause mortality. More aggressive measures for prevention of C. difficile infections are needed. 10.1093/ibd/izy086_video1izy086.video15779257979001.

    View details for PubMedID 29722832