Bio

Honors & Awards


  • Stanford Interdisciplinary Graduate Fellowship, Stanford University (2015-2018)
  • Graduate Research Fellowship, National Science Foundation (2011-2015)

Boards, Advisory Committees, Professional Organizations


  • Member, Stanford Military-Affiliated Advisory Committee (2019 - Present)
  • Member, American Society of Tropical Medicine and Hygiene (2014 - Present)
  • Member, American Society for Microbiology (2009 - Present)

Professional Education


  • Bachelor of Science, United States Military Academy, Environmental Engineering (2001)
  • Doctor of Philosophy, Stanford University, CEE-PHD (2019)
  • Master of Science, Pennsylvania State University, Environmental Engineering (2011)
  • PhD, Stanford University, Environmental Engineering, Microbiology, Global Health (2019)
  • MS, Penn State University, Environmental Engineering (2011)
  • BS, United States Military Academy at West Point, Environmental Engineering (2001)

Stanford Advisors


Research & Scholarship

Lab Affiliations


Publications

All Publications


  • Effects of water, sanitation, handwashing, and nutritional interventions on environmental enteric dysfunction in young children: a cluster-randomized controlled trial in rural Bangladesh. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America Lin, A., Ali, S., Arnold, B. F., Rahman, M. Z., Alauddin, M., Grembi, J., Mertens, A. N., Famida, S. L., Akther, S., Hossen, M. S., Mutsuddi, P., Shoab, A. K., Hussain, Z., Rahman, M., Unicomb, L., Ashraf, S., Naser, A. M., Parvez, S. M., Ercumen, A., Benjamin-Chung, J., Haque, R., Ahmed, T., Hossain, M. I., Choudhury, N., Jannat, K., Alauddin, S. T., Minchala, S. G., Cekovic, R., Hubbard, A. E., Stewart, C. P., Dewey, K. G., Colford, J. M., Luby, S. P. 2019

    Abstract

    BACKGROUND: We hypothesized that drinking water, sanitation, handwashing (WSH) and nutritional interventions would improve environmental enteric dysfunction (EED), a potential contributor to stunting.METHODS: Within a subsample of a cluster-randomized controlled trial in rural Bangladesh, we enrolled pregnant women in four arms: control, combined WSH, child nutrition counseling plus lipid-based nutrient supplements (N), and combined nutrition plus WSH (N+WSH). Among the birth cohort, we measured biomarkers of gut inflammation (myeloperoxidase, neopterin), permeability (alpha-1-antitrypsin, lactulose, mannitol), and repair (regenerating gene 1beta) at median ages 3, 14, and 28 months. Analysis was intention-to-treat.RESULTS: We assessed 1512 children. At age 3 months, compared to controls, neopterin was reduced by nutrition (-0.21 log nmol/L, CI -0.37, -0.05) and N+WSH (-0.20 log nmol/L, CI -0.34, -0.06) interventions; similar reductions were observed at 14 months. At 3 months, all interventions reduced lactulose and mannitol (-0.60 to -0.69 log mmol/L). At 28 months, myeloperoxidase was elevated in the WSH (0.23 log ng/ml, CI 0.06, 0.39) and nutrition (0.27 log ng/ml, CI 0.07, 0.47) arms and lactulose was higher in the WSH arm (0.30 log mmol/L, CI 0.07, 0.53).CONCLUSIONS: Reductions in permeability and inflammation at ages 3 and 14 months suggest that the interventions promoted healthy intestinal maturation; however, by 28 months the WSH and nutrition arms showed elevated EED biomarkers. These results underscore the importance of better understanding the pathophysiology of EED and targeting interventions early in childhood during the critical period when they are likely to have the largest benefit to intestinal health.(ClinicalTrials.gov NCT01590095).

    View details for PubMedID 30963177

  • Effects of lipid-based nutrient supplements and infant and young child feeding counseling with or without improved water, sanitation, and hygiene (WASH) on anemia and micronutrient status: results from 2 cluster-randomized trials in Kenya and Bangladesh. The American journal of clinical nutrition Stewart, C. P., Dewey, K. G., Lin, A., Pickering, A. J., Byrd, K. A., Jannat, K., Ali, S., Rao, G., Dentz, H. N., Kiprotich, M., Arnold, C. D., Arnold, B. F., Allen, L. H., Shahab-Ferdows, S., Ercumen, A., Grembi, J. A., Naser, A. M., Rahman, M., Unicomb, L., Colford, J. M., Luby, S. P., Null, C. 2019

    Abstract

    Background: Anemia in young children is a global health problem. Risk factors include poor nutrient intake and poor water quality, sanitation, or hygiene.Objective: We evaluated the effects of water quality, sanitation, handwashing, and nutrition interventions on micronutrient status and anemia among children in rural Kenya and Bangladesh.Design: We nested substudies within 2 cluster-randomized controlled trials enrolling pregnant women and following their children for 2 y. These substudies included 4 groups: water, sanitation, and handwashing (WSH); nutrition (N), including lipid-based nutrient supplements (LNSs; ages 6-24 mo) and infant and young child feeding (IYCF) counseling; WSH+N; and control. Hemoglobin and micronutrient biomarkers were measured after 2 y of intervention and compared between groups using generalized linear models with robust SEs.Results: In Kenya, 699 children were assessed at a meanąSD age of 22.1ą1.8 mo, and in Bangladesh 1470 participants were measured at a meanąSD age of 28.0ą1.9 mo. The control group anemia prevalences were 48.8% in Kenya and 17.4% in Bangladesh. There was a lower prevalence of anemia in the 2 N intervention groups in both Kenya [N: 36.2%; prevalence ratio (PR): 0.74; 95% CI: 0.58, 0.94; WSH+N: 27.3%; PR: 0.56; 95% CI: 0.42, 0.75] and Bangladesh (N: 8.7%; PR: 0.50; 95% CI: 0.32, 0.78; WSH+N: 7.9%, PR: 0.46; 95% CI: 0.29, 0.73). In both trials, the 2 N groups also had significantly lower prevalences of iron deficiency, iron deficiency anemia, and low vitamin B-12 and, in Kenya, a lower prevalence of folate and vitamin A deficiencies. In Bangladesh, the WSH group had a lower prevalence of anemia (12.8%; PR: 0.74; 95% CI: 0.54, 1.00) than the control group, whereas in Kenya, the WSH+N group had a lower prevalence of anemia than did the N group (PR: 0.75; 95% CI: 0.53, 1.07), but this was not significant (P=0.102).Conclusions: IYCF counseling with LNSs reduced the risks of anemia, iron deficiency, and low vitamin B-12. Effects on folate and vitamin A varied between studies. Improvements in WSH also reduced the risk of anemia in Bangladesh but did not provide added benefit over the nutrition-specific intervention. These trials were registered at clinicaltrials.gov as NCT01590095 (Bangladesh) and NCT01704105 (Kenya).

    View details for PubMedID 30624600

  • Identification of widespread antibiotic exposure in cholera patients correlates with clinically relevant microbiota changes. The Journal of infectious diseases Alexandrova, L., Haque, F., Rodriguez, P., Marrazzo, A. C., Grembi, J. A., Ramachandran, V., Hryckowian, A. J., Adams, C. M., Siddique, M. S., Khan, A. I., Qadri, F., Andrews, J. R., Rahman, M., Spormann, A. M., Schoolnik, G. K., Chien, A., Nelson, E. J. 2019

    Abstract

    A first step to combating antimicrobial resistance in enteric pathogens is to establish an objective assessment of antibiotic exposure. Our goal was to develop and evaluate a liquid chromatography-ion trap mass spectrometry (LC/MS) method to determine antibiotic exposure in cholera patients.A priority list for targeted LC/MS was generated from medication vendor surveys in Bangladesh. A study of cholera and non-cholera patients was conducted to collect and analyze paired urine and stool samples.Among 845 patients, 11% (n=90) were Vibrio cholerae positive; at least one antibiotic was detected in 86% and at least two in 52% of cholera stools. Among paired urine and stool (n=44), at least one antibiotic was detected in 98% and at least two in 84%, despite 55% self-reporting medication use. Compared to LC/MS, a low-cost antimicrobial detection bio-assay lacked sufficient negative predictive value (10%; 95% CI 6-16). Detection of guideline-recommended antibiotics in stool did (azithromycin; p=0.040) and did not (ciprofloxacin) correlate with V. cholerae suppression. A non-recommended antibiotic (metronidazole) was associated with decreases in anaerobes (Prevotella; p<0.001).The findings suggest there may be no true negative control group when attempting to account for antibiotic exposure in settings like those in this study.

    View details for DOI 10.1093/infdis/jiz299

    View details for PubMedID 31192364

  • Effects of lipid-based nutrient supplements and infant and young child feeding counseling with or without improved water, sanitation, and hygiene (WASH) on anemia and micronutrient status: results from 2 cluster-randomized trials in Kenya and Bangladesh AMERICAN JOURNAL OF CLINICAL NUTRITION Stewart, C. P., Dewey, K. G., Lin, A., Pickering, A. J., Byrd, K. A., Jannat, K., Ali, S., Rao, G., Dentz, H. N., Kiprotich, M., Arnold, C. D., Arnold, B. F., Allen, L. H., Shahab-Ferdows, S., Ercumen, A., Grembi, J. A., Naser, A., Rahman, M., Unicomb, L., Colford, J. M., Luby, S. P., Null, C. 2019; 109 (1): 148?64
  • HIGH-THROUGHPUT MULTI-PARALLEL NL-QPCR CHIP FOR THE DETECTION OF 17 ENTERIC PATHOGENS Grembi, J., Mayer-Blackwell, K., Luby, S., Spormann, A. AMER SOC TROP MED & HYGIENE. 2018: 199?200
  • Remediation of High-Strength Mine-Impacted Water with Mixed Organic Substrates Containing Crab Shell and Spent Mushroom Compost JOURNAL OF ENVIRONMENTAL ENGINEERING Grembi, J. A., Sick, B. A., Brennan, R. A. 2016; 142 (2)

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