Bismuth Subsalicylate's Role in the Prevention of Travelers' Diarrhea

  • End date
    Dec 1, 2022
  • participants needed
  • sponsor
    Centers for Disease Control and Prevention
Updated on 10 March 2022
Accepts healthy volunteers


The purpose of this study is to determine if the use of prophylactic bismuth subsalicylate (BSS) has an effect on the acquisition of travelers' diarrhea (TD) or antimicrobial resistance (AMR) genes in fecal samples among international travelers who departed from the United States to South East Asia, South Central Asia, or Africa. Our hypotheses will be tested using a double-blinded, placebo controlled randomized clinical trial with participants from a pre-travel health clinic in the United States.

Condition Diarrhea Travelers, Antibiotic Resistant Infection
Treatment Placebo Oral Tablet, Bismuth subsalicylate
Clinical Study IdentifierNCT03535272
SponsorCenters for Disease Control and Prevention
Last Modified on10 March 2022


Yes No Not Sure

Inclusion Criteria

Be ≥ 18 and <70 years of age at the time of enrollment
Sign an informed consent stating willingness to participate and comply with the study protocol
Plan on leaving for an international trip ≥7 days after their pre-travel consultation
Plan on traveling in country for ≥7 days but ≤21 days (21 day limit due to BSS duration recommendations and a lack of data on longer-term BSS use)
Traveling to either South East Asia, South Central Asia, North Africa, or Sub-Saharan Africa for at least 7 days of their itinerary
Be willing to complete an initial eligibility screening
Be willing to complete questionnaires and provide biologic specimens (stool) within 7 days of departure and within 10 days after return
Be willing to refrain from taking any pre-biotics, probiotic, synbiotic and/or herbal supplements throughout their study period

Exclusion Criteria

Are <18 years of age or >69 years of age
Are traveling in country for <7 or >21 days
Have known or suspected contraindications to taking BSS (including, but not limited to, travelers with kidney disease, diabetes, gout, a clotting disorder, or an allergy to any component of BSS)
Are pregnant (via self-report), are planning to become pregnant, or may become pregnant during travel (not actively using contraception and are sexually active), or are breastfeeding
Routinely take a medication known to interact with BSS (including, but not limited to, insulin, methotrexate, valproic acid, angiotensin-converting enzyme inhibitors, anticoagulants, or other salicylates)
Have taken an antibiotic in the 30 days before departure
Have taken any medications that may lower one's ability to fight infection (e.g., steroids, monoclonal antibodies, etc.)
Have previous diagnoses of immunocompromising conditions such as HIV/AIDS, complement deficiency, immunoglobulin deficiency, or undergoing active chemotherapy or participants with chronic gastrointestinal disorders, such as chronic diarrhea, irritable bowel syndrome (IBS), inflammatory bowel disease (i.e., Crohn's disease, ulcerative colitis), celiac disease, malabsorption syndromes, pancreatic insufficiency, gallbladder disease, or current gastrointestinal cancer
Have had diarrhea anytime in the previous 30 days, have diarrhea at the pre-travel consultation, or develop diarrhea before departure
Have been given doxycycline for malaria prophylaxis for the current trip (due to possible drug-drug interactions and decreased absorption of the doxycycline)
Have an allergy to any component of the placebo tablets
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Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

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If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

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Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

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