Diversity in probiotics and diversity in clinical trials: Opportunities for improvement

To the Editor—We read the report by Rauseo et al ¹ describing their randomized controlled trial of Lactobacillus rhamnosus GG (LGG) on antimicrobial-resistant organism (ARO) colonization. We agree that this pilot study leaves additional questions about the impact of probiotics on ARO colonization, and we hope future and larger studies will help to further answer this question. However, we were intrigued by the way the investigators approached the issue of race and ethnicity in the trial.

The investigators stated, “Diversity is an important quality of a healthy microbiome,” referencing the fact that their use of a single organism probiotic may have influenced the results of the study. ¹ According to the 2019 Barnes Jewish National Community Health Needs Assessment, the St Louis racial and ethnic breakdown of residents include the following: 47.2% White, 46.5% Black, 3.4% Asian, 0.3% American Indian/Alaska Native, 0.1% Native Hawaiian/Pacific Islander, and 4% Hispanic/Latino. ² Considering these population demographics, we submit that the authors missed two important opportunities to address participant diversity in their clinical trial.

First, non–English-speaking participants were excluded from participation, with no further clarification nor scientific justification for this decision. We acknowledge that there may be potential challenges in budgeting time and financial resources, which may influence how researchers enrolled participants, but without further discussion from the authors, the reader would not be aware of these challenges if they exist. With an expanding immigrant population in the United States, exclusion of non–English-speaking participants from such trials will limit the generalizability of results. ³

Second, in the description of demographics, the investigators chose to combine two racial groups (African American and Asian) into a single group called “nonwhite,” without explanation or scientific justification for this discussion. They did not describe ethnicity of participants, so we do not know what proportion of their cohort may have been Hispanic/Latino, if any. The choice to categorize race into White and non-White when there were apparently only three racial categories to describe is concerning, particularly since 46.5% of the St. Louis population is Black. Categorizing race like this subconsciously reinforces White race as the “default” and races that are not White as “other.”

Health Equity scholars like Boyd et al ⁴ have categorized the impacts of race and structural racism on scientific research and writing. They recommend rigorous standards for published material related to racial health inequities, which are critical to developing the science and language needed to understand and address these inequities. ⁴ We acknowledge that Rauseo et al did not intend to publish a paper focused on racial health inequities; however, we propose additional considerations for researchers and authors, institutional review boards, and journal reviewers and editors regarding race and ethnicity in publications, even if the focus of the article is not health inequities (Fig. 1).

Fig. 1. Considerations for researchers and journals regarding race/ethnicity in publications not specifically focused on health inequities.

We encourage researchers and authors to include costs of translation of study materials in their budgets in order to enroll participants who do not speak English and to ensure equity in screened and enrolled participants. Additionally, researchers and authors should provide justification for excluding or combining racial and ethnic groups and to avoid assigning White race as default in the analysis. Institutional review boards should include an ethical mandate of inclusion in underrepresented populations, including non–English-speaking subjects in their review criteria. ⁵ We hope that academic journals will invest in associate editors with expertise in diversity, equity, and inclusion to help navigate these issues in submissions, and that journals require authors to provide justification of any race-based analyses, language-based participant exclusion, and/or inequitable participant distribution in their studies (Fig. 1).

As we move toward building a more equitable future in healthcare, clinical research is an important area of focus. We call on both researchers and academic journals to commit to re-evaluate how they consider race in the design, conduct, and publication of clinical research.