MLK day gives us time to reflect on how racial disparity and inequity continue to show up in our world. MLK remarked, “Of all forms of inequality, injustice in health is the most shocking and the most inhumane.” (MLK 1965)
The microbiome world has started documenting racial differences. And indeed, there are differences in the microbiome between people of different races – but are they truly race-related? We would argue that these differences may be more related to age, nutrition, hygiene, medications and antibiotics, exposure to toxins, and stress. A recent paper in Nature called “Does the human microbiome tell us something about race?” written by Abigail Nieves Delgado & Jan Baedke provides the basis for our discussion.1 There are two main ways that science has historically viewed race. In the “environmentalist” version of race, there is a hierarchical view of civilization. In other words, environmentalists declare that some people are better than others simply because of the color of their skin or where they grew up.2
“Of all forms of inequality, injustice in health is the most shocking and the most inhumane.” (MLK 1965)
Essentially, people believed that natives and people with dark skin were designed to withstand harsh environments where they lived. Natives and people with dark skin were described as “degenerated, sick, and at-risk.”1 By the end of the 18th century, this derogatory view of native populations was standard. As time passed, and science of physiology advanced, the body was viewed specifically as a source of metabolism - an energy-burning machine. In the science that came out at this time, native peoples’ bodies were energy inefficient. People with darker skin may have carried more weight, and it was assumed they were metabolically substandard. Again, there was the perception of racial inferiority.
There’s a stereotype that has persisted in the description of native populations. Many times, native people are described in a way that is removed from a western lifestyle. The language used in scientific manuscripts implies that native people are primitive, incapable of progress, and free of industrialization.
Current microbiome research doesn’t suggest that native bodies are ‘degenerated, sick, or energy-efficient.’ In fact, native diets are often associated with health instead of disease. However, the language used is problematic. Current research often attaches particular values to indigenous groups. For example, studies may use comparative frameworks like civilized vs primitive, globalized vs uncontacted, normal vs abnormal, etc. The Delgado article suggests that “this should still be taken as a warning sign that microbiome research is following the argumentative patterns of exclusionary classifications of human diversity.” 1
“The microbiome changes over time during development, and there is substantial variability depending upon people’s hygiene, where they live, whether they have pets, etc.”
The second way that race can be viewed in scientific literature includes grouping people as a collective with their microbiome. This suggests that everyone from a particular group shares a common microbiome – which we know isn’t true. The microbiome changes over time during development, and there is substantial variability depending upon people’s hygiene, where they live, whether they have pets, etc. We also know that some groups share the same keystone species of microbes because they share socio-cultural patterns rather than racial ancestry.
The authors provided an example in which the oral microbiome of US Latinos was compared to non-Hispanic whites, non-Hispanic blacks, and Chinese living in the US. The idea was that they could develop a sort of ‘fingerprint,’ a microbiome signature that would discriminate between different ethnicities. This study demonstrated that a person’s oral microbiome could be analyzed, and the presence of specific microbes could be used to predict their ethnicity. This strategy used non-human species (microbes) to determine the race of people. In short, microbes living in and on Latinos biologically constitute their race.
So how (and perhaps the better question is why) do we continue to classify people according to race?
The greatest predictor of microbial diversity in infants is how they are delivered (vaginal or C-section), what they’re fed (breast milk or formula), and hygiene, not their race.3,4 The microbiome may be shaped by the socio-economic life of an individual, but it is not determined by their race.
“Human behavior, not race or geography, is the strongest predictor of microbial succession in the gut bacteriome of infants”
As Quin and Gibson point out in their article entitled, “Human behavior, not race or geography, is the strongest predictor of microbial succession in the gut bacteriome of infants”:
“All humans have similar microbial succession during infancy.” 4
According to the Delgado article, the most central mediators of microbial diversity are stress, environmental toxins, lifestyles, and nutritional habits. These factors can all be separate from race. Furthermore, when people from one area change diet (for example, change to a Western diet), their microbiome changes regardless of the color of their skin or the microbiome they started with.
Addressing racial injustice and health disparity means calling out research that uses comparators, moving beyond stereotypes, and acknowledging that people are not their microbiome. A microbiome can be thought of as a result of everything someone has interfaced with and experienced - and it is changeable; it is within these social determinants that the disparity lies. Racial ancestry does not dictate microbial and metabolic potential. There’s no doubt that the microbiome impacts every aspect of health, and that racial injustice causes stress that impacts the microbiome – the systems interact. However, we must not fall back into the patterns of the past which oversimplified race and led to the inhumane treatment of black, indigenous, and people of color.
- Nieves Delgado A, Baedke J. Does the human microbiome tell us something about race? Humanit Soc Sci Commun. 2021;8(1):97. doi:10.1057/s41599-021-00772-3
- Montesquieu: Selected Political Writings. Accessed January 18, 2022. https://www.hackettpublishing.com/selected-political-writings-montesquieu
- Milani C, Duranti S, Bottacini F, et al. The First Microbial Colonizers of the Human Gut: Composition, Activities, and Health Implications of the Infant Gut Microbiota. Microbiol Mol Biol Rev MMBR. 2017;81(4):e00036-17. doi:10.1128/MMBR.00036-17
- Quin C, Gibson DL. Human behavior, not race or geography, is the strongest predictor of microbial succession in the gut bacteriome of infants. Gut Microbes. 2020;11(5):1143-1171. doi:10.1080/19490976.2020.1736973