The infant gut microbiota – a bustling ecosystem of bacteria, fungi, and other microbes – begins to take shape in the earliest days of life.
While birth mode and feeding practices are well-known influencers, a growing body of research shows that ethnicity and culture also play pivotal roles in shaping this microbial landscape.
These early differences in gut microbiota composition are more than mere curiosities; they have lasting implications for immunity, metabolism, and long-term health outcomes.
Variations in gut microbiota tied to ethnicity are detectable in infancy – as early as three months of age, according to Mallott et al. (2023). These differences are not fleeting. Rather, they persist into later childhood and are influenced by both shared genetics and environmental exposures common within ethnic groups (Brooks et al., 2018; Xu et al., 2020).
These microbial fingerprints are distinguishable even before infants start consuming solid foods (Xu et al., 2020). This suggests that prenatal factors, delivery mode, breastfeeding practices, and traditional caregiving environments may already be setting divergent microbial trajectories from birth.
The specific microbial profiles vary significantly across ethnic groups. For example, South Asian infants show an increased abundance of lactic acid bacteria, while white Caucasian infants tend to have more microbes belonging to the order Clostridiales (Stearns et al., 2017).
Indian infants have higher levels of Bifidobacterium and Lactobacillus – genera commonly associated with gut health. Chinese infants, on the other hand, show elevated levels of Bacteroides and Akkermansia, bacteria known for their roles in metabolism and gut lining maintenance (Xu et al., 2020).
A Malaysian study further illustrated this diversity: indigenous children, aged 7 to 12 years old, exhibited the highest bacterial diversity, while Chinese children in the same region had the lowest, despite sharing similar environments (Chong et al., 2015).
These disparities point toward the role of inherited practices such as diet, breastfeeding norms, and hygiene habits that are culturally embedded.
The influence of ethnicity on gut microbiota isn’t erased by geography. Even in multi-ethnic populations living in the same cities, distinct gut microbial profiles persist along ethnic lines.
In the Netherlands, for instance, Deschasaux et al. (2018) found that individuals from different ethnic backgrounds maintained unique microbiota compositions, despite sharing the same urban environment. A similar trend was observed in Malaysia (Dwiyanto et al., 2021), where differences in microbial communities were attributed more to cultural and dietary traditions than to geographic location.
These findings underscore a vital point: while physical environment matters, cultural practices – what we eat, how we live, how we give birth – carry microbiological weight. Ethnicity thus acts as a proxy for a bundle of behaviors and exposures that coalesce to shape early gut ecosystems.
Why should we care about these early differences?
Because the infant gut microbiota plays a critical role in programming the immune system, influencing metabolic function, and even shaping brain development.
If ethnic variations in microbiota translate to different health trajectories, this raises crucial questions for personalized nutrition, medicine, and public health interventions.
Moreover, understanding ethnic microbiota patterns could help identify populations at higher or lower risk for conditions like allergies, obesity, and autoimmune diseases. It could also inform more culturally sensitive healthcare, where treatments and dietary guidelines are tailored not only to the individual but to the traditions and environments that shape them.
References
Brooks, A., Priya, S., Blekhman, R., & Bordenstein, S. (2018). Gut microbiota diversity across ethnicities in the United States. PLoS Biology, 16. https://doi.org/10.1371/journal.pbio.2006842
Chong, C. W., Ahmad, A. F., Lim, Y. A., Teh, C. S., Yap, I. K., Lee, S. C., Chin, Y. T., Loke, P., & Chua, K. H. (2015). Effect of ethnicity and socioeconomic variation to the gut microbiota composition among pre-adolescent in Malaysia. Scientific Reports, 5(1), 1-12. https://doi.org/10.1038/srep13338
Deschasaux, M., Bouter, K. E., Prodan, A., Levin, E., Groen, A. K., Herrema, H., Tremaroli, V., Bakker, G. J., Attaye, I., Pinto-Sietsma, S. J., van Raalte, D. H., Snijder, M. B., Nicolaou, M., Peters, R., Zwinderman, A. H., Bäckhed, F., & Nieuwdorp, M. (2018). Depicting the composition of gut microbiota in a population with varied ethnic origins but shared geography. Nature medicine, 24(10), 1526–1531. https://doi.org/10.1038/s41591-018-0160-1
Dwiyanto, J., Hussain, M. H., Reidpath, D., Ong, K. S., Qasim, A., Lee, S. W. H., Lee, S. M., Foo, S. C., Chong, C. W., & Rahman, S. (2021). Ethnicity influences the gut microbiota of individuals sharing a geographical location: a cross-sectional study from a middle-income country. Scientific reports, 11(1), 2618. https://doi.org/10.1038/s41598-021-82311-3
Mallott, E. K., Sitarik, A. R., Leve, L. D., Cioffi, C., Camargo, C. A., Jr, Hasegawa, K., & Bordenstein, S. R. (2023). Human microbiome variation associated with race and ethnicity emerges as early as 3 months of age. PLoS biology, 21(8), e3002230. https://doi.org/10.1371/journal.pbio.3002230
Stearns, J. C., Zulyniak, M. A., de Souza, R. J., Campbell, N. C., Fontes, M., Shaikh, M., Sears, M. R., Becker, A. B., Mandhane, P. J., Subbarao, P., Turvey, S. E., Gupta, M., Beyene, J., Surette, M. G., Anand, S. S., & NutriGen Alliance (2017). Ethnic and diet-related differences in the healthy infant microbiome. Genome medicine, 9(1), 32. https://doi.org/10.1186/s13073-017-0421-5
Xu, J., Lawley, B., Wong, G., Otal, A., Chen, L., Ying, T. J., Lin, X., Pang, W. W., Yap, F., Chong, Y. S., Gluckman, P. D., Lee, Y. S., Chong, M. F., Tannock, G. W., & Karnani, N. (2020). Ethnic diversity in infant gut microbiota is apparent before the introduction of complementary diets. Gut microbes, 11(5), 1362–1373. https://doi.org/10.1080/19490976.2020.1756150