Socioeconomic status shapes the gut microbiome in diverse U.S. population

By Dr. Priyom Bose, Ph.D.Reviewed by Benedette Cuffari, M.Sc.Mar 14 2024

Previous studies have reported an association between socioeconomic status (SES) and the gut microbiome, with various biological mechanisms potentially contributing to this relationship. A recent npj biofilms and microbiome study investigates how SES impacts the gut microbiome.

Study: Sociobiome - Individual and neighborhood socioeconomic status influence the gut microbiome in a multi-ethnic population in the US. Image Credit: Maciej Bledowski / Shutterstock.com

Background

There is a positive correlation between lower SES and mortality that is related to chronic diseases, including cardiovascular disease, cancer, and diabetes. However, the biological mechanisms involved in SES-related health disparities remain unclear.

Low SES is often associated with unhealthy eating behaviors, smoking, consumption of alcohol, and reduced access to medical services. These unhealthy SES-associated behaviors have implications for the development of chronic diseases and influence the gut microbiome. 

Ample evidence exists regarding the impact of maternal and family SES on the infant and childhood gut microbiome. Furthermore, twins who experience a different SES during adulthood exhibit differences in the composition of their gut microbiome. Nevertheless, these data have typically been obtained from small cohorts, thus necessitating the need for larger samples with information on area-related measures from racially diverse populations to confirm these findings. 

About the study

Data on 825 participants of diverse nativity and racial backgrounds were obtained from the Food and Microbiome Longitudinal Investigation (FAMiLI) study. SES was inferred by noting individual and neighborhood characteristics.

The researchers were primarily interested in determining whether low SES was associated with overall gut microbiota diversity and composition. Heterogeneity analyses were conducted to explore the role of race/ethnicity and nativity in the development of the gut microbiome.

Study findings

Within the study cohort, 36.7% were male, and the mean age was 59.6 years. About 38% of the participants were non-Hispanic White, 34.8% non-Hispanic Asian, 10.8% non-Hispanic Black, and 16.7% Hispanic.

Approximately 48% of the cohort were foreign-born, whereas 25% had completed high school or less education. Neighborhood- and individual-level SES were correlated with race/ethnicity and nativity.

A greater association was observed between lower individual educational attainment and microbial α-diversity, which was represented by the number of within-sample phylogenetic tree units. Participants from more deprived neighborhoods did not exhibit significant α-diversity. Moreover, β-diversity or overall composition differentials in gut microbiome correlated with neighborhood- and individual-level SES indicators. 

Ten bacterial species were differentially present by SES indicators. Some taxa associated with low SES included Collinsella sp000434535, Catenibacterium sp000437715, Prevotella copri, Prevotella stercorea, and Dorea_A formigenerans.

Monoglobus pectinilyticus, Lawsonibacter asaccharolyticus, Dysosmobacter welbionis, and Frisingicoccus caecimuris were associated with high SES. Comparatively, Dorea_A formicigenerans, Catenibacterium sp000437715, and Prevotella copri were associated with social deprivation index (SDI) scores and neighborhood income. Occupation and SDI scores were associated with Dysosmobacter welbionis. 

The abundance of Bacteroides and Prevotella, both of which are known biomarkers for diet and lifestyle, was compared. Consistent with previous reports, a higher abundance of Prevotella and a lower abundance of Bacteroides were associated with low SES. These differences could be attributed to varying dietary habits that entail a high consumption of animal products relative to carbohydrates.

Prior research has reported the potential role of Dysosmobacter welbionis in preventing diet-induced diabetes, obesity, and metabolic disorders in mice. In the present study, a reduced abundance of Dysosmobacter welbionis was observed among low SES participants, which could explain adverse health outcomes, such as diabetes and metabolic disorders, in this group.

Hispanic and Black participants were more likely to have lower SES, as reflected by parameters relating to education, occupation, neighborhood income, and deprivation. United States-born participants had higher SES as compared to foreign-born participants. Concerning race/ethnicity, none of the SES indicators showed marked heterogeneity. However, β-diversity varied significantly between ethnic/racial groups.

Conclusions

A significant association was observed between the gut microbiome and SES across a diverse population. Differences in the SES were associated with the abundance of bacterial species, α-diversity, β-diversity, and microbial functions. Taken together, the study findings emphasize the important role of SES in influencing the gut microbiome composition.

The term “sociobiome” describes the gut microbiota composition of residents of a particular geographic location. Socially minoritized populations are more prone to experiencing adverse health outcomes and environmental conditions. Future studies should consider the broader social context, aside from SES, while identifying microbial factors that influence health inequalities.

Despite the relatively large size of the study cohort, there was an unequal distribution of SES across ethnic/racial groups. Furthermore, the population distribution did not reflect the general American population with regard to the percentages of White, Asian, Black, and Hispanic individuals; therefore, the study findings should be generalized with caution. Residual confounding may have also been present, despite controlling for a wide array of key lifestyle variables.