Even Our Microbial Tenants Are Influenced by Disparity and Discrimination

Socioeconomic factors influence mental and physical health. The COVID-19 pandemic had a worse outcome in regions with poverty and poor economic situations. The belief that the coronavirus affects everyone equally is a myth.¹ Even noncommunicable diseases, such as cancer and diabetes, are more prevalent in regions with lower socioeconomic status. Social factors, however, are very diverse, making it difficult to pinpoint the exact factors that may affect human health.

It has been assumed that these social situations have a greater impact on mental health, leading to psychological stress, anxiety, and depression. So, physical illness can be a result of psychological disorders. However, new findings have revealed that social factors may impact physical health directly, and even living beings that reside in our bodies.

Every year, hundreds of thousands of people have to move from their high-stress countries to their dream destinations in search of better situations, satisfaction, and happiness. However, the new lands often bring them new stresses.

Social inequalities, discrimination, and the minority experience are the most stressful factors that individuals encounter during immigration to other countries. They show significant signs of mental stress. The hypothalamic-pituitary axis is altered, leading to increased cortisol levels in individuals. Among these, specific eating disorders, obesity, diabetes, higher blood pressure reactivity, and cardiovascular disease are more prevalent.² Furthermore, research has shown that ethnic discrimination is associated with high levels of cortisol, as measured using a hair cortisol assay-based method.³

Recent Research on Discrimination and the Gut Microbiome

A groundbreaking study has demonstrated that social inequalities and racism also impact the population of gut microbiome, leading to dysbiosis, and altering brain connectivity and inflammation markers. The Black study participants showed differences in nine bacteria species and an imbalance of microbiome markers on their faces. Hispanic and Asian participants who experienced discrimination also exhibited significant changes in their microbiota compared to control participants who did not experience social discrimination. Even white participants who experienced discrepancies in their environment showed changes in seven bacterial species.

In participants experiencing high levels of discrimination, there was a significant alteration in connectivity and rewiring in several regions of the brain. The markers of inflammation indicate a heightened risk of chronic inflammatory diseases such as obesity, diabetes, cardiovascular disease, and cancer.⁴ The study provides evidence that may help explain how discrimination contributes to health disparities and has specific effects on certain biological pathways for different groups.

In addition to the direct impact of social pressures on human health, mental stress-induced dysbiosis may contribute to physical illnesses associated with social disparities. Psychological stress can impact the permeability of the gut barrier, leading to "leaky gut" and exposing microbes to the immune system, triggering an inflammatory response. Mental stress also alters dietary habits, and dietary changes influence the microbiota. The dysbiosis associated with stress reciprocally affects mood through the gut-brain axis and worsens mental conditions such as distress and anxiety.⁵ This vicious cycle exacerbates the influence of social pressures on mental and physical health. Therefore, it should be noted that our microbial inhabitants are also affected by social discrimination, just like us.

Millions of people worldwide struggle with poverty and social inadequacies. These situations have worsened with the COVID-19 pandemic. Mental illnesses and communicable and noncommunicable physical illnesses are often more prevalent in these individuals. Several environmental factors have been suggested to contribute to a higher prevalence of many diseases in people experiencing social disparities. These factors include lower hygiene standards, poor diet, pollution, infections, and lifestyles such as smoking and drug abuse, which may result from social discrimination. These conditions influence the natural mechanisms that protect us from illness. Many people prefer to immigrate from these difficult social situations to other countries to escape inequality. However, their new destination often brings new problems, such as social discrimination.

The effect of environmental factors on the composition of gut microbiota has been observed; however, the influence of social disparities and inadequacies on the imbalance of the microbiome population is even more intriguing. It seems that mental stress resulting from social stressors influences the microbiota populations, leading to dysbiosis, inflammation, disruption of the immune system, dysregulation of metabolism, and, ultimately, several illnesses. These effects can, at least in part, explain the high prevalence of disease in regions with greater social disparities and misery.