Biopsychosocial and Environmental Factors That Impact Brain-Gut-Microbiome Interactions in Obesity

Despite significant advances in the understanding of the pathogenesis of obesity and influencing factors, its prevalence continues to increase at an alarming rate. Social determinants of health (SDOH) encompass a broad range of psychosocial and environmental factors, including economic stability, education, access to health care, social support, isolation, neighborhood disadvantage, discrimination, early life adversity, and stress, all of which have been recognized to significantly increase the risk of obesity. This review aims to elucidate the intricate relationship between SDOH and biological mechanisms related to the brain-gut-microbiome (BGM) system that lead to altered eating behaviors and obesity. We conducted a systematic review of the current literature to discuss how SDOH contribute to the development, progression, and management of obesity; and on the BGM mechanisms involved in the influence of SDOH on obesity. The BGM mediates the relationship between SDOH and obesity via orexogenic peptides, inflammatory markers, and neuroactive metabolites that affect ingestion-related decision-making and mood. Dysregulations in the BGM system as a result of environmental stressors can contribute to physiological changes in the gut microbial composition, hypothalamic-pituitary-adrenal axis signaling, and structural changes in the reward network, collectively leading to an increased drive toward the consumption of calorie-dense foods. By recognizing and addressing the impact of various SDOH on BGM interactions, health care providers can provide a more equitable and personalized approach that will enhance treatment adherence and the quality of life for individuals with obesity.