Individuals with abnormal cardiometabolic statuses are more vulnerable to smoking-induced alterations of the gut microbiome in a Colombian population undergoing Westernization

The “Western” diet and lifestyle is of increasing scientific interest due to its rising global prevalence and potential implications for human health. It is associated with a decline in gut microbiome diversity and an abnormal cardiometabolic status, which contribute to inflammatory responses and the development of non-communicable diseases. Additionally, smoking has been implicated in increased morbidity and mortality from cardiovascular diseases and metabolic disorders. However, interactions between smoking, cardiometabolic status, and the gut microbiome have not been previously characterized in the context of Westernization. In this study, we investigated the impact of smoking on the gut microbiome across westernized Colombian individuals with either healthy or abnormal cardiometabolic statuses which were collected during a study performed by Cuesta-Zuluaga et al. For those with an abnormal cardiometabolic status, smoking was associated with reduced microbial species richness, particularly distinct in 8 core microbiome members, including the commensal genera of Bifidobacteria, Christensenellaceae, and Blautia. For westernized individuals with either a healthy or abnormal cardiometabolic status, smoking was associated with a reduced relative abundance of bacterial genera. However, the number of genera experiencing a decrease in relative abundance was greater in individuals with abnormal cardiometabolic statuses. The decrease in relative abundance was represented primarily in the Firmicutes phylum. Furthermore, abnormal cardiometabolic status was associated with potentially harmful bacterial species, such as Desulfovibrio piger and Bacteroides ovatus, which was significantly differentially abundant in smokers and are also prevalent in inflammatory bowel disease patients. Our findings indicate that individuals with abnormal cardiometabolic statuses are more susceptible to smoking-induced changes of their gut microbiomes.