Microbial diversity of smokers is not influenced by dietary fiber intake although smoking alters functional pathway abundances

Abstract

The gut microbiome is crucial for maintaining human health and is influenced by many environmental factors such as age, ethnicity, lifestyle practices, and dietary habits. While studies have shown that smoking can alter the microbiomes of various body sites, such as the upper GI tract (esophagus and stomach), the impact of smoking on the gut microbiome remains understudied. Dietary fiber intake has been linked to increased gut microbiota diversity and reduced weight gain, but it is unclear whether dietary fiber intake can counteract the negative effects of unhealthy lifestyle practices such as smoking. In this study, we investigated the impact of smoking on the microbial and functional composition of the gut microbiome and the potential mitigative effects of fiber on these possible changes. Here, we showed that smoking status did not change gut microbiome alpha and beta diversity of 441 Colombian adults. However, our functional pathway analysis identified several differentially abundant pathways between smoking and non-smoking individuals. Examination of the interactive effects of fiber intake on the microbial composition of smoking and non-smoking individuals revealed that fiber intake has no significant effect on microbiome alpha diversity. Overall, our study highlights that single-factor predictors like smoking status may not significantly impact gut microbiomes.