Comparative analysis of gut and skin microbiota from the coastal and non-coastal populations in Tamil Nadu using 16S rRNA gene sequencing: a pilot study

Background The human gut and skin microbiota play a vital role in maintaining physiological balance and immune function. Factors such as age, diet, geography, and genetic factors influence their composition, and disruptions can contribute to metabolic alterations and chronic diseases. Coastal populations are exposed to environmental pollutants and experience disrupted gut microbial balance, impaired epithelial barrier integrity, and possibly dysbiosis-associated inflammatory responses. In this study, we aim to analyze microbiome diversity in coastal and non-coastal populations of Tamil Nadu, India, using 16S rRNA sequencing. Methods Fecal and skin swab samples were collected from 75 participants, 57 from coastal regions and 18 from non-coastal regions. DNA was extracted, and using the Illumina MiSeq platform, the 16S rRNA sequencing was performed. The alpha and beta diversity analyses compared the fecal and skin microbiota diversity and composition. Results The study revealed that Firmicutes dominated the gut microbiota in both coastal and non-coastal groups, with higher abundances of Bacilli and Clostridia in the coastal group. In skin swabs, Firmicutes and Proteobacteria were predominant, with different clustering patterns observed in coastal samples. Beta diversity analyses revealed overlapping but distinct microbial communities between the two groups. Conclusion This pilot study highlights differences in gut and skin microbiota between coastal and non-coastal populations. However, further study with a larger sample size is required to better understand the impact of environmental exposures on human health.