Integrated microbial and endocrine signatures of obesity: Enterobacteriaceae alterations, hormonal profiles, and dietary correlates in adult males.

INTRODUCTION: Obesity is a multifactorial metabolic disorder increasingly associated with alterations in gut microbial composition and endocrine imbalance. In the present study, microbiological analyses were limited to culture-based characterization of facultative anaerobic Enterobacteriaceae. Members of the Enterobacteriaceae family, particularly Klebsiella pneumoniae (Kpn), have been implicated in metabolic endotoxemia and inflammation; however, integrated data combining microbial profiling, metabolic hormones, and dietary patterns in Indian populations remain limited. METHODS: This case-control observational study involved 49 males (27 obese, 22 normal-weight controls). Anthropometric data were collected, and fasting serum leptin, ghrelin, and insulin were measured via ELISA. Stool samples were cultured for Enterobacteriaceae, identified biochemically, and genotyped using ERIC-PCR. Dietary patterns were evaluated with questionnaires. RESULTS: Obese participants showed significantly higher BMI, leptin (5.43±0.67 ng/mL), and insulin levels (3.21±0.27 mIU/L) than controls (p<0.05), while ghrelin levels did not differ significantly. Leptin positively correlated with BMI in obese individuals (r=0.423, p=0.028). Microbiological analysis yielded 82 isolates, with Kpn more prevalent among obese (92.86%) than controls (7.14%), whereas Escherichia coli predominated among controls (51.22%). ERIC-PCR demonstrated distinct genetic clusters among isolates. Obese participants also reported higher intake of fast food, refined carbohydrates, and soft drinks, correlating with elevated insulin levels. CONCLUSION: These findings suggest possible associations between Enterobacteriaceae prevalence, metabolic hormones, and dietary patterns in obesity and support microbiota-targeted and dietary interventions.