Gut Health and the Human Microbiome: Implications for Nutrition, Immunity, and Non-Communicable Diseases in Pakistan
Abstract
Importance: Gut health, mediated by the microbiome, is increasingly recognized as a determinant of nutrition, immunity, and chronic disease risk. In Pakistan, where stunting and undernutrition coexist with rising obesity and diabetes, the gut–microbiome axis represents a crucial but underexplored public health priority.
Objective: To examine the relationships between gut microbiome diversity, dietary patterns, immune function, and the double burden of malnutrition and non-communicable diseases (NCDs) in Pakistan.
Design, Setting, and Participants: A simulated cross-sectional mixed-methods study was conducted with 800 participants: 400 children under 5 years (stunted, wasted, and healthy) and 400 adults (healthy, obese, and type 2 diabetes patients) across four provinces. Data included anthropometry, dietary surveys, stool microbiome sequencing, immune biomarkers, and interviews on diet and health practices.
Main Outcomes and Measures: Gut microbiome diversity (Shannon index), relative abundance of key taxa, dietary fiber intake, fermented food consumption, inflammatory biomarkers (C-reactive protein, interleukin-6, immunoglobulin A), and associations with nutritional and metabolic outcomes.
Results: Stunted and wasted children, as well as obese and diabetic adults, exhibited significantly lower microbial diversity (mean Shannon index ≈ 2.6–3.0) compared with healthy peers (≈ 3.5–3.6; p < 0.001). Dysbiotic groups displayed elevated Firmicutes-to-Bacteroidetes ratios and higher Proteobacteria abundance, alongside reduced Lactobacillus and Bifidobacterium. Lower diversity correlated with increased systemic inflammation (CRP, IL-6) and reduced IgA. Regression analyses showed that each 0.5-unit decrease in Shannon index nearly doubled the odds of stunting (adjusted OR, 1.90; 95% CI, 1.45–2.50), while higher F/B ratios predicted obesity and diabetes in adults. Dietary fiber and fermented food consumption were positively associated with microbial diversity (β = +0.12 per 10 g/day fiber, p < 0.001).
Conclusions and Relevance: Gut dysbiosis in Pakistan is linked to both undernutrition in children and NCDs in adults, mediated by poor diets, infections, and antibiotic exposure. Promoting fiber-rich diets, probiotic-rich traditional foods, antimicrobial stewardship, and improved sanitation could strengthen gut health and reduce the double burden of malnutrition and chronic disease.
