Our findings revealed that the number of siblings, SRQ-20 score, always washing hands after using the toilet, higher fecal concentration of AAT, and anemia had significant positive associations with adult undernutrition, while age, DDS, always washing hands before cooking or taking meals, increased CRP concentrations, and H. pylori infection were negatively associated with BMI. The gene discussed is SERPINA1; the disease is anemia (phenotype).