This 12-week, randomized, single-blind clinical trial with C. butyricum enrolled a cohort of long-term care subjects in a community hospital (aged 83.2 ± 5.3) suffering from malnutrition (MNA-SF score ≤ 7, average albumin 36.38 ± 2.98 g/L). This evidence concerns the gene ALB and nutritional deficiency disease.