The oral administration of Bifidobacterium longum NK49, Lactobacillus plantarum NK3, and Bifidobacterium longum PI10 improved obesity in mice by improving intestinal barrier integrity via glucagon-like peptide 1 (GLP1) and IL-10 induction, modulating immune cells, and lowering TNF-α expression [114,115]. The gene discussed is GCG; the disease is obesity due to melanocortin 4 receptor deficiency.