The choice of H. alvei as a potential anti-obesity probiotic was based on its production of the caseinolytic protease B (ClpB) protein, which was previously identified as a conformational mimetic of α-melanocyte-stimulating hormone (α-MSH), a key anorexigenic peptide involved in the regulation of appetite [11,12]. The gene discussed is STAMBP; the disease is obesity due to melanocortin 4 receptor deficiency.