Jung DH, Youn YH, Kim DH, Lim C, Lim H, Moon HS, Lee JY, Park H, Hong SJ.  Esophageal Microbiota and Nutritional Intakes in Patients With Achalasia Before and After Peroral Endoscopic Myotomy.  J Neurogastroenterol Motil 2022;28:237-246.  https://doi.org/10.5056/jnm21057