Some people chew lots of chewing gum, and then swallow what they have chewed. Swallowing gum can lead to problems, as this medical study explains: “Chewing gum bezoars of the gastrointestinal tract,” David E. Milov, Joel M. Andres, Nora A. Erhart, and David J. Bailey, Pediatrics, vol. 102, no. 2 (1998): e22-e22. The authors write:
“In summary, chewing gum should not be swallowed and not given to children who cannot understand this point.”
That medical report is about children. Some adults, too, chew and swallow lots of gum. A January 23, 2017 news report, by The Cut, looks at one grown-up gum chew-and-swallower: “Sean Spicer Chews and Swallows 35 Pieces of Gum Every Day Before Noon“.