Plant proteases (papain, bromelain, etc.) have long been used to improve digestion (remember, for example, Pancreolan Spofa® when Spofa still existed). In South East Asia, a green papaya salad containing papain protease is used in the preparation of mainly fatty meals, which partially hydrolyse and thus improve their taste and digestibility.
Larger question marks are around the hypothetical intrinsic efficacy of these proteases. There are scientific reviews such as Lorkowski2012gab that attach to papain, bromelain, and plant proteases in general the ability to penetrate tight seals of the intestinal epithelium into the intercellular space. Just for information: The tight joints of the intestinal epithelium are zipping together with the epithelial cells of the intestine sewn together. The tight joint serves just to prevent any foreign organisms or proteins from the intestine (where foreign proteins are many) can not get inside the body. The discovery that papain and bromelain with this zipper can crawl inside was a little surprised but confirmed by the monograph on bromelain 2010bmo , which further quotes the experimental work White1988bob , Castell1997iau and others. If papain and bromelain get into the blood through tight joints, he would be unwelcome, but he would certainly have found plenty of proteolytic sites between plasma proteins. Injection of proteolytic enzymes into the blood is a very effective way to achieve large physiological effects with only a very small dose of the active substance (proteolytic enzyme). This strategy is used by poisonous animals (snakes, spiders ...) whose poisons - to be highly effective in small doses - contain proteases, phospholipases and other enzymes. Alien proteases are a threat to the body, and we have inherent defense against them - a specialized antiprotect called α 2 -macroglobulin. A- 2- macroglobulin is a large, bad protein that, when a protease tries to split it, gets so horribly angry, and a nice protease pulls into hell in her embrace. This protein is the essence of our resistance to poison poison and other serpents. With the re-emergence of foreign proteases, specific antibodies also appear in the blood to accelerate the inactivation of the proteases.
Plant proteases can be consumed either in the form of Wobenzym patent preparations or fairly easily without prescription. To demonstrate this giveaway good recipe for Thai salad of green papaya .