With today’s technology, is it possible to create an artificial digestive tract?
I envision it works like this: You swallow the device, it attaches in the stomach and goes all the way down to the colon. Using a wireless link, the user can program it to, for example, reduce caloric intake by 1/2.
The user eats normally, but the device skims off 1/2 the calories in the food and effortlessly burns it off, while leaving the nutrition, water, and fiber for the user. (or perhaps it produces compact, inert pellets from the food it skims)
I would imagine a huge market opportunity if the idea could be made workable.
The small intestine, which is where 90% of digestion takes place, is perhaps the most sophisticated and complicated organ in the body. More than half a million enzymes are needed to digest food, which then has to go through the extraordinary filtering mechanism of the microvilli.
We are closer to an interstellar spaceship than we are to a working small intestine.
What if it worked with an existing, healthy digestive tract? Its purpose is not to replace it, but just to skim off calories. Surely, a flexible tube is not on the level of interstellar travel.
It’s not exactly the same thing, but a Belgian conceptual artist named Wim Delvoye built a museum piece called Cloaca which is fed ordinary food and digests it to produce feces. It was 33 feet long (way too big to be inserted internally) but it does work.
When the piece was on display in Antwerp, the ed product was placed in large glass jars, and sold along with the menu of the associated meal, but when the piece was on display in New York, the end product was disposed of in the usual way.
And just how would this ‘flexible tube’ do your envisioned tasks? Re-program the gut? What program language does the gut use? Instead of binary language, it appears to have tens of thousands of discrete molecules, each of which subtly alters the gut function.
And when a few of those discrete gut functions go awry, the gut may malabsorb so bad that hyperalimentation via central IV line is needed to feed a person. Or the gut may necrose and die, taking the person with it.
We lack the technology at this time to do what you envision.
You build the tube out of safe materials, like those used in implants today.
The top of the tube has a computer controlled intake opening. Food from the stomach falls into the opening. After a certain amount goes in, the computer closes the opening for a period of time until the next cycle. The algorithm could be as simple as: less calories desired = less delay between cycles. Or, perhaps the user can initiate a cycle after eating a particularly rich meal.
Gravity helps the food travel down the tube. Along the way, the food is squeezed and some water + nutrients drains out the side of the tube, where it is absorbed by your regular, healthy, fully functional intestines along with food that was not taken into the tube.
The dried food pulp is then either burned or chemically dissolved and the inert results passes out of the bottom of the tube, perhaps into the large intestines or colon, where it mixes with feces formed by the regular, healthy, fully functional digestive tract and is expelled normally.
Are you telling me this can’t possibly work? (or are y’all just ‘pooh-poohing’ the idea, hah!)
Yeah, but your tube needs to identify molecule by molecule what constitutes “food” and what is “waste”. We just don’t have any technology that’s even close to being able to do that yet.
Presumably, anything in the stomach is assumed to be food. A certain amount of the food goes in. No identification at this point needed.
Once the food is in, it doesn’t need to do a 100% perfect, molecule by molecule separation. It just needs to do an adequate job.
Now, current technology is pretty good at separating liquids from solids. Anything that presses or squeezes food can do this (like a juicer). Liquids usually contain lots of water. Can the low-calorie mostly-water slurry be separated out with a semi-permeable membrane?
If we get more sophisticated, we might be able to further process the liquids to remove some of the fats, oils, and alcohols. Does today’s technology allow us to miniaturize something to burn those off or process out the calories?
Otherwise, just incinerate the solids, compress the ashes, and dump it into the colon.
Perhaps so, but many of the pipes in my home also bend around. Toilets still seem to flush okay despite this. Besides, I only mentioned that gravity helps the flow. I would dare to suggest that we have the technology to move liquids through a tube.
Here, we require some technical innovation. But we’re not describing something as complex as interstellar travel here.
Any new technology can be easily dismissed. Yet still, we have hovercrafts, submarines, and even working jetpacks.
So you’re basically talking a shunt, from the gastroesophageal junction to the large intestine, with a computer controlled flap which opens and shuts. When the shunt is shut, food goes to the stomach. When it’s open, food is diverted directly to the large intestine and excreted with the feces. The opening and shutting can be controlled on a timer or by the weight of the food in the stomach, or some combination thereof.
I think it’s not possible now, but I’d run like hell to the patent office, because when it’s possible, it will be very, very profitable.
Actually, what we need to do is combine the two, so you have an spaceship that can digest the thin matter that it finds in the interstellar medium. Two problems solved for the price of one!
But silliness aside, Exapno Mapcase is correct, at least insofar as stating the complexity of the function of this organ. This is unsurprising, as the mammalian omnivore digestive tract is the result of billions of years of evolution, fine tuned into breaking down a vast range of substances into required nutrients, and feeding our gignormous brains. We’ve got a lot of catching up to do before we can replicate this processes artificially.
Oh, but it does. As pointed out earlier, you can’t really count the stomach–heck, people can live without one, with some dietary restrictions. It’s main purpose is to convert solid foods to liquid form. The real separation magic happens in the small intestine, where various molecules are either broken down chemically or absorbed into the blood stream. The interface between the material in the small intestine and the blood stream must identify, molecule by molecule, what can pass through and what cannot. There is some usable material which is excreted, but this is due to the fact the intestine isn’t long enough to absorb all of it, not all the material passed through makes contact with the villi. Longer intestines can extract more usable material than shorter ones. Vegetarian animals like elephants have a very long intestine because it’s harder to extract nutrients from tough plant material. Our intestines are as long as they are because the law of diminishing returns says that the energy needed to grow a longer intestine would no longer be paid back by the energy extracted. At some point, good enough really IS good enough.
This is exactly wrong. Peristaltic action (undulations in the tract walls) is what causes consumed matter to move through the digestive tract. Gravity would be insufficient for this purpose, particulaly when reclined or prone. Material is broken down by the action of enzymes and bacteria that would otherwise be harmful if exposed to other organs; hence, trauma and surgery in this region of the anatomy is very serious, with a high risk of infection.
This seems to be the day for people to present [thread=400363]crazy crackhead notions[/thread] about biology and human anatomy. If you seriously want to understand the workings of the gastrointestinal system, I recommend reading the linked Wikipedia article on the topic. But don’t insist in blythe ignorance that it must be trivial after people demonstrate legitimate, technical objections to your concept.
