Eating cellulose?

Lactose is a B-1,4 disaccharide. Many people lack the lactase enzyme to break it down into glucose and galctose, and are therefore lactose intolerant. To address this, there exist tablets containing the enzyme that can be taken after ingesting lactose/foods containing it. It breaks down normally and all is well.
Cellulose is a long B-1,4 polysaccharide. No human produces the enzymes to break it down to useable sugars. Why not create a gel-coated tablet that passes through the stomach and allows humans to digest it?
If we could digest cellulose, nearly any soft vegetation would be a source of nutrients. I'm sure I'm being retarded somehow, but what am I missing?
Pic related

So poor people could eat grass? Would the production of the enzyme be cost effective? Grain already is cheap.

It's not as simple as that, lactose is a tiny molecule by comparison to cellulose; 2 sugar units compared to several hundred.
Breaking down cellulose into individual monomers is a pain in the arse of a process, under body temperature conditions it takes quite a long time to fully digest.
This is why cows have multi-chambered stomachs and rabbits eat their own shit.

Even if you did consume the right enzymes, your intestines would get clogged with hardly-digested plant matter very quickly.

So you're saying it would work if you would also eat your own shit?

It probably won't be cost-efficient and grass isn't high on calories. It's pretty obvious.

I'm saying you probably wouldn't be able to shit.

Ah, I should have remembered the whole herbivore gut length thing. Good point.
Cellobiose is probably a better comparison, but much less interesting to talk about since it's not nearly as common.
I think you could probably make cellulase fairly cheaply with a vat of GMO bacteria, similar to how they do insulin nowadays.

While we can not effectively digest cellulose, it is still important for our intestinal function. It scrapes against the intestinal walls, kicks out the old and weak gut bacteria and keeps healthy motility going.

If we could digest cellulose, it would make the worldwide obesity problem even bigger. Currently fibers are perfect for taking up space in stomach and decreasing appetite for overweight people.

But IIRC humans can perfectly well eat starch which consists of carbohydrate monomers
So there really should be a solution, but you would have to make special enzymes

monomers in starch are linked by different bond geometry than monomers in cellulose. in cellulose, the reaction site is a lot more sterically hindered IIRC.

That's why I suggested a tablet/pill you'd take each time rather than setting up symbiotic bacteria.
That way you could choose whether or not to turn the salad into energy or keep it as fiber.

Or indeed use algae.

Growing protein by GMO fungus is already a thing.

Cellulose is still a lot bigger than starch.

Starches are 300-600 sugar units long, cellulose chain lengths are up to 10,000.

Yeah and IIRC because of that geometry the hydrogen bonds around the glycosidic bonds link the monomers better
But I still think that that should tell you that it could be done

that is a whole different point though, worth considering
has it been shown that the "digestability" of biopolymers is directly linked with chain lengths of polymers in a detectable way
(I would think so too, but would be interested in some clear examples)

>has it been shown that the "digestability" of biopolymers is directly linked with chain lengths of polymers in a detectable way
There's a lot of common sense stuff that suggests that.
Like, a longer chain would need more hydrolysis reactions to break it down into useable sugars, so it takes longer, so for a digestive tract of given length it would be less digestible than a shorter one.
And longer chains tend to be less polar and therefore pretty insoluble, which can make reactions procede more slowly.
And longer chains can have more weird interactions (disulfide bonds, hydrogen bonds, etc.) that make it hard for enzymes to reach reaction sites
But that's just off the top of my head. In a biological system there might be more going on so idk

I'm mostly agreeing with you except for the last sentence.

>What is fibre

Also, there's ways the engineer enzymes that have better activity than the current enzymes nature uses to break down cellulose, so there's at least ways around that.

The problem is that this will be used to feed the poor and if you do that nature will run it's coarse and the world will be populated with 40 billion niggers by the end of this century. Think about it.

Why not just grow more wheat and rice which are cheap to produce? Try coming up with practical solutions for practical problems. The need to digest cellulose isn't a serious issue. When you can turn cellulose directly into a viable biofuel I'll be interested.

Grains are easy to produce, but hay/silage are common byproducts that are either burned or fed to animals. If they could be used that'd be cool.
Also
>implying science has to solve problems to be worthwhile

Cellulose is already being turned into a viable biofuel, you ignorant fool

So some version of methanol, that we eat?
However, you might well be right about the "being retarded" part.