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Name: Pamela S.
Status: Student
Age: 18
Location: N/A
Country: N/A
Date: N/A 

What bacteria is involved in digestion? or in the digestion of indigestible food? For example Celery is indigestible right?

Therefore bacteria eats it up rather than the stomach digesting it, what kind or type of bacteria does that? and why?

Bacteria are indispensable for food digestion. In a simplified view, food is degraded in the stomach by acids, then the bile destroys fats, and bacteria in the intestines degrade large biomolecules further into smaller ones that can pass the intestinal surface. Bacteria produce certain enzymes that can degrade biomolecules that higher organisms don't produce. A classical example are herbivores: they can only eat grass because of their bacteria that can degrade it. Or white ants that can eat wood because of the bacteria they carry. We are just as dependent on our native microflora in our gut.

Both Gram-positive and Gram-negative bacteria are present in our intestines, and there are many kinds of bacteria present at the same time. The bacteria florish on our food, but their products are again food for us, so who is eating what? Bacteria that live in a host and are beneficial to that host, at the same time being fed by that host are called commensals. If the bacteria would only be able to live in that host, and the host would be completely dependent on that kind of bacteria, it would be called symbiosis.

Trudy Wassenaar

Actually humans don't contain the bacteria necessary to digest cellulose. Cows and other ruminants do and therefore they can digest cellulose. Interestingly, termites aren't able to digest cellulose either. They have a symbiotic relationship with a bacterium that lives in their guts. The bacteria get a source of food, and they break down the cellulose into something that the termites can digest.


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