why do certain foods come out whole in fecal matter?

Question

while others disintigrate

Answer 1

The human body is simply not capable of fully digesting some foods. Many seeds for example (like corn and fruit seeds) have evolved to be hard shelled and resistant to digestion in birds and mammals to accomplish dispersal. The plants that produce seeds often package them in a nutritional "gift", such as a fruit. An animal eats the fruit, moves elsewhere, and defecates the seed out in another area. A wonderful adaptation for plants that are sedentary and have no other way of dispersing their seeds.

Answer 2

Plant material is mostly composed of cellulose. We lack the bacteria and mechanical action to fullly digest plant cellulose. Even cows would have a hard time except for a few things 1) they regurgitate the plant material and chew it again (called 'cud') 2) they have four stomachs to basically ferment the material and break it down further 3) they are colonized with more phytophyllic bacteria that live on plant cellulose.
As humans, we chew our food only once, and we have only one stomach, so many plant materials (like corn) pass out whole through our digestive tract. We are much more efficient at digesting proteins, which our intestinal enzymes and stomach acids can break down.
Cats (felidae) are obligate carnivors, and cannot digest plant material at all. They simply eat it for the roughage.
We are omnivorus, so we can get some nutritional value from both plant and animal sources.

Answer 3

If it is a hard substance that the digestive juices can not break down, it will come out whole. Many times, if you do now chew something into pulp before you swallow it, it will come out as whole as well. You will see seeds and nuts in your stool because you did not chew it all into a pulp first. The idividual pieces are so tiny to begin with, that your teeth will miss them sometimes.

Answer 4

Very often, these are seeds such as tomato and sweetcorn. It is a survival strategy by the plant. The fruit is eaten, then the seed drop somedistance away from the parent, along with a ready made supply of fertiliser.

Answer 5

if there is not much nutritional value in the food to begin with, then it usually just passes right through, without becoming very different looking. corn for example is mainly only good for amino acid intake. corn + beans = all the amino acids the body needs!! but considering that is all that it is really extracted from it, it comes out looking very similar to when it went it. corn is also a very good filler food.... like corn meal in dog food, but still, not very nutitious.

Answer 6

Fiber is not digestible, which is why it is also called roughage & bulk. It's purpose is to attach to solid waste & soak up liquid waste to move through the bowels easily & cleanly.. This is most noticeable with the "leftover" corn kernel husks in the toilet. Without fiber, we would constantly have either constipation or diahrea

Answer 7

Foods which are indigestible come out whole in fecal material. They are indigestible because they cannot be broken down by the digestive system.
http://encarta.msn.com/encyclopedia_761575197_2/Digestive_System.html

Answer 8

The things that nature intends our bodies to use for nutrition are digested the best. The things our bodies can't use come out whole.

Answer 9

Because our bodies have no way to digest these foods. An example of this would be cellulose-fiber. Our bodies cannot digest this long carbohydrate chain because we don't have the enzymes to perform the function.

Answer 10

These are also foods that our bodies don't digest very well or at all. Corn in particular, we don't digest at all, but it can work well to clean us out- so to speak.