Humans can’t digest cellulose. Some animals can – like cows and sheep. But why is this? What’s the difference between humans and these other animals? The answer lies in our stomachs. Humans, unlike some animals, have a simple stomach with only one compartment for food to pass through before moving into the intestines where it undergoes digestion by bacteria and enzymes from the pancreas, liver and small intestine. These various organs produce digestive juices that break down proteins, fats, oils and sugars so they are more easily digested by human cells. In contrast to this multi-chamber model of digestion found in humans, some herbivores (animals that eat mainly plants) have a multiple compartmented stomachs.
Animals with a multi-compartmented stomach have evolved this way because they need to extract the maximum amount of nutrients from plants, which are hard to break down and digest. The first compartment in an animal’s stomach is called the rumen, where hydrochloric acid helps kill bacteria that would otherwise compete for food sources in their intestines (a process known as “acidosis”). Next comes the reticular or omasum section, where microbes ferment plant material into volatile fatty acids providing more calories and fluids for animals like cows who eat mainly cellulose (plant fiber). In addition to these two compartments, some herbivores have up to four other chambers within their stomachs containing enzymes produced by microbial digestion of cellulose.
The rumen is the first compartment in an animal’s stomach that helps kill bacteria and then microbes ferment plant material into volatile fatty acids providing more calories and fluids for animals like cows who eat mainly cellulose (plant fiber). In addition to these two compartments, some herbivores have up to four other chambers within their stomachs containing enzymes produced by microbial digestion of cellulose.” “Humans can’t digest this because they need a lot of nutrients from plants which are hard to break down,” says Dr. Christine Drea, Curator at the Smithsonian National Museum of Natural History.
why can t humans digest cellulose why is the human digestive tract different than most mammals? how do humans digest cellulose? do people have enzymes to break down plant matter in the stomach? why are cows able to eat a high fiber diet and not experience constipation or other digestive disorders like humans? how do an animal’s intestines help them digest their food better than ours can, which is mainly what makes us different from herbivores?
“In order for our gut bacteria to grow and function well, we need more prebiotics such as soluble fibers,” says Dr. Christine Drea. One study examined whether adding linseed (a type of seed) helped improve symptoms of IBS by increasing levels of beneficial intestinal bacteria that ferment carbohydrates into short-chain fatty acids.
“We know that diets high in insoluble fiber can cause constipation. But oddly, the opposite seems to be true for soluble fibers,” says Dr. Christine Drea. Another study found that people who ate oats every day had a lower risk of type two diabetes and cardiovascular disease than those who didn’t consume any oatmeal at all.” why are cows able to eat a high fiber diet and not experience constipation or other digestive disorders like humans? why do humans have an increased risk of chronic diseases and constipation because they don’t eat enough fiber?
One small change that we can make to be healthier is in the way that we handle our diets. The average person should aim for a diet with 25 grams or more per day of insoluble fiber or 35 grams or more daily soluble fiber, which are present in foods like whole grains, broccoli, cabbage and other vegetables. Increasing your intake of dietary fibers will not only improve digestion but it may also help you lose weight!
If you’re wondering how much water to drink on a low-carb diet plan – remember there’s nothing magical about drinking eight glasses (or two liters) of fluid each day: just go by the color of your urine as a guideline. Again, if you’re drinking enough fluids to produce light-colored or clear urine then you know that’s good enough but it doesn’t mean you should drink more water than what feels comfortable.
A low-carb diet plan is one way in which people can lose weight and improve their health at the same time. The idea behind these plans is simple: eat fewer carbs! If we want to be healthier humans, maybe we need to rethink our diets? We may not be able to digest cellulose like herbivores (or cows), but it would seem there are other changes that could help us reach this goal nonetheless!
