You're not wrong in what you say, by bacteria breaking down plants you mean the cellulose, which is true, only mammals like cattle and insects like termites (and possibly paper wasps?) can break down cellulose, but only with the help of specialized gut bacteria. In humans and other mammals it passes right through undigested.
However humans and cats have very different digestive systems even so, humans produce the enzyme amylase in our mouths which helps us start breaking down starch early and having it in the mouth is a feature of herbivores and omnivores, not carnivores. Cats do not have this, they actually struggle to break down starch and other carbs as this only occurs in their gut, after leaving the stomach, and they produce much less of the necessary enzymes. Many domestic dog breeds produce amylase in their mouths, possibly from adaptations to domestic life in societies where their owners couldn't always feed them the meat they needed. It's worse for them than us, but they're better equipped to survive being cut off from meat than cats are.
Cats and obligate carnivores have much shorter intestines than us as they only eat easily digestible meat. We have long digestive tracts, unlike an obligate carnivore and more like an omnivore or herbivore, due to our mixed diet. Having longer intestines helps the bacteria in them digest plant matter more easily too (specifically starch and other nutrients, as we established cellulose passes through undigested), a feature which cats lack. For cats almost all plant matter just passes through, compared to us where we actually do get nutrients from it.
Having a highly acidic stomach does not rule you out from having gut bacteria as the digestive system is compartmentalized. From memory sharks, scavengers like vultures and birds of prey have very acidic stomachs like us, but many birds of prey will eat berries and can get nutrients from them. The reason for the highly acidic pH is to activate the digestive enzyme pepsin which breaks down proteins (not fats) and, possibly, to fight off infections. Horse stomach pH varies from around as acidic as ours to almost neutral depending on diet and which region of the stomach you take a sample from (closer to the intestines is less acidic, the foregut is more like our stomach in acidity).
When the food that is being digested leaves the stomach and enters the small intestine it is neutralized + the fats emulsified by bile from the gallbladder and becomes basic, which allows the enzymes the pancreas excretes to function, e.g. lipases which do most of the fat breaking down and do so in the small intestine at basic pHs.
Sugars are probably one of the few needs we have that are easier to get from carbohydrates than fats and proteins like cats get it. We definitely eat way too many carbs today and being overweight can fuck up the absorption of other nutrients, but the fact they've caused the obesity epidemic is testament to how much easier it is for us to get them from carbs than fats and proteins.
Interestingly, deer and some other herbivores will eat the bones of dead animals if their bodies are low in calcium.
Plants aren't digested in the large intestine alone, most digestion occurs in the small and that includes breaking down starch etc., in the large whatever is left and water gets absorbed. Cellulose as we established passes undigested.
I get the bile part, my point was having a low pH does not rule out an animal being an omnivore.
You're not wrong in what you say, by bacteria breaking down plants you mean the cellulose, which is true, only mammals like cattle and insects like termites (and possibly paper wasps?) can break down cellulose, but only with the help of specialized gut bacteria. In humans and other mammals it passes right through undigested.
However humans and cats have very different digestive systems even so, humans produce the enzyme amylase in our mouths which helps us start breaking down starch early and having it in the mouth is a feature of herbivores and omnivores, not carnivores. Cats do not have this, they actually struggle to break down starch and other carbs as this only occurs in their gut, after leaving the stomach, and they produce much less of the necessary enzymes. Many domestic dog breeds produce amylase in their mouths, possibly from adaptations to domestic life in societies where their owners couldn't always feed them the meat they needed. It's worse for them than us, but they're better equipped to survive being cut off from meat than cats are.
Cats and obligate carnivores have much shorter intestines than us as they only eat easily digestible meat. We have long digestive tracts, unlike an obligate carnivore and more like an omnivore or herbivore, due to our mixed diet. Having longer intestines helps the bacteria in them digest plant matter more easily too (specifically starch and other nutrients, as we established cellulose passes through undigested), a feature which cats lack. For cats almost all plant matter just passes through, compared to us where we actually do get nutrients from it.
Having a highly acidic stomach does not rule you out from having gut bacteria as the digestive system is compartmentalized. From memory sharks, scavengers like vultures and birds of prey have very acidic stomachs like us, but many birds of prey will eat berries and can get nutrients from them. The reason for the highly acidic pH is to activate the digestive enzyme pepsin which breaks down proteins (not fats) and, possibly, to fight off infections. Horse stomach pH varies from around as acidic as ours to almost neutral depending on diet and which region of the stomach you take a sample from (closer to the intestines is less acidic, the foregut is more like our stomach in acidity).
When the food that is being digested leaves the stomach and enters the small intestine it is neutralized + the fats emulsified by bile from the gallbladder and becomes basic, which allows the enzymes the pancreas excretes to function, e.g. lipases which do most of the fat breaking down and do so in the small intestine at basic pHs.
Sugars are probably one of the few needs we have that are easier to get from carbohydrates than fats and proteins like cats get it. We definitely eat way too many carbs today and being overweight can fuck up the absorption of other nutrients, but the fact they've caused the obesity epidemic is testament to how much easier it is for us to get them from carbs than fats and proteins.
Interestingly, deer and some other herbivores will eat the bones of dead animals if their bodies are low in calcium.
I didn't say they were mammals?
And plants are cellulose and starch yes.
Plants aren't digested in the large intestine alone, most digestion occurs in the small and that includes breaking down starch etc., in the large whatever is left and water gets absorbed. Cellulose as we established passes undigested.
I get the bile part, my point was having a low pH does not rule out an animal being an omnivore.