Chewing gum

**Note: "Eat or chewing gum?" This sentence would be considered a sentence fragment. You could make it flow from your previous sentence by saying "Perhaps you would want to eat or chew gum?"
**Note: You use the wording "for most of us" but then you narrow it down to people who don't want to gain weight. I think it would flow better if you wrote something like: "This would be fine for most of us; however, if we don't want to gain extra weight, chewing gum is the best option." I left out bubble gum since chewing gum and bubble gum are used with the same meaning.  

The modern gum are made by resin and propolis, It tastes sweet and very good for chewing.

**Note: "Modern gum is..." sounds more natural.

We are lucky living the 21 century, when our ancestors wanted to console their mouths, they were not as lucky as us, a report shows that dated back to stone age, we humans already had gums, in Finland, the archeologist had found a chewing gum which were made by tar, it hasn’t any pleasant flavor at all, our ancestors chewed that only for satisfying and consoling their mouth.

**Note: This is a long run-on sentence, so I recommend trying to break it down into sections. Think of it like one thought per sentence.
"We are lucky to be living in the 21st century. When our ancestors wanted to console their mouths, they were not as lucky. Although archaeologists in Finland have discovered gum dating back to the stone age, it was made by tar and was far from the pleasant flavors we have today.

With the excessive supply of tasting food, we would have never wanted to chew a tar for the sense of consolation.

**Note: Use the word "tasty" instead of "tasting". This sentence sounds a bit strange try writing, "we will never have to chew tar to console our mouths."