Step zero is only accepting news from legit sources. Not using AI or anything – just make a list of legit sources.
The first step is to create a very fine hierarchy of news story categories. For example:
Death or Injury > From Nature > Animals > Sharks > Injury
Death or Injury > From Nature > Animals > Sharks > Death
The key is understanding the psychology of what people like to see in news. A wrong way of doing it would be
Animals > Dangerous > Sharks
Recreation > Water Sports > Surfing > Mistaken for a Seal
The second step is to make it proactively opt-in. Basically just copy FaceBook. Users discover stories in general, and then choose to receive more of those finely tuned story categories (when they like or follow someone).
Like: Death or Injury > From Nature > Animals > Sharks > Injury
Prompt: Do you want to include:
Death or Injury > From Nature > Animals > Sharks > Death as well?
Prompt: Would you be interested in other Death or Injury > From Nature > Animals?
The end result is (the same as Facebook) except it is just news from legit sources. You get too see all sorts of news because your friends like it, or it is like what you have liked, or it is trending or regional.
You also get to see very precise stories from niches you have opted into.
And some hashtags and easy social sharing and you have the easiest most trusted source of news there is.