If you want to fix your gut:

Salt and ruminant meats, minimum 3 months. First 2-3 weeks, you might hate life, but after that, your gut will thank you.

Some people just cannot do well on that, but I would still try it for three weeks and go from there.

Considering this from my end, I will be trying this early next year. I will be eating meat and dairy, so not the strict "lion's diet."