Yes, with proper regulation, a monogastric diet can help heal most human bodies from some diseases.
Here is how it works. In the short term, mono diets can provide health benefits by simplifying digestion and reducing the workload on your digestive system.
A meat-only or carnivore diet is a form of a mono diet. A carnivore is an animal that feeds on other animals. Humans have come a long way from the times of “Adam” living in harmony and at peace with “animals’ to chasing them down to shed their blood.

Think of the digestive system as a tennis player with a racket, and someone throwing multiple balls at her at once overwhelms her, making her miss more tennis balls than she’s hitting.
Keep throwing ten or fifteen balls at a time. The player will hit one, two, or three balls each time “you” throw; he misses most of the balls.

Think of the digestive system as seven main tennis players fielding 70 tennis balls at once.

A Carnivore Diet:

A carnivore diet that comprises meat, dairy, poultry, fish, seafood, eggs, etc. Such a diet would be bereft of vegetables, fruits, seeds, and nuts. Once all ultra-processed foods have been removed, someone following a strict carnivore diet for 30 to 120 days would shed several pounds. In the long term, such a diet is an extreme health hazard.