Dr Art Ayers at http://coolinginflammation.blogspot.com/search?q=gut+dysbiosis
He is convinced that most diseases of civilization are caused gut flora being less than optimal. Roam around his site for a lot of enlightment about gut flora.
He does advocate inulin products...which are artichokes, jerusalem artichokes, jicama, burdock root, chicory and pectin to heal the gut. I mix the burdock root, chicory and pectin in my Greek yogurt.
Stephan at http://wholehealthsource.blogspot.com/search?q=inulin also talks about inulin in improving gastrointestinal Health.
I would avoid all forms of sugar...whether it comes from fruit like blueberries or from carbs that are converted to sugar in the gut...as yeast loves a sugary environment to thrive.
Regarding your sub optimal soccer performance on paleo, I would bet you are not taking in enough meat and fat to fuel your body to the level necessary to sustain the energy you need to be constantly on the move...as required in soccer. Thus you think you need the energy from 100g of carbs to fuel yourself. When folks decide to go paleo, they do not realize it takes a while to keto adapt (converting to using meat and fat to fuel the body rather than using carbs) and they do not realize they must replace the lost energy from carbs with animal protein and fat.
Try this. For a couple of weeks, breakfast 5 eggs fried in coconut oil or butter. 1/4 pound of bacon...best value I find at Wal-Mart...Wrights Brand bacon ends, 3 pounds for $4.92. Lunch 1/2 pound hamburger, no bun with some steamed veggies slathered in butter. Dinner 16 oz steak with lots of fat around the edges with more green veggies slathered in butter. Plus a green salad with olive oil and vinegar. Eat like this and I bet your performance will improve. If you run out of energy during the day, take along with you a small jar of coconut oil and have a few spoonfuls. I carry a jar with me all the time.
Keep the group updated as to your progress.