Whoa gary: I am not as smart as I look. I will take a shot at this,but believe what I say at your own risk. Also the doc's have been trying to answer your questions for the past 100 or so years. I have the time and somewhat
good at finding stuff,once the info is found then figuring out what it mean is the tuff part. For instance the doc's might get misled by going too far down the immune cascade. Seems that just about everything about our immune systems is defective,or perhaps its a normal event when the immune system is exposed to huge amounts of bacteria for a long time.
First from the study on early onset UC in kids that have not had meds,there is not a dysbiosis that they
could find. I believe the dysbiosis comes sometime later,from inflammation killing off certain strains,and lack of mucus,which they feed on.
So unless you have some kind of trigger event like antibiotics or gut infection,or even a scope prep,you don't get dysbiosis first. That being said,people on a Western diet may have dysbiosis when compared to say African people. What I am trying to say here is that all westerners may have a messed up gut population and the docs think it is normal,because most other westerners have the same types.
Yes, UC starts distally/rectum. The rectum has the thickest mucus layer,has the most mechanical abraision,also has the highest bacterial load,might even have the least blood flow but cant remember that for sure. Also by the time the stool gets to the rectum contains lots of toxins.
Yes the gut flora varies in type and amounts along the length of the gut.
Yes there could be something going on in the small intestine,that manifests in the rectum,not sure what
it might be though. High fat diet can make the wrong kind of bile,sulfate reducers feed on it,gluten.
Why it starts lower and moves up,perhaps from the inflammation creating the dysbiotic bacteria,these move up and create inflammation,which lets the bad bacteria grow,creating more inflammation.
So yes it is possible dysbiotic bacteria that they find in UC people is collateral damage from the inflammation and lack of proper mucus to feed on.
Just some of my wild guesses, could be 100% wrong.
Post Edited (Old Mike) : 9/24/2013 1:33:11 PM (GMT-6)