I'm not a full success story quite yet but wanted to post my experience thus far with NSD.

I started tracking my flare ups in 2014 and they happen every ~25 days and I've had 8 flare ups thus far.

I've been on the diet for 7 weeks. I had a flare up 2 weeks into my diet but that is also because I was going through an iritis flare in the weeks prior. I think my leaky gut + Klebsiella levels were still abnormal.

Since then, I have had 31 days of no back inflammation. This is almost my 2nd longest duration of the year and I am hopeful it will continue past my longest (43 days). In addition to NSD, my naturopath put me on caprylic acid and grapefruit seed extract to eliminate some yeast that was detected through a stool test. Also, these 2 antimicrobials are strong against Klebsiella. I also started taking 12B probiotics every day a few weeks back to help add in good bacteria.

I believe the actions I have taken above are working to eliminate Klebsiella but probably more importantly leaky gut (I have posted previously how leaky gut is a precursor to A.S. at least in one study of it). I hope to get to a point where I have no back inflammation and no chronic iritis flare-ups.
Pre-As (sacriolitis) dx 2013
Chronic iritis in right eye
HLA-B27 Negative
3g fish oil, vitamin D, multivitamin, bacillus coagulans, digestive enzymes, curcumin, l-glutamine, butyrate (Alex Shikhman gut-based protocol)
Ibuprofen as needed a few times a month