Many patients keep asking me about the role of ‘Low starch diet’ to control Ankylosing Spondylitis. This has been a hot topic of discussion on most Ankylosing spondylitis groups on social media & many confirming the good results of a low starch diet.
The original idea of a ‘low starch diet for Ankylosing Spondylitis’ comes from Dr. Alan Ebringer, Prof of Immunology at King’s College London. He found high levels of a gut pathogen called Klebsiella Pneumoniae in stool samples of patients with Ankylosing spondylitis. He also found high levels of antibodies to klebsiella in the blood of patients with Ankylosing spondylitis. These findings indicated the presence of the bacteria in the gut of patients with Ankylosing spondylitis & the body’s immune reaction to it.
These findings evoked further research & Dr. Alan’s further research showed that K. pneumoniae was isolated more frequently during the active phase of Ankylosing Spondylitis & clinical relapse was preceded by appearance of the bacteria in fecal samples. This meant that Klebsiella Pnemoniae was somehow related to inflammation of Ankylosing Spondylitis.
Dr. Alan’s research continued & he went on to show that there are similarities in structure of the HLA-B27 molecule & enzyme Pullulanase produced by the Klebsiella bacteria. There is also similarity between the enzyme & type I, III & IV collagens found in joints & other organs. This gave rise to the ‘Molecular mimicry theory’. The human immunity recognizes Klebsiella as foreign & attacks it. However, since HLA-B27 & collagens have similar structure, they get attacked to. This may be responsible for the inflammation in joints & other structures like the eyes in Ankylosing spondylitis.
One can infer from the proposed ‘molecular mimicry theory’ that by reducing the klebsiella bacteria in the gut, one can reduce the inflammation associated with Ankylosing spondylitis.
Various studies have shown that the gut bacteria including klebsiella grow on undigested starch in the gut. Hence a reduction in starch in the diet may help reduce the klebsiella bacteria in the gut. Klebsiella bacteria is well adapted to the human gut & produces the Pullulanase enzyme that can break down the starch, derive nutrition & thrive in the gut.
The rationale of the ‘low starch diet’ is to cut down on the starch, make life difficult for the klebsiella bacteria. This may indirectly help control the Ankylosing spondylitis.
This is the exact basis of the ‘low starch diet’ for Ankylosing Spondylitis.
Now that we know the basis of the theory, we also need to look at the following points—
1. What is a ‘low starch diet’?
2. Are there any studies conducted in patients with Ankylosing spondylitis to prove the benefits of ‘low starch diet’?
3. If the concept looks so convincing, why do Rheumatologists not recommend it on a regular basis?
I would be answering these questions in the subsequent blog posts. These posts are coming soon & follow my blog so that you don’t miss out on any of those useful posts.
References: Erbinger A, Wilson C. J Med Microbiol 2000; 49: 305-311 http://jmm.sgmjournals.org/content/49/4/305.abstract