Published: 2021 – Ongoing
Authors: Universidade do Porto, Portuguese Institute of Rheumatology, Centro de Investigação Interdisciplinar Egas Moniz

Completion Date: 30th September 2021 (awaiting results)

⚠️ Editors Note: You can see further details about this study below. First, I want to flag an important issue.

Like so many in the AS community, I was over the moon when I heard this study was taking place. Finally, this could provide some hard data to back up the efficacy of diet and gut health in managing AS. If it raises more widespread awareness and filters down to the medical profession, it would be incredible.

I really hope we get great, positive findings from this study and thank everyone who has organised this and taken part.

My one concern is the ‘40% reduction’ of starch figure. I don’t think it is enough. My own personal experience, and the experience of the vast majority of people I know who manage their AS with diet, is this:

It needs to a 100% reduction of starch (and certain forms of lactose).

This is something many of us have learned the hard way through a great deal of painful trial and error. Personally, it took me at least a month of 0% starch in my diet to start seeing profoundly positive effects.

Ankylosing spondylitis, like coeliac disease, is an autoimmune condition. As the NHS describes it: “In coeliac disease, the immune system mistakes substances found inside gluten as a threat to the body and attacks them.”

While not a perfect analogy this is similar, in principle, to the theory regarding Klebsiella and molecular mimicry in ankylosing spondylitis. It is ‘friendly fire’, or to put it another way, an overzealous attack on substances that people with AS are not genetically and biologically tuned to deal with.

Coeliacs don’t reduce their gluten intake by 40%, they have to reduce it 100% to remain symptom-free.

This, I believe, may be the best course of action for many ankylosing spondylitis patients with starch, if they are to get to ‘pain-free’ through diet and exercise alone.

I hope this is proved to be wrong, and that the participants get fantastic results as it is. I just don’t want them, or others, to be disheartened if the findings are not as dramatic as hoped. Either way, I applaud the move to study this.

Here are the details of the study:

Brief: “The aim of this study is to explore the effect of a low starch diet (reduction of at least 40%) in the gut bacteria modulation, especially Klebsiella pneumoniae, and its relation to disease activity, functional impairment and quality of life in patients with Ankylosing Spondylitis (AS).”

Background: “Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease characterized by axial inflammation and with unknown aetiology.

The immune system dysregulation is known, where genetic factors play a key role, in particular, the susceptibility associated to the HLA-B27 allele.

The presence of this genetic marker, seems to trigger an abnormal response of the individual, under the action of determine microorganisms, and probably, the combination of these two factors may contribute to the manifestation of the disease, through the induction of an immune and cytolytic response, leading to tissue injury and promoting the inflammation.

Intestinal microbiota involvement in spondylarthritis is a controversial issue, however, was observed an increased concentration of Klebsiella pneumoniae bacteria in the faeces of AS patients.

It has been suggested that an intervention aiming these bacteria’s starving could benefit the reduction of the inflammatory processes and be a part of AS treatment. The bowel microflora depends on dietary intake, like undigested starch, for their growth. Some studies have highlighted the relation between the intake of starch and the disease activity.

The modulation of the microbiota, particularly, the reduction of Klebsiella, may be beneficial as a complementary approach to AS therapy.

A sample of 300 patients with AS, followed-up at Portuguese Institute of Rheumatology in Lisbon, will be randomly assigned in two groups.

The group A will adopt a balanced diet based on the general recommendations for healthy eating by the World Health Organization, for a period of 6 weeks.

In Group B will be implemented an individual balanced low starch diet, which is characterized by the significant reduction of starchy food, of at least 40% of the total daily ingested starch.

The change in biometric data, body composition, intestinal Klebsiella will be related to food intake, disease activity and quality of life assessments. These data will be compared between the 2 groups (diet A versus diet B), obtaining measures on the effect of each diet on the analyzed variables.”

For more details and updates on this vital research take a look here: