Efficacy of Modification of Lifestyle in the Treatment of Ankylosing Spondylitis: a Pilot Study (EMLAS)

Axial spondyloarthritis (axSpA) is a chronic inflammatory immune disorder with a global prevalence that ranges from 20 to 160 cases per 10000 individuals. axSpA has two forms of clinical presentation (radiographic and non-radiographic) based on the presence or absence of radiographic sacroiliitis. This condition mostly affects the vertebral spine, and is characterized by joint pain and stiffness, fatigue, and restricted function, which leads to a substantial physical, psychological, and socioeconomic burden. The clinical management of axSpA needs to combine pharmacological and non-pharmacological approaches to reduce inflammation and improve health-related quality of life. The aim of the study will be to determine if a 12-week probiotic supplementation will be more effective than an online-delivered strength training program at improving functional capacity in adults with non-radiographic axSpA. As a secondary aim, we will compare the impact of both interventions on disease activity, spinal mobility, quality of life and biochemical measures. This will be the first randomized controlled trial where probiotics are compared with an active intervention.

The control group will undergo a 12-week online-delivered Tabata program, as a form of high-intensity interval training.

During the first 4 weeks, patients will be instructed to take two capsules of Enterelle plus (Bromatech lab, Manno, Switzerland) during morning time, before or after breakfast. Enterelle plus contains specific strains, i.e., S boulardi, E faecium, and acidophilus, that contribute to reduce the mycotic flora and modulate the gastrointestinal transit. For the next 8 weeks, participants will be told to ingest two capsules of Adomelle (Bromatech lab, Manno, Switzerland) at night, during or right after dinner. Adomelle contains several strains, including Bifidobacterium breve, that help to reduce abdominal fat, pain, and gas, and control the frequency of deposition

This type of intervention has shown to benefit patients with several chronic conditions 23, including axSpA 13. Exercises combined high knees, lunges, basic burpees, plank, skipping, mountain climbers, and squats with jumps. The training routine will be conducted three times per week, and each session will last around 8 minutes (2 sets of 4 minutes, with a 10 second rest between them). All sessions will be individually tailored and supervised by a senior professional with a degree in Physiotherapy and Sciences of Physical Activity and Sport. Overall, participants will be told to continue exercising if low to moderate bearable pain appeared during training.

The primary outcome will be functional disability during daily life activities, evaluated with the Bath Ankylosing Spondylitis Functional Index.

The Bath Ankylosing Spondylitis Functional Index includes 10 items (scale of 0 to 10, higher scores denoting worse performance), and is among the recommended core set of instruments for axSpA.

The secondary outcome will be disease activity during daily life activities, evaluated with the Bath Ankylosing Spondylitis Disease Activity Index.

Disease activity will be assessed with the Bath Ankylosing Spondylitis Disease Activity Index. The Bath Ankylosing Spondylitis Disease Activity Index explores five different constructs (fatigue, spinal or peripheral joint pain, localized tenderness, and morning stiffness), with lower scores representing less disease activity (scale of 0 to 10).

Bath Ankylosing Spondylitis Metrology Index as a composite index including lumbar flexion and side flexion (cm), tragus-to-wall and intermalleolar distance (cm), and cervical rotation (degrees). Final scores of the BASMI range from 0 "no mobility limitation" to 10 "severe limitation".

The Ankylosing Spondylitis Quality of Life Questionnaire (ASQoL) 30 will be used to determine health-related quality of life

The ASQoL is valid, feasible and reliable. Total score range between 0 and 18, with higher scores indicating poorer quality of life.

A PeliKine compact enzyme-linked immunosorbent assay (ELISA) kit will be used to explore two inflammatory biomarkers

Inclusion Criteria: Participants must be aged 18 years or older and have a confirmed diagnosis of non-radiographic axSpA following the 2009 Assessment of the SpondyloArthritis International Society classification criteria Exclusion Criteria: Any systemic disease or comorbidity that may severely impair exercise capacity. A high sensitivity C-reactive protein 10-fold greater than the normal upper limit (2.87 mg/l). Any changes to medical treatment within the previous 2 months, and having an active peripheral arthritis