Table 1

Data collected at study visit

Study period	Screening	Enrolment baseline	Intervention		Follow-up
Weeks	−2	0	2	16	24
Informed consent	X
Serum antitransglutaminase	X
Eligibility criteria		X
Randomisation		X
Assessments
Sociodemographic characteristics		X
Medical history		X
Concomitant medications*		X		X	X
Physical examination		X		X	X
X-ray of the pelvis (if not available)		X
Primary outcome: Quality of life (ASAS-HI)		X		X	X
Patient-reported outcome†		X		X	X
Dietician consultation		X	X	X	X
Laboratory samples		X		X
Faecal samples: gut microbiota analysis		X		X

*Including disease modifying antirheumatic drugs, non-steroidal anti-inflammatory drug, painkillers, corticoids.
†Including Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index, Hospital Anxiety and Depression Scale, Fibromyalgia Rapid Screening Tool, Functional Assessment of Chronic Illness Therapy and a digestive discomfort questionnaire.
ASAS-HI, Assessment of SpondyloArthritis International Society—Health Index.