In this randomized double-blind clinical trial , female patients with established RA for more than 1 year , 20-80 years of age and body mass index ( BMI ) lower than 40 , who followed stable medication for 3 months prior to the supplementation , were randomly allocated to receive either one capsule containing 10 ( 8 ) colony forming units ( CFU ) of L. casei 01 , or a placebo for 8 weeks ; allocation was stratified by BMI and menopausal status .