IFNB1 and myeloid sarcoma: There were inconsistent results from the studies analyzing the relationships between risk of MS and use of antibiotics due to infections.147,148 Two small trials showed a positive effect of doxycycline (combined with IFN-β) or minocycline on clinical and radiological indices of MS activity, but the composition of gut microbiota was not taken into account.149,150 Despite some promising results, adverse effects of long-term treatment with antibiotics (including growth of opportunistic and resistant pathogens) are a significant barrier to use of these interventions in pwMS.