['Secretory otitis media (SOM) is characterised by persistent fluid in the middle ear cavity, but the cause is unknown. We investigated the clinical, bacteriological and immunological effects of treatment with probiotic bacteria on SOM.', 'In this double-blind pilot/preliminary study, 60 children with long-standing SOM (median 6 months) who were scheduled for insertion of tympanostomy tubes were randomised to nasal spray treatment with Streptococcus sanguinis, Lactobacillus rhamnosus or placebo for 10 days before surgery. Clinical evaluation was carried out after 10 days of treatment. Middle ear fluid (MEF) was collected during surgery for quantification of cytokines and detection of bacteria by culture and polymerase chain reaction (PCR). Nasopharyngeal swabs were obtained before treatment and at surgery.', 'Complete or significant clinical recovery occurred in 7/19 patients treated with S sanguinis compared to 1/17 patients in the placebo group (p<0.05). In the L rhamnosus treatment group, 3/18 patients were cured or much better (p = 0.60 compared with placebo). Spray treatment did not alter the composition of the nasopharyngeal flora or the cytokine pattern observed in the nasopharynx or MEF, except for a higher level of IL-8 found in the nasopharynx of L rhamnosus treated children.'] Does spray bacteriotherapy decrease middle ear fluid in children with secretory otitis media?