Oral purified bacterial extracts in chronic bronchitis and COPD: systematic review

Oral lyophilized extracts of bacteria species have been used since the early 1970s to improve symptoms and to prevent exacerbations in COPD patients. The value of these treatments, which are thought to be immunomodulating, is poorly understood. Our aim was to quantify the efficacy of oral bacteria extracts in patients with chronic bronchitis and COPD.

Systematic review of randomized trials.

Electronic databases, bibliographies, and contact with authors and manufacturers.

Randomized comparisons of oral purified bacterial (active) extracts with placebo or no treatment (control) were selected. Meta-analyses were performed using fixed and random-effects models, and the results were expressed as relative risk (RR), odds ratio (OR), number needed to treat for one to benefit (NNTB), or number needed to treat for one to be harmed (NNTH), with 95% confidence interval (CI).

Thirteen trials (1,971 patients), most of which were of low quality, tested OM-85BV (Broncho-Vaxom; OM Pharma; Geneva, Switzerland), LW-50020 (Luivac; ALTANA Pharma; Bad Homburg, Germany), or SL-04. Two trials (731 patients) had appropriate methodologies and reported on exacerbations. The RR in favor of the oral bacterial extract (active) was 0.83 (95% CI, 0.55 to 1.25), and the NNTB was 15.4 (95% CI, 5.5 to infinity; NNTH, 27.5). Five trials (591 patients) reported on observer-assessed improvement of symptoms RR in favor of active extracts was 0.57 (95% CI, 0.49 to 0.66), and the NNTB was 4 (95% CI, 2.8 to 5.4). Two trials (n = 344), reported on patient-assessed improvement (RR, 0.44; 95% CI, 0.31 to 0.61) [NNTB, 4; 95% CI, 3.0 to 5.9]. In two trials (163 patients), the average duration of an exacerbation was shorter with the active extracts (weighted mean difference, -2.7 days; 95% CI, -3.5 to -1.8). Itching or cutaneous eruptions was reported in 3.3% of patients (four trials; 802 patients) who received active extracts compared with 1.0% of control subjects (OR, 2.94 95% CI, 1.12 to 7.69) [NNTH, 50; 95% CI, 14 to 161]. Urologic problems (two trials; 671 patients) were reported in 8% of patients who received active extracts compared with 3.0% of control subjects (OR, 2.62; 95% CI, 1.35 to 5.11) [NNTH, 22; 95% CI, 10 to 61].

Oral purified bacterial extracts improve symptoms in patients with chronic bronchitis and COPD. There is not enough evidence to suggest that they prevent exacerbations. Cutaneous and urologic adverse effects are common.