In vitro evaluation of the anti-pathogenic activity of Okoubaka aubrevillei on the human gastrointestinal tract.

BACKGROUND

is used in traditional West African medicine and in homeopathy for treatment and prevention of several gastrointestinal problems. The aim of this study was to evaluate the effect of repeated doses of two products (10 % ethanolic tincture, mother tincture (MT); 3 decimal potency, 3X) on the microbial activity of physiological human colon microbiota using a Simulator of the Human Intestinal Microbial Ecosystem (SHIME) and to investigate any preventive effect against infections with diarrhea-causing pathogens.

METHODS

Upon inoculation with fecal microbiota from a healthy donor, 4 parallel proximal colon compartments of the SHIME were treated either with MT, 3X, ethanol control or blank control for 7 days. Using the -adapted microbial community from SHIME, 48 h challenge tests were performed with enterotoxigenic (ETEC) and in 4 different doses (10-10 colony forming units as typical infectious doses). Pathogen concentrations, short-chain fatty acids (SCFAs) and branched SCFA production were measured in triplicate at 0, 24 and 48 h.

RESULTS

In the challenge tests, both products were able to restrict the colonization of ETEC and at 3 of the 4 pathogen doses (except the highest doses), with a stronger anti-pathogenic effect for MT, which included a reduction of 2.0 log-units of ETEC (p < 0.0001) and 1.1 log-units of (p < 0.0001). Total SCFA levels remained unaffected, but butyrate increased during the first 24 h (p < 0.0001 for ETEC), accompanied by decreased acetate production.

CONCLUSION

We observed a systemic activating effect of on intestinal microbiome resistance, which resulted in an anti-pathogenic effect, especially against ETEC. We hypothesize that the mode of action is also based on systemic regulative effects.