Bifidobacterium longum W11: an antibiotic-resistant probiotic

Abstract

Possible unwanted consequences of antibiotic use include: (a) the selection of antibiotic-resistant pathogenic bacteria; (b) increased susceptibility of the host to new infections; (c) gram-negative bacterial overgrowth; (d) diarrhoea; and (e) Clostridium difficile colonization [1]. Theoretically, except for antibiotic resistance, all these effects could be alleviated with probiotics. However, even a small delay between antibiotic administration and supplementation with probiotics severely reduces the positive impact of the probiotics as they are unable to integrate into the gut microbiota. The high sensitivity of probiotics to antibiotics prevents stable colonization of the gut, thus ensuring only non-significant and transient effects. However, the use of antibiotic-resistant bacteria could be beneficial. Of course, for safety reasons, this resistance must not be transferable and must not be located in plasmid DNA as probiotics could otherwise be responsible for dangerous horizontal gene transfer (Fig. 1) to pathogens [2]. Antibiotic-resistant probiotics sound very attractive, even tempting pharmaceutical companies to falsely claim some probiotic strains have antibiotic-resistant properties.