Nondigestible Oligosaccharides Enhance Bacterial Colonization Resistance against Clostridium difficile In Vitro

Abstract

Clostridium difficile is the principal etiologic agent of pseudomembranous colitis and is a major cause of nosocomial antibiotic-associated diarrhea. A limited degree of success in controlling C. difficile infection has been achieved by using probiotics; however, prebiotics can also be used to change bacterial community structure and metabolism in the large gut, although the effects of these carbohydrates on suppression of clostridial pathogens have not been well characterized. The aims of this study were to investigate the bifidogenicity of three nondigestible oligosaccharide (NDO) preparations in normal and antibiotic-treated fecal microbiotas in vitro and their abilities to increase barrier resistance against colonization by C. difficile by using cultural and molecular techniques. Fecal cultures from three healthy volunteers were challenged with a toxigenic strain of C. difficile, and molecular probes were used to monitor growth of the pathogen, together with growth of bifidobacterial and bacteroides populations, over a time course. Evidence of colonization resistance was assessed by determining viable bacterial counts, short-chain fatty acid formation, and cytotoxic activity. Chemostat studies were then performed to determine whether there was a direct correlation between bifidobacteria and C. difficile suppression. NDO were shown to stimulate bifidobacterial growth, and there were concomitant reductions in C. difficile populations. However, in the presence of clindamycin, activity against bifidobacteria was augmented in the presence of NDO, resulting in a further loss of colonization resistance. In the absence of clindamycin, NDO enhanced colonization resistance against C. difficile, although this could not be attributed to bifidobacterium-induced inhibitory phenomena.

Prebiotics in Chronic Intestinal Inflammation

“…Hopkins and others showed that FOS, GOS, and inulin inhibit intestinal colonization of Clostridium difficile in vitro. 43,44 Prebiotic oligosaccharides induce antimicrobial effects by selectively stimulating the growth of intestinal protective bacteria. Such intestinal organisms can then secrete antimicrobial compounds and compete with disease-inducing bacteria for intestinal epithelial receptors, reducing their ability to colonize and affect the host, as mentioned above.…”

Bacteroides: the Good, the Bad, and the Nitty-Gritty

“…Recent studies suggest that Bacteroides, and possibly specific species of Bacteroides, have a role in preventing infection with Clostridium difficile (122,123). As detailed above, the development of the immune response that limits entry and proliferation of potential pathogens is profoundly dependent upon B. fragilis.…”

Probióticos e prebióticos na atenção primária ao câncer de cólon

“…Estudos in vitro e in vivo têm demonstrado que o ecossistema bacteriano intestinal normal representa barreira extremamente efetiva, em oposição a microorganismos patogênicos e oportunistas, através do equilíbrio entre as espécies de bactérias residentes (16,28) . Assim, situações de desequilíbrio entre espécies podem representar potencial ameaça para o surgimento de diversas doenças, associadas ou não à diminuição da defesa imunológica do hospedeiro (3) .…”