Bacteria Use Host's Own Chemicals to Fuel Deadly Gut Infection

1 min read

In the dense and nutrient-rich environment of the large intestine, enteric pathogens must employ their virulence factors to establish distinct niches that facilitate colonization and disease. The mechanisms underlying how anaerobic pathogens construct these nutrient niches remain poorly understood.

Enterotoxigenic Bacteroides fragilis is a classically anaerobic bacterium implicated in inflammation-associated diseases, such as colitis and colorectal cancer. To colonize their host and cause disease, ETBF uses its virulence factor, Bacteroides fragilis toxin (BFT), to manipulate the environment.

By inducing changes in colonic epithelial signaling and the bile acid recycling pathway, BFT triggers a metabolic shift in the epithelium from oxidative phosphorylation to glycolysis. This shift increases local concentrations of lactate and oxygen, creating an oxidative niche that supports ETBF's growth.

This unexpected strategy reveals how a classically anaerobic pathogen leverages host metabolic remodeling to generate an oxidative niche in the inflamed gut. By understanding this mechanism, we gain insight into the complex interactions between pathogens and their hosts, highlighting the intricate relationships within the human microbiome.

1 min read

In the dense landscape of the large intestine, a tiny invader sets up shop. To survive and thrive, enteric pathogens like ETBF must claim their own territory within this crowded environment. For years, scientists have been trying to understand how these microbes construct their nutrient niches, but the process remains shrouded in mystery.

One pathogen that's particularly adept at exploiting its surroundings is ETBF. This bacterium has a potent tool at its disposal: BFT. By using BFT, ETBF can manipulate the signals sent by the colon's epithelial cells and even hijack the way the body recycles bile acids. As this process unfolds, the epithelium undergoes a surprising transformation, shifting from relying on oxidative phosphorylation to glycolysis.

The result of this metabolic shift is a localized environment that supports ETBF's own oxidative metabolism. The concentration of lactate and oxygen increases, creating an ideal niche for ETBF to grow and multiply. This finding offers a glimpse into the clever strategies employed by enteric pathogens like ETBF, which can adapt their host's very metabolism to fuel their own survival.

This discovery matters because it sheds light on how certain pathogens exploit the human body's metabolic processes to their advantage. By understanding this mechanism, researchers can gain valuable insights into the biology of disease and develop more effective strategies for prevention and treatment.

1 min read

In the dark corners of our bodies, where oxygen is scarce, a tiny invader has found a way to thrive. The enteric pathogen Bacteroides fragilis has developed a clever trick to colonize its host and cause disease. It uses a toxin called BFT to rewire the host's metabolism, creating a new way for it to grow in an environment where oxygen is plentiful.

Imagine the gut as a crowded city, with colonic epithelial cells like skyscrapers that line the walls of the intestines. The anaerobic pathogen BFT infiltrates this city and manipulates the signals between the cells, turning on a different way for them to make energy - glycolysis, which relies on lactate and oxygen. This new metabolic pathway creates an unexpected oasis in the midst of inflammation, where the pathogen can flourish and spread its influence.