Improve understanding of bifidobacteria on the molecular level.

The complex microbial communities that inhabit the gastrointestinal tract play a vital role in maintaining gut health and homeostasis. But we do not completely understand the mechanisms involved in their activity.

Scientists at the U.K.'s Institute of Food Research are using molecular techniques to improve their understanding of these processes. The institute's focus on the biology of lactic acid bacteria and bifidobacteria is relevant to food fermentation and probiotics.

Researchers want to increase their knowledge of the molecular genetics of lactic acid bacteria. They have completed a collaborative project to determine the genome sequence of the protype strain Lactococcus lactis MG1363, which was developed at the institute. Investigators also plan to develop functional genomics with an initial focus on metabolism, especially in the context of metabolic engineering.

On one front, researchers are interested in learning more about commensal bacteria--normal bacteria which make up part of the mucosal flora (the mouth, the nose, the lungs, and the gastrointestinal and urogenital tracts of humans) but which do not cause disease. The institute is also extending its work to include Lactobacillus strains with demonstrated ability to compete with pathogens, and Bifidobacterium species which have been associated with positive health in the gastrointestinal tract.

One of the most challenging aspects of microbiology involves the behavior of individual species in the context of their natural environment. This will be a focus of future work on the microflora of the gastrointestinal tract. Researchers will explore the interactions and communication processes that take place between bacterial species in the context of the complex microflora, and they will probe the two-way communications that take place with the host.

A focus will be the impact of bacteria on the gut epithelium and the mucosal immune system and the impact of stress-related hormones, such as noradrenaline, on the bacterial community. In particular, scientists will examine any cross-talk between GI tract bacteria and the host immune system.

This effort should lead to: new insights into complex GI tract microbial communities, including their molecular profiles and communication within and between these communities and the host; the application of functional genomics to selected species of commensal lactic acid bacteria, including bifidobacteria; a predictive approach to metabolic engineering; biologically based antimicrobials; and smart probiotics that eliminate pathogens, alleviate inflammatory disease and deliver vaccine antigens.

Further information. Mike Gasson, Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, U.K.; phone: [phone]; fax: [phone]; email: [e-mail].