Fate of Bacillus thuringiensis bacteria, applied for biological pest control, in the gastro-intestinal tract.

Bacillus thuringiensis (Bt), which forms specific insecticidal toxins during sporulation, constitutes the active organism in many products used for biological control of insects. Bt is therefore often present on treated fruits and vegetables sold for consumption.

The aim of the project is to assess specific putative risks associated with ingestion of Bt spores. The project seeks to answer the following questions: (i) Do Bt spores germinate in the intestinal tract, (ii) does heat treatment prior to ingestion induce the germination, (iii) do they influence the composition of the intestinal microflora, (iv) do they produce enterotoxins in the gut, and (v) are they capable of exchanging genetic material with the indigenous gut microorganisms?