Biofilm-associated bacterial amyloids dampen inflammation in the gut: oral treatment with curli fibres reduces the severity of hapten-induced colitis in mice.

Oral treatment with an amyloid protein found in bacterial biofilms helps to reduce inflammation in a mouse model of colitis. A research team led by Cagla Tukel from Temple University in Philadelphia, Pennsylvania, USA administered a single dose of curli—the protein secreted in the biofilms of both commensal and pathogenic bacteria—to mice with experimentally induced colitis. They observed elevated levels of interleukin-10 (IL-10), an anti-inflammatory immune molecule, and less severe symptoms of the gut disorder. The therapeutic benefit of curli was similar to that of an antibody therapy commonly used today in people with colitis. Using in vitro systems, the researchers showed that an immune receptor called TLR2 (toll-like receptor 2) recognized the curli and triggered the beneficial IL-10 response. The authors suggest that pills containing curli may hold potential for treating colitis in humans.