Thumb sucking or nail biting in childhood and adolescence is associated with an increased risk of Crohn's disease: results from a large case-control study.

Background: The hygiene hypothesis suggests that a reduction in microbial exposure contributes to an impaired immune response later in life and increases the incidence of immune-mediated diseases such as inflammatory bowel diseases (IBD). Thumb sucking and nail biting are two early habits that modulate the oral microbiota composition and antigen load.

Objective: We hypothesized a lower risk of Crohn's disease (CD) and ulcerative colitis (UC) in adults with prior thumb sucking and nail biting.

Immunoproteomics of Helicobacter pylori infection and relation to gastric disease.

The Gram negative bacterium Helicobacter pylori is a human pathogen which infects the gastric mucosa and causes an inflammatory process leading to gastritis, ulceration and cancer. A systematic, proteome based approach was chosen to detect candidate antigens of H. pylori for diagnosis, therapy and vaccine development and to investigate potential associations between specific immune responses and manifestations of disease.