Modulation of the gastrointestinal immune environment by chitosan microparticles loaded with Mycobacterium bovis BCG in a Cavia porcellus model in vivo, leading to reduced experimental H. pylori gastric colonization (dataset)

Abstract

Mycobacterium bovis BCG bacilli potentially may train immune cells against microbial pathogens. The increasing antibiotic resistance of the gastric pathogen Helicobacter pylori (Hp) prompts a search for new therapeutics. This study aimed to assess the properties of MPs loaded with M. bovis BCG against Hp infection in Cavia porcellus. Animals were inoculated orally only with chitosan microparticles (MPs) modified with N-Acetyl-D-Glucosamine (Glc-NAc) (G MPs) or with Pluronic F127 (P MPs)-loaded with M. bovis BCG, with both types of MPs, with Hp alone or first with tested MPs and then with Hp. Oral inoculation of animals with studied MPs resulted in release of mycobacteria in the stomach or the gut, which was followed by the reduction of Hp colonization due to diminishing of mucin production and Hp attachment as well as infiltration of T lymphocytes, including CD4+, CD8+, and Foxp3+ regulatory cells, memory lymphocytes and eosinophils, which all could control Hp infection. The anti-Hp effect of the studied MPs may partly be a result of chitosan's antibacterial and immunomodulatory properties. In conclusion, chitosan MPs (G and P variants) loaded with M. bovis BCG are candidates for a new anti-Hp formula, based on the immunomodulatory and antibacterial properties of mycobacteria and chitosan.