Lactobacillus and Bifidobacterium species do not secrete protease that cleaves the MUC2 mucin which organises the colon mucus.

• The colon epithelium is covered by two layers of mucus built around the MUC2 mucin. An inner dense and attached mucus layer does not allow bacteria to penetrate, thus keeping the epithelial cell surface free from bacteria. An outer loose mucus layer is the habitat for the commensal bacterial microbiota. The inner mucus layer is renewed from the epithelial side and gets converted into the outer layer due to proteolytic cleavages by host proteases. We have now analysed if potential probiotic bacteria, namely Lactobacillus brevis, Lactobacillus plantarum, Lactobacillus bulgaricus and Bifidobacterium lactis, can secrete protease that cleaves the MUC2 mucin. We found that none of the potential probiotic bacteria Lactobacillus and Bifidobacterium could cleave the MUC2 core protein in the form of recombinant MUC2 N and C-termini although they secreted active proteases. This was in contrast to crude mixtures of oral and faecal bacteria that cleaved the MUC2 mucin. This observation further supports the view that these potential probiotic bacteria are of no harm to the host, as these bacteria cannot disrupt the mucin organised mucus as long as they are covered by glycans.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Mikrobiologi inom det medicinska området (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Microbiology in the medical area (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Fysiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Physiology (hsv//eng)

Keyword

Animals

Bacterial Proteins

genetics

metabolism

Bifidobacterium

enzymology

genetics

isolation & purification

Cell Line

Colon

metabolism

microbiology

Extracellular Space

enzymology

genetics

Humans

Intestinal Mucosa

metabolism

microbiology

Lactobacillus

enzymology

genetics

isolation & purification

Mice

Mucin-2

chemistry

genetics

metabolism

Peptide Hydrolases

genetics

metabolism

Protein Processing

Post-Translational

Protein Structure

Tertiary

proteolytic

large intestine

ulcerative colitis

inflammation

Publication and Content Type

ref (subject category)

art (subject category)