Inactivation of Lactobacillus rhamnosus GG by fixation modifies its probiotic properties

Area of Science:

• Microbiology
• Cell Biology
• Biochemistry

Background:

• Probiotics offer health benefits but pose risks to immunocompromised individuals.
• Inactivation of probiotics is necessary in certain clinical situations.
• Understanding how inactivation affects probiotic properties is crucial.

Purpose of the Study:

• To evaluate the impact of different fixation methods on Lactobacillus rhamnosus GG.
• To assess changes in biological properties relevant to probiotic function.
• To investigate the interaction of fixed probiotics with host enterocytes.

Main Methods:

• Lactobacillus rhamnosus GG cells were fixed using ethanol, 2-propanol, glutaraldehyde, paraformaldehyde, and heat treatment.
• Enzyme activities (alkaline phosphatase, peroxidase, β-galactosidase) were measured.
• Bacterial cell hydrophobicity and adhesion capacity were assessed.
• Gene expression changes in enterocytes exposed to fixed cells were analyzed.

Main Results:

• Fixation significantly decreased enzyme activities.
• Most fixation methods reduced hydrophobicity and increased adhesion.
• Fixed cells elicited different gene expression patterns in enterocytes compared to live cells.
• Some inactivation methods preserved partial enzymatic activity.

Conclusions:

• Probiotic inactivation methods can modify biological properties like adhesion.
• Enterocyte response to fixed probiotics differs from that of live bacteria.
• Inactivation offers a way to maintain and modify key probiotic characteristics.