Functional Properties of Heat-Killed Lactic Acid Bacteria Isolated from Vietnamese Feces

Area of Science:

• Microbiology and Food Science
• Immunology and Gut Health
• Biotechnology and Functional Ingredients

Background:

• Lactic acid bacteria (LAB) are known for their health benefits.
• Heat treatment is a common method for inactivating microorganisms.
• Understanding the functional properties of inactivated LAB is crucial for developing functional foods.

Purpose of the Study:

• To evaluate the functional properties (antioxidant, immunomodulatory) of heat-treated LAB from Vietnamese feces.
• To determine optimal heat-treatment conditions for LAB inactivation.
• To assess the potential of heat-treated Lactiplantibacillus plantarum V10 as a functional ingredient.

Main Methods:

• Isolation and selection of LAB strains based on acid/bile resistance and enzymatic activities.
• Application of various heat treatments (65°C for 60 min, 95°C for 10 min).
• Assays for antioxidant activity, lipoteichoic acid (LTA) content, immunomodulatory effects (nitric oxide inhibition, cytokine expression), and enzyme resistance.

Main Results:

• Heat treatment inactivated LAB, with 65°C for 60 min being optimal.
• Heat-treated Lactiplantibacillus plantarum V10 demonstrated significant antioxidant and anti-inflammatory activities.
• HT L. plantarum V10 showed high LTA content and resistance to digestive enzymes like pepsin and amylase.

Conclusions:

• Heat-treated Lactiplantibacillus plantarum V10 is a viable functional ingredient with enhanced antioxidant and immunoregulatory functions.
• The optimal heat treatment (65°C for 60 min) preserves beneficial properties.
• This strain holds potential for applications in functional foods, particularly for the Southeast Asian market.