The characteristics of lactic acid bacteria isolated from fermented food as potential probiotics

This study aims to determine the characteristics of Lactobacillus acidophilus and Lactobacillus reuteri from fermented soursop fruit juice and cow's milk, respectively as probiotic candidate based on exposure to pH, bile salts, pathogenic bacteria, and antibiotics.

In vitro studies were conducted to examine the resistance of Lactobacillus acidophilus and Lactobacillus reuteri in pH 2, 2.5, 3.2, and 7.2, resistance to bile salts, resistance to pathogenic bacteria (Escherichia coli, Staphylococcus aureus and Enterococcus faecalis) and antituberculosis antibiotics.

Viability of Lactobacillus acidophilus and Lactobacillus reuteri isolates remained unchanged (6.3 × 10⁷ CFU/mL and 5.03 × 10⁷ CFU/mL) at various acidic pH, and had a low survival rate in Ox gall 0.3% (bile salts). These isolates also showed antibacterial properties against pathogens in the gastrointestinal tract. Both of these bacteria are quite safe to be used together with ofloxacin, linezolid, moxifloxacin, and levofloxacin, antibiotic for tuberculosis therapy.

The results showed that Lactobacillus acidophilus and Lactobacillus reuteri from fermented soursop fruit juice and cow's milk respectively fulfilled the characteristics of probiotic and could potentially be used as adjunct therapy in tuberculosis drug-resistance.