Probiotic Properties of Lactic Acid Bacteria (LAB) Isolated From Kunu-zaki Produced from Composite Grains

Abstract

Probiotic properties of lactic acid bacteria (LAB) isolated from nine kunu zaki ready- to- drink beverages were investigated in vitro using exposure to pH and bile concentration at gastrointestinal conditions, antimicrobial activity and adhesion to intestinal epithelial cells. In vivo investigations assessed the liver function, haematology and histopathology of apparently healthy albino rats in feeding trials. The beverages were produced using Sorghum bicolor (Sorghum), Pennisetum americanaum (Pearl Millet) and Digitaria exilis (Fonio) cereal grains in composite and non-composite proportions. Twenty- three of the lactic acid bacteria which survived the stressful simulated human gastrointestinal conditions, inhibited test reference pathogens and exhibited significant in vitro adhesion capacities, were identified to species level by the API 50CH test kit. Sorghum-millet kunu zaki contained the highest percentage (40%) of probiotic lactic acid bacteria. All isolates inhibited test reference human pathogens with inhibition zones of ranging between 11 and 29mm. Percentage in vitro adhesions to guinea pig intestinal epithelial cells ranged between 40 and 100% for all the isolates. Five of the isolates which demonstrated significant probiotic properties were selected for in vivo assessment. Liver function enzymes alanine aminotransferase (ALT) reduced significantly from 75.3 I.U/L in control rats to ranges from 33-66.6 I.U/L in all probiotic lactic acid bacteria fed rats. Level of liver enzyme aspartate aminotransferase (AST) also reduced significantly (p<0.05) in rats that were dosed with L.plantarum112 isolated from sorghum-millet kunu zaki compared to the control rats which were not fed with the probiotics. Erythrocyte Sedimentation Rate (ESR) which increased in the control rats was reversed in all LAB fed rats. Packed cell volume (PCV) and Haemoglobin concentration (Hb) increased significantly in all lactic acid bacteria dosed rats compared to the control (p<0.05). Blood cholesterol significantly reduced from 113.3 mg/dl in control rats to ranges from 51-68.3mg/dl in all LAB fed rats (p<0.05). Histopathological studies revealed well preserved liver, heart and intestine in all probiotic LAB dosed Wistar albino rats. Panelists scored the acha-sorghum composite germinated kunu-zaki drink highest in overall preference. The fermenting LAB in ready-to-drink kunu-zaki produced from composite grains have antimicrobial, anti-hypercholesterol and haematinic properties which may potentiate the good health of drinkers. Composite Sorghum and Millet kunu-zaki could therefore have very good applications as a natural health beneficial drink.