Abstract: The ecology and the antibacterial potential of lactic acid bacteria associated with the fermentation of cereals and cassava, during the production of ogi and fufu were reported. Whereas the concentration of the Lactic Acid Bacteria (LAB) increased in all the substrates throughout the 96h fermentation period, the total bacteria reduced by about 29.3% in fufu, 20.3 and 37.84% in the maize ogi and sorghum ogi respectively after 72 h fermentation. Thirteen strains of LAB were isolated in all with the species of Lactobacillus predominating. The LAB cells constituted between 3.63 to 43.1%, 7 to 48.5% and 3.8 to 62.6% of the total bacteria concentration in fufu, maize ogi and sorghum ogi. The cells of Leuconostoc lactis, Lactobacillus fermentum, L. casei and Pediococcus acidilacti were isolated early during fermentation and therefore regarded as the natural flora of the food substrates. Only nine of the LAB isolates exhibited inhibitory activity against the indicator organisms. The bacteriocins produced by Lactobacillus brevis and L. casei were very active against Escherichia coli, Salmonella Group B and Shigella flexneri, thus showing great potential as bio-preservative against some food- borne pathogens.