Salmonella colonization of fowl may be effectively controlled or inhibited using a defined composition of anaerobic bacteria (i.e., probiotic). the probiotic includes a first culture of substantially pure anaerobic bacteria effective for fermenting lactic acid to produce volatile organic acids including acetic, propionic and/or butyric acids. A second culture of at least one anaerobic bacteria effective for fermenting carbonhydrates to produce lactic acid is also employed in combination with the above-mentioned first cuture. Suitable organisms for use in this first culture include bacteria of the genera Veillonella, Megasphaera, and mixtures thereof. These first and second cultures are administered to the subject fowl in amounts effective for inhibiting Salmonella colonization thereof. In one embodiment, the above-mentioned probiotic may be combined with a conventional feed, providing a novel feed product which may be orally ingested by the fowl.