An apparatus and method for containing bacteria in an infant bottle that prevents unswallowed formula from returning to the unused formula in the bottle. The apparatus includes a plurality of one-way valves positioned across a containment chamber and all located between the bottle opening and the nipple. The plurality of one-way valves allows uncontaminated formula to flow out of the bottle portion during suction on the nipple. However, once suction is removed and if formula that has come into contact with the infant makes its way back into the nipple, the plurality of one-way valves close blocking the return path to the bottle portion. Should any contaminated formula makes its way through one of the one-way valves, the contaminated fluid is then trapped within the containment chamber and the remaining one-way valve is closed when suction is removed. Gaskets in and beneath the containment chamber form further sealing means.