The invention provides a Probiotic microcapsule and a preparation method thereof, relating to the technical field of Probiotic products. The method includes the following steps: (a) preparing a capsule core containing Probiotics: mixing the capsule core materials including Probiotic powder, microcrystalline cellulose and starch, then adding a hydroxypropyl methylcellulose solution thereinto, while mixing evenly, making the obtained mixture materials into spherical particulate capsule cores by the extrusion spherization method; (b) coating by atomization: coating the microcapsule cores with a coating material solution in a single layer or multiple layers by atomization, getting core-shell microcapsules. The Probiotic microcapsules prepared by the present invention have a large encapsulation, uniform microcapsule particles, controllable particle size, storage-resistance, targetability to intestinal tracts, resistance to gastric acids and high temperature stability.

Provided herein, inter alia, are compositions of organic acid-producing microorganisms and methods of making and using the same to inhibit pathogenic bacterial populations in the gastrointestinal tracts of an animal and additionally promote improvement of one or more metrics in an animal, such as increased bodyweight gain, decreased feed conversion ratio (FCR), improved gut barrier integrity, reduced mortality, reduced pathogen infection, and reduced pathogen shedding in feces.