Compositions of microbiota and methods related thereto

Methods and compositions are provided for treating weight related conditions and metabolic disorders by altering microbiota in a subject. One aspect provides methods and compositions to alter microbiota in a subject by administering to the subject a composition that includes a substantially purified microbiota from phyla such as Bacteroidetes, Proteobacteria, Firmicutes and Verrucomicrobia or orders such as Bacteroidales, Verrucomicrobiales, Clostridiales and Enterobacteriales or genera such as Alistipes, Clostridium, Escherichia , and Akkermansia . Another aspect includes a pharmaceutical composition for altering microbiota that includes a therapeutically effective amount of substantially purified microbiota and a pharmaceutically acceptable carrier. Yet another aspect includes methods for treating a disorder, such as obesity, in a subject in need of such treatment by changing relative abundance of microbiota in a gastrointestinal tract of the subject without or in addition to a surgical procedure.