Compositions comprising bacterial strains

Abstract

The invention provides a composition comprising a bacterial strain of the genus Megasphaera, for use in stimulating the immune system in subject.

1 .- 28 . (canceled) 
     
     
         29 . A method of stimulating an immune system in a subject in need thereof, the method comprising administering to said subject a pharmaceutical composition comprising a therapeutically effective amount of a bacteria strain of the genus  Megasphaera , wherein said bacteria strain comprises a 16S rRNA gene sequence that has at least 95% sequence identity to the polynucleotide sequence of SEQ ID NO: 1,
 wherein said subject has (i) reduced immune response or (ii) a disease or condition associated with reduced immune response, wherein said administering is effective to increase immune response in said subject compared to prior to said administering, thereby stimulating said immune system.   
     
     
         30 . The method of  claim 29 , wherein said administering selectively decreases the number and/or percentage of regulatory T (Treg) cells in a cell population in said subject. 
     
     
         31 . The method of  claim 30 , wherein said cell population comprises peripheral blood mononuclear cells (PBMCs). 
     
     
         32 . The method of  claim 29 , wherein said administering enhances secretion of one or more cytokines. 
     
     
         33 . The method of  claim 32 , wherein said one or more cytokines comprise IL-1β, TNF-α, MIP-3α, IL-23, IL-8, or IL-6. 
     
     
         34 . The method of  claim 29 , wherein said therapeutically effective amount of said bacteria strain comprises at least about 1×10 3  colony forming units per gram (CFU/g) of said bacteria strain with respect to the total weight of said pharmaceutical composition. 
     
     
         35 . The method of  claim 29 , wherein said therapeutically effective amount of said bacteria strain comprises from about 1×10 3  to about 1×10 11  colony forming units per gram (CFU/g) of said bacteria strain with respect to the total weight of said pharmaceutical composition. 
     
     
         36 . The method of  claim 29 , wherein said pharmaceutical composition is formulated for oral, rectal, nasal, buccal, sublingual, or subcutaneous administration. 
     
     
         37 . The method of  claim 29 , wherein said bacterial strain is lyophilized. 
     
     
         38 . The method of  claim 29 , wherein said pharmaceutical composition is formulated for delivery to an intestine of said subject. 
     
     
         39 . The method of  claim 29 , wherein said bacteria strain is capable of at least partially colonizing an intestine of said subject. 
     
     
         40 . The method of  claim 29 , wherein said pharmaceutical composition is encapsulated. 
     
     
         41 . The method of  claim 29 , wherein said pharmaceutical composition is formulated in a form of tablet, capsule, or powder. 
     
     
         42 . The method of  claim 29 , wherein said at least 95% sequence identity is determined by a Smith-Waterman homology search algorithm using an affine gap search with a gap open penalty of 12 and a gap extension penalty of 2. 
     
     
         43 . The method of  claim 29 , wherein said bacteria strain comprises a 16S rRNA gene sequence that has at least 98% sequence identity to the polynucleotide sequence of SEQ ID NO: 1. 
     
     
         44 . The method of  claim 29 , wherein said bacteria strain comprises a 16S rRNA gene sequence that has at least 99% sequence identity to the polynucleotide sequence of SEQ ID NO: 1 
     
     
         45 . The method of  claim 29 , wherein said bacteria strain comprises a 16S rRNA gene sequence that is the polynucleotide sequence of SEQ ID NO: 1, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, or SEQ ID NO: 12. 
     
     
         46 . The method of  claim 29 , wherein said bacterial strain is the strain deposited under accession number NCIMB 42787, NCIMB 43385, NCIMB 43386, NCIMB 43387, NCIMB 43388, or NCIMB 43389. 
     
     
         47 . The method of  claim 29 , wherein said bacterial strain is of the species  Megasphaera massiliensis.    
     
     
         48 . The method of  claim 29 , wherein said pharmaceutical composition further comprises a pharmaceutically acceptable excipient, carrier, or diluent.