The present invention relates to a prebiotic composition comprising a galacto oligosaccharide (GOS) produced from one or more Propionibacterium bacterial strains, wherein the GOS acts as a selective growth medium for Propionibacterium bacterial strains, and wherein the GOS is substantially the same as the form produced by reverse β- galactosidase reaction for Propionibacterium bacterial strains. The present invention also relates to methods of producing GOS and related composition incorporating the GOS and is particularly useful in increasing propionate levels in colon of an individual so as to promote the growth of propionate secreting bacteria and regulate appetite.
