The present invention relates to a use of an active substance selected from nicotinic acid； nicotinamide； tryptophan； nicotinic acid esters； nicotinamide adenine dinucleotide (NAD)； nicotinamide adenine dinucleotide phosphate (NADP)； an intermediate in the biosynthesis of NAD or NADP selected from the group consisting of N-formylkynurenine, L-kynurenine, 3-hydroxy-L-kynurenine, 3-hydroxyanthranilate, 2-amino-3-carboxymuconate semialdehyde, quinolinate, and beta-nicotinate D-ribonucleotide； a tryptophan dipeptide； or a combination thereof for the manufacture of a pharmaceutical composition for positively influencing the intestinal microbiota, wherein the pharmaceutical composition is adapted or formulated for release of the active substance for topical efficacy in the terminal ileum, the colon or both.
