A composition comprising viable, live bacteria strains (i), intermediate metabolites, (ii) end metabolites (iii) and a dispersing medium (iv), characterized in that said bacteria strains (i) being selected from: ▪ strains consuming sugars, fibers, and resistant starch, producing formate and acetate, and being selected from the genera Ruminococcus, Dorea and Eubacterium; ▪ strains consuming sugars, starch and acetate, producing formate and butyrate, and being selected from the genera Faecalibacterium, Roseburia and Anaerostipes; ▪ strains consuming sugars and oxygen, producing lactate, and being selected from the genera Lactobacillus, Streptococcus, Escherichia, Lactococcus and Enterococcus; ▪ strains consuming sugars, starch, and carbon dioxide, producing lactate, formate and acetate, and being selected from the genus Bifidobacterium; ▪ strains consuming lactate or proteins, producing propionate and acetate, and being selected from the genera Clostridium, Propionibacterium, Veillonella and Megasphaera; ▪ strains consuming lactate and starch, producing acetate, butyrate and hydrogen, and being selected from the genera Eubacterium, Clostridium and Anaerostipes; ▪ strains consuming sugar, starch, formate producing lactate, formate and acetate, and being selected from the genus Collinsella; ▪ strains consuming succinate, producing propionate and acetate, and being selected from the genera Phascolarctobacterium and Dialister; and ▪ strains consuming sugars, fibers, formate and hydrogen, producing acetate and butyrate and being selected from the genera Acetobacterium, Blautia, Clostridium, Moorella, Methanobrevibacter, Methanomassiliicoccus and Sporomusa; wherein said bacteria strains are in each case identified through classification of the full 16S gene with assignment for the different taxonomic levels Phylum: 75%, Class: 78.5%, Order: 82%, Family: 86.5%, Genus: 94.5%, sequence similarity; wherein bacteria strains (i) of all nine groups to are present; wherein said bacteria strains (i) being present in a total concentration of over 10 9 bacteria per ml composition; and wherein said bacteria strains (i) having a viability of over 50%, preferably over 70%, as determined by flow cytometry; and said intermediate metabolites (ii) being selected from: ▪ succinate in an amount of less than 5 mM, and ▪ formate in an amount of less than 5 mM, and ▪ lactate in an amount of less than 5 mM; and said end metabolites (iii) being selected from ▪ acetate in an amount of at least 10 mM, and ▪ propionate in an amount of at least 2 mM, and ▪ butyrate in an amount of at least 2 mM; and said dispersing medium (iv) preferably being selected from: ▪ culture media, or ▪ cryoprotecting media, or ▪ aqueous gels, or ▪ polymeric supports. ▪ strains consuming sugars, fibers, and resistant starch, producing formate and acetate, and being selected from the genera Ruminococcus, Dorea and Eubacterium; ▪ strains consuming sugars, starch and acetate, producing formate and butyrate, and being selected from the genera Faecalibacterium, Roseburia and Anaerostipes; ▪ strains consuming sugars and oxygen, producing lactate, and being selected from the genera Lactobacillus, Streptococcus, Escherichia, Lactococcus and Enterococcus; ▪ strains consuming sugars, starch, and carbon dioxide, producing lactate, formate and acetate, and being selected from the genus Bifidobacterium; ▪ strains consuming lactate or proteins, producing propionate and acetate, and being selected from the genera Clostridium, Propionibacterium, Veillonella and Megasphaera; ▪ strains consuming lactate and starch, producing acetate, butyrate and hydrogen, and being selected from the genera Eubacterium, Clostridium and Anaerostipes; ▪ strains consuming sugar, starch, formate producing lactate, formate and acetate, and being selected from the genus Collinsella; ▪ strains consuming succinate, producing propionate and acetate, and being selected from the genera Phascolarctobacterium and Dialister; and ▪ strains consuming sugars, fibers, formate and hydrogen, producing acetate and butyrate and being selected from the genera Acetobacterium, Blautia, Clostridium, Moorella, Methanobrevibacter, Methanomassiliicoccus and Sporomusa; wherein said bacteria strains are in each case identified through classification of the full 16S gene with assignment for the different taxonomic levels Phylum: 75%, Class: 78.5%, Order: 82%, Family: 86.5%, Genus: 94.5%, sequence similarity; wherein bacteria strains (i) of all nine groups to are present; wherein said bacteria strains (i) being present in a total concentration of over 10 9 bacteria per ml composition; and wherein said bacteria strains (i) having a viability of over 50%, preferably over 70%, as determined by flow cytometry; and ▪ succinate in an amount of less than 5 mM, and ▪ formate in an amount of less than 5 mM, and ▪ lactate in an amount of less than 5 mM; and ▪ acetate in an amount of at least 10 mM, and ▪ propionate in an amount of at least 2 mM, and ▪ butyrate in an amount of at least 2 mM; and ▪ culture media, or ▪ cryoprotecting media, or ▪ aqueous gels, or ▪ polymeric supports.