The present invention relates to a composition comprising one or more minerals selected from the group consisting of selenium, molybdenum or tungsten, which is carried out galenically or chemically in a way that the mineral or minerals are released completely or in part, just before, during or shortly after arrival at the large intestine, and their use in the manufacture of a medicament for administering to a mammal for the prevention or reduction of gas formation in the colon thus conditioned abdominal complaints, particularly bloatings, meteorism or abdominal cramps. Furthermore, the invention relates to a procedure for the isolation of acetogenic and butyrogenic bacterial strains that are suitable for therapeutic purposes outlined above.