To indicate direction of change , in comparison with the habitual diet the low FODMAP diet reduced total bacterial abundance and the typical Australian diet increased relative abundance for butyrate-producing Clostridium cluster XIVa ( median ratio 6.62 ; p < 0.001 ) and mucus-associated Akkermansia muciniphila ( 19.3 ; p < 0.001 ) , and reduced Ruminococcus torques .