ðɪs θˈiəɹi wʌz dɪvˈɛləpt fɹʌm hɪz məlˈɛkjʊlɚ ænd dʒɪnˈɛɾɪk wˈɜːk ˌɔn ɡlˈuːkjʊɹɹˌɑːnaɪd mətˈæbəlˌɪzəm baɪ vˈɜːɾɪbɹˌeɪɾɐsˈoʊsɪˌeɪɾᵻd mˈaɪkɹoʊbz, ɪŋklˈuːdɪŋ ðə ɹˈoʊl ʌv ɡlˈuːkjʊɹɹˌɑːnɪdˌeɪsᵻz, sˈʌlfɐtˌeɪsᵻz ænd ˈʌðɚɹ ˈɛnzaɪmz ɪn mˈɑːdʒuːlˌeɪɾɪŋ ænd ɪfˈɛktɪŋ ˌɛntɚɹˌoʊhɪpˈæɾɪk sˌɜːkjʊlˈeɪʃən ʌv stˈɛɹɔɪd hˈoːɹmoʊnz.
This theory was developed from his molecular and genetic work on glucuronide metabolism by vertebrate-associated microbes, including the role of glucuronidases, sulfatases and other enzymes in modulating and effecting enterohepatic circulation of steroid hormones.