thank you for the information, but in the recommended journal it turned out that the sample was an animal (mouse) could the 16S rNA applied on the control for human faeces / stool to find out the number of firmicutes-bacteroidetes ?
16s rRNA gene is used to identify bacterial isolates using gene sequence similarity and the source of your bacterial isolate does not really affect the RT-PCR process. I think it will still work. Perhaps you can check other published reports, too.