Scientific American ran an article on this not too long ago. Yes they found that the so called bad bacteria indeed communicates with the body to signal hormones. Come to find out all this time we have been attempting to rid ourselves of this bad gut bacteria, we need it to survive.
Remember a couple decades ago colon cleansing was the big rage, And now we are once again using fecal transfer from family members to reinvigorate the gut of the ill one

The presence of this type of bacteria could also explain the presence of gold in areas that have already been extensively mined and considered worked out. When modern day prospectors go over the area again with their modern metal detectors they're finding mostly very small gold nuggets in the soil. The nuggets are thought of as having 'grown' there.