Thank you guys! It was great to read. Research on the gut microbiome is becoming more and more popular which is very important. We are on the way to understand how our microbiome affects us. Current research is also investigating a connection between certain gut bacteria and neurodegenerative diseases (Gut mircroboes augment neurodegeneration). It seems that this might be very likely.
RE: How many bacterias live in our bodies? The Human Microbiota and Microbiome.