The Human Body Contains More Bacterial Cells Than Human Cells
For decades, scientists estimated the human body harboured 10 times more bacteria than human cells. A 2016 revision by the Weizmann Institute placed the ratio closer to 1:1 — roughly 38 trillion bacteria to 30 trillion human cells. Either way, we are as much microbial as we are human. The gut microbiome alone contains over 1,000 bacterial species and weighs about 200 grams, influencing digestion, immunity, and even mood.