Scientists identify vast underground ecosystem containing billions of micro-organisms

[kiri]

2. There are only 6 trillion mammalian cells in a human

6 trillion mammalian cells with an individual's DNA in an adult homo sapiens. 6x10^12. These cells have cell membranes.

Out numbered by us are about 5 times more bacteria, for example the famous E.Coli, its friends and relatives. These guys have cell walls and amount to about 30 trillion cells. Their army does all kinds of things in our upper and lower intestines. They also appear on our skin, in our mouths, orifices, and in general, they are loving, essential, and benign. [Yogurt, cheese molds, bread moulds--later.]

Let's have decent respect for the unheralded cell-wall (cf. plant phylum) guys/gals/ambiguous/interchanging sex{gasp}.

http://www.differencebetween.net/science/difference-between-cell-wall-and-cell-membrane/
https://www.majordifferences.com/2013/10/difference-cell-wall-vs-and-cell.html