I believe you are talking about Stem Cells.
<span>The main difference of renewable and non-renewable resources lies in the capacity of
the environment to replenish itself. Renewable resources are resources that can
be easily replenished by the environment over a short period of time, while
non-renewable resources take more time. <span>
Examples
of renewable resources are solar energy, harnessing the sun's power that shines
day to day. Wind energy that exists naturally is also a renewable source.
Geothermal energy, heat coming from the center of the Earth, and Biofuels,
fuels made from living organisms, are all renewable energy.
<span>Non-renewable
energy resources are the fuels we use in our cars, minerals from the soil,
coal, among others are supplies that also come from Earth. These are all materials that might take a long time (probably millions of years)
to be fully restored. </span>
</span></span>
Bacteria in our gut help to protect us by crowding out some of their dangerous relatives that can cause disease. Other good bacteria have been used in medicine to create antibiotics, and others still are used in food production to make fermented foods (think sauerkraut, yogurt, kimchi and kombucha.)
I believe it is number 3.
Hope this helps!