Key points from article :
Bacteria that live in the gut may influence our weight.
Study of metabolites in more than 300 pairs of UK twins.
Most of the variation (68%) was down to gut bacteria.
Genes responsible for only 18% of the variation.
Gut bacteria is partly inherited but strongly influenced by what we eat.
No association between age and the levels of 915 of the metabolites.
The study was published in the Nature Genetics journal.