Can accidental skin contact during sample collection affect my gut test results, including Staphylococcus levels?

In the context of a fecal microbiome test, the contamination from accidental skin contact is likely to be overwhelmed by the fecal material on the swab.  Feces is one of the most dense microbial communities known, while the microbial load on skin is very low in comparison.  For example, you may have picked up a hundred thousand or so bacterial cells when you accidentally touched your skin, but then when you sampled the fecal material, you likely picked up ~25 billion bacterial cells.  The contamination from your skin likely represents a vanishingly small proportion of the total sample (~0.0001%).  This means that as long as you followed our sampling guidelines, you can trust that the results are largely representative of your gut microbiome.

It is possible that the Staphylococcus in your sample is from your skin; however, Staphylococcus is known to be a transient member of the human gut microbiome, and we do routinely detect these species in adult stool samples, though they are somewhat less common.

Staphylococcus haemolyticus is detected in ~2.5% of adult stool samples
Staphylococcus epidermidis is detected in ~3% of adult stool samples