Chanona found that
only a few bacterial
genes have been
proven to damage
human DNA, a piece
of information he
used to pinpoint
why a strain of E.
coli triggers colon
Gut Busters: The ‘Good’ Bacteria
Might Not Be So Good
If you eat yogurt, you eat bacteria. Billions of microbes per serving — Lactobacillus aci- dophilus, Streptococcus thermophilus, Bifi-dobacterium. They’re called probiotics and are
supposed to help the naturally occurring “good”
bacteria in our digestive tracts keep the “bad” bacteria in check. But do they do that for all of us?
And how bad can those “bad” bacteria really get?
UNC scientists are starting to find out, and
some of the news is a bit troubling.
Our bellies are rife with bacteria, even certain
strains of Escherichia coli. But these E. coli are
what scientists call commensal bacteria — we
don’t bother them and they don’t normally bother
us, because our digestive tracts are protected by
our immune systems and lined with a layer of
mucus. But what if that layer is compromised?
That’s what happens to patients with inflam-
matory bowel disease. They suffer through
chronic inflammation, which can lead to DNA
damage, mutated colon cells and cancer. IBD
patients are seven times more likely to develop
colon cancer than are people without IBD. Car-
olina researchers already have found that bacteria
can trigger inflammation. But can bacteria trigger
cancer? UNC microbiologists Christian Jobin
and Janelle Arthur ’09 (PhD) wanted to find out.