Sophia Kathariou is the kind of scientist who can turn food-borne bacteria into great dinner conversation.

The associate professor of food science and microbiology at N.C. State University in Raleigh, N.C., spoke about her work Thursday night at Mitch’s Tavern, a longtime haunt for professors and students alike. The talk was one of Sigma Xi’s Science Cafés, which aim to promote science among the public.

Over local craft brews, Greek salads and gumbo, Kathariou was quick to mention the softer side of bacteria. Whether we hear about them “attacking our immune system” or “weakening our defenses,” she said the militaristic tone of communication about microbes has to change.

“Society has been trained to think about microbes and bacteria as enemies. This could not be further from the truth,” she said. “They are part of who we are and what we do.”

Symbiotic microorganisms in the digestive tract, for example, edge out the more harmful ones that would normally make people sick. Probiotic supplements are even supposed to increase the role these “good bacteria” play in the gut, a claim that prompted questions from one of the audience members. Although Kathariou said it’s always possible to have too much of a good thing, some data have shown probiotics can promote better function of the immune system.

“In my interpretation, they don’t hurt,” Kathariou said.

But there are plenty of microbes that do cause harm. That’s why Kathariou said the overuse of antibiotics is increasingly becoming a problem. While organisms often obtain their genes through biological parents, or vertical transfer, many microbes are able to adapt and mutate through horizontal transfer — simply swapping bits of DNA with each other. Because nature allows for that rapid change in genetic material, Kathariou says patients should avoid “self-medicating the ghost.”