Wanna know one of the most interesting books I've read in the past five years?

Know why? It explains gossip. It explains why we care about people we don't know. It explains why Entertainment Tonight exists. And it explains why you shouldn't feel ashamed about gossiping at work.

Gossip is cultural currency. We use it to express allegiance and affinity. Our tribe is who we gossip about, and if we are talking to someone not within our tribe, gossip about someone more important than either of our tribes gives us a cultural thread to pull ourselves together with. When Joe and Jane talk behind Jerry's back, Joe and Jane are forming an ingroup. Jerry may or may not be a part of that group - If Joe is letting Jane know Jerry has a crush on Janet, and Jane interacts with Janet, Joe is giving Jane a piece of cultural currency she can use in her relationship with Janet.

Within small groups (like your workgroup), gossip is the fundamental tie that binds you all together. It's the free-form voluntary information that connects everyone. Within large groups (like, say "Ohio"), gossip is the coin of exchange between tribes. You may not know Biff from Centerville but if both of you have a negative opinion about Michigan you're buds.

So don't sweat the gossip. Sweat slander, which is gossip that isn't true. The negative impact on emotions and drive is your ingroup effectively shunning one or more people from the tribe. This is management's problem, not yours (I'm assuming they're management). Management needs to make sure that the ingroup includes everyone in the organization. And if y'all are shunning someone who isn't management, someone needs to sack up and get management on the page.

Don't fear gossip. Don't denigrate it. We need it. It's what makes us social, and being social is what makes us human.