Kate DiCamillo's title indicates that Winn-Dixie accomplished a lot for all the characters in the story, especially for the protagonist, Opal. The title indicates that, because of Winn-Dixie, loneliness was eased; unity was created in the town of Naomi; and tribulations were overcome.
It is because lonely Opal meets the stray dog she adopts and names Winn-Dixie that Opal starts getting to know the people in the town she has just moved to. For example, Opal meets the librarian, Miss Franny Block, Opal's first friend in Naomi, because Winn-Dixie likes to stand on his hind legs to watch Opal through the library window choosing books and one day scares Miss Franny, who thinks Winn-Dixie is a bear. Opal comforts Miss Franny, and as Opal gets to know Miss Franny, she also gets to know about her loneliness. Another example is that Winn-Dixie runs into Gloria Dump's overgrown yard one summer day, which leads to Gloria and Opal being introduced and to developing their newfound friendship. As Opal phrases it, "Just about everything that happened to me that summer happened because of Winn-Dixie" (Ch. 9).
By the end of the story, Opal gets the idea to throw a party in Gloria's yard, and even to invite her antagonists, such as Stevie and Dunlap Dewberry, who tease Opal and call Gloria a witch, and Amanda Wilkinson, who ignores Opal. While at the party, Gloria convinces the Dewberry boys she is not a witch, and all the guests join in song as Otis plays his guitar. As Gloria states, "We all got to be good friends," and this friendship is due to both Winn-Dixie and to Opal.