The combination of prolonged rL. lactis pre-treatment followed by infection with C. perfringens resulted in a significant increase of both IgA+ (p ≤ 0.0001) (Figure 9B) and IgY+ (p ≤ 0.0001) (Figure 9C) Bu1+ B cell frequencies within the duodenum, jejunum and ileum when compared to control chickens. Here, CD79A is linked to infection.