FIG 5.

Effect of SCFA supplementation during IAV infection on secondary Salmonella Typhimurium (S.t) infection. (A and B) Mice were infected or not (mock) with IAV (H3N2). At 7 dpi, mice were (super)infected or not with S. Typhimurium. (A) Body weight evolution (percentages of initial body weights). (B) The survival of singly infected and doubly infected animals was monitored. (A and B) Results from two pooled experiments are shown (n = 16). (C to E) The same operation was repeated for IAV-infected mice treated or not with acetate, propionate, and butyrate (150 mM, 50 mM, and 20 mM, respectively, in drinking water) at 2 dpi. (C and D) The numbers of bacteria in the cecum (C) and liver (D) were determined 7 days after the bacterial challenge (n = 8; a representative experiment out of two). The body weight (E) and survival rate (F) of superinfected animals were monitored (n = 24; results from three pooled experiments are shown). (C and D) Significant differences were determined using the Mann-Whitney U test. (B, F) Rates of mouse survival were compared using Kaplan-Meier analysis and the log rank test (*, P < 0.05).