ATG5 and escherichia coli infection: Compared with untreated control cells, the expression of ATG5 protein was decreased at 6 h after E. coli infection in cells infected with E. coli alone (p = 0.026), while there was a statistically dramatic increase in ATG5 protein expression in cells incubated with L. johnsonii L531 alone or pretreated with L. johnsonii L531 followed by E. coli infection when compared with that in cells only infected with E. coli (p = 0.005 and p = 0.001, Figure 5A).