CD4 and digestive system infectious disorder: In the murine intestinal infection model, the experimental group treated with phage cocktail in combination with ciprofloxacin (CIP) demonstrated significant therapeutic effects, reaching 90% survival rate, restoring the CD4<sup>+</sup>/CD8<sup>+</sup> T cell balance, and decreasing the levels of pro-inflammatory factors, which were significantly superior to those of phage or CIP alone.