Figure 5

Release and distribution of target phages encapsulated by sodium alginate. Phages, both encapsulated and with sodium alginate (Alg-coated) and free (without encapsulation), were incubated in simulated gastric fluid (SGF) at pH 2. The free phages completely lost their activity after 30 min of incubation, while the titres of encapsulated phages decreased by only 1.62log₁₀ pfu/g after 120 min (A). After being incubated in SGF for 2 h, the encapsulated phages transferred to simulated intestinal fluid (SIF) at pH 6.7 for further incubation. During this time, the titres of phages in the supernatant gradually increased. At 30 min, 32.9% of the encapsulated phages had been released, and at 120 min, 92.6% were released (B). 1 h after oral administration, the titres of phages in the duodenum, jejunum, and ileum were higher than those in the gizzard, cecum, and rectum. However, at 2 h post administration, the titres in the cecum were slightly higher than in the duodenum and gizzard (C and D). Values are expressed as mean ± SD (n = 6). Statistical significance is indicated as follows: *P < 0.05, **P < 0.01, and “ns” indicates no statistical difference.