Salmonella phages affect the intestinal barrier in chicks by altering the composition of early intestinal flora: association with time of phage use

Salmonella phages affect the intestinal barrier in chicks

The use of antibiotics in chicken production has led to concerns about bacterial resistance, which has sparked interest in alternatives such as bacteriophages.

In a recent study, researchers investigated the effect of phages on gut barrier function and microbiome composition in chicks.

The results showed that oral phage administration altered the composition of the microbial communities in the appendix, particularly within the first few days of treatment. These changes were associated with improved gut barrier function and reduced colonization by Salmonella bacteria.

These results suggest that phages could potentially be used as a safe and effective alternative to antibiotics for disease prevention in young chicks. However, further research is needed to fully understand the effects of phage use on gut health and overall growth of the birds.

The authors Hongze Zhao, Yue Li, Peilin Lv, Jinmei Huang, Rong Tai, Xiue Jin, Jianhua Wang, Xiliang Wang published their findings in the article: Salmonella Phages Affect the Intestinal Barrier in Chicks by Altering the Composition of Early Intestinal Flora: Association With Time of Phage Use on 14 July 2022.

Main findings:

Phages may replace antibiotics in treating or preventing bacterial diseases in chickens.
• Chicks are easily affected by their environment during early growth, so this study investigated whether oral phages could affect the intestinal barrier function of chicks with a focus on the cecal microbiome.
In a two-week trial, forty one-day-old hens were randomly divided into four groups: (1) NC, negative control; (2) Phage 1, 109 PFU phage/day (days 3-5); (3) Phage 2, 109 PFU phage/day (days 8-10); and (4) AMX, 1 mg/mL amoxicillin/day (days 8-10).
High-throughput sequencing results of cecal contents showed that oral administration of phages significantly affected microbial community structure and community composition. The number of different species in the Phage 1 group was much higher than that in the Phage 2 group.
Particularly in the first stage of cecal microbiota development, oral administration of bacteriophages targeting Salmonella may cause substantial changes in chicks. This implies that phages may affect intestinal health by regulating the intestinal flora.

Abstract

Phages show promise in replacing antibiotics to treat or prevent bacterial diseases in the chicken breeding industry.

Chicks are easily affected by their environment during early growth. Thus, this study investigated whether oral phages could affect the intestinal barrier function of chicks with a focus on the cecal microbiome.

In a two-week trial, forty one-day-old hens were randomly divided into four groups:

NC, negative control;
Phage 1, 109 PFU phage/day (days 3-5);
Phage 2, 109 PFU phage/day (days 8-10); and
AMX, 1 mg/mL amoxicillin/day (days 8-10).

High-throughput sequencing results of cecal contents showed that oral administration of phages significantly affected microbial community structure and community composition, and increased the relative abundance of Enterococcus.

The number of different species in the Phage 1 group was much higher than that in the Phage 2 group, and differences in alpha and beta diversity also indicated that the magnitude of changes in the composition of the cecal microbiota correlated with the time of phage use.

Particularly in the first stage of cecal microbiota development, oral administration of bacteriophages targeting Salmonella may cause substantial changes in chicks, as evidenced by the results of the PICRUSt2 software function prediction, reminding us to be cautious about the time of phage use in chicks and to avoid high oral doses of phages during the first stage.

Additionally, the Phage 2 samples not only showed a significant increase in the relative abundance of Bifidobacterium and Subdoligranulum, but also improved the intestinal morphology (jejunum) and increased the mRNA expression level of occludin and ZO-1.

We concluded that phages do not directly interact with eukaryotic cells. The enhancement of intestinal barrier function by phages in chicks may be related to changes in the intestinal flora induced by phages. This implies that phages may affect intestinal health by regulating the intestinal flora. This study provides new ideas for phage prevention of intestinal bacterial infections and promotes large-scale application of phages in the poultry industry.

Keywords: Enterococcus; cecal microbiota; chicks; intestinal barrier; phage.