Fig. 5. Sodium acetate (SA) has no protective effect on mastitis induced by S. aureus.

Mice were administered an intraperitoneal injection of sodium acetate (SA, 100 mg/kg) 1 h before infection with S. aureus (1 × 10⁷ CFU). Twenty-four hours later, mammary gland tissues were collected and used for testing. a Mammary gland tissue sections of untreated and gut microbiota-dysbiosis mice were stained with H & E (100×). The black arrow was the normal tissues. The red arrow was the infiltration of inflammatory cells. The blue arrow was the hyperplastic of alveolar wall. Levels of pro-inflammatory cytokines, including TNF-α (b), IL-1β (c), and IL-6 (d), as well as MPO activity (e) in mammary gland tissues was tested 24 h after infection in untreated and gut microbiota-dysbiosis mice. The results are presented as the mean ± SEM of three independent experiments (n = 6–8); *p < 0.05 is significantly different from each group.