Dietary supplementation of garlic ( Allium sativum ) modulates gut microbiota and health status of tilapia ( Oreochromis niloticus ) against Streptococcus iniae infection

Abstract

This study was conducted to characterize the causative agent of streptococcosis in tilapia (Oreochromis niloticus) and control of Streptococcus infection by means of garlic (Allium sativum) supplementation. The morphological, biochemical and polymerase chain reaction amplification confirmed 11 isolates belong to Streptococcus iniae from the infected fish eyes and tissue samples. Random screening of 12 well‐known medicinal plant parts against S. iniae revealed the garlic extract as the most effective herbal recovery against Streptococcus infection. In vivo challenge test with dietary supplementation of garlic powder significantly improved survival rates of fish against S. iniae infections, and modulate the microbial community and cytokine gene expression profiling in the intestine of the experimental tilapia. Among the two garlic supplemented treatments, 1.0 g garlic supplemented diet significantly increased (p < 0.05) the survival rates of tilapia and the gut bacterial operational transitional units abundance for Proteobacteria and Tenericutes, the phyla associated with healthy intestinal flora. The bacterial diversity index also found high with garlic supplemented diets. Significant upregulations of IL‐10 and IL‐17F gene expression in the intestinal tissue were observed with 1.0 g garlic supplemented diet where IL‐8 and IL‐1β expression levels were relatively static. The dietary supplementation of garlic, therefore, could be effective in the prevention of S. iniae infection in fish.

Unveiling the effect of dietary essential oils supplementation in Sparus aurata gills and its efficiency against the infestation by Sparicotyle chrysophrii

“…In our study, the Serpin Family B Member 1 (serpinb1), a protein that inhibits neutrophil elastases protecting tissue from damage at inflammatory sites, was also up-regulated by dietary EOs, corroborating its anti-inflammatory properties. In fish, the up-regulation of inflammatory cytokine genes was observed in the gut of tilapia fed dietary garlic powder (1.0%) 17 . In juvenile gilthead seabream, the dietary inclusion of a commercial encapsulated combination of carvacrol and thymol EOs (0.01%) resulted in an enhancement of the intestine absorptive capacity that was attributed to the induction of anti-inflammatory and anti-proliferative gene markers 12 .…”

“…has been demonstrated in several fish species [14][15][16][17][18] ; the inclusion of garlic extract in fish diets is effective against monogenean parasites 19,20 .…”

The effects of microencapsulated garlic (Allium sativum) extract on growth performance, body composition, immune response and antioxidant status of rainbow trout (Oncorhynchus mykiss) juveniles

“…Therefore, the global interest is focused on the development of new strategies that allow to improve its sustainability and profitability while reducing its environmental impact. One way to improve growth, antioxidant capacity, immune response, and resistance of aquatic animals to stress or infectious diseases is the inclusion of herbal supplements to the diet (Sivaram et al 2004;Inoue et al 2016;Foysal et al 2019;Yousefi et al 2020), as a possible alternative to synthetic substances in order to increase the safety of derived food products and meet the consumer expectations (Hoseini and Yousefi 2019).…”

Phytogenic Bioactive Compounds Shape Fish Mucosal Immunity

“…are shown in Table 1. Similar to studies testing phytogenics from Lamiaceae family origin, the evaluation of the supplementation of phytogenics derived from Allium sp., also focuses on few immune markers in skin mucus (88,93), histopathological observations or some inflammatory and oxidative markers in gills (89,96) and intestine (90,(94)(95)(96)102), or incomplete microbiological examination that lacks in-depth the functional interpretation of their mode of action at cellular level (87,90,92).…”