Pengaruh Suplementasi Probiotik, Prebiotik, dan Sinbiotik dalam Pakan Terhadap Ekspresi Gen, Imunitas Non-Spesifik dan Ketahanan Ikan Nila Merah (Oreochromis sp.) terhadap Infeksi Streptococcus agalactiae

Putri Sasmitha Ritonga, Indah Istiqomah, S.Pi., M.Si., Ph.D. ; Dr. Senny Helmiati, S.Pi., M.Sc.

2026 | Tesis | S2 ILMU PERIKANAN

Intervensi pakan berupa probiotik, prebiotik, dan sinbiotik telah menunjukkan potensi dalam memodulasi sistem imun inang, namun pengaruhnya terhadap ekspresi gen imun bawaan serta ketahanan terhadap penyakit pada ikan nila merah (Oreochromis sp.) selama infeksi Streptococcus agalactiae masih belum jelas. Penelitian ini mengkaji pengaruh suplementasi probiotik, prebiotik, dan sinbiotik terhadap ekspresi gen imun, respons imun nonspesifik, serta ketahanan terhadap S. agalactiae pada ikan nila merah (Oreochromis sp.). Ikan ditebar dengan kepadatan 125 ekor/m³, diaklimatisasi selama 7 hari, dan diberi pakan perlakuan sebanyak 3% biomassa per hari selama 60 hari. Perlakuan pakan meliputi probiotik Bacillus tropicus PCP 1 dan Lactococcus garvieae JAL 37 (108 sel/g pakan), prebiotik inulin (5 g/kg pakan), serta kombinasinya (sinbiotik). Hasil penelitian menunjukkan bahwa meskipun hanya pakan sinbiotik yang meningkatkan ekspresi gen musin-2 di usus, seluruh kelompok perlakuan menunjukkan peningkatan yang cukup besar pada aktivitas ledakan respirasi dan fagositosis sel darah putih. Tidak ada peningkatan ekspresi gen IL-1? dan TNF-? di limpa. Uji tantang menunjukkan bahwa perlakuan probiotik mengurangi kematian ikan menjadi 7%, sinbiotik dan prebiotik 3%, sedangkan pakan basal mengalami kematian 100% pada hari ketujuh setelah infeksi. Penelitian ini menyimpulkan bahwa suplementasi probiotik B. tropicus PCP 1 dan L. garvieae JAL 37 menunjukkan respons paling efektif dalam meningkatkan ketahanan awal ikan nila merah terhadap infeksi S. agalactiae, sementara pemberian prebiotik dan sinbiotik memberikan efek protektif yang lebih terbatas, sehingga berpotensi digunakan sebagai strategi pendukung pengelolaan kesehatan ikan sebelum imunisasi.

Feed interventions comprising probiotics, prebiotics, and synbiotics have demonstrated potential to modulate the host immune system; however, their impact on the expression of innate immune genes and disease resistance in red hybrid tilapia (Oreochromis sp.) during Streptococcus agalactiae infection remains unclear. This research investigated the effects of probiotic, prebiotic, and synbiotic supplementation on the expression of immune-related genes, nonspecific immunological responses, and resistance to S. agalactiae in red hybrid tilapia (Oreochromis sp.). Fish were introduced at a density of 125 fish/m³, acclimatized for 7 days, and then provided with a daily treatment meal comprising 3% of biomass for 60 days. The intervention comprised the probiotic Bacillus tropicus PCP 1 dan Lactococcus garvieae JAL 37 (108 cell/g feed), the prebiotic inulin (5 g/kg feed), and the combination (synbiotic). The findings indicated that whereas only the synbiotic diet elevated mucin-2 gene expression in the gut, all treatment groups showed a notable enhancement in leukocyte respiratory burst activity and phagocytosis. No elevation in IL-1? and TNF ? gene expression was observed in the spleen. Challenge tests indicated that the probiotic treatment reduced fish mortality to 7%, while synbiotic and prebiotic treatments resulted in 3% mortality. In contrast, fish fed the basal diet experienced 100% mortality by the seventh day post-infection. The study concluded that supplementation with the probiotics B. tropicus PCP 1 and L. garvieae JAL 37 showed the most effective response in enhancing the early resistance of red tilapia against S. agalactiae infection, whereas prebiotic and synbiotic supplementation provided more limited protective effects and may therefore be used as supportive strategies for fish health management prior to immunization. 

Kata Kunci : Probiotik; prebiotik, sinbiotiik, ledakan respirasi, fagositosis/Probiotic, prebiotic, synbiotic, respiratory burst, phagocytosis