<![CDATA[Abstract. Prebiotics are compounds that cannot be digested by human intestinal digestive enzymes, but can be fermented by beneficial bacteria in the colon. So that prebiotics in the large intestine will support the growth of beneficial bacteria (probiotics). koja bay leaves are reported to contain phenol prebiotic compounds but have not been studied for their prebiotic effects, so this study aims to evaluate the prebiotic activity of koja bay leaf extract (Bergera koenigii (Linn) Spreng) against the growth of Lactobacillus acidophilus and Escherichia coli bacteria in vitro. The prebiotic activity test was conducted using the turbidimetric method, which calculates the number of bacteria based on the absorption at a wavelength of 600 nm (OD600). OD600 value was measured at hour 0 and hour 24. In addition, total phenol content and total carbohydrate content were also calculated. Phenol content was carried out using spectrophotometric method using Folin-Ciocalteu reagent, while the determination of carbohydrate content was carried out using spectrophotometric method using phenol-sulfuric acid. The results of the determination of total phenol content obtained total phenol content of 77.150 mg GAE / g extract, and total carbohydrate content obtained by 13.57%. The results of prebiotic activity showed that koja bay leaves (Bergera koenigii (Linn) Spreng) can suppress the growth of e.coli but do not have a prebiotic effect. Abstrak. Prebiotik merupakan senyawa yang tidak dapat dicerna oleh enzim – enzim pencernaan usus manusia, tetapi dapat difermentasi oleh bakteri menguntungkan dalam usus besar. Sehingga prebiotik di dalam usus besar akan mendukung pertumbuhan bakteri menguntungkan (probiotik). daun salam koja dilaporkan mengandung senyawa prebiotik fenol namun belum diteliti efek prebiotiknya maka,penelitian ini bertujuan untuk mengevaluasi aktivitas prebiotik ekstrak daun salam koja (Bergera koenigii (Linn) Spreng) terhadap pertumbuhan bakteri Lactobacillus acidophilus dan Escherichia coli secara in vitro. Uji aktivitas prebiotik dilakukan dengan metode turbidimetri, yaitu menghitung jumlah bakteri berdasarkan serapan pada panjang gelombang 600 nm (OD600). Nilai OD 600 diukur pada jam ke-0 dan jam ke-24. Selain itu dilakukan pula perhitungan kadar fenol total dan kadar karbohidrat total. Kadar fenol dilakukan dengan menggunakan metode spektrofotometri menggunakan pereaksi Folin-Ciocalteu, sedangkan untuk penentuan kadar karbohidrat dilakukan dengan menggunakan metode spektrofotometri menggunakan fenol-asam sulfat. Hasil penentuan kadar fenol total didapatkan kadar fenol total sebesar 77,150 mg GAE/ g ekstrak, dan kadar karbohidrat total didapat sebesar 13,57 %. Hasil aktivitas prebiotik menunjukan daun salam koja (Bergera koenigii (Linn) Spreng) dapat menekan pertumbuhan e.coli tetapi tidak memiliki efek prebiotik.]]>
