Penelitian ini bertujuan untuk mengkaji efek pemberian inulin dari umbi Dahlia variabilis, baik dalam bentuk tepung maupun ekstrak, terhadap keberadaan mikroba usus halus pada ayam kampung persilangan periode starter. Materi penelitian adalah 280 ekor ayam kampung persilangan unsex, dan tepung maupun ekstrak umbi dahlia sebagai sumber inulin yang mulai diberikan pada umur 22 hari. Penelitian menggunakan rancangan acak lengkap dengan 7 perlakuan dan 4 ulangan (masing-masing 10 ekor ayam). Perlakuan terdiri dari : T0 (ransum basal/RB), T1 (RB+0,4% tepung umbi dahlia), T2 (RB +0,8% tepung umbi dahlia), T3 (RB+1,2% tepung umbi dahlia), T4 (RB+0,39% ekstrak umbi dahlia), T5 (RB+0,78% ekstrak umbi dahlia), dan T6 (RB+1,17% ekstrak umbi dahlia). Parameter yang diamati adalah bakteri asam laktat (BAL), Escherichia coli, pH digesta usus halus (duodenum, jejunum dan ileum), laju digesta, dan pertambahan bobot badan harian (PBBH). Data dianalisis ragam dan dilanjutkan dengan uji wilayah ganda Duncan, serta polinomial ortogonal. Hasil penelitian menunjukkan bahwa pemberian inulin dalam bentuk tepung maupun ekstrak umbi dahlia nyata (P<0,05) meningkatkan populasi BAL dan PBBH, tetapi menurunkan jumlah Escherichia coli, pH, dan memperlambat laju digesta. Simpulan penelitian adalah pemberian inulin dari umbi dahlia dalam bentuk tepung optimum pada taraf 0,9% dan dalam bentuk ekstrak masih linier sampai taraf 1,17%. Kata kunci : ayam kampung persilangan, inulin umbi dahlia, mikroba usus halus, pertambahan bobot badan harian ABSTRACT The purpose of the research was to study the effects of feeding inulin derived from Dahlia variabilis tuber powder and extract on the existence of intestinal microbes in crossbred native chicken starter. Experimental animals were 280 unsex crossbred native chickens and powder and extract of dahlia tuber as source of inulin, which were started to be fed on day 22. The present experiment was assigned in a completely randomized design with 7 treatments and 4 replications (10 birds each). The treatments were: T0 (basal diet/BD), T1 (BD+0.4% powder form), T2 (BD+0.8% powder form), T3 (BD+1.2% powder form), T4 (BD+0.39% extract form), T5 (BD+0.78% extract form), and T6 (BD+1.17% extract form). Parameters measured were the number of Lactic acid bacteria (LAB), Escherichia coli, intestinal potential hydrogen (pH) (duodenal, jejunal and ileal), rate of passage and daily body weight gain (DBWG). Data were subjected to ANOVA and followed by Duncan and polynomial orthogonal test. The results indicated that feeding inulin derived from dahlia tuber powder and extract form significantly (P<0.05) increased LAB population and DBWG, but decreased Escherichia coli number and intestinal pH, and slow the rate of passage. In conclusion, feeding inulin of dahlia tuber powder was optimum at 0.9% but that of extract is linier until 1.17%. Keywords : crossbred native chicken, inulin of dahlia tuber, intestinal microbes, daily gain Inulin Derived from Dahlia variabilis Tuber on Intestinal Microbes (L. Krismiyanto et al.