Effects of a high-fat diet on azoxymethane-induced aberrant crypt foci and fecal biochemistry and microbial activity in rats

• Published in: Nutrition and cancer Vol. 27; no. 1; pp. 84 - 91
• Main Authors: Morotomi, M. (Yakult Central Institute for Microbiological Research, Kunitachi, Tokyo, Japan.), Sakaitani, Y, Satou, M, Takahashi, T, Takagi, A, Onoue, M
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis Group 1997; Taylor& Francis
• Subjects: ACIDE BILIAIRE; ACIDE GRAS; ACIDOS BILIARES; ACIDOS GRASOS; ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; AGUA; Alkaline Phosphatase - analysis; Animals; Azoxymethane - adverse effects; Bile Acids and Salts - analysis; Bile Acids and Salts - metabolism; Biological and medical sciences; Carcinogens - adverse effects; Cholesterol - analysis; Cholesterol - metabolism; Colon - drug effects; Colon - microbiology; Colon - pathology; COMPOSE ORGANOAZOTE; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; COMPUESTO ORGANICO DEL NITROGENO; CONTENIDO DE HUMEDAD; CORPS GRAS; DIETA; Dietary Fats - pharmacology; DIGESTA; EAU; Enterococcus - isolation & purification; ENZIMAS; ENZYME; ESTEROLES; EXPERIMENTACION; EXPERIMENTATION; Fatty Acids, Nonesterified - analysis; Fatty Acids, Nonesterified - metabolism; FECES; Feces - chemistry; Feces - microbiology; FLORA MICROBIANA; FLORE MICROBIENNE; FOSFATASA ALCALINA; Gastroenterology. Liver. Pancreas. Abdomen; GRASAS; HECES; INGESTION DE NUTRIENTES; INGESTION DE SUBSTANCES NUTRITIVES; INTESTIN; Intestine, Large - chemistry; Intestine, Large - drug effects; Intestine, Large - metabolism; INTESTINOS; Lactobacillus - isolation & purification; LESION; LESIONES; Male; Medical sciences; MEMBRANA MUCOSA; Microvilli - drug effects; Microvilli - ultrastructure; MUQUEUSE; PHOSPHATASE ALCALINE; RAT; RATA; Rats; Rats, Inbred F344; REGIME ALIMENTAIRE; Staphylococcus - isolation & purification; STEROL; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; TENEUR EN EAU; Tumors; Biochemical analysis; Carcinoma; Premalignant lesion; Rat; Bile salt; Rodentia; Supplemented diet; Malignant tumor; Bacteriological investigation; Colonic disease; Vertebrata; Experimental disease; Microbiological investigation; Mammalia; Animal; Fat; Digestive diseases; Intestinal disease; Colon; Feces
• ISSN: 0163-5581; 1532-7914
• DOI: 10.1080/01635589709514507

To shed light on the association of dietary fat with the development of colon cancer, we studied the ability of azoxymethane (AOM) to induce aberrant crypt foci (ACF) and biochemical changes in rats fed high- or normal-fat diets. Six-week-old male Fischer 344 rats were placed on a high-fat 17% (wt/wt) soybean oil + 15% (wt/wt) beef tallow or a normal-fat (7% soybean oil, AIN-93G) diet. Rats fed each of these diets were given two weekly subcutaneous injections of AOM (15 mg/kg body wt) or saline at seven and eight weeks of age. Fecal samples were obtained at 10 weeks of age, and animals were sacrificed for ACF scoring and analysis of cecal contents at 13 weeks of age. We observed greater numbers of ACF in the high- than in the low-fat group. Biochemically, rats fed the high-fat diet showed dramatically elevated fecal and cecal long-chain free fatty acid levels and intestinal alkaline phosphatase activity. These animals also showed increased cholesterol and decreased coprostanol levels. We did not detect significant differences in the fecal and cecal concentrations of total and soluble bile acids or total neutral sterols (cholesterol + coprostanol) between the two groups. Thus a high-fat diet does show certain striking effects on colon biochemistry in rats