title: Phytosterols have an unfavourable effect on bacterial activity and no evident protective effect on colon carcinogenesis.
abstract: The effects of physiological dietary phytosterol supplements on intestinal microflora activity and faecal sterols and their capacity to protect rats fed a normal or high saturated fatty-acid diet against tumour development were studied. A group of 80 female Wistar rats were fed an 8% lipid diet for 4 weeks (adaptation period) and then randomly assigned in a factorial experimental design study to diets containing 8% or 24% hydrogenated coconut oil, with or without a 24-mg/day/rat phytosterol supplement. They were instilled intrarectally with saline or methyl-nitroso-urea (MNU). Faecal sterol output was analysed for one week each month. Pathological analysis was done at the end of the 30-week experiment. Animals treated with MNU and given phytosterol supplements had tumour frequencies (8/20) similar to those not fed phytosterols (11/20). The fat-supplemented diet had no significant influence. Colonic glands were found in area of lymphoid follicles in all the groups, but were more frequent in rats on high-fat diets (P < 0.01). The coprostanol and the cholesterol excretion of the phytosterol-supplemented rats was significantly enhanced. Therefore phytosterols have an unfavourable effect on bacterial activity. These data confirm the capacity of phytosterols to decrease cholesterol absorption, but indicate that a large excess of phytosterol must be avoided until further research on its effects on carcinogenesis has been done.
authors: Centre de Nutrition Humaine, Université de Nancy I, France. d.quilliot@chu-nancy.fr
authors: D
authors: D
authors: Quilliot
authors: F
authors: F
authors: Boman
authors: C
authors: C
authors: Creton
authors: X
authors: X
authors: Pelletier
authors: J
authors: J
authors: Floquet
authors: G
authors: G
authors: Debry
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000009:adverse effects* / Q000494:pharmacology; D004083:Cholestanol / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism; D003110:Colonic Neoplasms / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D004041:Dietary Fats / Q000009:adverse effects; D004195:Disease Models, Animal; D005243:Feces / Q000737:chemistry; D005260:Female; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000382:microbiology*; D010840:Phytosterols / Q000009:adverse effects* / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D016588:Anticarcinogenic Agents; D004041:Dietary Fats; D010840:Phytosterols; D004083:Cholestanol; D002784:Cholesterol