Hydrogenation of polyunsaturated fatty acids by human colonic bacteria.
Emulsions of the fatty acids linoleic (C18:2 n-6), alpha-linolenic (C18:3 n-3) and arachidonic acid (C20:4 n-6) were incubated for 4 h under anaerobic conditions with human faecal suspensions. Linoleic acid was significantly decreased (P < 0.001) and there was a significant rise (P < 0.05) in its hydrogenation product, stearic acid. Linolenic acid was also significantly decreased (P < 0.01), and significant increases in C18:3 cis-trans isomers (P < 0.01) and linoleic acid (P < 0.05) were seen. With each acid, there were non-significant increases in acids considered to be intermediates in biohydrogenation. The study provides evidence that bacteria from the human colon can hydrogenate C18 essential polyunsaturated fatty acids. However, with arachidonic acid there was no evidence of hydrogenation.
Howard
F A
FA
Department of Nutrition and Dietetics, Radcliffe Infirmary, Oxford, UK.
Henderson
C
C
D016718:Arachidonic Acid / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism*; D003106:Colon / Q000382:microbiology*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D005243:Feces / Q000382:microbiology; D006801:Humans; D006865:Hydrogenation; D019787:Linoleic Acid / Q000378:metabolism
D005231:Fatty Acids, Unsaturated; D016718:Arachidonic Acid; D019787:Linoleic Acid