As a supplement to the recent post on fat and microbiota, I am posting a summary of what is known about various fats’ effects on the composition of gut microbiota and on intestinal barrier function.
High fat diet causes dysbiosis and impaired intestinal barrier function
Cani et al 2007 Metabolic Endotoxemia Initiates Obesity and Insulin Resistance
Ma 2014 High-fat maternal diet during pregnancy persistently alters the offspring microbiome in a primate model – high fat diet reduces commensal Campylobacter
Huang 2013 Composition of Dietary Fat Source Shapes Gut Microbiota Architecture and Alters Host Inflammatory Mediators in Mouse Adipose Tissue- n-6 PUFA, LARD and Milk Fat change microbiota and induce insulin resistance.
Deopurkar 2010 Differential Effects of Cream, Glucose, and Orange Juice on Inflammation, Endotoxin. Saturated fat causes endotoxemia
Kim 2012 High Fat Diet-Induced Gut Microbiota Exacerbates Inflammation and Obesity in Mice via the TLR4 Signaling Pathway – increased Enterobacteriaceae and endotoxemia
Le Roy Intestinal microbiota determines development of non-alcoholic fatty liver disease in mice. Microbiota are the causal feature controlling the inflammatory response to high fat diet.
Ridaura 2013 Gut Microbiota from Twins Discordant for Obesity Modulate Metabolism in Mice – high saturated fat diet prevented phenotypic rescue of obese mice during co-housing of lean and obese mice.
Saturated fats cause dysbiosis
Devkota et al. 2012 Dietary fat-induced taurocholic acid production promotes pathobiont and colitis in IL-10−/− mice. saturated fat increased δ-Proteobacteria Bilophila wadsworthia.
Mani 2013 Dietary oil composition differentially modulates intestinal endotoxin transport and postprandial endotoxemia – saturated FA increased endotoxemia
Oleic acid (monounsaturated fat) prevents HFD dysbiosis and increases Bifidobacteria
Oleic acid improves insulin sensitivity compared to saturated fat
Omega-3 fatty acids prevent dysbiosis and promote beneficial microbes
Mani 2013 Dietary oil composition differentially modulates intestinal endotoxin transport and postprandial endotoxemia – omega-3 FA decreased endotoxemia
Patterson 2013 Impact of dietary fatty acids on metabolic activity and host intestinal microbiota composition in C57BL/6J mice – omega-3 FA increased Bifidobacteria.
Omega-6 fatty acids cause dysbiosis
Zeng 2013 Fatty Liver Accompanies an Increase in Lactobacillus Species in the Hind Gut of C57BL/6 Mice Fed a High-Fat Diet – n-6 fat caused expansion of bile salt resistant bacteria associated with fatty liver.
Hildebrandt 2009 High-fat diet determines the composition of the murine gut microbiome independently of obesity. n-6 safflower oil increased Proteobacteria
Prebiotics increase protect against dysbiosis and increase Bifidobacteria and improve metabolism
Short chain fatty acids
Rahat-Rozenbloom 2014 Evidence for greater production of colonic short-chain fatty acids in overweight than lean humans – proving that nothing is simple!
Bottom line: Avoid excess saturated fats (and n-6 PUFA). For metabolic health, consume omega-3 fatty acids, olive oil, and prebiotics that promote short chain fatty acids.