Wednesday, March 7, 2012

Back to the microbiota - impact of the type of dietary fat

So back to another sexy term.  Not epigenetics this time but the microbiome.  There are studies out there that show that the gut midrobiome of the obese differs from that of the lean (and fecal transplants from lean to obese can make them lose fat).   This study seems to show that saturated fats shift gut microbiota profiles toward those typical of obese individuals, and that dietary fatty acid saturation influences shifts in gut microbiota independently of changes in body mass.

Oh noes, don't tell me that my saturated fat bias is being challenged?

Gut bacteria profiles of Mus musculus at the phylum and family levels are influenced by saturation of dietary fatty acids.


Anonymous said...

It's too early to panic Chris. Mus Musculus, the house mouse, is not known to be a big saturated fat consumer in the wild (insects, their natural animal food, are similar to fish and poultry in saturated fat content). So the scientists created an unnatural diet in order to measure unnatural results.

And it is a rodent study after all.

Anonymous said...

I will stay with what works for me and disregard this study as it is another study posted that I can,t really understand where they are right or where that screwed up. My Paleo diet has changed my life, fat and all.

FeelGoodEating said...


I happen to think not. No sat fat challenge.......BUT
WE CAN'T EAT BACON 4 times a week.
In the defense of the argument that fat is good for us......the trends in primal eating have over done it IMHO .

Moderation but crucial to well being when it comes to quality fats ...included in that saturated fats and excluded industrial oils naturally .


Purposelessness said...

I just wanted to add to Anon above - while mice do eat insects, they eat mainly plant food in the wild.

bunya said...

Fecal transplants eh? Blimey!

Matthew Clarke said...

Are you eating much "hydrogenated soybean oil"?

2.2. Diet composition and analysis

Isocaloric semisynthetic diets containing a total of 13.4% fat by weight (32.5% of kJ from fat) were prepared by Harlan-Teklad (Madison, WI). The n-3 PUFA-rich (TD.08160), n-6 PUFA-rich (TD.04230) and SFA-rich (TD.04229) diets were created by supplementing a nutritionally complete diet with flaxseed oil, soybean oil or a mixture of soybean oil and fully hydrogenated soybean oil (Archer Daniels Midland, Decatur, IL), respectively. The n-6 PUFA-rich and SFA-rich diets are identical in the distribution of fatty acid chain lengths and thus differ only in the degree of saturation. Flaxseed oil was chosen over fish oil as a source of n-3 PUFAs because the distribution of chain lengths of flaxseed oil more closely approximated that of the two soybean oil based diets. Flaxseed oil differs substantially from n-3-rich fish oils, however, in containing only very small amounts of the long chain fatty acids eicosapentaenoic acid (EPA, 20:5) and docosahexaenoic acid (DHA, 22:6). Because trans fatty acids are generated during partial hydrogenation, using a mixture of fully hydrogenated and unhydrogenated soybean oils allowed production of intermediate levels of saturation without the inclusion of trans fatty acids. All diets were kept at 4 °C under nitrogen (to prevent oxidation) until use.

To determine dietary fat composition, fatty acids were extracted using a method modified from Folch et al. [30]. Lipids from a homogenized diet sample were extracted with a 2:1 mixture of chloroform:methanol, followed first by two rounds of acidification, centrifugation and removal of the lipid-containing chloroform layer and then by a final filtration. After being dried under nitrogen, fatty acids were methylated by direct transesterification according to a method based on Lepage and Roy [31]. Component fatty acid methyl esters in toluene were identified on a Varian 3900 gas chromatograph, using helium as a carrier gas in a WCOT fused silica column (100 m × 0.25 mm), a flame ionization detector, and a 5-step temperature program beginning at 150 °C and ending at 227 °C for a total program time of 32 min. Peaks were identified based on comparison of retention time with fatty acid standards (Supelco #24056), and composition is expressed as percent of identified fatty acid peaks (Table 1).

Erik said...

Good point, Purposelessness. Also, bug fat is mostly unsaturated (mono and poly).

Pasi said...

Diet will modify gut microbiota every time:

Is the gut microbiota a new factor contributing to obesity and its metabolic disorders?