Category Archives: fermentation

Sweet’n Low

I didn’t want to blog about the artificial sweetener study; to be honest, I didn’t even want to read it.  I just wanted to report: 1) how many Diet Cokes are we talking about; and 2) when are you going to die.

Artificial sweeteners induce glucose intolerance by altering the gut microbiota (Suez et al., 2014)

Non-caloric artificial sweeteners (NAS) = saccharin, sucralose, and aspartame. Saccharin worked the best (worst) in the mouse study, so they tested it in humans.  This was the part I found most relevant: seven healthy volunteers (5 men & 2 women, aged 28-36) who did not typically consume a lot of sweeteners were recruited and given 120 mg saccharin three times per day.  360 mg saccharin is ~10 packets of Sweet’n Low.

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Meat digestion – fresh and raw or medium rare.

“If a dog team is worked hard daily for two weeks and fed with fresh fish caught under the ice and frozen without opportunity of becoming high, that team will lose weight and show definite signs of wear and tear.  If the team is fed with hung or high fish, they will be as good at the end of that time as the start, and often will have put on a little weight.”

-quote from a cool book Duck Dodgers sent me about digestive enzymes. 

“High” doesn’t mean psychedelic, but rather letting the meat sit for a time so as to allow it to tenderize, or “pre-digest.”

One study showed that protein breakdown, measured by desmin degradation, increased by roughly 33% if the meat was removed from the cow 24 hours after slaughter (“conventional”) instead of immediately after (“rapid”) (King et al., 2003).

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Animal fibre

Fruits and veggies, fermented or otherwise, aren’t the only source of prebiotics in your diet.  Eat a whole sardine and some of the ligaments, tendons, bones, and cartilage will surely escape digestion to reach the distal intestine where they will be fermented by the resident microbes.  

sardines

Salmon skin and the collagen in its flesh, the tendons that hold rib meat to the bone, and maybe even some of the ligaments between chicken bones.  All of these are potential prebiotics or “animal fibres.”  And it may explain why fermented sausages are such good vessels for probiotics.


 
“Animal prebiotic” may be a more appropriate term because the food matrix is quite different from that of non-digestible plant polysaccharides.  And while I doubt those following carnivorous diets are dining exclusively on steak, these studies suggest it might be particularly important to eat a variety of animal products (as well as greens, nuts, dark chocolate, fermented foods, etc.) in order to optimize gut health.

almonds

These studies are about the prebiotics in a cheetah’s diet.  Cheetah’s are carnivores, and as such, they dine on rabbits, not rabbit food.

cheetah

As somewhat of a proof of concept study, Depauw and colleagues tried fermenting a variety of relatively non-digestible animal parts with cheetah fecal microbes (2012).  Many of the substrates are things that are likely present in our diet (whether we know it or not).

Cartilage

Collagen (tendons, ligaments, skin, cartilage, bones, etc.)

Glucosamine-chondroitin (cartilage)

Glucosamine (chitin from shrimp exoskeleton? exo bars made with cricket flour?)

Rabbit bone, hair, and skin (Chicken McNuggets?)

Depauw ferments

The positive control, fructooligosaccharides (FOS), was clearly the most fermentable substrate; however, glucosamine and chondroitin weren’t too far behind.  Chicken cartilage and collagen were also well above the negative control (cellulose).  Rabbit skin, hair, and bone weren’t particularly good substrates.

As to fermentation products, collagen, glucosamine, and chondroitin were actually on par with FOS in terms of butyrate production:

Depauw SCFAs

Glycosaminoglycans (glucosamine and chondroitin) are found in cartilage and connective tissues (ligaments and tendons) and may have been mediating some of these effects as they’re some of the carbiest parts of animal products.  Duck Dodgers wrote about this in a guest post at FTA and in the comments of Norm Robillard’s article (probably elsewhere, too); very interesting stuff.

The authors also mentioned that the different fermentation rates in the first few hours suggests an adaptive component (some took a while to get going), or that certain substrates induced the proliferation of specific microbes.  “Animal prebiotics.”

Depauw close up

This is particularly noticeable for FOS (solid line), which is a plant fibre that wouldn’t really be present at high levels in a cheetah’s diet, so the microbes necessary to ferment it were probably not very abundant (initially).  Chicken cartilage (long dashes), on the other hand, started immediately rapidly fermenting, perhaps because this is more abundant in the cheetah’s diet.


 
Depauw took this a step further and fed cheetahs either exclusively beef or whole rabbit for a month (2013). Presumably, the beef had much less animal fibre than whole rabbit.  When they initially examined fecal short chain fatty acids, there were no major differences between the groups:

SCFAs per gram

However, if you take into consideration that the whole rabbit-fed cheetahs produced over 50% more crap than meat-fed cheetahs, then some other differences become apparent.  For example, the concentration of total SCFAs is actually greater in the feces from whole rabbit-fed cheetahs:

updated table

edit: la Frite pointed out that the table in the original manuscript is incorrect; the total SCFA numbers are reversed. The excel table above is corrected.

Further, the mere fact that there was 50% more fecal mass per day pretty much confirms way more animal fibre in whole rabbits.  And while neither of these studies were accompanied by microbial analysis, a more recent study on cheetahs fed primarily meat, “randomly interspersed with unsupplemented whole rabbits,” showed low levels of Bacteroidetes and Bifidobacteria, two potentially health-promoting groups of microbes (Becker et al., 2014).  I suspect this may have been at least partially due to a relative lack of animal fibre, compared to the Depauw’s exclusive whole rabbit diet.

Human digestive physiology and gut microbes are certainly far different from that of a cheetah, but maybe we too receive some prebiotic benefits from these animal fibres… just something to think about next time you’re eating sardines or pork ribs.

calories proper

 

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Fermented meat & probiotics

From Slate: “Sausage made with bacteria from baby poop isn’t as gross as it sounds.” 

and my favorite: “Pooperoni? Baby-poop bacteria help make healthy sausages.

Much ado about: Nutritionally enhanced fermented sausages as a vehicle for potential probiotic lactobacilli delivery (Rubio et al., 2014)

The media seems to have missed the ball, but not by far.  They focused on healthy microbes being incorporated into fermented meats, whereas the scientists seemed to want to make a “healthier” low-salt, low-fat sausage.

The low-salt part seems to partially make sense from a fermentation-perspective: using probiotics instead of salt to reduce the potential for pathogenic microbial contamination.  However, I doubt reducing the sodium by 25% will have any appreciable impact on health outcomes.  The effect of adding beneficial microbes, on the other hand, might.

They also mentioned making it lower in fat, but that doesn’t make as much sense; I don’t think there’s a big contamination risk of having a higher fat content.  #lipophobia

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