Category Archives: Microbial

A New Source of Protein for the Athletic and the Sedentary?

A New Source of Protein?

This is an odd and interesting bit of research.  It relates to reaborption of nitrogen . . . and presents the possibility that more protein is conserved than previously thought.  First dietary nitrogen 101: Nitrogen is a major component of amino acids.  Amino acids are needed to form proteins.  We can synthesize some amino acids ourselves, but others need to be obtained through diet.  Dietary protein provides nitrogen and amino acids from plant or animal sources which are resynthesized into human proteins.  Unused nitrogen is converted into Ammonia and Urea and excreted.

Can nitrogen be reabsorbed from the intestines?

WODMasters Eye Pood Kettle Bell
Even if you don’t have the right microbial stuff, you can still look awesome and powerful with the right shirt

The answer is a shocking “maybe.”  A new nutritional study (published ahead of print in the Journal of Nutrition) has found that nitrogen appears to be reabsorbed.  This makes little sense at first glance.  Until we consider the vast populations of microorganisms that reside in the gut.  Until recently, they were all thought of as “germs” that needed to be quashed.   That has changed.  We are learning more and more about how important they are for our health and even our survival.

The study is titled:

Nonprotein Nitrogen Is Absorbed from the Large Intestine and Increases Nitrogen Balance in Growing Pigs Fed a Valine-Limiting Diet.

Valine is an essential Amino Acid, so these animals were fed a protein-deficient diet.   Then researchers administered urea or casein into the cecum of pigs.  Let’s consider this research a step toward greater understanding of how nitrogen may be recycled in living animals.  Not a new way to increase protein for strength.  (Although who knows.  It might work.) The urea was synthesized using Nitrogen-15.  Dietary nitrogen is Nitrogen 14.  Using nitrogen-15 lets the team know where the cecum-delivered nitrogen ended up.

Findings:

Researchers found that more than 80% of the cecum delivered nitrogen was absorbed.  Some of it was excreted in urine, but some was retained. This is a shocker.  I know.   Humans cannot synthesize protein using nitrogen.  So WTF?  The researchers propose that urea traveled through the bloodstream and into to the small intestine.   Bacteria (some of which can make amino acids using urea or plain nitrogen) in the small intestine then used the extra urea to make amino acids.  Amino acids produced by bacteria could then be absorbed the host (animals).

Takeaway:

More research would need to be done to confirm that this happens.  But it is very interesting.  Humans vary in the types of bacteria they host.  Bacterial populations vary according to diet, environment, chance (?) and who knows what else.  Do people get extra protein from bacteria?  Does this happen under normal circumstances (i.e. not piped in through the back end.)?  One thing is sure: there is a lot to learn. ResearchBlogging.org

Columbus DA, Lapierre H, Htoo JK, & de Lange CF (2014). Nonprotein Nitrogen Is Absorbed from the Large Intestine and Increases Nitrogen Balance in Growing Pigs Fed a Valine-Limiting Diet. The Journal of nutrition PMID: 24647394

Celiac Disease: protecting children from Celiac and Gluten Intolerance

What is Celiac Disease?

Celiac disease is a problem of auto-immunity and exposure to the plant protein gluten.  It can be a rough road, especially for children.  They can’t eat the same things other children eat.  Other kids and even adults may not understand that something that seems so normal to them, like a cupcake or sandwich, can cause serious pain and discomfort for a celiac child.

two children without celiac disease
Two children enjoy a Box lunch at CrossFit Seven in Fort Worth, TX.

Celiac disease is more common in people of European descent and probably has a strong genetic component.  However, there are other factors involved as well.  An individual may be predisposed to developing Celiac disease but not get it unless a combination of other factors line up as well.

Can Celiac Disease be Prevented?

One thing I had written about in an earlier post was the possibility that gut flora (microbial species and ratios of species) might influence the development of Celiac disease.  Intestinal flora in infants will be dependent on whether the infant was born by C-section and on whether he or she was breast fed or bottle fed.  The infant digestive system is not completely developed at birth.  It is suited for breast milk.  New research published this month (October 2012) supports a role for bacterial ecology in Celiac Disease.

Delaying introduction of wheat until the infant reaches 12 months of age appears to reduce risk that a genetically at-risk child will develop the disease.  Children with a genetic predisposition to Celiacs may take longer to develop an intestinal ecology favorable for wheat (and possibly other foods) than other children.  The study was a joint project of the University of Maryland School of Medicine and the Universita` Politecnica delle Marche, in Ancona, Italy.

Should I let my children eat gluten?

The answer to that seems to be yes.  Not exposing your children to gluten may make them more likely to develop celiac disease.A Systematic Review of infant feeding practices and incidence of Celiac (Coelicac) disease has also been published very recently (Szajewska et al. 2012).  The authors suggest that the best time to introduce wheat into an infant’s diet is between 4 and 7 months, and that it should be done while the child is still breastfeeding.   Introducing wheat before a child is under 4 months increases the likelihood that he or she will develop Celiac Disease.  Likewise, delaying introduction until a child is older than seven months may also increase risk of Celiac’s.

Gluten-free diets, such as the Paleo Diet, are very popular right now, especially within the CrossFit community.  If you are wondering “what is CrossFit?” here is a link.  If you are wondering “what is the paleo diet?” try this link.  Do parents who raise their non-celiac children on gluten free diets put them at risk of developing celiac disease? That could be the case.  This website, “Growing Up Gluten Free” is written and maintained by a child with celiac disease.  It helped me understand what life is like for kids like her.

There are lots of unknowns still.  The Szajewska paper does a great job of defining what they are.  

Sellitto M, Bai G, Serena G, Fricke WF, Sturgeon C, Gajer P, White JR, Koenig SS, Sakamoto J, Boothe D, Gicquelais R, Kryszak D, Puppa E, Catassi C, Ravel J, & Fasano A (2012). Proof of concept of microbiome-metabolome analysis and delayed gluten exposure on celiac disease autoimmunity in genetically at-risk infants. PloS one, 7 (3) PMID: 22432018

Szajewska H, Chmielewska A, Pieścik-Lech M, Ivarsson A, Kolacek S, Koletzko S, Mearin ML, Shamir R, Auricchio R, Troncone R, & PREVENTCD Study Group (2012). Systematic review: early infant feeding and the prevention of coeliac disease. Alimentary pharmacology & therapeutics, 36 (7), 607-18 PMID: 22905651