Category Archives: microbiota

Are potatoes a wonder drug for your gut and health???

So in some of the original Paleo books and sites that came out, there was this notion that potatoes should be excluded from your diet.  Most notably, Loren Cordain (THE original Paleo guy) was cited as saying that there are inflammatory aspects to potatoes and that they should be removed to help heal the gut.  He’s right to an extent in that potatoes contain relatively high amounts of glycoalkaloids, which are basically nature’s pest repellants.  What’s interesting though is that most of the glycoalkaloids are concentrated into the skin of the potato, making it easy to reduce the content by peeling them…. simple enough it seems.

The question remains though, is there a good reason even bother eating potatoes outside of taste?  Well, if you’re a very lean active person then they can be a great energy source of course… but not everyone is lean and active as we know.

However, I think there’s another reason to start getting interested in potatoes again, and its all about Resistant Starch which I’ll refer to as RS for simplicity sake.  What is RS?  Good old wikipedia defines it as “starch and starch degradation products that escape from digestion in the small intestine of healthy individuals. Resistant starch is considered the third type of dietary fiber, as it can deliver some of the benefits of insoluble fiber and some of the benefits of soluble fiber.”  Interestingly, potatoes (and to some extent rice) are loaded with resistant starch.

A little bit of background:

RS was discovered in the 80’s and since then a TON of studies have been conducted on its affects on humans and other animals.  Many of these studies correlated RS consumption with improved colon health, improved cholesterol, better glucose control, weight management, improved satiety, and better gut function as it relates to nutrient absorption.  All good things!!!

Anyway, why are there so many studies linking RS to improved health markers? Biologically, we now know that there are specific bacteria in our GI tracts, most accurately the large intestine that use RS as a fuel source.  As the bacteria grow on RS, they produce by-products.  One of the by-products that gets produced by bacteria consuming RS is a short chained fatty acid called butyrate.  Interestingly, epithelial cells of the gut use butyrate as an energy source in many of their normal processes which helps keep them healthy, which in turn keeps your gut intact.  Its absolutely critical to have an intact GI tract to prevent microbial translocation of bacteria.  To state it simply, You want to keep your poo separate from you.”

If you’ve read my author description, you know I’m an immunologist by training and at heart.  So when I came across this HIGH profile paper linking butyrate to the induction of regulatory T cells, I was ecstatic.  Regulatory T cells are one of the immune systems most important ways of preventing autoimmune disease and overt inflammatory disorders.  Remember my post from a few weeks back where I made the argument that obesity is linked to inflammation as well.  Basically, at the end of the day, inflammation is connected to almost every disease you can think of.  What this paper says is that butyrate, produced by specific bacteria in our guts is critical to the formation of these regulatory T cells which prevent inflammation…. AWESOME.

So what’s the take home message???? Having adequate levels of butyrate will likely be extremely helpful for maintaining a healthy gut and overall health.  Most of your butyrate is going to come as a result of eating RS.  I’m not convinced that this can be done with a diet using just fruits and veggies as your carbohydrate source.  Potatoes and rice appear to be a great source of RS, but they require a very specific preparation.  You have to cook them and then let them cool which is a little less than ideal so I’m going to try a couple of other options.

1) I’ve been taking a sodium butyrate supplement for the last 3 weeks or so.  I’ve noticed some subtle changes (less gas, more energy, clearer thinking).  Side note: the pills smell like butter… which isn’t surprising because butter is a great source of butyrate!  One more reason to love Grass Fed butter.

That said, the results could be better still in my opinion so…

2) I’m going to try taking 4 TBSP of Bob’s Red Mill Potato Starch every day and see if I can get even better results.  I’ve read several other successful stories using this exact approach so I’m excited to see how it goes.

http://freetheanimal.com/2013/04/resistant-assimilation-resistance.html

http://www.diabetes-warrior.net/2014/01/08/omg-intense-exercise-another-resistant-starch-test/

Anybody else want to give it a try???

 

 

Inflammation and obesity

Over the past couple of years, there’s been a conversion in belief that the macronutrient source of food is more important than the quantity of food consumed when it comes to causing obesity.  People like Gary Taubes have basically stated that high carbohydrate diets induce changes in metabolic hormones like insulin which essentially instruct the body to store energy in the form of fat… and he’s right.  In his very popular yet incredibly boring book “Good Calories Bad Calories” Taubes cites studies showing nearly equal weight loss in people consuming high protein diets with either caloric excess or caloric deficit which is a pretty strong argument.

Other very smart people have responded by coming up with groups of people (notably the Kitavans) that eat pretty high carb diets and yet do not have signs of obesity or obesity-related diseases.  Pretty good counterpoint in my opinion as well.

http://wholehealthsource.blogspot.com/2008/08/kitavans-wisdom-from-pacific-islands.html

What gives????? How are these people eating high carb diets and not getting sick?  Well for one, they are relatively active compared to most Western societies.  Additionally, there may be genetic factors at work here as well that cannot be ruled out.  However, another potential explanation is starting to emerge as well.  For years now we’ve known that the human body gastrointestinal tract is literally covered in bacteria that we call “commensals.”  In fact, its estimated that the human body contains 10X the number of bacteria in the GI tract as there are human cells in the rest of the body.  These commensal bacteria grow both off of the food we consume as well as on products from the GI tissues such as mucus.  In turn, our bodies use enzymes produced by the commensal bacteria to help break down and digest the food that we eat into usable energy sources.  This symbiotic relationship is absolutely necessary for optimal health as we’ve recently learned using germ free (AKA bacteria free) studies in mice.

Well, recently we’ve learned that the bacteria that live in our GI tract are extremely responsive to the different types of foods that we eat.  More importantly, these changes in the microbiota may be directly linked to changes in metabolic hormones that are involved in obesity, insulin resistance,  etc.

http://www.ncbi.nlm.nih.gov/pubmed/?term=comparison+with+ancestral+diets+suggests+dense+acellular

http://www.ncbi.nlm.nih.gov/pubmed/23768553

The diets of the world we live in appear to modify the bacterial composition of the bacteria that live within our body.  Instead of having benign commensals that really pose no threat to us or are anti-inflammatory, the modern diets induce the outgrowth of a higher percentage of inflammatory bacteria, namely gamma proteobacteria like E.coli and P.mirabilis.  These “inflammatory” bacteria cause activation of the innate immune system causing low-level systemic inflammation which has been linked to everything from autoimmune disease, to allergies, to cancer AND insulin resistance!

http://www.ncbi.nlm.nih.gov/pubmed/?term=Innate+sensors+of+pathogen+and+stress%3A+Linking+inflammation+to+obesity 

Interestingly, the review above also cites studies showing that the innate immune system also seems to be able to sense nutrient excess as well, both through modulation of the microbiome but also through production of ligands that bind to the pattern recognition receptors that normally are built to detect pathogens.

So is it caloric excess or the quality of food that we consume which is responsible for obesity???  The answer (for now) appears to be both.  I love this answer because it fits in so accurately with personal experience with clients.  Most people do just fine by focusing on eating real foods and getting away from processed grains and artificial sweeteners.  However, there are some people that really struggle to lose weight despite eating similar high quality foods.  In my experience, these people are inadvertently eating way more calories than they thought they were… usually in the form of almonds and other nuts.  I’m not saying that ALL of the reason they struggle to lose weight is as a result of the bacterial changes/immune activation but it cannot be ruled out as a contributing factor as well.

At the end of the day, focusing on eating non-processed food  is a great place to start if you’re looking to improve your body composition and overall health.  If you hit struggle to lose weight with this approach, then understanding how many total calories you’re eating is the next step as sometimes we can unintentionally consume way more calories than we really think we are eating.