Thursday, March 27, 2014

4 Steps for a diverse microbiome

What constitutes a healthy microbiome?  If you are looking for a specific answer to this question you are not in luck.  Not only do we not know what a healthy microbiome looks like, it's likely different for every one of us.  In addition, we've only classified about 10% of the microbes found in the gut so it would be hard to tell you one way or another which ones are beneficial and which ones are potentially harmful when we've studied so few.  We do know that certain strains of bacteria are associated with certain beneficial effects and others can become problematic if not held in check.  We also know that hunter gatherer cultures who don't typically see the same sorts of chronic diseases and digestive problems that we see tend to have a much more diverse microbiome than us.  So how do we develop a more diverse microbiome?  Let's take a look at 4 tips you can use to develop a diverse microbiome.

1)Ditch the probiotics and eat fermented food

Probiotics are very popular these days as some have shown some clinical benefit in studies.  I do not discount what these studies say, but it's hard to believe that taking a pill that simply contains the organism is the most effective way to increase the amount in your colon.  For one, they have to make it through your acidic stomach and the rest of your digestive tract to set up shop in the colon.  While some bacteria can be found in the small intestine, it is far fewer than the number found in the colon and may not be something you want in large numbers in your small intestine, as is the case with small intestinal bacterial overgrowth.  Eating probiotic foods, however, makes a lot more sense.  For one, since these organisms are found in the food, the food contains nutrients(Called prebiotics) that the bacteria can use to make the byproducts of fermentation that are beneficial to us.  These effects appear to be directed through the vagus nerve which can be found all throughout our digestive tract, so you may get some benefit even though the bacteria don't make it to the colon where they can set up shop.  Secondly, if the organisms themselves don't make it to the colon, the prebiotics they are packaged with may and feed any organisms that you already have residing there.

2)Eat a lot of fiber...a lot!

In order for beneficial bacteria to colonize the colon, they need to have food.  They get food from you, but they tend to only get the food you don't completely digest.  This makes it important to get a lot of fiber from your diet.  Since we don't digest fiber, it makes it's way through our digestive tract in tact and bacteria in the colon can act upon it to produce nutrients that we can't and provide other forms of beneficial behavior such as crowding out bad bacteria and aiding in mineral absorption.  It is estimated that ancestral hunter gatherers consumed 100-150g of fiber today and this evidence is supported by what Jeff Leach of the Human Gut Project has seen in modern day hunter gatherers.  Beneficial bacteria in our gut ferment fiber in to short-chain fatty acids such as butyric acid which promote a healthy digestive tract and a healthy digestive process as a whole.

3)Eat a diverse diet, and not just the most edible parts of plants

Not only is the American diet the polar opposite of diverse, most people dispose of the parts of the few vegetables they eat that contain the most fiber.  While it is common to see some people eating broccoli, most of them eat just the crowns and trash the stems.  Root vegetables such as turnips and beets also contain greens that are high in fiber and polyphenols that are often delicious when sauteed in ghee or coconut oil.  You should shoot for 30 or more different plant foods per week and attempt to eat as much of the plant as possible.  In addition, striving for 5 different colors of fruits and vegetables per day will give you many different polyphenols that will also help promote a diverse microbiome.

4)Limit hard to digest proteins

Hard to digest proteins such as gluten, dairy, and legumes should be limited to reduce the amount of substrate available to amino acid fermenting bacteria in the colon such as Candida Albicans. C. Albicans and other amino acid fermenting organisms can generate ammonia as a byproduct of fermentation that can negatively impact digestion when they overgrow.  How hard these proteins are to digest is likely specific to the individual and some people may have no problems with them at one point in time but develop sensitivities to them later as certain strains of bacteria overgrow.  If they overgrow to the point they impact digestion, other forms of protein can become problematic as protein digestion becomes compromised.

While we try to untangle the specific strains of bacteria that make up a healthy microbiome, as well as the ones that are less than ideal, the best we have at this point is to try to have as diverse of a collection of bacteria in your gut as possible,  While this certainly doesn't guarantee you lifelong health, you are imitating the patterns of cultures that don't have the chronic diseases and digestive problems that we have today.  Most of these diseases, particularly autoimmune diseases and digestive issues, are related to specific changes in the gut microbiome that are likely, at least in some way, related to your diet.  Other chronic issues we see today, including obesity and Type 2 diabetes, are also related to changes in the microbiome.  You can't help but think that the Western diet has something to do with this.  The tips contained within this blog identify a few of the likely factors that contribute to a less than ideal microbiome, and eliminating these common dietary faux pas' should take you a long way in improving the landscape of your inner ecosystem.