Eat Dirt: How to Improve Your Gut Microbiome Diversity

Bacteria have gotten such a bad rap over the last century. They were deemed detrimental to our health and we had to get rid of them. Antibiotics started to be prescribed at the slightest onset of snot, we were instructed to wash our hands with antibacterial soap before every meal and every dummy that was pelted across the floor by a gravity-curious toddler had to be boiled before being handed back for the next pelting. It was clear-bacteria were bad and sanitation was good.

Now, science has started to change its tune, bacteria actually aren’t all that bad. Of course, there are some guys that are detrimental to our health, however, more often than not, we need bacteria for our health!

However, people have been living in fear of dirt for too long now, and this coupled with the appalling Standard Australian Diet (SAD (Irony at its finest)) is literally seeing us become sick from too little bacterial diversity within our gut, not only do we have less overall numbers of microbes in our gut, we have fewer numbers of microbial species too. We have quite simply become too clean.

Impact of Evolution on Diversity

It’s not new news that humans are ecosystems, we are home to trillions of microorganisms that reside on and in us and we require them for almost every aspect of who we are. They are like little microbial nomads that sleep on our sofas, eat our food yet are the life of the party, and we wouldn’t have a neighbourhood gathering without them.

Our little microbial nomad friends have been with us since the dawn of man, they have evolved and adapted to new environmental surroundings and diets with us, in fact, they probably played a huge part of our evolution into the two-legged, skin covered, walking, talking Homo sapiens we are today.

Although our microbes have evolved with us, they haven’t all made the cut. Today, human gastrointestinal microbial diversity is far lower than our ape, gorilla and chimpanzee ancestral counterparts, with humans lacking at least 30 gut bug species behind [1]. Even humans living a very hunter-gatherer lifestyle in small towns in Malawi, or villages in the Amazonas or Venezuela still show a lower bacterial diversity compared to our ape ancestors, however, they have a greater microbial diversity than that of a city-dwelling USA resident [2]. Bangladeshi children have been shown to have significantly more bacterial diversity in their gut compared to their USA counterparts [3], and Papua New Guineans have also shown greater diversity than Americans [4].  Making one wonder is it that the more ‘human’ and ‘westernised’ we become…the fewer gut bugs we have?

The reasons behind this diversity drop would, of course, be multifaceted with reasons including, the introduction of cooked food, the introduction of washed food, medical intervention at birth, filtered water, the fact we no longer eat our own poop…and of course sanitation, medications, and pollution [5,6].  Of course, it’s a no-brainer that some of these facets have also contributed to an increase in our health and longevity as well, however, gone are the days that we truly lived as one with our environment and food. We are now seeing new diseases arise without any obvious explanation and a lot of these diseases remain relatively unheard of in the regions of human populations with the greatest microbial diversity. They are diseases of the westernized!

Impact of Diversity on Our Health

Nearly every scientific study performed that has attempted to correlate the micro biome with specific traits or diseases has been successful [7]. So this influx of ‘new’ diseases that are affecting not only adults but babies…BABIES, especially in the western societies; such as Autism, ADD/HD, cancers and autoimmune conditions are perhaps on the rise as our gut flora (or lack thereof) are on the decline.

The gut microbiota has a range of functional contributions to our over health and disease-fighting capabilities:

 Our Immune System

There is so much more to our immune system than most people think, and far too much to discuss in the context of this article. Quite simply, we have an innate immune system and an adaptive immune system our adaptive immune responses are antigen-specific, meaning they develop a specific disease-fighting key that fits into viruses lock, and develop when the innate immune response, our white blood cell soldiers, are unable to control the infection. The development of adaptive immunity is dependent on the cells and early signals of the innate immune system. When these two aspects of our immune system do not work together, or one becomes more dominant…autoimmune states can begin. It is vital that these are established correctly during childhood.

75% of our immune system is located in our gastrointestinal tract and, surprise, surprise, our gut bugs help modulate the balance between the immune levels. Lower levels of bacterial diversity within our gut have been connected to autoimmune, inflammatory conditions such as Crohn’s Disease, Ulcerative Colitis, Celiac Disease (and other allergies), Hashimotos Thyroiditis, Multiple Sclerosis, Eczema and Psoriasis [7,8,9].

Influence on Nutrition

Our gut bugs are not only responsible for synthesizing certain vitamins such as vitamin K and some of the B group vitamins [10], they are also responsible for breaking down many of the complex molecules found in food and turning them into other, even more, beneficial compounds that our bodies can utilize. Short Chain Fatty Acids (SCFA), such a butyrate is just one of these beneficial compounds and has been shown to aid in the prevention of colorectal cancer [8]. Westernised diets are notoriously low in fiber which our gut bugs can turn into SCFA, low fiber, heavily processed diets starve off these gut bugs minimising our microbial diversity and the number of beneficial compounds they can create.

Beneficial alterations to the microbiome have also had positive effects on obesity and its related metabolic disorders such as Type 2 Diabetes [8].

Influence on our behavior

There are many nerve endings in the gut which transmit signals to the brain via the superhighway that is the vagus nerve. This is why gut-brain diseases go hand in hand. These range from depression, bi-polar disorder, schizophrenia, autism and ADD. Usually, in most of these conditions there is a little more going on in the gut than decreased diversity; however, studies conducted on these mental health disorders have shown a decrease in beneficial bacteria and an increase in pathogenic bacteria, creating a dysbiotic state [11, 12].

Re-establishing microbial diversity

Keeping a healthy, nourished and most importantly, a diverse gut microbiome is the cornerstone to achieving optimal health and wellbeing in more diseases than we are led to believe.

Eating a wide variety of foods helps to feed multiple strains of bacteria as each one has a different preference; so eating a wide variety of vegetables, meats, fruit, and legumes (if your digestion is strong enough to handle them) offers wide and diverse food choices for your gut bugs.

Of course, eating fermented foods that are flooding with a wide variety of bacterial strains diversify the microbiome and supply them with a food source at the same time.

Supplementing with a Probiotic can be helpful, although most Probiotic supplements only contain 3-5 different bacterial strains, still lacking that diversity. However, they tend to have high levels of the bacteria that they do contain. The Kultured Wellness cultures have a wide range of bacterial strains with the Coconut Yoghurt containing 41 billion CFU per cup and Coconut Kefir 27 billion CFU per cup.