Microbiome Vs. Human

If an alien came to Earth and randomly took a gene sample from one of us… they would most likely end up with a microbial, not human gene. Humans are outnumbered: we have 10 times more microbial cells and 100 times more microbial genes than our own. (February 2017 correction: apparently, that 10:1 ratio was based on one sample from the 70s… while actually, the ratio is more 1:1, so a human body has equivalent amounts of microbial and own cells 😉 gut

Today I heard a fantastic talk by Dr. Alcock- a practicing physician and a PhD in evolutionary biology (great combination that more health professionals should/will be getting in the future!). The question he and many other researchers are now asking is: can microbioms manipulate us to behave in their favor? Perhaps we are not autonomous in our eating; perhaps some of our behaviors represent another genetic interest.

The talk included a lot if interesting outcomes from animal studies on the subject, but that is material for a longer post ( by somehow who is more qualified than I). I will simply summarize some interesting points:

  • Microbiota and humans are not enemies- it is a marriage of convenience where the interests of one are also beneficial to the other. The bugs in our gut do need us to stay alive, as it is good for them also. However, microbiota might not always act in the best interest of the host as the interests of two might result in conflict. Even small differences in gene relatedness can result in conflict (pregnant mothers and fetus, for example, share 50% of genes). And there is zero relatedness in humans and bugs in our guts.A cool example of a conflict is mice infected by toxoplasmosis- such mice in fact seek out feline urine and are attracted to it (vs. having an innate aversion in non-infected mice); they thus look for cat urine, increasing the chances of being eaten by a cat and the parasite spreads further. Microbes can manipulate behavior in other ways- the cordyceps fungus causes its hosts (ants) to act completely out of “character” and leave their normal ground habitat to move onto the high leaves, helping the parasite disperse more spores [The Last of Us video game probably has you familiar with this fun fungus!]. Lastly, human organisms harbor known pathogens as well, yet they do not cause us harm (e.g. e-coli); it is interesting that these pathogens do not produce virulent factors when given simple carb solution (sugar!), a nutrient they require and would otherwise need to get aggressive for.FullSizeRender (1)
  • We can surely manipulate our microbioms. The diet we eat has a huge effect on who’s in our guts- a bug profile of a vegetarian and meat eater are quite different (see photo above). There appears to be a witch-hunt for the bacteria that might be responsible for obesity in humans, but this search has been unproductive with the same suspects being either related or completely unrelated to weight gain.What seems to matter most is the diversity of the bacteria, not having a certain type of it. A Mediterranean style diet with high fiber, for example, produces a more diverse gut environment, while a fast food diet creates a limited one. Some other determinants of a diverse vs. limited environment are on the slide below.  Key Point: Low diversity= Bad health outcomes. Some non-dietary ways to ensure a healthy diverse gut population are probiotics intake (and decreasing antibiotic use), vaginal birth, and breastfeeding; Babies not born vaginally in fact acquire a less complex microbiota that harbors more pathogens.FullSizeRender
  • Can microbioms manipulate…us?? That is the question. Can the gut bugs make us behave differently? Can they make us eat badly and become overweight? While we shouldn’t assume anything for humans yet, there are some examples of potential mechanisms through which bacteria could have an effect on the host.
    • Bacteria has been shown to produce hormones (some are important in stimulating appetite) and neurotransmitters (e.g. serononin that makes us feel good). We need to ask though- do these things pass from the gut to the brain and are actually successful in influencing us? The human body does fight these hormones and neurotransmitters by producing enzymes and antibodies that degrade them and prevent them from crossing barriers (another mechanisms is encapsulating the gut in fat, which also protects the body from escaped bacteria “signals”). It is interesting to note that the microbes might have evolved the ability to produce these things before humans did (as environmental microbes do this too, not only ones that inhabit us), thus they are not primarily meant to affect us.

In conclusion, what we can take out of this knowledge is that we need to encourage people to have high diversity of bacteria in their gut! A whole food diverse diet is a great way to do so, for example. Should we blame our gut bacteria for making us eat junk? Probably not. We can’t pin the blame for obesity and other chronic conditions on a particular microbe, though an overgrowth of one specific group in the gut might be a conceivable issue with their signals interfering with the bodily signals (e.g. in terms of how to eat via hormones and neurotransmitters).

There is so much more fascinating material to cover on the subject but that is for a later date! Lastly, an interesting question was asked in the audience- obese individuals in fact have a low diversity of bacteria… would unhealthy weight gain then be a bad thing for the microbes? Wouldn’t it be a “win” for the human and loose for the bacteria? Interesting question to test 🙂

All material was obtained by a lecture “Allies or Enemies? Gut micribiota & the war on fat” by Dr. Joe Alcock, MD. 2014.

A bit more on Obesity

Since i pondered on the varying rates of overweight and obesity in my previous post, I thought it’d be good to share some epidemiology [social statistics of obesity] on the subject!

So while in the US 1/3 of Americans have obesity (BMI of 30 or higher), it is definitely not an American problem. All over the world there are 1.5 billion people that are obese. In the US particularly , the societal factors most linked to obesity are: education years, socio-economic status, food habits, socio-cultural environment, and poverty.

Some folks argue that the most important factor in causing obesity is the change in culture- global modernization, urbanization, computer lifestyle, access to fast food, driving a car vs. walking. In China and India, for example, modernization goes along with the development of obesity (obesity rates accelerate there way faster than ever seen in the US!).

These cultural changes are not really “changes” to us any more- they are pretty much natural. For example: eating at a fast food place on the run once every other day or your job consisting of sitting on the chair 90% of the time.

The concept being talked about is the “toxic environment”– having increased access to unhealthy food choices that are convenient and inexpensive, sedentary-promoting environment.

This of course is a nice potential explanation. Even as I think of Ukraine and a lower rate of extra body weight: for the most part people cook meals at home vs. eat out. Why? It is simply cheaper. As a bonus- it is also seen as much healthier (depends if you want it to be). But would people spend time on making a healthy dinner at home if McDonald’s became 5 times cheaper? No, I think we would have the same situation in the US where 44% of people eat fast food once a week at least.

That is the official information shared by Dr. Levine from Mayo (who also works at my university with the Obesity Solutions initiative). I have heard many other explanations for why the world’s population is getting heavier. The ones related to food range from  toxic food (GMOs, high fructose corn syrup), artificial sweeteners and other ingredients, MSG, gluten, pasteurized foods (e.g. dairy) and so on.

My thought is… Living your life in this new world is definitely a struggle if you want to have a normal weight and feel your best- it is almost a fight against nature (nature now being replaced by the iron jungle of the city).  Suddenly you have to pay attention to every ingredient, find the time to sign up for a gym and squeeze in some physical activity in your schedule, spend energy on finding not-so-toxic products that probably cost more, etc. But of course it is all about trade-offs… people all over the world are looking for convenience, for a break from hard work. They seek ways to improve their live by modernizing, having transportation, not needing to spend half a day cooking meals and then cleaning after. Yet this comes at a price of poor health eventually. :/




Ukraine and US- Food&Health

Tea time at home 🙂

As my yearly trip to Ukraine came to an end, I sit on the porch drinking my green tea with saponins at 6am (still jet-lagged) and reflect. Something happened during this particular trip- probably due to the fact that I traveled with an “anthropologist” mindset this time around as I had an assignment.

What happened is that I lost my idealistic view of the Ukrainian diet- some morally superior way to eat and take care of one’s health. I realized this as I read yet another “alternative health” article on how Bolivians kicked out McDonald’s out of their country supposedly due to their preference for Real foods. That is very untrue- they simply could not afford to go to the place enough. They didn’t despise fast food in their fantastic and intuitive understanding of nutrition- they just didn’t have enough money to eat it frequently.

Sugary water machine

The same fact struck me in Ukraine. But first- our obesity rates are much lower than in the United States [2010: 48.5% females & 41.2% males- overweight or obese. For US: 76.7% females & 80.5% males*]; slimness is valued higher (especially among young girls) as being overweight is almost unacceptable and publicly so. And yet, you see plenty of people with excess weight- only they tend to be on the older side. As in the United States, being healthy, fit, and in charge of your health is also a fashionable thing, so folks try to read up on nutrition and go to the gym, etc…

In terms of lower obesity rates- I also suspect the USSR legacy is at work here, where overindulgence of any kind was not OK. In USSR era variety was low, portions were small, and getting much than someone else was quire unpopular. This is just a tiny theory though. My other theory is that eating norms are different than those in the US- smaller portions and less snacking is more the norm (can not prove this yet), a normal lunch/dinner is thought to include a warm soup, combining heavy foods (e.g. meat, potatoes, bread) is seen as less ideal, eating out is much less normal than cooking at home..

Is our overall lower weight due to the fact that we choose to eat healthier than Americans?

Well, let me tell you- Ukraine has plenty of “fast food” spots around the cities. Most often they’re some deep fried combinations of bread and either sausages or cabbage.

Street fast food

Of course we also have McDonald’s and you will never see it without a huge line. It is necessary to admit that vegetables are a much more natural addition to our diet in comparison to North Americans- many dishes feature vegetables (they are also the cheapest thing you can buy in a store) and many people know how to cook them in a tasty way. I believe there is less skill among US folks and that’s partially the reason they can’t get enough plants in their diet. Also, my observation has been that, even though Americans call really bad foods “junk food” they still eat plenty of it. The idea of snacking on junk in Ukraine seems to be less popular and a bit more unacceptable (not like I didn’t see folks on the streets with Coke or people buying chips at the store though..).

To summarize my thoughts in 1 sentence: I think Ukrainians are less heavy not because they eat healthier, but simply because they eat less for a number of reasons.

So.. what makes US obesity rates so much higher? Are people there simply more weak and ignorant about what and how much to eat!?  I don’t think so. I think the human animal is born with strong survival instincts- i think we are programmed to consume food, even in excess, since throughout the majority of our time on earth tomorrow was unpredictable in terms of nourishment. I believe it is natural to eat more than we need for this reason. United States simply created an environment that becomes unhealthy- opportunities to eat strong-tasting calorie-rich foods are too abundant, too varied, and too affordable.

Slimness&fashion-  crucial tool for social mobility in Ukr.

Lastly, my thoughts and theories do not even begin to cover the potential reasons Ukrainians are not as heavy as Americans. Moreover, they could be simply wrong.  But no despair! My trip home was also a research trip- I collected 42 surveys on food and health.

Once I collect enough responses from Americans, I hope the analysis will give me a glimpse at the differences in the two cultures. Hopefully it will add to my understanding of our lower obesity rates. Would be good to make my opinions slightly more scientific 😉

* http://www.guardian.co.uk/news/datablog/interactive/2013/feb/19/obesity-map-of-world-weight


Buckwheat- a staple. Considered a superfood in US
Buckwheat- a staple. Considered a superfood in US
Sushi is a terribly popular lunch item
Sushi & Japanese food is a terribly popular lunch item. (this lunch is $3)
Weight loss teas, coffees, and so on 🙂
Lots of pastry items… Considered very fattening yet sell well.