Gene for gene, you and I are more microbe than human. In fact, microbial cells that reside within us outnumber our human cells by ten to one! (1)
So in effect, you are never alone… our body contains billions and billions of microbial cells, mostly bacteria, some good and some bad, and according to a new study(2) some of the nasty little buggers within us might be hijacking our mood and our food choices.
Before we delve into the study findings and what you can do about them, allow me to offer a little context first.
Microbes and human health
We have long known that the human body is home to a diverse array of bacteria and other microbes (collectively known as the microbiome). But fascinating and evolving scientific research is bringing to light the profound impact that these microbes can have on our health, even our mood – and that the wrong or inadequate mix of microbes in our gut can set the stage for disease.
The mix of microbes within us is determined by a complex array of factors beginning from the moment we are born. From a vaginal birth which is our first “inoculation” with good bacteria and being breast-fed which provides prebiotics that support the growth of these good microbes, to our environment, use or misuse of antibiotics, stress, disease, physical activity or lack thereof, and the foods we eat and don’t eat – all impact the composition of our microbes within.(3-6) In general, healthful behaviors and healthy dietary choices promote the growth of a more diverse and favorable ecosystem in our gut.(2,3,6)
Studies have shown that damaging alternations to our gut flora can be seen with and/or contribute to diseases as diverse as obesity, diabetes, atherosclerosis, colorectal cancer, nonalcoholic fatty liver disease, and even select mental health conditions including depression, anxiety, and autism.(6-11)
Feeding the bugs within
Most recently, a new review of the scientific literature completed by Alcock et. al, (2) has suggested that the bugs that reside in our gut may actually influence our mood and our food choices. It seems they exert this power over us in two key ways:
- they generate a craving within us for certain foods that either supports their growth or inhibit the growth of their competitors and
- they induce an unsettled feeling within us; a feeling of discomfort or anxiety until we provide them with the food they crave.
That’s right, Alcock and his colleagues reported that these manipulative little buggers inside our belly may influence our satiety and hunger cues by producing toxins that can alter our mood and taste receptors and by triggering the release of hormones that impact our feelings of satiety. They can even hijack signals between our gut and brain by targeting the connecting nerve called the vagus nerve. (2)
A new accomplice for junk food cravings
It seems that each of the bacterial species within us require specific nutrients to thrive and they compete with one another for survival. Some may require sugar or carbohydrates, while others need fat, for example. Some of the bugs have dietary needs that align with our own; others do not. So your cravings for sugar or for the over-consumption of fast foods may now have a legitimate scapegoat – it is no longer just lack of will power that drove you to eat that barrel of ice cream; your bugs made you do it!
Healthy living: the cryptonite for harmful gut microbes
The good news is, we can alter the composition of our gut flora in as little as 24-hours by modifying our lifestyle and food choices.(2) It appears that our gut flora is much like a stock portfolio; diversity is good. And, by choosing to adhere to a healthful manner of eating and living we can help restore a more diverse population of gut microbes and nurture the survival of beneficial bugs. A healthy Manner of Living can therefore quiet the nasty little buggers that are sabotaging your health, while magnifying the voice and promoting the growth of the supportive bugs within.
The Bottom Line:
I find this to be a truly fascinating and mind-boggling area of scientific research. As our understanding of this complex relationship between humans and our bugs within evolves, the implications for human health are staggering. At this time, there are still more questions then answers about the impact our microbiome has on our health, but what we do know to be true is that we are not powerless against these buggers!
What we choose to eat and how we live our life influences the type of bugs within us. In addition to adhering to an overall healthy manner of eating, consuming foods sources of probiotics (such as yogurt, kefir, and fermented foods including miso, kimchi, and sauerkraut) and prebiotics (such as apples, asparagus, bananas, oats, and Jerusalem artichokes) can cultivate the growth of a more favorable inner ecosystem.(2,3,6)
So, resist the manipulative cravings and forgo the sugars and overly processed foods. Instead, choose to eat complex, whole, real, minimally processed foods. It is win win – you will nurture your own overall health including the survival of the good bugs within and in turn, those good bugs will take care of you.
Curious to learn more?
For more information about the human microbiome, check out the website of the National Institutes of Health, Human Microbiome Project. Scientists involved in this fascinating project are working to help us better understand the role of microbes in human health and disease. Their findings to date are remarkable.
- American Society for Microbiology. (2008, June 5). Humans Have Ten Times More Bacteria Than Human Cells: How Do Microbial Communities Affect Human Health?. ScienceDaily. Retrieved August 24, 2014 from http://www.sciencedaily.com/releases/2008/06/080603085914.htm
- Alcock, J., Maley, C. C. and Aktipis, C. A. (2014), Is eating behavior manipulated by the gastrointestinal microbiota? Evolutionary pressures and potential mechanisms. Bioessays. doi: 10.1002/bies.201400071
- Hawrelak JA, Myers SP., The causes of intestinal dysbiosis: a review. Altern Med Rev. 2004 Jun;9(2):180-97.
- Sekirov I., Russell S., Caetano L., Antunes M., Finlay B.B. Gut microbiota in health and disease. Am. Physiol. Soc. 2010;90:859–904.
- E, Cosola C, Dalfino G, Daidone G, De Angelis M, Gobbetti M, Gesualdo L., What Would You Like to Eat, Mr CKD Microbiota? A Mediterranean Diet, please! Kidney Blood Press Res. 2014 Jul 29;39(2-3):114-123.
- Guarner F, Malagelada JR.Gut flora in health and disease. Lancet. 2003 Feb 8;361(9356):512-9.
- Chan YK, Estaki M, Gibson DL.Clinical consequences of diet-induced dysbiosis. Ann Nutr Metab. 2013;63 Suppl 2:28-40.
- Power SE, O’Toole PW, Stanton C, Ross RP, Fitzgerald GF, Intestinal microbiota, diet and health. Br J Nutr. 2014 Feb;111(3):387-402.
- Rescigno M., Intestinal microbiota and its effects on the immune system. Cell Microbiol. 2014 Jul;16(7):1004-13.
- Petrof EO, Claud EC, Gloor GB, Allen-Vercoe E., Microbial ecosystems therapeutics: a new paradigm in medicine? Benef Microbes. 2013 Mar 1;4(1):53-65.
- Bested AC, Logan AC, Selhub EM., Intestinal microbiota, probiotics and mental health: from Metchnikoff to modern advances: Part II – contemporary contextual research. Gut Pathog. 2013 Mar 14;5(1):3.