What is the Gut Microbiome?
Trillions of microorganisms that coexist within the body, with the largest population found within the large and small intestines. The gut contains hundreds of different species of bacteria, and at least ten different phyla. Altogether, the microbiome is composed of bacteria, achea, viruses, and eukaryotic microbes. This microbiome is responsible for a variety of bodily functions. Ranging from digestion, to weight management, fighting infections, and regulating sleep, and mood.

What are the benefits of a healthy microbiome?
The research on the human microbiome and its relation to health is a relatively new topic in the world of scientific research. However the research that is available has indicated a very strong relationship between a diverse gut flora and overall wellness.

The microbiota present within the digestive system support nutrient absorption and utilization. As simple carbohydrates like sucrose and lactose are rapidly digested in the small intestine, the complex carbohydrates like resistant starches and fibers travel to the lower intestine where the microbiota help to break them down. Here, the microbiome can generate new compounds that serve as energy sources for the body’s cells, help to regulate metabolism, reduce inflammation, and reduce oxidative stress.

A diverse microbiome can also support a healthy immune system. It is estimated that 60-80% of the immune system is located within the gut. When the gut has a healthy balance of “good bacteria” they help to prevent overgrowth of harmful bacteria by competing for energy sources and attachment sites within the gut. They can also stimulate the immune system and educate the immune system on how to appropriately respond to pathogens.

Research has established a connection between the gut microbiome and mental wellbeing. The gut houses a large number of the body’s serotonin receptors. A healthy microbiome allows the body to effectively use serotonin and potentially help to manage symptoms of anxiety and depression. A healthy and diverse microbiome can also be linked to our circadian rhythm, in turn helping to regulate sleep patterns.

What are Pre and Probiotics?
Probiotics are live microorganisms within the gut, or more simply put: the “beneficial bacteria”. Prebiotics are the non-digestible carbohydrates fermented by the gut microbiota, or simply: “food” for the probiotics.

Prebiotics are typically available in high fiber foods: fruits, vegetables, whole grains, and legumes. These resistant starches are not easily digested by the body, and are able to pass through the digestive system to become a fuel source for the microbiota further down the digestive tract.

Live probiotics can also be obtained through diet through fermented foods such as yogurt, kimchi, kefir, sauerkraut and others.

How to Maintain a Healthy Gut
Make food choices that promote a diverse microbiome. Fuel your body with a variety of prebiotics, in order to fuel and stimulate the function of probiotics. The Dietary Guidelines for Americans is an ideal eating pattern to help promote gut health. It recommends making half your grains whole, a variety of fruits and vegetables, variety of protein sources, and plant based oils. Overall, the gut microbiome is a relatively young field of research. And further work is needed before a causal relationship can be established as a treatment for disorders in humans.

Sources
Marchesi JR, Adams DH, Fava F, et al. (2016). The gut microbiota and host health: a new clinical frontier. Gut. 65(2):330-9
Thakur AK, Shakya A, Husain GM, Emerald M, Kumar V (2014) Gut-Microbiota and Mental Health: Current and Future Perspectives. J Pharmacol Clin Toxicol 2(1):1016.
Ursell, L.K., et al. Defining the Human Microbiome. Nutr Rev. 2012 Aug; 70(Suppl 1): S38–S44.
den Besten, Gijs., et al. The role of short-chain fatty acids in the interplay between diet, gut microbiota, and host energy metabolism. J Lipid Res. 2013 Sep; 54(9): 2325–2340
Morowitz, M.J., Carlisle, E., Alverdy, J.C. Contributions of Intestinal Bacteria to Nutrition and Metabolism in the Critically Ill. Surg Clin North Am. 2011 Aug; 91(4): 771–785.
Canny, G.O., McCormick, B.A. Bacteria in the Intestine, Helpful Residents or Enemies from Within. Infect and Immun. August 2008 vol. 76 no. 8, 3360-3373.