"First, we should give thanks for microbes because they are intricately involved in digestion. The human diet is very complex -- we take in a plethora of plant and animal products. In order to digest many of these foods, we must rely on the tools that bacteria have at their disposal. While an individual species may only be able to use its tool to help digest one particular carbohydrate, the collective bacterial community comprises a large and diverse toolkit that can break down the smorgasbord of food we eat into usable energy.
Interesting work from the Jeffrey Gordon Lab at Washington University in St. Louis has shown that different groups of microbes are present in the guts of obese and lean twins1. Based on this finding, an ongoing area of research is to understand the connection between your microbial consortium, how it extracts energy from the food you eat and how this could be tied to obesity or leanness. Ultimately, a better understanding of these processes can possible lead to modulating your microbial communities to avert obesity (or diabetes, which microbes are believed to play a part in as well).
Furthermore, let's give thanks for our microbial friends because they play an essential role in the development of our immune system. Ever since birth, we are inoculated with microbes (thanks, Mom!). One of the most important functions of these microbes is to help the immune system mature and become fully functional. Studies in germ-free mice show that mice without their normal bacterial members suffer from a dysfunctional immune system2. An important area of focus is to understand how your immune system discriminates between foreign bacteria (e.g. E. coli in the last column) and the bacteria that are naturally present in your gut. This difference is important because it will give us basic knowledge of how our immune system discriminates friend from foe.
Lastly, let's say thanks to our microbial cooperators because of our mutual self-interest. In biology we call a relationship between two organisms that benefit both as a mutualistic relationship. In essence, our bodies are warm, wet and energy-rich: perfect for microorganisms to thrive. In exchange, we utilize bacteria for the enzymes and factors to help us break down food and for the proper development of our immune system to fend off parasitic pests. It's a beautiful example of the interconnectedness of the biological world.
Next time you are enjoying a meal or fighting off a cold, give due thanks to your microbes. They not only make our world better, they make it possible."

-Caleb Fischer

http://www.gcdailyworld.com/blogs/1589/entry/42781/