A Few More Thoughts on the Microbiome

June 29, 2012 in General, Health, Immune System, Weight Management by Mary Ireland

I wanted to report just a few more findings regarding the human microbiome - the microbacteria that inhabit our bodies. There is just so much new data regarding the microbiome and exciting new research regarding it's impact on our health.

Basic Findings

Researchers found that there are just three types of gut-microbe populations - Bacteroides, Prevotella and Ruminococcus. Researchers expected to find many more. Researchers were also surprised to find that the types aren't related to age, gender, nationality or diet. The three types are:

  • Bacteroides are good at breaking down carbohydrates. Researchers speculate that people with this type might struggle more with obesity.
  • Prevotella are good at breaking down protein. In addition, they tend to degrade slimy mucus in the gut, which researchers speculate could increase gut pain.
  • Ruminococcus are good at breaking down cellulose. They help cells to absorb sugars, which might contribute to weight gain.

Other basic findings include:

  • According to Curtis Huttenhower, assistant professor of computational biology and bioinformatics in the Department of Biostatistics at Harvard School of Public Health, "There are tremendous differences in which particular bugs are present in an individual, but different bugs perform the same sorts of functions in specific areas of the body.”

    Huttenhower speculates that the study of gut microbiota might not only revolutionize therapeutic strategies for many diseases, but also improve the productivity of the pharmaceutical industry.

  • In contrast to the human genome which is stable and rarely changed by substances the cells come in contact with, the composition of the microbiome is readily changeable. This dynamic nature may account for the changes in gut microbiota associated with host diseases.

  • Research suggests that the drug metabolism in humans is not pre-arranged or determined absolutely, but is probabilistic and conditional based on microbiome of the person. The researchers report, "With the same perspective, disease onset at a specific time point and with a unique phenotype among individuals can be considered a result of complex and probabilistic metabolic co-regulation by the host genome and the intrinsic microbiome."
The basic function of microbiome

We have a mutually beneficial, symbiotic relationship with our microbiome. Our gut microbacteria perform beneficial functions such as fermenting undigested fiber, training the immune system, preventing growth of harmful bacteria, producing vitamins (such as biotin, vitamin B12 and vitamin K), and producing hormones for the storage of fats.

Research shows metabolites, the byproducts of microbacterial action on the contents of the intestines, are absorbed by the gut and together with various non-nutrient compounds produced by the microbiota, are co-metabolized by enzymes in the liver. The resulting metabolites are then returned to the gut through the bile and possibly other secretions for further metabolism and/or excretion. This process regulates the composition of gut microbacteria. Microbacteria can modify gene expression to create a suitable environment for themselves and prevent the growth of other competitive bacteria.

The link to obesity

Other research shows obesity is associated with differences in the microbiota, a significantly reduced bacterial diversity, and an increase in the population expression of enzymes which result in an increased efficiency of calorie harvest.

Although there isn't anything a person can do to change the type of their microbiome or to reverse the effects of inadequate exposure to microbacteria in early life, these findings emphasize the importance of maintaining an environment conducive to microbacteria. The advise is the same thing you have been reading about on the pages of our blogs since we began posting blogs: eat a variety of nutritious, high-fiber foods, reduce sugar intake and drink adequate amounts of water. It may take years or even decades of research to fully determine how to manipulate our microbiome to our best benefit, but in the mean time, the Mediterranean lifestyle is a good bet for achieving optimal health.