More on the Microbiome

June 22, 2012 in fiber, General, Health by Mary Ireland

I want to continue my discussion about the microbiome - the bacteria on and in the human body. As I stated last week, this is cutting edge research, the full implications of which we may not know for many years, decades or ever. What is clear is that these bacteria play an important role in our health.

According to Jeff D. Leach, a science and archaeology writer and founder of the Human Food Project the rise in allergic and automimmune disorders may be due to a lack of exposure to the microorganisms that humans had been exposed to as part of everyday life until the last couple of centuries. Leach believes that all of our squeaky cleanness has disrupted our "co-evolutionary process" with bacteria that allows our bodies not to react with foreign bodies. He gives Caesarean section births as an example of the disruption of exposure to microorganisms.

In a study published last week in PLoS One, Kjersti Aagaard-Tillery, an obstetrician at Baylor College of Medicine published results regarding the changes in the vaginal microbiome in pregnant women. According to the research, the microbacteria Lactobacillus johnsonii, rare in the birth canal before pregnancy, proliferate in the birth canal during pregnancy. These bacteria produce enzymes that digest milk. After a normal birth process, the baby is covered with the microbacteria and ingests some, which prepares the baby's system for digesting breast milk.

Anyone who has ever been to Mexico and experienced Montezuma's Revenge has probably wondered why the locals can drink the water without getting sick. This is a classic example of adaptation by the microbiome to the environment. Another example may be the Maasai, a semi-nomadic people located in Kenya and northern Tanzania. Traditionally, the Maasai diet consisted of raw meat, raw milk, and raw blood from cattle. Studies conducted in 1935 by Dr. Weston A. Price reported that most Maasai tribes were disease-free. Note: I'm glad that Ancel Keys went to the Mediterranean and found that lifestyle to be healthy for Western civilization.

Research on populations in Western culture shows that the Maasai diet is not healthy to us. Findings reported in Nature shows that a diet high in saturated fat derived from milk changes conditions for microbes in the intestines and promotes an increase in a type of bacteria that increases inflammation and incidence of colitis in mice who were genetically predisposed. The research shows there is a balance in the intestines between microbes and the immune system. Disturbing the balance can lead to unregulated immune responses that can damage tissues and be difficult to switch off.

In the study, twenty percent of mice genetically modified to not have the molecule that regulates the immune system response to intestinal bacterial developed colitis when fed a low-fat diet or a diet high in polyunsaturated fats. When fed a diet high in milk fats, the incidence of colitis in genetically modified mice rose to 60%. It is important to note that milk fats are "abundant in processed and confectionery foods."

Previous research discussed in our blog posts has shown that what we eat can affect gene expression. It may be that the microbiome plays a role in how that process works. More research will likely shed light on this connection. However, as adults, there are some things that we cannot change as seen in study with the Lactobacillus johnsonii mentioned above and the link between serotonin production and the presence of gut microbes in early development in my blog last week. However, it is not too late to support the gut microbiome that you do have. One important way to do this is to get enough fiber.

According to eHealth MD, a high fiber diet impacts digestion in the following ways:

Fiber is important because it has an influence on the digestion process from start to finish:

  • Fiber causes you to chew your food more thoroughly and therefore slows down the eating process.
  • Fiber helps contribute to a feeling of being full, which can help prevent overeating.
  • Fiber slows digestion and absorption so that glucose (sugar) in food enters the bloodstream more slowly, which keeps blood sugar on a more even level.
  • The simple organic acids produced when fiber is broken down in the colon by bacteria help to nourish the lining of the colon.
  • The organic acids also provide fuel for the rest of the body, especially the liver, and may have an important role in metabolism.

Dr. Grandma gives some excellent advice about fiber and introducing more into your diet in her blog Roughage Restored to Its Place on the Plate. Nature provides the best source of fiber through plant-based foods. As we have discussed frequently in our blogs, plant-based foods provide the complete package, providing nutrients in addition to fiber. Start on the road to better health by nourishing your microbiome in natural ways.