Thursday, April 8, 2010

Are Your Dining Companions Making You Sick?

“You never dine alone,” according to biologist Jeff Gordon of the Human Gut Microbiome Initiative (HGMI). About 10-100 trillion gut microbes join you every time you eat. The reaction of your dinner guests greatly affects your health which depends not just on what you eat but also on how your intestinal microflora react to it.

Most of us think of diabetes as having a genetic component. Could it be that the genetic makeup of the microbes that have come to inhabit our gut affects us as much or more than our own DNA?

We are born with no microbes in our gut. They are all acquired after birth from our mothers, families, friends and communities. What we eat can radically alter the balance of our microbial communities, sometimes in ways that are very difficult to change. There are over 500 varieties of bacteria in our intestines, but their different attributes are not still fully understood. Science is just beginning to map the genetic code of our intestinal bacteria.

Already, a clear link has been established between obesity and our gut microflora. Fat people have very different gut microbes. Why? It seems to be a function of the bacteria we have been exposed to, what we eat and our degree of obesity. Some of the foods that I rant about in my blog can radically change your gut ecology in a rather short period of time. These changes are not easily reversed. We do know that the gut microflora changes some when people lose weight, so there is hope for improving our gut health and overall health.

Some intestinal bacteria are associated with inflammation and autoimmune disease, including diabetes. Because the role of gut bacteria in disease is complex and our understanding is still incomplete, most scientists caution against attempts to radically change gut ecology by using powerful antibiotics to eliminate intestinal bacteria and then attempting to re-colonize our guts with a healthier microbiological environment. Let me give an example of a man-made disease where tampering with the intestinal environment my lead to more serious risks.

Asthma has become much more prevalent in recent decades. After WW II, our overuse of antibiotics destroyed the common bacterium Helicobacter pylori in the guts of many people. People without H. pylori are much more likely to have asthma, allergies, and acid reflux. Writing on the ecology of human disease, one scientist has postulated that the destruction of this ancient microbe may also be a factor in the post-modern Type II diabetes and obesity epidemics. So, why not reintroduce H. pylori into our GI tracts? As it turns out, this microbe can also lead to ulcers and stomach cancer if it becomes too dominant. Tipping the scale to the other side might be even more damaging. Modern medicine’s weapons of mass microbial destruction are hardly adequate to preserve delicate balances.

Wholistic medicine has suggested that probiotics and prebiotics might help bring GI tracts ravaged by processed foods and modern drugs back into balance. Maybe, but do we really know which probiotic organisms and probiotic substances our bodies need?

Probiotics are micro-organisms which are believed to be beneficial to the human body. Yogurt with its lacto acidophilus and other live cultures has long been believed to strengthen immunity and improve health in general. Many other probiotics have been developed as nutritional supplements but our knowledge about the specific benefits of the hundreds of varieties of bacteria in our gut is currently at best partial. Anyway, yogurt tastes great and makes me feel good.

Prebiotics like fructo-oligosaccharides (FOS), inulin, and beta-glucan are believed to feed the good bacteria in the gut and improve gut health. They can be found in infant formula, nutritional supplements and some foods. I have tried them and found the short-term effects to be more embarrassing than life changing. As they ferment in your intestine, you can become quite pneumatic. One can only hope that these are the sounds of beneficial bacteria feeding well. Prebiotics, however, are not without critics. Some believe that they may also support some strains of harmful bacteria in your gut.

Here’s what we know for sure. High carbohydrate consumption, especially fructose, feed the bad bacteria and can seriously damage your gut ecology. We can also assume that healthy, fresh foods with abundant nutrients and natural fiber will improve the balance of the gut microflora.

1 comment:

  1. Denny,

    Growing up in the country we always played outside in the dirt. The old wives saying was all kids needed to eat a pound of dirt. We never got sick. We didn't live in sterile environments, like kids today. I have a brother who is a scientist at MIT. He claims those anti bacterial soaps are the culprit. He claims they kill good bacteria as well as bad. The diet has definitely changed, too over the last 50 years. Most people consume far too many processed carbs.