“Connecting the dots” is a phrase borrowed from Dr. Noel T. Mueller of Columbia University Medical Center, author of “The Gut Microbiome and Childhood Obesity: Connecting the Dots.” The microbiome is the collective name for the approximately 100 trillion tiny creatures that live inside the human gastrointestinal tract. Around 1,000 of them have been identified, and some researchers believe there may be as many as 5,000 different species.
Not all of them live in everyone. In any person, various kinds of bacteria are present or absent, which makes a difference of course. But what seems to matter more is the presence of a large variety of microorganisms in the person’s interior. Some scientists draw the conclusion that the most important factor of all is that their populations should be balanced, according to rules and standards that we don’t yet begin to understand.
Another way to say it is:
It is becoming clear that the microbiota normally has a balanced compositional signature that confers health benefits and that a disruption of this balance confers disease susceptibility.
When the balance is out of kilter, the condition is called gut dysbiosis, which appears to be the origin of inflammation that fosters many categories of disease — metabolic, autoimmune, and even infectious. A lot goes on in there. The gut is lined with immune cells that make up between 70% and 90% of the entire immune system.
The microbiome seems to have extensive links with everything from the elementary and obvious element of diet to more complicated and mysterious factors like addiction, allergies, antibiotics, appetite, artificial sweeteners, Caesarean sections, chronic inflammation, cognitive development, diabetes, emotional health, gestational influences, leaky gut syndrome, mental health, metabolic syndrome, neurosteroids, and of course, obesity.
The dot comparison refers to a type of puzzle for children, where the page is filled with numbered points that, when connected in the right way, form a recognizable picture. The concept is ancient, dating from before paper was invented. People looked up at the stars and by mentally drawing imaginary lines between the bright dots, they saw such figures as the ones shown on this page — Orion the hunter, and Sagittarius (one of the 12 constellations that make up the Zodiac).
Of course, the visionaries who commandeer the unconnected points and take it upon themselves to create pictures are often looked at askance. As University of California microbiologist Michael Fischbach says:
The scientific community has a way of remaining skeptical until every last arrow has been drawn, until the entire picture is colored in.
Similarly, a review in Nature expressed the same dot-connecting idea in different words:
Although the microbiota — gut–brain axis is a relatively new concept, information about communication along this axis has been delineated through different, converging means.
Getting back to the importance of diversity among the gut microbiota, MedicalNewsToday reported on a study which found that…
[…] infants with less diverse gut bacteria at the age of 3 months were more likely to be sensitized to specific foods — including egg, milk and peanut — by the age of 1 year, indicating that lack of gut bacteria diversity in early life may be a driver for food allergies.
The bacterium H. pylori, although it is capable of doing much harm, also performs some useful functions. Despite its bad behavior, it can apparently also calm the inflammatory response and convince the immune system to settle down and not be so defensive. The evidence is that groups of people that still have plenty of H. pylori are less susceptible to asthma and allergies.
Next time, Childhood Obesity News will look further into the relationship between the microbiome and allergy.
Your responses and feedback are welcome!
Source: “Mind-altering microorganisms: the impact of the gut microbiota on brain and behaviour,” October 2012
Source: “Can the Bacteria in Your Gut Explain Your Mood?,” NYTimes.com, 06/23/15
Source: “The gut microbiome: how does it affect our health?,” MedicalNewsToday, 03/11/15
Source: “Some of My Best Friends Are Germs,” MichaelPollan.com, 05/15/13
Photo credit: garlandcannon via Visual hunt/CC BY-SA