What Is Your Gut Telling You?
Aug. 20, 2014 -- Scientists have long studied the link between our genes and our health. Now, in a growing area of scientific research, they're studying the link between the bacteria in our intestines and virtually every disease that ails us.
Bacteria -- along with viruses and fungi -- are microbes, and we're filled with them. For each one of your human cells -- that is, for every cell that’s “you” -- there are an estimated 10 microbial cells. They live everywhere in your body: on your skin and inside your mouth, your nose, your genitalia, urinary tract, and intestines.
Together, they form your body's unique collection of microbes, called microbiome -- partly inherited from your mother at birth and partly determined by your lifestyle. Due to their sheer number, there’s little question as to whether microbes have an impact on our health. Until recently, though, scientists didn’t know much more than that.
Bacteria are most likely the most abundant microbes in your intestines, and they're the focus of most scientific study. Looking at the DNA of the bacteria in stool samples, researchers want to know whether the bacteria cause particular diseases and what we can do to change it.
“There’s a good chance your microbiome is associated with every disease you can think of -- diabetes, cancer, autism,” says Michael Snyder, PhD. He's the director of Stanford University’s Center for Genomics and Personalized Medicine. “And the area where bacteria have a huge impact is your gut.”
What Is Gut Bacteria?
Bacteria line your intestines and help you digest food. During digestion, they make vitamins that are vital for life, send signals to the immune system, and make small molecules that can help your brain work.
“Without gut bacteria, we wouldn’t be anything. They are a critical part of us and essential to our health,” Snyder says.
Ongoing research reveals that people with certain diseases often have a very different mix of bacteria in their intestines compared to healthier people. Researchers are working to define the makeup of gut bacteria in a healthy person vs. the gut bacteria that can point to higher risk or presence of certain diseases.
Some evidence suggests it’s not the presence or absence of one particular type of bacteria that makes a microbiome a healthy one, but rather the diversity of bacteria.
“If you have a wide array of bacteria that can break down lots of different food sources, produce lots of different molecules that help mature your immune system, and produce the molecules that your brain needs to function properly, you can see how that would potentially be a benefit over a less diverse gut microbiome,” says Joseph Petrosino, PhD. He's the director of the Alkek Center for Metagenomics and Microbiome Research at Baylor College of Medicine.