Summary: A new study shows that gut bacteria explain almost 58% of the differences in blood (plasma) metabolites, the small chemicals in your blood. So we may soon get blood tests that track changes in the gut microbiota. The gut microbiota (the bacteria living in your gut) plays a big role in health, especially in complex regional pain syndrome and pancreatic pain. Any shift in gut bacteria can raise the risk of many health problems, including these two. Yet we still know little about gut bacteria. And there are no reliable tests to measure changes in them.
More than 100 trillion microorganisms live in the human gut. Yet we know shockingly little about them. One thing is clear: they are not parasites. They live in partnership with us. Both sides gain.
Over time, the human body came to depend on these tiny one-celled beings. They help train the immune system. They supply vitamins, brain chemicals (neurotransmitters) and other active compounds. Studies show that when the gut population is thrown off, many health problems follow, including complex regional pain syndrome and pancreatic pain. Shifts in gut bacteria are tied to gut problems and to metabolic health problems. An unbalanced gut (dysbiosis) even raises the risk of mental health problems.
Many studies show that changes in gut bacteria cause disease. But there is one big problem. Science still does not know what a healthy gut population looks like. The reason is the huge variety of microbes in the gut. They are bacteria and fungi from many classes, orders and species.
However, untangling this puzzle is essential if we want to understand the human body fully. Understanding the gut microbiota and its role in health would help us prevent various health disorders and even treat health conditions. Of course, it does not mean that we do not know anything about them. We do know a lot, but it is still the tip of the iceberg. Science knows that bacteria like Lactobacillus are good for health.
Gut bacteria are hard to study. First, we need to know exactly what makes up this huge population. Second, we need to know what nutrients and active compounds they make. Right now we only know that these microbes number in the trillions. They probably make hundreds of useful compounds.
Still, science is learning fast. It already knows a lot about the metabolites gut bacteria make. In the new study of 8,583 people aged 50 to 64, about 58% of the differences in each person’s blood metabolites were tied to the mix of their gut bacteria. That is a massive number. It shows gut bacteria can shape many body functions by changing these blood chemicals. It appears gut bacteria have more say in our health than anyone once thought.
If we learn how blood metabolites shift when gut bacteria shift, we can manage disease better. We can also track the gut bacteria themselves.
Until now, the main way to study gut bacteria was to test gut tissue or stool in a lab. But it appears blood metabolites can also tell us a lot about gut bacteria. That matters in the clinic, because a blood test for metabolites is far easier than a lab study of gut tissue.
So in the future, we may see blood tests that show exactly how your gut bacteria are changing. Those tests could guide treatment and track whether it works.
Frequently asked questions
Can a blood test show your gut bacteria?
Not reliably yet, but the science is heading there. In a study of 8,583 people aged 50 to 64, about 58% of the differences in blood plasma metabolites were tied to differences in gut bacteria. That link suggests a simple blood test may one day show how your gut microbiota is changing. It could also track whether treatment is working.
How do doctors check gut bacteria today?
Right now the main way to study the gut microbiota is to test gut tissue or stool in a lab. These tests are harder than a blood draw. And there is still no reliable test for measuring changes in the gut microbiota. Blood tests for plasma metabolites are much easier. That is why this research matters in the clinic.
What do gut bacteria do for your health?
More than 100 trillion microorganisms live in the human gut, in a partnership that helps both sides. They help train the immune system. They supply vitamins, brain chemicals and probably hundreds of other useful compounds. They release metabolites into the blood. Through them, gut bacteria have more say in how the whole body works than scientists once thought.
What happens when gut bacteria are out of balance?
A thrown-off gut population is called dysbiosis. It is linked to gut problems, metabolic health problems and a higher risk of mental health conditions. It is also tied to painful disorders, including complex regional pain syndrome and pancreatic pain. Science still cannot define a healthy gut population because it is so varied. That is why better testing matters.
Dr. Gurpreet Singh Padda, MD, MBA, MHP
