Kiran Krishnan answers important questions about the Human Microbiome.
What factors affect one’s microbiome and where does it come from?
“We’ve got 100 trillion organisms in our gut, actually in a very highly ordered system. What types of bacteria live in which sections of the gut is something that they’ve discovered to be a highly ordered system. You don’t find the same types of bacteria within the small bowel as you do in the large bowel for example, or even in the cross section of the intestine. You don’t find the same type of bacteria in the lumen versus the mucosa versus the epithelium layer.
These are layers within tissue that are millimeters apart, yet they are totally different ecologies.
The microbiome is really made up of thousands of different ecologies, micro-ecologies that work together synergistically in order to facilitate overall wellness.
Where does that complex ecology come from?
It actually comes from mom for the most part. 99.9% of our microbiome comes during the birthing process, passing through the vaginal canal and then also from breastfeeding in the early stages right after birth. Breast milk contains 600 to 800 different species of probiotic bacteria, and one of the biggest nutritional components of breast milk are almost 200 different oligosaccharides that the baby can’t even digest for energy. It’s there to act purely as a prebiotic to see the baby’s gut after birth. That’s how powerful the influence of mom’s microbiome is to the baby.
Mom passes on her microbiome to the baby.
It becomes extremely important for mom to have a healthy microbiome while she’s pregnant and giving birth so that she passes on a healthy microbiome to the baby.
A lot of allergies and a lot of these immune dysfunctions and all, we used to think came from genetics, from mom and dad, but it’s not.
It actually comes with the microbiome that the mom passes on to the child. If the mom is allergic to things and has environmental allergies or food sensitivities, she’s going to pass it onto the kids through her microbiome. That’s where it comes from.
838 days after you’re born, that’s about two and a half years after you’re born, you’ve basically established your full adult microbiome.
You’ve got 100 trillion cells in there. You’ve got 2,000 to 3,000 species in there. You’ve got your full adult microbiome already in two and a half years of age. From that point on, it’s a matter of creating an environment within your gut to facilitate the growth of the good bacteria versus the bad bacteria, because everybody’s gut has got a combination of good and what we would call bad bacteria.
Most of the bad bacteria in our gut really aren’t bad in the sense. They have a function. They play an important role. Like H. pylori, for example, something that most people hear about. If medical doctors see H. pylori in your test, they’re going to put you on a whole regimen of antibiotics to try to get rid of it, and there’s a whole book that’s been written by Martin Blaser of NYU called “Missing Microbes: How the Overuse of Antibiotics Is Fueling Our Modern Plagues Paperback – February 3, 2015″ where he really focuses on the H. pylori epidemic where we’ve been systematically getting rid of H. pylori and that has actually increased the risk of gastro-esophageal reflux disease and also cancers, because H. pylori plays a very important role in the acidity of the gut and control of the gastric system as well.
What are some of those things that actually creates an impact to the microbiome in a negative way?
For one, antibiotics use. Antibiotics, especially early on in life, if you use antibiotics within the first four years of life, it dramatically increases your risk for developing things like metabolic syndrome, allergies, asthma, psoriasis, and eczema and so on. So it really affects how the rest of your life is going to look if you’ve used antibiotics in the first couple of years of life.
Most of us know that kids have ear infections quite frequently, sinus infections. Many kids within the first four years of life had been on full five, six rounds of antibiotics already. That has a big impact.
But even as an adult, an antibiotic course can have a major impact. One study shows that a single 10-day course of clindamycin, it took your microbiome almost a year to recover from it, assuming you didn’t take any real specific steps to try to gain it and recover.
The second factor is food. Diet plays a huge role in your microbiome. In fact, diet can change your microbiome within a 24-hour period. It can change what your microbiome looks like. Remember, your diet is what feeds the bacteria within your gut, and what you eat will select for the types of bacteria that grow in dominance within your gut. So that has a major effect.
Age has a major effect. As you age, your microbiome diversity tends to shrink, and what you want to do as you age is you want to try to increase the diversity of the microbiome because a diverse microbiome is the healthiest form of a microbiome. As the diversity shrinks, you increase risk for chronic illnesses.
The other thing that affects the microbiome is of course your environment. Households that use things like Clorox based cleaners tend to have kids that get more frequently sick. In fact, they tend to have high incident rates of allergies and asthma because those household type cleaners actually affect the microbiome.
Fluoride in the drinking water and preservatives in packaged foods and other antimicrobials that are found.
Just the hygiene hypothesis alone, just living too clean of a lifestyle has a negative impact on your microbiome. Not getting out there in the dirt as much, not getting dirty as much as we used to as a civilization and as a species has a huge impact on the microbiome.
There’ve been these studies where they compare the microbiome of people who are living in rural populations versus urban populations, same type of people, same type of food and genetics. The people in the rural population tend to have much more diverse and strong microbiome than those who live in urban population, which are much more sterile and less exposure to good environmental bacteria.
That’s the microbiome in a nutshell as far as what influences it and what has the negative impact and where does it come from.”
Kiran Krishnan is a clinical researcher and microbiologist with 18 years of experience.