Bacteria, Guts and Brains - Who’s In Charge?

Bacteria, Guts and Brains - Who’s In Charge?

written by: Dr. David Alter
by: Dr. David Alter
Gut image 1 Gut image 1

Bellies Before Brains

Living creatures didn't always have what we picture today as brains. Before actual brains there were bellies, or at least some primitive way to absorb nutrients from the environment existing outside the organism. If there was plenty of food available, flowing toward and past the ancient organism like in ancient oceans, there was no real need for a primitive brain in the head. After all, in those times there wasn't even a head to house a brain even if one were available! While it is strange to consider, brains developed largely to enable ancient life to move toward food sources. Still later, brains enabled creatures to successfully escape from other creatures determined to devour them! Brains were useful in this cat and mouse, eat or be eaten world.

Over time, ancient "guts" became more sophisticated as greater complexity of life forms required greater sophistication of their digestive processes, which were necessary for fueling ever-more complex metabolic needs. This is one reason that guts developed their very own brain called the enteric nervous system or enteric brain. There are so many nerves in the enteric system it has now come to be called our 2nd Brain. But, I think this is wrong. Our gut is really our 1st brain; it is our original brain! Recent medical science findings are beginning to recognize the primary and fundamental role that our enteric brain plays in powerfully shaping not only the health of the brain that sits inside our skulls but the health of the rest of our physical body, too.

Bacteria: Our Tiny, Innumerable and Essential Resident Aliens

The story of which of our brains is in charge of us gets even more interesting when we begin to consider that our enteric brain takes its orders from trillions of tiny creatures that live inside our gut. I am talking about the various families of bacteria that define our gut's diverse microbiome. Our guts contain more 30 trillion bacterial cells, which is more cells than what makes up our physical bodies! And, those bodies could not survive without the assistance of these tiny but essential creatures that live inside our digestive tracts. It sometimes seems our bodies exist largely to serve the needs of our bacterial resident aliens.

How "Good" Bacteria Help

Here is a short list of necessary health functions that bacteria perform. They are essential for pre-digesting certain foods so we can gain access to essential nutrients they contain. The gut microbiome enables the manufacture of key vitamins, enzymes and messenger molecules that travel through our bodies and brain and which are necessary for our survival. The gut's intestinal flora are powerful mood regulators and impact many brain functions involving attention, information processing and memory. Our gut's microbiome helps regulate our immune system and is involved in hormone production and regulation. The bacteria are essential for warding off infection and are generally important in detoxifying substances that could otherwise make their way into our bloodstream and cause untold misery and even death!

How "Bad" Bacteria Hurt

However, the news is not all rosy when it comes to the bacteria making up our gut microbiome. Different colonies of bacteria compete for dominance just as people and countries and cultures do. The gut's microbiome is an internal ecosystem. Like ecosystems in nature, our gut environment is in constant flux. Each bacterial type increases or decreases in number and influence on our overall health depending upon what we eat, drink and consume (e.g., nicotine or other drugs), how we sleep, how stressful our lives are, how meaningful and enlarging our work is, and how enriching and joyful our relationships are.

When the microbiome's "culture" is suboptimal for supporting our bacterial balance, our overall health suffers. We face a wide range of health challenges affecting our central brain and body.Those challenges include:

· Autoimmune diseases

· Wide-spread inflammatory conditions in the body and brain

· Infectious conditions, like Clostridium difficile (or C-diff)

· Irritable bowel syndrome (the most common gut disorder in the world)

· Depression, anxiety and other mood-related disorders

· Attentional difficulties, like ADHD

· Memory disorders, with evidence of increased risk of Alzheimer's disease

· Hypertension

· Menstrual and menopausal dysregularities, likehot flashes

· Diabetes

· Obesity

· Insomnia

Eating Our Way to Better Brain & Body Health

Quite a list, no? The connection between microbiome health, gut health and overall physical and mental health is highlycomplex. What we do know is that a powerful, overlooked, underappreciated and underutilized tool for health improvement involves paying attention to how we nourish our gut and the microbiome contained within it. Here are some basic starting blocks you can begin using right away. * (Talking with your medical professional about dietary changes is often an important first steps when using diet to help manage health conditions you may have.)

1. Probiotics: Introduce high quality probiotics into your diet.

a. Yogurts, kimchi, pickled vegetables, sauerkraut, tempeh, kefir

b. These fermented foods feed healthy bacteria so they're more able to block or kill off unhealthy bacteria that would otherwise contribute to illnesses.

c. These probiotics heal and maintain the lining of the digestive tract. This lining is a critical barrier that keeps "bad stuff" from moving through the lining into the blood stream and invading the rest of the body

2. Prebiotics: Introduce prebiotic foods into your diet.

a. Cooked onion, raw or lightly steamed asparagus, artichoke or leeks

b. Prebiotic foods feed healthy bacterial growth, a byproduct of which is the production of short-chain fatty acids that help regulate mineral and calcium absorption

c. Prebiotics make the intestinal ecosystem more acidic. This makes for an environment hostile to many "bad" bacterial growth and limits the mischief they can produce.

3. More Healthy Fat; Less Simple Carbs: Adjust the balance of these foods in your diet.

a. Leafy green vegetables, avocado, coconut oil, nuts, seeds, zucchini, broccoli, mushrooms, yogurt (and other probiotic rich foods)

b. These foods take a while to be broken down in the gut, which means that as they are converted to sugars (which all foods are), they are slowly released into the bloodstream. This regulates blood sugar levels, minimizes pre-diabetic pressures, and avoids the roller-coaster energy/attention highs and lows of high simple carb diets.

c. A diet rich in these foods is clearly connected to healthier brain functioning.

I invite you to educate yourself about your internal ecosystem. Your main brain depends on your enteric brain to function well. In turn, our enteric brain can't do its job without the support of our trillions of bacterial guests. As we seek to live our fullest and most joy-filled lives, we ignore the critical role of our gut-body-brain-mind connections in becoming our best selves at our own peril.

Material in this blog draws on the work of David Perlmutter, MD and described in Brain Maker, Little Brown Press, 2015

written by: Dr. David Alter

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