The Thoughtful Gut: Part II

The Thoughtful Gut: Gut-Brain Axis

The Thoughtful Gut: Part II

If you missed The Thoughtful Gut: Part I, click here

Gut-Brain Axis

Our microbiome and brain are like best friends who talk through a special line called the gut-brain axis. They send messages using nerves, hormones, inflammation, and other signals. This connection helps keep our microbiome and gut healthy.

Some scientists say the gut works like a second brain and call it the “enteric nervous system” (ENS). This is because the gut does more than digest food. It plays a big role in keeping us healthy and fighting off sickness.

Gut-Brain Axis


Here are several reasons why the gut is considered a “brain”:

The Gut Has So Many Feelings

There are many influences on our behavior, mood, and gut health. Research has found that tiny bugs in our gut, known as gut flora can alter our behavior and mood. The types of gut flora in our microbiome contribute to various health conditions along the gut-brain axis. They can have effects like increasing feelings of depression, irritation, or anxiety. They also have an impact on conditions like autism and adhd. This shows that the microbiome and brain work together in a complicated way.

If you’re a science geek, this is a nice research article highlighting their relationship.

Here’s how they interact:

Neurotransmitter Production: Some gut flora can actually make neurotransmitters like serotonin, dopamine, and GABA. In Part 1, I discussed how neurotransmitters influence mood, behavior, and gut health.

Short-Chain Fatty Acids (SCFAs): Gut flora make SCFAs by breaking down dietary fibers. This process is “fermentation.” SCFAs can modulate the production and function of gut neurotransmitters. Fibers that are often broken down by gut flora into SCFAs include:

Soluble fiber: This dissolves in water in our microbiome and turns into a gel-like substance. Good gut flora in our microbiome ferment this into chemicals. These chemicals, such as acetate, propionate, and butyrate, improve gut health. Foods like oats, beans, apples, and sweet potatoes have lots of soluble fiber.

Resistant Starch: This is a type of starch that resists digestion in the small intestine. It travels to the large intestine where gut flora ferment it. Resistant starches convert into SCFAs by gut flora. Sources of resistant starch include green bananas, cooked and cooled potatoes, and legumes.

Inulin and Fructooligosaccharides (FOS): These are prebiotic fibers. Beneficial gut flora ferment them to produce SCFAs. Foods rich in inulin and FOS include onions, garlic, leeks, and chicory root. These fiber types are fuel for the beneficial gut flora. These are crucial for gut health, metabolism, and general well-being.

If certain foods make you feel gassy, bloated, or change your mood, it’s best to get tests to figure out the problem. I have ways to check your microbiome and brain messengers. I use this information to improve gut health and boost mood.

This will balance your gut-brain axis.

Dendrites Microbes Communicate


The Gut Is A Protective Barrier

Your gut also has a big job in making sure you stay healthy. It works to keep the bad gut bacteria away and helps you fight off sickness.

There is interaction between commensal (friendly and necessary) gut flora and immune cells. This interaction signals infection through detailed and sophisticated processes.

Let’s break this down into more straightforward terms:

Dendritic Cells: These are cells in our body’s defense system that “walk around” in our microbiome. When the good gut flora notice bad gut bacteria or sickness, they send out signals to alert the dendritic cells. The dendritic cells then either fight the sickness or tell the other immune cells about it.

Macrophages: These are another type of bad gut bacteria fighting cells in our microbiome. When our body’s friendly gut flora find harmful gut flora they release special chemicals. These act like messages that get sent to the macrophages.

Once they get these messages, the macrophages become more alert. They are better equipped to recognize and attack the harmful gut flora. The molecules from the good gut flora act as a signal booster for the macrophages. They get more efficient at their job of detecting and destroying harmful gut flora in the microbiome.

T Cells: Good gut flora can tell dendritic cells to make signals that activate T cells. T cells are important because they can fight off infected cells. They also make the microbiome and immune system stronger, and help it not to attack the body’s own healthy cells. When the body’s immune cells attack it’s own healthy cells that’s called an autoimmune condition.

B Cells: These cells make antibodies that fight off bad gut bacteria. Good gut flora can help these B cells by sending special signals. They might use dendritic cells to make antibodies that target specific bad gut bacteria.

Inflammation and Barrier Function:

Inflammation is another way to send immune system messages. When gut flora irritate the gut they can weaken the microbiome and barrier. The cells become puffy and irritated, allowing harmful things to get into areas they don’t belong.

These gut flora, and the inflammation they cause, can send messages to our brain. This happens through the neurotransmitters we discussed in Part 1. These messages can affect how we feel. The way we eat, manage stress, keep our microbiome healthy– they are part of a foundation of health. They help this barrier stay strong.


The Gut Does Its Own Thing


Your gut is pretty cool because it can take care of its work on its own. It knows how to handle the food you eat. It makes sure everything runs smoothly without you having to think about it. It is able to change functions in response to a variety of messages entering the gut-brain axis. This demonstrates a form of ‘decision-making’ in the digestive process.

The gut is like a “brain” or a thinking organ, but not because it has conscious thought. It is because of its complex nervous system, the production of neurotransmitters, and involvement in the gut-brain axis. It also has a significant impact on mood, behavior, and overall health. This is why maintaining a healthy gut is so important for physical and mental well-being.

That was A LOT of information. I’ll let you “digest” (lol) it and we’ll get into the hormones in Part 3.

Schedule your free phone consultation HERE.

Dr. Lisa Fortes-Schramm
Naturopathic Doctor
(408) 357-3422
San Jose Integrative Medicine
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Dr. Lisa Fortes Schramm

Dr. Lisa Fortes-Schramm is a Naturopathic Doctor, a Doctor of Traditional Chinese medicine, and has two degrees in the mental health field. She is experienced in treating people with anxiety and depression. If you’re experiencing anxiety and/or depression, or suspect you may be, talk with Dr. Fortes and she can tell you about your Naturopathic options.