The Gut-Brain Axis – Where your big brain meets your little brain
We often hear the phrase “the gut is the 2nd brain”, but what does this mean exactly? Whilst many of us can admit to thinking with our tummies on the odd occasion, the brain and the gut remain 2 very separate systems with very different functions. What they do share in common is the ability to communicate.
Picture your gut and brain as 2 familiar friends having a phone conversation.
The gut is the “chatterbox” of the two, with most of the ‘conversation’ being directed from the gut to the brain, mainly via the vagus nerve.
Now picture the various pathways via which the gut and brain communicate (such as hormonal, neural and immune) as the phone line.
To help the conversation flow a little easier, the gut and the brain speak the same language in the form of messenger molecules such as hormones, neurotransmitters and cytokines.
What messages are sent depends on many factors, including the balance of microbes in your gut.
The gut microbiome sets the ‘tone’:
The gut-brain axis is now more commonly referred to as the microbiome-gut-brain axis, due to the significant role the microbiome plays in coordinating communication between the two systems. Think of the microbial balance in the gut as setting the ‘tone’ of the conversation. If the gut microbiome is in balance according to the hosts needs, the conversation is filled with ‘good’ messages which are expressed in the form of a healthy body and mind.
If the gut microbiome is imbalanced (AKA dysbiosis), the conversation can lead to ‘bad moods’ on both ends. In other words, both the gut and the brain can express signs and symptoms of health imbalances, including digestive discomfort, stress and mild anxiety for example.
Supporting the gut-brain axis with a healthy food (and thought) diet:
One of the ways you can support the health of your microbiome, gut and brain is via your diet.
This not only involves your food diet, but also your ‘thought diet’.
Just like with food, your thoughts need to be consumed and processed before they can then be expressed in a physical way. For example, eating a diet rich in nutrients can help support a healthy body and mind, whereas eating a diet rich in junk food does the opposite.[i] The same goes for your thoughts. Over-consuming ‘junk thoughts’ like reading too much negative news, or engaging in frequent negative conversations or arguments, can lead to physical signs of stress and tension. Whereas, resting the mind, meditating and taking peaceful strolls in nature, can lead to improved health outcomes.
Synbiotics to support healthy brain(s) function:
Another way to support the health of your microbiome-gut-brain axis is through supplementing with a synbiotic. A synbiotic is defined as the combination of a probiotic with a prebiotic. A probiotic being a live microbe that offers health benefits, and a prebiotic being a food source that can be utilised by the probiotic.[ii]
Specific types of probiotics and prebiotics have shown to support the gut-brain axis by helping to restore beneficial gut bacteria, as well as support healthy gastrointestinal, immune and nervous function. Some species of probiotic bacteria have even begun to show promising outcomes in the reduction of symptoms of stress and mild anxiety.1
Polyphenols, including those found in herbs like saffron, can also act as prebiotics, in addition to having their own inherit stress relieving properties.[iii]
We all enjoy a friendly chat!
By understanding the role of the micobiome-gut-brain axis and its importance in health maintenance, we can take better steps to ensure our gut and brain enjoy the health benefits of a ‘friendly conversation’ for years to come!
If seeking specific advice on supporting your mental or physical health, talk to your health professional.
[i] Taylor AM, Holscher HD. A review of dietary and microbial connections to depression, anxiety, and stress. Nutritional neuroscience. 2020 Mar 3;23(3):237-50.
[ii]Swanson KS, Gibson GR, Hutkins R, Reimer RA, Reid G, Verbeke K, Scott KP, Holscher HD, Azad MB, Delzenne NM, Sanders ME. The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of synbiotics. Nature Reviews Gastroenterology & Hepatology. 2020 Nov;17(11):687-701.
[iii] Thilakarathna WW, Langille MG, Rupasinghe HV. Polyphenol-based prebiotics and synbiotics: potential for cancer chemoprevention. Current Opinion in Food Science. 2018 Apr 1;20:51-7.