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How does Gut Health Affect Mental Health?

You may be wondering what in the world gut health and mental health have to do with each other! What in the world does digestion have to do with things like depression, anxiety and mental health? Quite a bit it turns out. You have probably heard that good digestion is foundational for good overall health, but I want to dive in a bit deeper and connect the dots specifically between digestion and mental health.

Why in the world would your digestive health have anything to do with your mood or mental health? Let’s start with serotonin. Serotonin production happens in the gut. Approximately 95% of your serotonin is produced in the intestines (1) Serotonin has a big impact on our mood. It makes us feel good. It helps regulate mood and it is very important for good sleep. So, if your gut isn’t producing the right amount of Serotonin because of digestive dysfunction, it can lead to feelings of depression, moodiness, cravings, poor sleep and addictive or OCD tendencies. Women seem to see these symptoms more commonly than men, although they are seen frequently in both males and females.

There are many prescription medications to address these symptoms. They are called SSRI medications or Selective Serotonin Re-uptake Inhibitors. They may temporary improve mood or symptoms of depression, but they do not address root cause and have many side effects (2) They can also be very addictive. I feel like a much better approach is to find the reason for the symptoms and treat the issue at the source.

Serotonin is just one issue with mental health. There are many other neurotransmitters (or brain chemicals) that are effected by digestive deficiencies. The B vitamins are very crucial for the proper production of these neurotransmitters (3) Vitamin B6 is especially critical. I do a lot of lab testing in my clinical practice, and I can tell you that I see B vitamin deficiencies in almost everyone I test!

A complicating factor in B vitamin status is a genetic variant called MTHFR which can lead to a functional deficiency in Vitamin B9 (folate) and B12 as well as an intolerance to certain forms of B9. As many as 40% of people in the general population are effected to some degree by this MTHFR variant. (4) When someone is effected by this, it can elevate levels of homocysteine, which causes inflammation. Inflammation is another topic entirely, but increased inflammation has been linked to many chronic health problems. You can find out if this genetic mutation effects you, or you can simply make sure you consume a good amount of B vitamins in a a format that is tolerated by everyone, even those with this genetic condition. Unfortunately, most B vitamins are not in this form.

I see clients very frequently who have developed anxiety, depression, or are struggling with mood issues. Many times they also can not sleep, which makes everything worse. They have tried the prescription medications and are not happy with the results or are worried about the long term side effects (which I think is wise). So, we begin the journey to assessing the situation and the health of the gut and improving on what needs help.

How do we do this? We start with a great conversation. Review your health history. Find out what you are eating, doing, what have you tried. All the things that we need to know about to form a helpful opinion. Next we add some testing. We look at all the major body systems, like your blood sugar handling, inflammation, nutrient markers, gut health, hormones, etc. so we can see where there are weaknesses. Then we will know what needs to be addressed. If you only look at things on lab testing that you think are the problem, you often miss other things that are really part of the underlying root cause, but just not as obvious. For example, I find that almost nobody has a proper blood sugar or thyroid evaluation and those are problems for so many people. They simply get missed because most doctors don't take a whole person approach.

We combine those labs, plus a good history and consider things like antibiotic use, oral contraceptives, and antacid or PPI medications can have a huge impact on gut health. Travel and exposure to pathogens that live in the gut can also be an issue. In cases where that is suspected, a digestive test can be a life-saver by helping us identify what is in the digestive tract that shouldn’t be there and then using the appropriate natural remedy to help eliminate it. The absence of healthy bacteria and undigested food particles also show up on a GI-Map test and help us narrow in on a good solution.

Some people want and need that level of analysis and testing. Others want to try the basics first. Here are some great starting points:

  • Clean up your diet – Eat an anti-inflammatory diet rich in health proteins (organic, grass fed), lots of veggies, some fruits and very limited amounts of grains and/or sugar if any

  • Drink plenty of pure, clean water (1/2 your body weight in oz) away from meals. Excessive drinking near meal times can cause stomach acid to dilute

  • Eat protein first in a meal – your stomach acid is strongest at the beginning of a meal and protein requires the strongest stomach acid

  • Supplement as needed with high-quality digestive supports. For most people, this looks like a good probiotic to help facilitate the growth of “good” bacteria, digestive enzymes to help break down and digest the nutrients in your food, a multi-vitamin with high quality, activated (methylated B vitamins) and some herbs that help with gut health like olive leaf and oregano.

If you have tried the strategies above and want to dig a bit deeper, consider meeting with a functional doctor to see what can be done. If you would like some custom 1:1 consulting, I am happy to help with that as well. You can click this link to schedule a short free consulation to ask quesitons. I will listen and if I think I can help, I'll tell you what that looks like in your case.

I hope this helped connect some dots between digestion and mental health. I find that frequently people have no idea of this connection and feel like their only answer is to struggle or to take prescription medications that they aren’t crazy about. I think there is a better way, a more natural way.

To your health,

Dr. Jeni

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I am interested in what you are saying about gut healt/mental health issue…I demanded blood work to be done, because I’m so worn out most of the time & weight gain in my belly & back mostly, my focus, my motivation, sugar craving, hair loss, dry skin…now feeling depressed because of it all…I know I could be worse, but I feel that if this keeps up..more health issues are waiting to come..

my blood work showed my B 12 as deficient as well as my doctor said, she doesn’t treat these issues so she doesn’t recommend or prescribe anything to help me. So, here I am, a whole year later, still feeling & looking I just give up..I’m…

Jeni St Onge
Jeni St Onge
Mar 20, 2023
Replying to

Hello Judy, Thanks for reaching out. If you would like to chat, you can use the link below to schedule a free consult. We can talk through what we could do to get you feeling better and back to doing what you love! I work with people all over the country via tele-health, so if we are a good fit, I would love to help!

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