Probiotics, Your Microbiome and Your Mood

Have you ever noticed that what you eat impacts your mood? Have you felt worse after binging on junk food or after a night of drinking? There is compelling research suggesting that it may not be just the guilt talking - your microbiome may be contributing in a large way to the conversation.  

What is the microbiome?  

There are 10- to 100-trillion symbiotic microbes of various species existing in and around the human body, collectively referred to as the microbiome [1]. These friendly microbes outnumber your own human cells and have recently become popularized for the growing body of evidence detailing the vast impacts they have on human physiology and behaviour. 

The microbes in your intestines make vitamins, amino acids, hormones, neurotransmitters and other signaling molecules that impact the way your brain and body function [2], [3]. They also produce short-chain fatty acids as byproducts that your intestinal cells use for energy, which contributes to healthy gut function [3].  

These microbes live in our digestive tract and survive off the foods that we eat. Just like any other living organism, their health (and therefore ours) depends on consuming a healthy diet. It has been shown that dietary changes (e.g. from animal-based to plant-based), as well as any significant systemic stress and inflammation can alter the composition (i.e. diversity and abundance of species) of your microbiome within just 24 hours [3].  

Altered microbiome composition has been associated with many conditions, such as inflammatory bowel disease (IBD), psoriasis, atopic dermatitis, autoimmune arthritis, type 2 diabetes, obesity, and atherosclerosis [3]. This is not surprising given the significant role these organisms have in regulating metabolism and immunity. In fact, researchers are finding that the microbiome composition in a given disease seem to have a different complement of microbes associated with it. For example, an IBD microbiome has less diversity (fewer species of healthy microbes), and lower numbers of good bacterial species. Therefore, it has lower short-chain fatty acid production [3]. Short-chain fatty acids (SCFAs) are essential to the health of your intestinal cells and are also thought to be anti-inflammatory in the gut [3]. 

The Microbiome’s Effect on Mood & Behaviour  

Gut microbes relay messages to the brain via various direct and indirect mechanisms - bacterial metabolites, metabolic precursors, immune signalling, vagus nerve signalling, and Hypothalamic Pituitary-Adrenal axis activation [4], [5]. It is through these mechanisms that neurodevelopment or neurodegeneration are influenced [5]. A significant portion of the microbiome influence on the brain comes via the gut-brain axis: a bi-directional pathway connecting the nervous system in your digestive tract to the central nervous system (your brain) [4], [5]. As shown in the graphic below, your gut and your brain communicate directly via nerves that transmit different signals and molecules, which can have a profound effect both ways to both systems [6].

Photo credit: https://fhs.mcmaster.ca/forsythe-lab/microbiota_gut_brain_axis.html 

Considering the gut-brain axis and the physical manifestations that different microbiome composition can produce, it should be no surprise that there are mental/emotional implications as well. Many psychiatric and neurological pathologies have gastrointestinal co-morbidities, including schizophrenia, autism, neurodegenerative diseases, anxiety, and depression [7]. As noted above, different pathologies have different microbiome composition. This extends to mood and neurodegenerative disorders, such as major depressive disorder, schizophrenia, Parkinson’s disease, and autism spectrum disorder [2], [5], [8]. There is also data suggesting that alterations in the microbiome from addictions (e.g. alcohol, cocaine) may be associated with substance cravings and increased risk of developing associated psychiatric disorders, such as anxiety and depression [9], [10]. 

Probiotics & Your Mood 

Probiotics are supplements that contain healthy microbes that ,when ingested, influence the health of your microbiome. Probiotics used to benefit mood and cognition have been coined “psychobiotics,” and are a burgeoning new area of interest in research. A study by Tillisch et al. used brain scans (functional magnetic resonance imaging) to demonstrate the ability of probiotics to alter brain activity in areas associated with processing emotion and sensation, and to reduce negative thinking associated with sad mood [4], [7], [11], [12]. While most studies indicate that further research in this area is needed, associations between specific strains of microbial species and their benefits on various conditions are rapidly emerging [7], [13][14]. A recent human clinical trial of adjunctive probiotic intervention for Major Depressive Disorder (MDD) showed that compared with placebo, probiotic intervention exhibited greater improvement in depressive symptoms [15]. Participants who received the probiotic intervention experienced reductions in both depression and anxiety, and the probiotics were well-tolerated, prompting the authors to suggest probiotics as an acceptable adjunctive intervention for adults with MDD [15]. 

How Can I Support My Microbiome? 

Lifestyle 

A healthy lifestyle goes a long way in supporting your microbiome, and healthy eating is just one part of it. As mentioned earlier, dietary changes, significant systemic stress, and inflammation can alter your microbiome within just 24 hours. There are many different types of stress - physical, mental and emotional - that can lead to physiologic changes that can alter the microbiome. Practicing stress management through self-care, meditation, social connection, thoughtful schedule planning, getting adequate sleep, and setting appropriate boundaries with people and responsibilities will help you be more resilient in dealing with stress. The better you are at managing stress, the less likely it will spill over into added physical or mood-related symptoms.  

Digestive Supports 

Probiotics are a great start to improving your gut health and mood, though quality and potency matter!  Our naturopathic doctors are here to assess if and which type of probiotics are most suitable for you, as well as to review if any further testing or treatments are indicated to optimize your digestive and mental health.  

We are here to help, so reach out if you are looking for professional guidance! 

In Health,  

Dr. Jacalyn Sieben, ND 

[1] Ursell, L.K. et al. (2012). Defining the human microbiome. Nutrition Reviews. Vol. 70 (Suppl. 1):S38- S44. doi:10.1111/j.1753-4887.2012.00493.x

[2] Dinan, T.G. & Cryan, J.F. Mood by microbe: Towards clinical translation. Genome Medicine. 8:36. DOI  10.1186/s13073-016-0292-1

[3] Corfe, B.M. et al. (2015). The multifactorial interplay of diet, the microbiome, and appetite control:  current knowledge and future challenges. Proceedings of the Nutrition Society. 74, 235-244.  doi:10.1017/S0029665114001670

[4] Dinan, T.G., Stilling, R.M., Stanton, C., Cryan, J.F. (2015). Collective unconscious: How gut microbes shape human behavior. Journal of Psychiatric Research. 63:1-9. http://dx.doi.org/10.1016/ j.jpsychires.2015.02.021

[5] Sharon, G. et al. (2016). The central nervous system and the gut microbiome. Cell. 167. http:// dx.doi.org/10.1016/j.cell.2016.10.027

[6] McMaster University. (2019). The microbiota-gut-brain axis. [Digital Image] Retrieved from: https:// fhs.mcmaster.ca/forsythe-lab/microbiota_gut_brain_axis.html

[7] Sampson, T.R. & Mazmanian, S.K. (2015). Control of brain development, function, and behavior by the microbiome. Cell Host & Microbe. http://dx.doi.org/10.1016/j.chom.2015.04.011

[8] Jiang, H. et al. (2015). Altered fecal microbiota composition in patients with major depressive disorder. Brain, Behavior, and Immunity. 48:186-194. http://dx.doi.org/10.1016/j.bbi.2015.03.016

[9] Hillemacher, T., et al. (2018). Alcohol, microbiome, and their effect on psychiatric disorders. Progress in Neuro-Psychopharmacology and Biological Psychiatry. Volume 85, Pages 105-115. https://doi.org/ 10.1016/j.pnpbp.2018.04.015

[10] Kiraly, D.D. et al. (2016). Alterations of the host microbiome affect behavioral responses to cocaine. Scientific Reports. 6:35455. DOI: 10.1038/srep35455

[11] Rea, K., Dinan, T.G., Cryan, J.F. (2016). The microbiome: A key regulator of stress and neuroinflammation. Neurobiology of Stress. 23-33. http://dx.doi.org/10.1016/j.ynstr.2016.03.001

[12] Tillisch, K., Labus, J., Kilpatrick, L., Jiang, Z., Stains, J., Ebrat, B., Guyonnet, D., Legrain-Raspaud, S., Trotin, B., Naliboff, B., et al. (2013). Consumption of fermented milk product with probiotic modulates brain activity. Gastroenter- ology 144, 1394–1401. DOI: https://doi.org/10.1053/j.gastro.2013.02.043

[13] Foster, J.A., Rinaman, L., & Cryan, J.F. (2017). Stress & the gut-brain axis: Regulation by the microbiome. Neurobiology of Stress. 124-136. http://dx.doi.org/10.1016/j.ynstr.2017.03.0 01

[14] Sarkar, A. et al. (2016). Psychobiotics and the manipulation of bacteria-gut-brain signals. Trends in Neurosciences. Vol 39, No. 11. http://dx.doi.org/10.1016/j.tins.2016.09.002

[15] Nikolova VL, Cleare AJ, Young AH, Stone JM. (2023). Acceptability, Tolerability, and Estimates of Putative Treatment Effects of Probiotics as Adjunctive Treatment in Patients with Depression: A Randomized Clinical Trial. JAMA Psychiatry. doi:10.1001/jamapsychiatry.2023.1817

How Optimizing Gut Health Can Keep Your Cholesterol Levels in Check

First off, what is cholesterol anyway?

Cholesterol is a waxy, fat-like substance that is produced by your liver. Cholesterol is actually vital for many different structures and functions in the body such as the formation of cell membranes, hormone production, and the synthesis of vitamin D from the sun. So if it plays all of these key roles, why are we so concerned when cholesterol levels get high?

You may have heard by now that we have “good” (HDL) and “bad” (LDL) types of cholesterol. HDL and LDL stand for high density and low density lipoprotein. These are particles made from fat and protein that attach themselves to cholesterol to transport them throughout the blood stream. LDL is associated with the bad form of cholesterol as its function is to carry cholesterol to the arteries. When LDL levels get too high it may collect in vessel walls and contribute to plaque formation (atherosclerosis) in addition to increasing your risk of heart disease and stroke. HDL on the other hand functions by transporting cholesterol back to the liver – almost like a clean up crew- to prevent blood cholesterol levels from getting too high. So when cholesterol gets returned to the liver – what happens next? In the liver, cholesterol is secreted directly into bile where it is then secreted into the intestines. This is where optimizing gut health comes into play.

Once cholesterol reaches the intestines one of two things can happen. One, the bile is removed from the body via fecal excretion or two, the cholesterol is re-absorbed by enterocytes (cells that line our gut) and returned back to circulation. The intestine typically absorbs about 50% of the cholesterol presented to it – but this can vary from 20%-80% depending on the person. Of the absorbed cholesterol, approximately 80% comes from bile and only ~20% comes from diet (which is why eggs might not be so bad after all). Given that it seems our bodies own production and subsequent elimination of cholesterol seems to be the larger issue, how can we help swing our reabsorption percent from 50-80% down to 20%?

1. FIBER:

   • Soluble fiber can reduce the absorption of cholesterol into your blood stream. Insoluble fiber decreases intestinal transit time thus promoting regular bowel movements to ensure your LDL cholesterol is being eliminated efficiently. It is suggested to consume between 25-30g of fiber per day.

   • Soluble fiber foods: Brussels sprouts, avocados, flax seeds, and black beans

   • Insoluble fiber foods: nuts, beans and vegetables, such as cauliflower, green beans and potatoes

2. Probiotics:

• Probiotics are healthy bacteria found in our gut. Fermented foods contain them and fiber containing foods feed them. Probiotics are suggested to reduce cholesterol by deconjugating bile acids, using cholesterol for nourishment, and/or incorporating cholesterol into the cell wall of the probiotic bacteria. Probiotics also help to keep us regular which decreases the chance for cholesterol to become re-absorbed.

• Sources of probiotics: yogurt, sauerkraut, kimchi, kombucha, miso, tempeh, pickles.

Lastly, outside of gut health and moving more into diet in general, the Mediterranean diet has been shown to be an effective approach to supporting healthy cholesterol levels. The Mediterranean diet includes the following:

Increased Omega 3 consumption:

• Foods high in omega 3’s can increase HDL while reducing triglycerides — a type of fat found in blood — as well as reduce your blood pressure and risk of developing blood clots.

• Omega 3 rich foods: Fish and other seafood (especially cold-water fatty fish, such as salmon, mackerel, tuna, herring, and sardines) Nuts and seeds (such as flaxseed, chia seeds, and walnuts)

Increased consumption of Nuts/Seeds:

• Almonds and other tree nuts can improve blood cholesterol levels by reducing LDL. Almonds have been suggested to reduce LDL levels by reducing LDL reabsorption in the gut, increasing cholesterol and bile secretion into the gut, and regulating enzymes involved in cholesterol syntheses. 

Olive oil:

• Foods that contain monounsaturated fats (including olive oil) may raise HDL (good) cholesterol. The least processed form of olive oil to use is cold pressed extra virgin olive oil.

In health,

Dr. Brittany Pearce, ND., RHN.

References:

Vrins CL. From blood to gut: direct secretion of cholesterol via transintestinal cholesterol efflux. World J Gastroenterol. 2010;16(47):5953-5957. doi:10.3748/wjg.v16.i47.5953

Jesch ED, Carr TP. Food Ingredients That Inhibit Cholesterol Absorption. Prev Nutr Food Sci. 2017;22(2):67-80. doi:10.3746/pnf.2017.22.2.67

Freeman AM, Morris PB, Aspry K, Gordon NF, Barnard ND, Esselstyn CB, Ros E, Devries S, O'Keefe J, Miller M, Ornish D, Williams KA, Batts T, Ostfeld RJ, Litwin S, Aggarwal M, Werner A, Allen K, White B, Kris-Etherton P. A Clinician's Guide for Trending Cardiovascular Nutrition Controversies: Part II. J Am Coll Cardiol. 2018 Jul 31;72(5):553-568. doi: 10.1016/j.jacc.2018.05.030. PMID: 30049315.

Cohen DE. Balancing cholesterol synthesis and absorption in the gastrointestinal tract. J Clin Lipidol. 2008;2(2):S1-S3. doi:10.1016/j.jacl.2008.01.004

Cartolano FC, Dias GD, Miyamoto S, Damasceno NRT. Omega-3 Fatty Acids Improve Functionality of High-Density Lipoprotein in Individuals With High Cardiovascular Risk: A Randomized, Parallel, Controlled and Double-Blind Clinical Trial. Front Nutr. 2022 Feb 23;8:767535. doi: 10.3389/fnut.2021.767535. PMID: 35281761; PMCID: PMC8905646.

Berryman CE, Preston AG, Karmally W, Deckelbaum RJ, Kris-Etherton PM. Effects of almond consumption on the reduction of LDL-cholesterol: a discussion of potential mechanisms and future research directions. Nutr Rev. 2011 Apr;69(4):171-85. doi: 10.1111/j.1753-4887.2011.00383.x. PMID: 21457263.