Tuesday, 01 August 2017 18:13

Nutrients for Brain Health

The best nutrients for brain health (and how to get them)
 
There are so many nutrients that you need for overall health. Vitamins, minerals, probiotics, and essential fats, just to name a few.
 
But which ones are the most important for your brain? 
 
Which nutrients can help with brain development of infants, improve moods, and reduce the risk of dementias like Alzheimer’s?
 
Yes, of course, you need an array of nutrients! But, there are five real brain health “winners” here.
 
Let’s go over the brain boosting benefits of omega-3s, vitamin D, B vitamins, magnesium, and probiotics.
 
OMEGA-3s
 
Omega-3s are a type of essential fat. They are arguably the most important nutrients for brain health. 
 
If you take away the water weight, your brain is 60% fat. And 25% of this fat is omega-3s; in particular, the omega-3 called “DHA” (docosahexaenoic acid).
 
Omega-3s have many functions in the brain, for example, they help nerve cells insulate their electrical signals, stabilize their membranes, and reduce inflammation.
 
Omega-3s are critical for baby’s brain development. Getting enough omega-3s during pregnancy can help improve baby’s intelligence and reduce the risk of behavioural problems. 
 
People who regularly eat and/or have higher blood levels of omega-3s are less likely to be depressed. And several studies have shown that when people with mood swings, depression, or anxiety start taking omega-3 supplements, some of their symptoms improve.
 
In terms of age-related mental decline, studies also show that people with higher Omega-3 intakes have a lower risk of Alzheimer’s.
 
OK - They’re great for brain health, but how do I get enough omega-3s?
 
You can get the recommended amount of omega-3s, including DHA, from eating two servings of fatty fish each week.
 
Simple! Have a wild salmon steak and a shrimp stir fry one week. Then have some smoked mackerel and baked cod another week.
 
In terms of supplements, as little as 0.5 grams (500 mg) of fish oil each day is enough for most people to get the minimum recommended levels. Many fish oil supplements come in 1 g (1,000 mg) doses, and that may be just fine on a daily basis (check your labels to make sure).
 
VITAMIN D
 
Vitamin D is another vitally important brain nutrient.
 
Vitamin D is both neuroprotective (protects nerve cells) and neurotrophic (help nerve cells grow).  And there are vitamin D receptors in areas of the brain involved with depression.
 
Prenatal vitamin D status is thought to play an important role in brain development, cognitive function (ability to think), and psychological function. For example, children born of mothers with low blood levels of vitamin D have a higher risk of developing schizophrenia later in life.
 
In adults, low blood levels of vitamin D have been associated with multiple sclerosis, depression, and cognitive impairment, including Parkinson’s Disease.
 
How can I get enough vitamin D?
 
Your skin makes vitamin D when it’s exposed to the sun. There are many factors that can affect how much sunshine you need to make enough vitamin D, for example, location, season, clouds, clothing, etc.. However, you don’t necessarily want to trade a vitamin D deficiency for potential skin cancer concerns.
 
Vitamin D is naturally found in a few foods such as fatty fish, liver, and egg yolks. It is also added to certain foods such as milk, some orange juices, breakfast cereals, and yogurt; so check your labels to find out if yours have it.
 
When it comes to vitamin D, supplementation may be a good way to go.
 
Ideally, your health care provider would test your blood for levels of vitamin D and recommend a certain amount.
 
However, if you don’t have a blood test, the safest way to take the vitamin D supplements is to use them as directed on the label. And never take more than 10,000IU/day, unless specifically told to by your health care provider. 
 
B VITAMINS
 
There are several essential B vitamins (B1, B2, B3, B5, B6, B7, B9, B12), and they’re particularly important for brain health. In fact, B vitamin deficiency is a leading cause of neurological impairment and disability throughout the world!
 
The B vitamins are so important for brain health that each one is actively transported across the blood brain-barrier. This means that your body spends energy to pull those B vitamins into the brain. And many of these vitamins are found in the brain in much higher concentrations than in the blood.
 
The B vitamins work together and sometimes work with enzymes. They have many roles in brain function. These include as antioxidants, helping the neurons (nerve cells) maintain their structure and function, helping the brain to produce energy (which your brain needs a lot of). B vitamins are also necessary for the production of essential neurochemicals as well.
 
Chronic low levels of several B vitamins are associated with depression, ALS (amyotropic lateral sclerosis), some psychiatric conditions, as well as neurodegenerative diseases such as Alzheimer's and Parkinson's.
 
And low levels of B12, in particular, are associated with some symptoms of mental disorders, smaller brain size, and poor memory.
 
In fact, some of the benefits of B vitamins on brain health seem to work with omega-3s. So make sure you get enough of both.
 
You can get B vitamins, except B12, from plants. Leafy greens, fruits, and vegetables are great sources, and by eating animal products (who ate those plants), you are also getting some B vitamins. Not to mention that some foods have B vitamins added to them, so check your labels.
 
Vitamin B12 is found in meat, fish, eggs, and algae.
 
B vitamins can be found individually or in supplements as a complex (B complex). Some of those complexes may not include vitamin B12, so again, check your labels. You may need to take B12 supplements separately, especially if you avoid animal products.
 
MAGNESIUM
 
Magnesium is an essential mineral used by the body for over 600 functions.  Functions like: energy production, nerve function, and blood pressure.
 
Magnesium deficiency has been associated with a number of brain diseases, including migraine headaches, depression, Alzheimer’s, and stroke.
 
One of the ways that magnesium helps neurons is that it helps to control the flow of calcium into and out of those cells. If there isn’t enough magnesium, this can lead to nerve cell damage.
 
Getting more magnesium has been shown to help improve moods and can help to prevent migraines and reduce their symptoms.
 
The foods highest in magnesium include spinach, nuts, legumes, and potatoes.
 
In terms of supplements, magnesium is available in many formats including magnesium citrate, magnesium sulfate, magnesium chloride, and magnesium oxide. If you do need a magnesium supplement, I recommend the forms without oxide because they’re more easily absorbed and cause less digestive disturbances.
 
PROBIOTICS
 
You may have heard new research about the gut-brain connection, and this has great potential to help us use foods and supplements for optimal brain health.
 
You have friendly health-promoting microbes that live in your gut. Probiotics, on the other hand, are similar microbes that you can eat and supplement with. They’re what turn milk into yogurt, and cabbage into sauerkraut. They’re great for your gut health, and brain health as well.
 
Several studies show that after a few weeks of ingesting probiotic foods or supplements, healthy people’s negative thoughts and sad moods reduce. Several other studies show that taking probiotic supplements helped improve symptoms of anxiety, depression, and stress in otherwise healthy people. In one study, people diagnosed with depression took probiotic supplements and their symptoms improved as well. 
 
Studies also show a reduction in some symptoms of multiple sclerosis after supplementing with probiotics.
 
There are a wide variety of probiotic supplements available for sale.
 
SUMMARY
 
Overall, there are several key nutrients for optimal brain health. They are omega-3s, vitamin D, B-vitamins, magnesium, and probiotics.
 
They have wide-ranging brainy benefits from helping baby’s brains develop, to improving moods, to reducing symptoms of depression and multiple sclerosis, to reducing risk of dementias like Alzheimer’s and Parkinson’s.
 
Many of them work together, and it’s important to get enough of each of them every day.
 
Overall, I recommend a variety of nutrient-dense, minimally-processed foods to meet your daily needs, but sometimes a supplement may help.
 
REFERENCES:
 
Akkasheh, G., Kashani-Poor, Z., Tajabadi-Ebrahimi, M., Jafari, P., Akbari, H., Taghizadeh, M., Memarzadeh, M.R., Asemi, Z. & Esmaillzadeh, A. (2016). Clinical and metabolic response to probiotic administration in patients with major depressive disorder: A randomized, double-blind, placebo-controlled trial. Nutrition.32(3):315-20. 
 
Annweiler, C., Schott, A.M., Allali, G., Bridenbaugh, S.A., Kressig, R.W., Allain, P., Herrmann, F.R. & Beauchet, O. (2010). Association of vitamin D deficiency with cognitive impairment in older women: cross-sectional study. Neurology. 74(1):27-32.
 
Barragán-Rodríguez, L., Rodríguez-Morán, M. & Guerrero-Romero, F. (2008). Efficacy and safety of oral magnesium supplementation in the treatment of depression in the elderly with type 2 diabetes: a randomized, equivalent trial. Magnes Res. 21(4):218-23.
 
Benton, D., Williams, C. & Brown, A. (2007). Impact of consuming a milk drink containing a probiotic on mood and cognition. Eur J Clin Nutr. 61(3):355-61.
 
Chang, C.Y., Ke, D.S. & Chen, J.Y. (2009). Essential fatty acids and human brain. Acta Neurol Taiwan. 18(4):231-41.
 
Cole, G.M., Ma, Q.L., & Frautschy, S.A. (2009). Omega-3 fatty acids and dementia. Prostaglandins Leukot Essent Fatty Acids. 81(2-3):213-21.
 
Coletta, J.M., Bell, S.J. & Roman, A.S. (2010). Omega-3 Fatty Acids and Pregnancy. Rev Obstet Gynecol. 3(4): 163–171.
 
de Baaij, J.H.F, Hoenderop, J.G.J. & Bindels, R.J.M. (2015). Magnesium in Man: Implications for Health and Disease. Physiological Reviews 95(1):1-46.
 
Dolan, K.E., Finley, H.J., Burns, C.M., Gasta, M.G., Gossard, C.M., Parker, E.C., Pizano, J.M., Williamson, C.B. & Lipski, E.A. (2016). Probiotics and Disease: A Comprehensive Summary-Part 1, Mental and Neurological Health. Integr Med (Encinitas). 15(5):46-58.
 
Eby, G.A. & Eby, K.L. (2006). Rapid recovery from major depression using magnesium treatment. Med Hypotheses. 67(2):362-70.
 
Faridar, A., Eskandari, G., Sahraian, M.A., Minagar, A. & Azimi, A. (2012). Vitamin D and multiple sclerosis: a critical review and recommendations on treatment. Acta Neurologica Belgica. 112(4);327–333.
 
Fontani, G., Corradeschi, F., Felici, A., Alfatti, F., Migliorini, S. & Lodi, L. (2005). Cognitive and physiological effects of Omega-3 polyunsaturated fatty acid supplementation in healthy subjects.
Eur J Clin Invest. 35(11):691-9.
 
Gintya, A.T. & Conklinb, S.M. (2015). Short-term supplementation of acute long-chain omega-3 polyunsaturated fatty acids may alter depression status and decrease symptomology among young adults with depression: A preliminary randomized and placebo controlled trial. Psychiatry Research. 229(1–2); 485–489.
 
Grosso, G., Galvano, F., Marventano, S., Malaguarnera, M., Bucolo, C., Drago, F., & Caraci, F. (2014). Omega-3 Fatty Acids and Depression: Scientific Evidence and Biological Mechanisms. Oxidative Medicine and Cellular Longevity, 2014, 313570. 
 
Helland, I.B., Smith, L., Saarem, K., Saugstad, O.D. & Drevon, C.A. (2003). Maternal supplementation with very-long-chain n-3 fatty acids during pregnancy and lactation augments children's IQ at 4 years of age. Pediatrics. 111(1):e39-44.
 
Huang, R., Wang, K. & Hu, J. (2016). Effect of Probiotics on Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients. 8(8).
 
Jernerén F., Elshorbagy A.K., Oulhaj A., Smith S.M., Refsum H. & Smith A.D. (2015). Brain atrophy in cognitively impaired elderly: The importance of long-chain ω-3 fatty acids and B vitamin status in a randomized controlled trial. Am. J. Clin. Nutr. 102:215–221. doi: 10.3945/ajcn.114.103283.
 
Kennedy, D.O. (2016). B Vitamins and the Brain: Mechanisms, Dose and Efficacy--A Review. Nutrients. 8(2):68.
 
Kiecolt-Glaser, J.K., Belury, M.A., Andridge, R., Malarkey, W.B. & Glaser, R. (2011). Omega-3 supplementation lowers inflammation and anxiety in medical students: a randomized controlled trial. Brain Behav Immun. 25(8):1725-34. 
 
Kjærgaard, M., Waterloo, K., Wang, C.E., Almås, B., Figenschau, Y., Hutchinson, M.S., Svartberg, J. & Jorde, R. (2012). Effect of vitamin D supplement on depression scores in people with low levels of serum 25-hydroxyvitamin D: nested case-control study and randomised clinical trial. Br J Psychiatry. 201(5):360-8.
 
Kröger, E. &, Laforce, R.Jr. (2016). Fish Consumption, Brain Mercury, and Neuropathology in Patients With Alzheimer Disease and Dementia. JAMA. 315(5):465-6. 
 
Kouchaki, E., Tamtaji, O.R., Salami, M., Bahmani, F., Daneshvar Kakhaki, R., Akbari, E., Tajabadi-Ebrahimi, M., Jafari, P. & Asemi, Z. (2016). Clinical and metabolic response to probiotic supplementation in patients with multiple sclerosis: A randomized, double-blind, placebo-controlled trial. Clin Nutr. S0261-5614(16)30214-X. 
 
Langlois, K. & Ratnayake, W.M. (2015). Omega-3 Index of Canadian adults. Health Rep. 26(11):3-11.
 
Lin, P.Y. & Su, K.P. (2007). A meta-analytic review of double-blind, placebo-controlled trials of antidepressant efficacy of omega-3 fatty acids. J Clin Psychiatry. 68(7):1056-61.
 
Mikkelsen, K., Stojanovska, L., Tangalakis, K., Bosevski, M. & Apostolopoulos, V. (2016). Cognitive decline: A vitamin B perspective. Maturitas. 93:108-113. 
 
Mohammadi, A.A., Jazayeri, S., Khosravi-Darani, K., Solati, Z., Mohammadpour, N., Asemi, Z., Adab, Z., Djalali, M., Tehrani-Doost, M., Hosseini, M. & Eghtesadi, S. (2016). The effects of probiotics on mental health and hypothalamic-pituitary-adrenal axis: A randomized, double-blind, placebo-controlled trial in petrochemical workers. Nutr Neurosci. 19(9):387-395. 
 
National Institutes of Health, Office of Dietary Supplements, Vitamin D. Accessed Feb 14, 2017.
 
Peet, M. &, Stokes, C. (2005). Omega-3 fatty acids in the treatment of psychiatric disorders. Drugs. 65(8):1051-9.
 
Pet, M.A. & Brouwer-Brolsma, E.M. (2016). The Impact of Maternal Vitamin ,D Status on Offspring Brain Development and Function: a Systematic Review. Adv Nutr. 7(4):665-78. doi: 10.3945/an.115.010330. Print 2016 Jul.
 
Rimmelzwaan, L.M., van Schoor, N.M., Lips, P., Berendse, H.W. & Eekhoff, E.M. (2016). Systematic Review of the Relationship between Vitamin D and Parkinson's Disease. J Parkinsons Dis. 6(1):29-37.
 
Sechi, G., Sechi, E., Fois, C. & Kumar, N. (2016). Advances in clinical determinants and neurological manifestations of B vitamin deficiency in adults. Nutr Rev. 74(5):281-300. doi: 10.1093/nutrit/nuv107. Epub 2016 Mar 31.
 
Serefko, A., Szopa, A., Wlaź, P., Nowak, G., Radziwoń-Zaleska, M., Skalski, M. & Poleszak, E. (2013). Magnesium in depression. Pharmacol Rep. 2013;65(3):547-54.
 
Steenbergen, L., Sellaro, R., van Hemert, S., Bosch, J.A. & Colzato, L.S. (2015). A randomized controlled trial to test the effect of multispecies probiotics on cognitive reactivity to sad mood.
Brain Behav Immun. 48:258-64.
 
Takada, M., Nishida, K., Kataoka-Kato, A., Gondo, Y., Ishikawa, H., Suda, K., Kawai, M., Hoshi, R., Watanabe, O., Igarashi, T., Kuwano, Y., Miyazaki, K. & Rokutan, K. (2016). Probiotic Lactobacillus casei strain Shirota relieves stress-associated symptoms by modulating the gut-brain interaction in human and animal models. Neurogastroenterol Motil. 28(7):1027-36.
 
Tangney, C.C., Aggarwal, N.T., Li, H., Wilson, R.S., Decarli, C., Evans, D.A. & Morris, M.C. (2011). Vitamin B12, cognition, and brain MRI measures: a cross-sectional examination. Neurology. 77(13):1276-82.
 
Tarleton, E.K. & Littenberg, B. (2015). Magnesium intake and depression in adults. J Am Board Fam Med. 28(2):249-56.
 
Volpe SL. (2013). Magnesium in disease prevention and overall health. Adv Nutr. 4(3):378S-83S.
 
Wang, H-X., Wahlin, A., Basun, H., Fastbom, J., Winblad, B. & Fratiglioni, L. (2001). Vitamin B12 and folate in relation to the development of Alzheimer’s disease Neurology 56(9):1188-1194
 
Watanabe, F., Takenaka, S., Kittaka-Katsura, H., Ebara, S. & Miyamoto, E. (2002). Characterization and bioavailability of vitamin B12-compounds from edible algae. J Nutr Sci Vitaminol (Tokyo). 48(5):325-31.
 
Weiser, M.J., Butt, C.M. & Mohajeri, M.H. (2016). Docosahexaenoic Acid and Cognition throughout the Lifespan. Nutrients. 8(2):99.
Published in Deanna's Blog
Friday, 26 May 2017 14:12

Probiotics for Moods and Stress? Yes!

 
 
What do you do when your mood is off or you’re stressed to the max?

 Eat ice cream? Binge watch Netflix? Call your bestie?

 After reading this article, you may consider yogurt, a handful of walnuts, or maybe even some dark chocolate as your go-to mood-boosters and stress-busters.

Today, we’ll unpack some of the exciting (and preliminary) new research about the link between your gut health and moods/stress. 
 
We’ll talk about your friendly resident gut microbes (mostly bacteria), probiotic foods and supplements, as well as foods to feed those gut microbes and probiotics (aka “prebiotics”). 

WHAT THE HECK ARE “GUT MICROBES?  ”

Oh, our friendly “gut microbes.” 

They are the trillions of microbes that happily live in our gut. They help us by digesting foods, making vitamins, and even protecting us from the not-so-friendly microbes that may get in there.

Believe it or not, these friendly microbes have mood-boosting and stress-busting functions too!

FUN FACT: There are more microbes
 
FUN FACT: There are more microbes inside our gut than all of the human cells that make us. Yup, we’re more than half microbe! So, how can they NOT impact our health?

It’s a hotbed of research right now and we’re finding out more about their awesome health, and mood/stress benefits every day.

And, while the research is just starting to figure out the many gut microbe-brain connections, it’s such a cool new topic that I couldn’t wait to share it with you!

GUT MICROBES AND PROBIOTICS

The microbes that live in our guts are known as our “gut microbiota”. 
 
The microbes that we can ingest are known as “probiotics”.

“Probiotics” are live organisms that you can eat, drink, or take as a supplement. They’re what turn milk into yogurt, and cabbage into sauerkraut; and they are great for both your gut health and mental health.

Special probiotics that have mental health benefits are called “psychobiotics,” (psycho = mental health, and biotics = live). They’re live organisms that can benefit our psyche.

So, what’s the link between gut microbes, probiotics, and moods/stress?

  BAD MOODS/STRESS CAN MEAN BAD MICROBES

.  Stress can affect our friendly gut microbes.

 Several studies show that stressed rodents not only have increased stress hormones and stressed behaviours; but, they also have different gut microbes!

And this has been studied, to a small extent, in people too.

 One study showed that moms with high levels of stress hormones during pregnancy had infants with more of the “bad” gut microbes. 

But, can it work the other way around? Can changing our gut microbes affect our moods and stress responses?

Studies of rodents that grow up without any gut microbes at all (in a “bacteria-free” environment) respond to stress more than mice with normal gut microbes. Then, when they’re given either a probiotic or gut microbes from non-stressed mice, their stress responses often go back to normal.

The gut microbe, probiotic, and mood/stress connections are starting to get interesting, aren’t they?

  BAD MICROBES CAN MEAN BAD MOODS
 

“Gut microbiota and probiotics alter behavior and brain neurochemistry.” (Ait-Belgnaoui, et. al., 2012)

That’s a pretty powerful statement, don’tcha think?

Many animal studies show positive effects on behaviour when they get probiotic supplements.

For example, after a probiotic, stressed rats had lower levels of both stress hormones and an inflammatory molecule associated with depression (“LPS” - lipopolysaccharide).
 
 
One fascinating study showed that when people took probiotics, brain MRI (magnetic resonance imaging) tests showed reduced brain activity for negative and aggressive thoughts!

So, as you can see, there is some exciting research on the positive effect that probiotics can have on moods and stress.
 
You might be wondering how exactly your gut can influence your moods...
 
HOW IS THIS GUT-BRAIN CONNECTION POSSIBLE?
 
It may not seem obvious or intuitive, but your body is interconnected in many ways.
 
And more and more research is figuring out the “microbiota-gut-brain axis.” It’s the very complex connection between your gut, its microbes, and your brain.
 
This new field has been called a “paradigm shift in neuroscience” (Dinan, 2017).
 
In fact, there are a number of ways that we’re beginning to understand how our gut microbes can affect our brain.
 
One is via the “vagus” nerve, which is a nerve that directly connects your gut to your brain. 
 
The other ways are through “biochemical messengers.” Biochemicals that are made in your gut and travel through the body to communicate with other parts, including your brain. Biochemicals like short chain fatty acids, cytokines, and even tryptophan (the amino acid that the neurotransmitters melatonin and serotonin are made from).
 
The exciting thing is that this may help us with not only moods and stress, but the microbiota-gut-brain axis may one day prove to be helpful for other conditions like autism and Parkinson’s.
 
So, your trillions of gut microbes seem to be more closely interconnected with our moods than we used to think.

So, what can you do to nurture your own healthy gut microbes?
 
HOW TO NURTURE HEALTHY GUT MICROBES - PROBIOTICS
 
First, eat (and drink) probiotics. 
 
Probiotics can be eaten in yogurt, sauerkraut (and other fermented veggies), miso, tempeh, and kimchi. You can drink them in kefir or kombucha. Be sure to choose unpasteurized ones that will be refrigerated in your local grocer. 

Of course, there are a number of probiotic supplements available too. Look for one that’s refrigerated and has at least 10 billion active cultures. I also suggest you look for one that has been “third party tested,” which means someone outside the company has tested it and says it’s a quality product.

  Oh, and always read the label before taking any supplements.

 The probiotics with the most research are of the Bifidobacterium and Lactobacillus types. But we still don’t know enough about the psychobiotic effects to make specific mood-boosting recommendations...just yet.
 
HOW TO NURTURE HEALTHY GUT MICROBES - PREBIOTICS
 
Second, consider that our resident gut microbes don’t just live inside us to help us - they get something out of the deal too.

Food!

PREbiotics are “compounds that, when fermented in the gut, produce specific changes in bacterial composition or activity”. They are your friendly gut microbes’ favourite delicacies so they’ll happily grow, and multiply. 
 
Prebiotics are basically foods that contain fibre. Things like fruits, vegetables, nuts, and seeds. Even dark chocolate (preferably with at least 70% cocoa).
 
Giving animals prebiotics can reduce stress hormones and anxiety-related behaviours.
, and in people, studies show that taking psychobiotic's along with prebiotics can improve both the microbes in our gut, as well as our mood. 
 
How amazing is that?

CONCLUSION

The science behind interactions of gut microbes and mental health is still new and ongoing. Much of it is in rodents, with a few studies in people. Some show interesting links and promising potential to help with moods and other areas of mental and brain health.
 
CONCLUSION

:  The science behind interactions of gut microbes and mental health is still new and ongoing. Much of it is in rodents, with a few studies in people. Some show interesting links and promising potential to help with moods and other areas of mental and brain health.
 
More research, especially in humans, is needed; so I’ll be on the lookout for new studies in this young and promising area of mood-boosting and stress-busting nutrition.

What if one day we were able to help mental health by fixing gut health? What an amazing, and less moody, a world that could be!
 
Try eating more probiotics like in yogurt, kefir, miso, kimchi, and kombucha. Consider taking probiotic supplements (making sure you read the label and follow directions).
 
And don’t forget their favourite foods called prebiotics. Those are in fruits, vegetables, nuts and seeds (and even dark chocolate). 
 
Optimize your gut for more than just gut health, but mood-boosting and stress-busting too.
 
Buh bye blah moods.
 
REFERENCES
 
Ait-Belgnaoui, A., Durand, H., Cartier, C., Chaumaz, G., Eutamene, H., Ferrier, L., Houdeau, E., Fioramonti, J., Bueno, L. & Theodorou, V. (2012). Prevention of gut leakiness by a probiotic treatment leads to attenuated HPA response to an acute psychological stress in rats. Psychoneuroendocrinology. 37(11):1885-95. doi: 10.1016/j.psyneuen.2012.03.024.
LINK:  https://www.ncbi.nlm.nih.gov/pubmed/22541937
 
Bailey, M.T., Dowd, S.E., Galley, J.D., et al. (2011). Exposure to a social stressor alters the structure of the intestinal microbiota: implications for stressor-induced immunomodulation. Brain Behav Immun. 25(3):397–407.
 
Bharwani A, Mian MF, Foster JA, et al. (2016). Structural & functional consequences of chronic psychosocial stress on the microbiome & host. Psychoneuroendocrinology. 63:217–227.
 
Cryan, J.F. (2016). Stress and the Microbiota-Gut-Brain Axis: An Evolving Concept in Psychiatry. 
Can J Psychiatry. 61(4):201-3. doi: 10.1177/0706743716635538. 
LINK:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4794959/
 
De Palma, G., Blennerhassett, P., Lu, J., Deng, Y., Park, A.J., Green, W., Denou, E., Silva, M.A., Santacruz, A., Sanz, Y., Surette, M.G., Verdu, E.F., Collins, S.M. & Bercik, P. (2015). Microbiota and host determinants of behavioural phenotype in maternally separated mice. Nat Commun. 2015 Jul 28;6:7735. doi: 10.1038/ncomms8735.
LINK:  http://www.nature.com/articles/ncomms8735
 
Dinan, T.G. & Cryan, J.F. (2016). Mood by microbe: towards clinical translation. Genome Med. 8(1):36. doi: 10.1186/s13073-016-0292-1.
LINK:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4822287/

Dinan TG1, Cryan JF. (2017). The Microbiome-Gut-Brain Axis in Health and Disease. Gastroenterol Clin North Am. 2017 Mar;46(1):77-89. doi: 10.1016/j.gtc.2016.09.007.
 
Kelly, J. R., Kennedy, P. J., Cryan, J. F., Dinan, T. G., Clarke, G., & Hyland, N. P. (2015). Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders. Frontiers in Cellular Neuroscience, 9, 392. 
 
Messaoudi, M., Lalonde, R., Violle, N., Javelot, H., Desor, D., Nejdi, A., Bisson, J.F., Rougeot, C., Pichelin, M., Cazaubiel, M. & Cazaubiel, J.M. (2011). Assessment of psychotropic-like properties of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in rats and human subjects. Br J Nutr. 105(5):755-64. doi: 10.1017/S0007114510004319.
LINK:  https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/div-classtitleassessment-of-psychotropic-like-properties-of-a-probiotic-formulation-span-classitaliclactobacillus-helveticusspan-r0052-and-span-classitalicbifidobacterium-longumspan-r0175-in-rats-and-human-subjectsdiv/2BD9977C6DB7EA40FC9FFA1933C024EA/core-reader
 
O’Mahony, S.M., Marchesi, J.R., Scully, P., et al. (2009). Early life stress alters behavior, immunity, and microbiota in rats: implications for irritable bowel syndrome and psychiatric illnesses. Biol Psychiatry. 65(3):263–267.
 
Rea, K., Dinan, T.G. & Cryan, J.F. (2016). The microbiome: A key regulator of stress and neuroinflammation. Neurobiol Stress. 4:23-33.
LINK:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5146205/
 
Rieder, R., Wisniewski, P.J., Alderman, B.L. & Campbell, S.C. (2017). Microbes and mental health: A review. Brain Behav Immun. 2017 Jan 25. pii: S0889-1591(17)30016-8. doi: 10.1016/j.bbi.2017.01.016. 
LINK:  http://www.sciencedirect.com/science/article/pii/S0889159117300168
 
Romijn, A.R. & Rucklidge, J.J. (2015). Systematic review of evidence to support the theory of psychobiotics. Nutr Rev. 73(10):675-93. doi: 10.1093/nutrit/nuv025. 
LINK:  https://www.ncbi.nlm.nih.gov/pubmed/26370263
 
Sarkar, A., Lehto, S.M., Harty, S., Dinan, T.G., Cryan, J.F. & Burnet, P.W. (2016). Psychobiotics and the Manipulation of Bacteria-Gut-Brain Signals. Trends Neurosci. 39(11):763-781. doi: 10.1016/j.tins.2016.09.002.
LINK:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5102282/
 
Sender, R., Fuchs, S. & Milo, R. (2016). Revised Estimates for the Number of Human and Bacteria Cells in the Body. PLoS Biol 14(8): e1002533. doi:10.1371/journal.pbio.1002533
 
Sherwin, E., Sandhu, K.V., Dinan, T.G. & Cryan, J.F. (2016). May the Force Be With You: The Light and Dark Sides of the Microbiota-Gut-Brain Axis in Neuropsychiatry. CNS Drugs. 2016 Nov;30(11):1019-1041. doi: 10.1007/s40263-016-0370-3
LINK:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5078156/
 
Steenbergen, L., Sellaro, R., van Hemert, S., Bosch, J.A. & Colzato, L.S. (2015). A randomized controlled trial to test the effect of multispecies probiotics on cognitive reactivity to sad mood.
Brain Behav Immun. 48:258-64. doi: 10.1016/j.bbi.2015.04.003.
LINK:  http://www.sciencedirect.com/science/article/pii/S0889159115000884
 
Zijlmans, M.A., Korpela, K., Riksen-Walraven, J.M., de Vos, W.M. & de Weerth, C. (2015).  Maternal prenatal stress is associated with the infant intestinal microbiota. Psychoneuroendocrinology. 2015 Mar;53:233-45. doi: 10.1016/j.psyneuen.2015.01.006.
LINK:  http://www.psyneuen-journal.com/article/S0306-4530(15)00020-7/abstract
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