How to Get Rid of Brain Fog: Your Action Plan

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How to Get Rid of Brain Fog: Your Action Plan

Improve Mental Clarity by Reducing Inflammation and Healing the Gut

Key Takeaways:

  • Brain fog is an often misunderstood, yet very treatable symptom of many chronic illnesses and conditions. 
  • Common causes of brain fog include chronic inflammation, gut imbalances, poor digestion, hypothyroidism, vitamin B12 deficiency, ADHD, and more.
  • Finding your anti-inflammatory diet and incorporating probiotics are foundational steps in treating brain fog.
  • Improving your sleep quality, addressing hormone imbalances, and correcting nutrient deficiencies are also essential when needed.

Brain fog is one of the most frustrating symptoms to deal with, in part because it’s not always recognized by healthcare providers. Although it’s a common symptom (and now much more well-known since the pandemic and the emergence of “long COVID”), there’s not much direct research about brain fog, and there are no standard tests, treatments, or criteria to aid diagnosis. 

However, for practitioners and patients who are willing to dig a bit deeper, there’s a lot that can be done to relieve symptoms of brain fog. I want to reassure you that having brain fog does not mean that you are experiencing permanent cognitive decline. Brain fog is treatable, and you can restore your cognitive abilities. 

Learning how to get rid of brain fog can help you to get back to your life and through your days without such a struggle. Based on the research that is available so far, reducing systemic inflammation, supporting the gut, addressing hormonal imbalances, and correcting nutrient deficiencies seem to be among the most promising strategies when it comes to reducing mental fatigue and fogginess [1, 2, 3, 4, 5, 6, 7].

Specific treatments may include adjusting your diet, taking probiotics for gut and digestive support, correcting a vitamin B12 deficiency through supplementation, and many other options.

Here, we will explore the research behind the root causes of brain fog and how to get rid of this elusive symptom.

What is Brain Fog?

Brain fog is a term that is used to describe symptoms including slow or cloudy thinking, difficulty focusing, reduced memory or forgetfulness, and difficulty completing cognitive tasks [8, 9].

Brain fog has been described or reported in relation to several different chronic health conditions, including:

  • Chronic fatigue syndrome [9]
  • Crohn’s disease [10]
  • Fibromyalgia [11] (sometimes referred to as “fibro-fog”)
  • “Post-COVID syndrome” and other chronic viral infections [12, 13, 14
  • Small intestinal bacterial overgrowth (SIBO) [15]
  • Celiac disease and non-celiac gluten sensitivity [13, 14, 16, 17]
  • Hypothyroidism [15, 16, 18, 19]
  • Postural tachycardia syndrome (POTS) [20]
  • Mast cell disorders [21]
  • Menopause [22]

How to Get Rid of Brain Fog: A Snapshot

Let’s take a quick look at some of the simple steps that can be taken in order to get rid of brain fog:

  • Start with the basics
    • Prioritize sleep 
    • Get regular exercise  
    • Practice stress management 
  • Reduce inflammation
    • Follow an anti-inflammatory diet 
    • Determine individual trigger foods (ex. gluten) 
    • Consider the role of histamine and mast cells 
  • Support your gut
    • Consider probiotics  
    • Identify and treat any underlying imbalances such as SIBO
  • Pursue other treatments
    • Correct any nutrient deficiencies
    • Balance your hormone levels

We’ll explore each of these steps in more detail later, but first, let’s take a look at some of the common root causes of brain fog.

Underlying Causes of Brain Fog 

There is no single cause of brain fog, but several key factors, including inflammation, gut and hormonal imbalances, and nutrient deficiencies appear to contribute. 


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Chronic inflammation throughout the body has been associated with cognitive dysfunction, and it is a common thread across many of the conditions that are linked to brain fog [16, 23, 24].

Brain fog has been observed in various disorders, including fibromyalgia, multiple sclerosis, and among patients undergoing chemotherapy. As noted in one review on brain fog and cognitive impairments among patients with celiac disease: 

“All of these disorders have one thing in common with [celiac disease] — they are associated with systemic inflammation” [16].

Getting your inflammation levels under control is essential when it comes to getting rid of brain fog.

Mast Cells and Histamine Intolerance

Brain fog is a common symptom of mast cell disorders and histamine intolerance, which both involve excess or chronic inflammation [25, 26]. 

Mast cells are specific kinds of white blood cells that release inflammatory molecules, including histamine, in response to various triggers. This is a normal function of a healthy immune system. But in some cases, mast cells are triggered too often or without appropriate cause, which can lead to excess inflammation and histamine levels throughout the body (including in the brain). 

Gut Imbalances

The gut and the brain are connected in a multitude of ways, and brain fog may be caused by imbalances in the gut [27, 28]. For example, intestinal inflammation and leaky gut can lead to inflammation in the brain [29, 30, 31, 32]. Imbalances in the gut microbiome can also directly contribute to brain function [27, 33, 34].

Brain fog is one of the most common symptoms I see among my patients, and it often comes alongside fatigue and digestive symptoms. In the clinic, when we target and treat gut health, mental clarity and brain function also tend to improve.

SIBO and Liver Dysfunction

The gut-liver-brain connection might not seem obvious, but it may have a role to play in brain fog. Think of the connection this way: all toxins in your gut are processed by your liver. If your liver is overburdened for any reason, these toxins may build up in your blood and get into your brain by crossing the blood-brain barrier.

A type of cognitive impairment that sometimes occurs in liver disease, hepatic encephalopathy (HE), has been linked to small intestinal bacterial overgrowth (SIBO). While HE is fairly uncommon and is usually seen in those with chronic, severe liver disease, it does underline the connection between a taxed liver, a disrupted gut, and cognitive dysfunction.

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In fact, the presence of SIBO is often what sets cirrhosis (liver disease) patients with mild cognitive impairments apart from cirrhosis patients without brain issues [35]. 

Research has also shown that Rifaximin, an antibiotic that is often used to treat SIBO, can prevent and improve HE [36, 37]. In a 2020 study, treatment of SIBO significantly improved mild HE, while treatment of the stomach infection Helicobacter Pylori (H. pylori), did not [38]. This further highlights the significance of a gut-liver-brain connection. 

These findings may be relevant for brain fog and cognitive function in the general population, as they suggest that treating bacterial overgrowth in the gut can help to reduce mental fogginess and cognitive dysfunction.

Vitamin B12 Deficiency

New research suggests that addressing vitamin B12 deficiency may improve brain fog. Vitamin B12 is closely related to energy levels and brain function, and many people do not consume or make enough of this essential vitamin due to a compromised gut microbiome, low or no meat consumption, and certain medications. 

An observational study was conducted to see if vitamin B12 supplementation could improve minimal cognitive impairment (MCI). The selected patients reported symptoms such as memory loss, forgetfulness, poor focus and concentration, generalized tiredness, lethargy, poor balance, and feeling pins, needles, and tingling sensations. 

A total of 202 patients with brain fog symptoms and low vitamin B12 levels (either mild, moderate, or severe deficiency) were included in the study and given vitamin B12 for three months. The results showed that 84% of participants reported symptom improvement and 78% had improved cognitive scores after three months of taking vitamin B12 [39].


Hypothyroidism also appears to be linked with brain fog symptoms. One survey study found that over 90% of participants reported frequent brain fog despite being treated with thyroid hormone medication

This data corresponds with my clinical observation that gut imbalances are often a trigger for thyroid issues. If you have been diagnosed with thyroid disease and medication is not helping your brain fog, it may be time to take a closer look at your gut health as a root cause. 

The above study also found that nearly half of the participants reported having brain fog prior to their diagnosis, suggesting that brain fog can be an early sign of hypothyroidism.  

Additionally, the participants reported several factors that improved their brain fog, including adjusting their thyroid hormone dose, changing thyroid medication, getting more rest, exercising, improving their nutrition, and reducing stress [40]. 

Making sure to take thyroid medication consistently is especially important for managing brain fog in hypothyroid patients [41].

Hormonal Changes (Menopause)

Hormonal changes related to menopause may contribute to brain fog. One study found that 62% of middle-aged women reported having brain fog, and many of them attributed their brain fog to hormonal changes, stress, aging, sleep disturbances, and emotional factors [42].

One literature review noted that hormonal changes related to menopause are often accompanied by brain fog symptoms [22]. The review also noted that 40-56% of women report sleep difficulties during menopause [22], and brain fog and reduced sleep are likely related. 

Overall, these findings suggest that the normal hormonal changes that occur during menopause are associated with brain fog in some women, and other issues such as sleep and mental health disturbances may also occur during this time of life.

But just because these hormonal shifts are normal, doesn’t mean you have to suffer through the side effects. If you need help with balancing your hormones naturally, reach out to our functional medicine clinic or check out one of our many articles on hormonal health

Attention Deficit Hyperactivity Disorder (ADHD)

Fascinatingly, the symptoms of attention deficit hyperactivity disorder (ADHD) can closely resemble those of brain fog. For example, a 2021 systematic review found that adults with ADHD had deficits in cognitive functions related to attention, processing speed, and verbal memory (43).

Sleep deprivation is also a common issue in ADHD patients. One study found that 43% of people with ADHD had significant insomnia [44]. Another study found that improving sleep hygiene helped reduce ADHD symptoms in children [45]. This suggests that improving sleep hygiene could potentially reduce cognitive symptoms (including brain fog) in people with ADHD [45].

Dietary changes may also reduce cognitive symptoms of ADHD. One small study found that a 12-month gluten-free diet normalized ADHD symptoms in people with celiac disease [46]. This suggests that some people’s ADHD-like symptoms are actually linked to gluten autoimmunity. 

Additionally, one study showed that an elimination diet significantly reduced ADHD symptoms in over 60% of child participants [47], while another review found that an elimination diet can substantially improve ADHD symptoms in children [48].

How to Treat Brain Fog 

Now that we have a better idea of what’s behind brain fog, it’s time to dive into treatments that address these underlying causes.

Start With the Basics

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A few fundamental lifestyle changes can help reduce inflammation and improve brain fog. 


  • One of the most important things you can do to support brain health is to eat an anti-inflammatory diet that focuses on whole foods. 
  • Avoiding sugar, processed foods, and other inflammatory foods can make a huge difference when it comes to cognitive function [1, 2]. In the next section, we’ll break down and simplify the different diet options so you can find what’s best for you.

Think about what you eat on a daily basis. Are there any processed foods that you’re consuming every day without thinking, and what could you replace those foods with? For example, if you put vanilla-flavored coffee creamer in your coffee every morning, you could replace it with pure coconut milk and stevia or monkfruit drops for sweetener. Small changes like these add up over time!


  • A 2020 systematic review of 29 studies concluded that exercise or physical activity may help to treat brain fog associated with cancer and chemotherapy (“chemo fog”) [49].
  • Exercise has been shown to reduce inflammation and improve the microbiome, which may help to explain the cognitive benefits [50, 51].

Find a type of movement you can do for 30 minutes a day. If 30 minutes seems like a lot, remember that it doesn’t have to be all at once. You could do a 10-minute yoga video in the morning and a 20-minute walk at lunch. Or a 10-minute walk, 10 minutes of weightlifting, and 10 minutes of active stretching. Find what works for you and makes you feel good.


  • Getting enough sleep might be one of the most important things you can do for your gut and your brain. 
  • Lack of sleep can lead to leaky gut and inflammation [52].
  • A study on cognitive impairment in Crohn’s disease also found a strong association between poor sleep quality and cognitive dysfunction [10].

If you’re not getting to bed early enough (and I’ve been guilty of this myself), set an alarm on your phone to get ready for bed just 10 minutes earlier than you normally would. Follow this schedule for a few days and then push it another 10 minutes earlier. Repeat until you are going to bed at the ideal time for you (typically somewhere between 9–11pm for most people).

Improving your sleep will depend on a number of factors, including hormonal causes, but there are many factors in your control such as having a nighttime wind-down routine before bed, going to bed at a consistent time every night, and getting sun exposure early in the day to normalize your circadian clock.


  • Chronic stress is a common cause of inflammation and leaky gut, which can have a negative impact on cognitive function [53, 54]. 
  • Practicing mindfulness meditation and reducing stress levels in other ways may help to calm inflammation and reduce brain fog.

If you’re feeling stressed right now, a quick reset might help. There are hundreds of short, guided meditation videos on YouTube for stress and anxiety relief. Emotional freedom technique, also called EFT tapping, can calm the nervous system and help lower stress fast (guided videos are also available on YouTube). 

Otherwise, taking a quick break to practice a hobby such as playing an instrument or making art can provide stress relief. Give yourself permission to leave when you need a break and come back to whatever you were doing when you feel calmer. 

What’s the Best Diet for Brain Fog

The most important thing to remember when choosing your ideal diet for brain fog is that you want to reduce inflammation.

A healthy, anti-inflammatory diet eliminates processed and refined foods, added sugar, and other inflammatory foods. The emphasis is on a balance ​​of nutrients and a variety of fresh, whole foods.

  • A 2019 review suggested that an anti-inflammatory diet may prevent or reduce leaky gut and brain inflammation, thereby reducing cognitive symptoms like brain fog [1].
  • Another review suggested that a diet high in omega-3 fatty acids and low in added sugar may help reduce inflammation and brain fog in cancer patients undergoing chemotherapy [2].

There are a few different templates for an anti-inflammatory diet. However, I often recommend the Paleo diet. The Paleo diet eliminates processed foods, grains, dairy products, and additives, and it focuses on fresh fruits and vegetables, fish, eggs, grass-fed meats, and healthy fats.

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I would recommend trying a Paleo diet for brain fog if: 

  • Your current diet is higher in inflammatory or processed foods, and; 
  • You don’t have any other known conditions or intolerances that may benefit from a more specialized diet.

Gluten and Other Food Sensitivities  

Some specific foods might trigger an immune system response and inflammation. Gluten is one example of a food sensitivity or intolerance that has been linked to brain fog: 

  • Brain fog has been reported as a common symptom among patients with both celiac disease and non-celiac gluten sensitivity [16, 17].
  • One small study on patients with celiac disease (an autoimmune condition) found that brain fog was resolved after following a gluten-free diet for 12 months [3].

Does this mean that everyone who has brain fog should avoid gluten? No. Gluten is highly inflammatory to those who are sensitive to it, but not everyone needs to go gluten-free. A 2-3 week gluten-free trial is a great way to determine if you are gluten-sensitive. If your brain fog (or any other health symptom) improves on a gluten-free trial, continue with the gluten-free diet. If not, there is no need to go gluten-free.

Low FODMAP Diet 

The low FODMAP diet may help some people with brain fog, especially those with irritable bowel syndrome (IBS) or SIBO [4]. Studies have found that a low FODMAP diet can reduce inflammation and digestive symptoms [55, 56]. 

One study showed that a low FODMAP diet led to improvements in brain fog for patients with IBS [4]. These improvements were related to changes in the gut microbiome and a significant reduction in the inflammatory molecule histamine. 

A low FODMAP diet eliminates certain kinds of carbohydrates that are fermented by (and feed) gut bacteria. High FODMAP foods include various types of legumes, grains, and certain fruits and vegetables.

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I would recommend trying a low FODMAP diet if: 

  • Symptoms do not improve on an anti-inflammatory or Paleo diet, and; 
  • You have suspected or diagnosed SIBO or IBS. 

Low Histamine Diet

A low histamine diet may help some people to reduce brain fog. This diet reduces the intake of dietary histamine, which is important if your body is producing excess histamine, such as in mast cell disorders. (25, 26)

A low histamine diet eliminates aged and fermented foods, alcohol, and certain kinds of fruits and vegetables.

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I would recommend trying a low histamine diet if: 

  • Symptoms do not improve on an anti-inflammatory or Paleo diet, and;
  • You have suspected or diagnosed histamine intolerance or a mast cell disorder.

Probiotics for Brain Fog

Recent studies have shown that probiotics can help to improve cognitive function [5, 6, 7, 27, 57]. 

  • A 2020 meta-analysis of 7 human and 11 animal studies concluded that probiotics enhanced cognition. The effects of probiotics on cognitively impaired individuals were greater than those on healthy ones [57].
  • A 2020 clinical trial on healthy older adults showed that probiotics changed the makeup of the gut microbiome and improved cognitive function and mood [5]. 
  • Two clinical trials have demonstrated that supplementing with probiotics for 12 weeks can improve cognition in patients with Alzheimer’s [6, 7].
  • A study found that probiotics can help to improve cognitive function in fibromyalgia [27]. 

Probiotics work by restoring balance to the gut ecology. This stops the cycle that leads to leaky gut and systemic inflammation. Research confirms that probiotics reduce inflammation [32, 58]

Other Treatments

There are a few other treatments that have been shown to provide some benefits for patients with brain fog:

  • One review found that luteolin, a flavonoid (a type of chemical found in plants) with anti-inflammatory and antioxidant properties, can improve brain fog in patients with the mast cell disorder mastocytosis [25].
  • Another review found that fasting can help to improve cognition and brain health for those with neurological diseases and slow down age-related cognitive decline [59]. 
  • In the case of a B12 deficiency, correcting the deficiency through oral supplementation or B12 injections can improve brain fog [39].
  • For patients with non-gut-related hypothyroidism, taking thyroid medication consistently and supporting the thyroid with nutrients like selenium can improve cognitive function. [60, 61]

Other anti-inflammatory supplements, such as curcumin, fish oil, and resveratrol may also help to reduce brain fog, but research is lacking. However, these supplements are generally considered to be safe and can be effective in getting rid of brain fog if diet and lifestyle changes don’t seem to work.

However, they are contraindicated in select health conditions, so check with your doctor first before starting a new supplement.

How to Get Rid of Brain Fog — For Good

Brain fog is a signal that your body and brain are inflamed and may be an indication of  imbalances in the gut. By following a few key strategies, you can reduce inflammation, heal your gut, and clear up brain fog. 

Eating to reduce inflammation is essential to getting rid of brain fog. Supporting a healthy gut with high-quality probiotics is another important step. It’s also important to get 7-9 hours of sleep per night, practice stress management techniques, and get regular exercise.

More specific conditions like vitamin B12 deficiency, hypothyroidism, menopause, and ADHD are also among the common causes of brain fog. If you have been diagnosed with one of these conditions and are experiencing ongoing fogginess, consult with your practitioner.

For a more detailed and personalized plan to heal your gut and reduce inflammation, check out my book, Healthy Gut, Healthy You.

The Ruscio Institute has developed a range of high quality formulations, including Brain Boost, to help our patients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you.

➕ References
  1. Riccio P, Rossano R. Undigested food and gut microbiota may cooperate in the pathogenesis of neuroinflammatory diseases: A matter of barriers and a proposal on the origin of organ specificity. Nutrients. 2019 Nov 9;11(11). DOI: 10.3390/nu11112714. PMID: 31717475. PMCID: PMC6893834.
  2. Orchard TS, Gaudier-Diaz MM, Weinhold KR, Courtney DeVries A. Clearing the fog: a review of the effects of dietary omega-3 fatty acids and added sugars on chemotherapy-induced cognitive deficits. Breast Cancer Res Treat. 2017 Feb;161(3):391–8. DOI: 10.1007/s10549-016-4073-8. PMID: 27933449. PMCID: PMC5526680.
  3. Lichtwark IT, Newnham ED, Robinson SR, Shepherd SJ, Hosking P, Gibson PR, et al. Cognitive impairment in coeliac disease improves on a gluten-free diet and correlates with histological and serological indices of disease severity. Aliment Pharmacol Ther. 2014 Jul;40(2):160–70. DOI: 10.1111/apt.12809. PMID: 24889390.
  4. McIntosh K, Reed DE, Schneider T, Dang F, Keshteli AH, De Palma G, et al. FODMAPs alter symptoms and the metabolome of patients with IBS: a randomised controlled trial. Gut. 2017 Jul;66(7):1241–51. DOI: 10.1136/gutjnl-2015-311339. PMID: 26976734.
  5. Kim C-S, Cha L, Sim M, Jung S, Chun WY, Baik HW, et al. Probiotic Supplementation Improves Cognitive Function and Mood with Changes in Gut Microbiota in Community-Dwelling Older Adults: A Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial. J Gerontol A Biol Sci Med Sci. 2021 Jan 1;76(1):32–40. DOI: 10.1093/gerona/glaa090. PMID: 32300799. PMCID: PMC7861012.
  6. Akbari E, Asemi Z, Daneshvar Kakhaki R, Bahmani F, Kouchaki E, Tamtaji OR, et al. Effect of Probiotic Supplementation on Cognitive Function and Metabolic Status in Alzheimer’s Disease: A Randomized, Double-Blind and Controlled Trial. Front Aging Neurosci. 2016 Nov 10;8:256. DOI: 10.3389/fnagi.2016.00256. PMID: 27891089. PMCID: PMC5105117.
  7. Tamtaji OR, Heidari-Soureshjani R, Mirhosseini N, Kouchaki E, Bahmani F, Aghadavod E, et al. Probiotic and selenium co-supplementation, and the effects on clinical, metabolic and genetic status in Alzheimer’s disease: A randomized, double-blind, controlled trial. Clin Nutr. 2019 Dec;38(6):2569–75. DOI: 10.1016/j.clnu.2018.11.034. PMID: 30642737.
  8. Kovalchuk A, Kolb B. Chemo brain: From discerning mechanisms to lifting the brain fog-An aging connection. Cell Cycle. 2017 Jul 18;16(14):1345–9. DOI: 10.1080/15384101.2017.1334022. PMID: 28657421. PMCID: PMC5539816.
  9. Ocon AJ. Caught in the thickness of brain fog: exploring the cognitive symptoms of Chronic Fatigue Syndrome. Front Physiol. 2013 Apr 5;4:63. DOI: 10.3389/fphys.2013.00063. PMID: 23576989. PMCID: PMC3617392.
  10. van Langenberg DR, Yelland GW, Robinson SR, Gibson PR. Cognitive impairment in Crohn’s disease is associated with systemic inflammation, symptom burden and sleep disturbance. United European Gastroenterol J. 2017 Jun;5(4):579–87. DOI: 10.1177/2050640616663397. PMID: 28588890 PMCID: PMC5446137.
  11. Galvez-Sánchez CM, Reyes Del Paso GA, Duschek S. Cognitive Impairments in Fibromyalgia Syndrome: Associations With Positive and Negative Affect, Alexithymia, Pain Catastrophizing and Self-Esteem. Front Psychol. 2018 Mar 22;9:377. DOI: 10.3389/fpsyg.2018.00377. PMID: 29623059. PMCID: PMC5874325.
  12. Hugon J, Msika E-F, Queneau M, Farid K, Paquet C. Long COVID: cognitive complaints (brain fog) and dysfunction of the cingulate cortex. J Neurol. 2022 Jan;269(1):44–6. DOI: 10.1007/s00415-021-10655-x. PMID: 34143277. PMCID: PMC8211714.
  13. Asadi-Pooya AA, Akbari A, Emami A, Lotfi M, Rostamihosseinkhani M, Nemati H, et al. Long COVID syndrome-associated brain fog. J Med Virol. 2022 Mar;94(3):979–84. DOI: 10.1002/jmv.27404. PMID: 34672377. PMCID: PMC8662118.
  14. Theoharides TC, Cholevas C, Polyzoidis K, Politis A. Long-COVID syndrome-associated brain fog and chemofog: Luteolin to the rescue. Biofactors. 2021 Mar;47(2):232–41. DOI: 10.1002/biof.1726. PMID: 33847020. PMCID: PMC8250989.
  15. Rao SSC, Rehman A, Yu S, Andino NM de. Brain fogginess, gas and bloating: a link between SIBO, probiotics and metabolic acidosis. Clin Transl Gastroenterol. 2018 Jun 19;9(6):162. DOI: 10.1038/s41424-018-0030-7. PMID: 29915215. PMCID: PMC6006167.
  16. Yelland GW. Gluten-induced cognitive impairment (“brain fog”) in coeliac disease. J Gastroenterol Hepatol. 2017 Mar;32 Suppl 1:90–3. DOI: 10.1111/jgh.13706. PMID: 28244662.
  17. Volta U, Bardella MT, Calabrò A, Troncone R, Corazza GR, Study Group for Non-Celiac Gluten Sensitivity. An Italian prospective multicenter survey on patients suspected of having non-celiac gluten sensitivity. BMC Med. 2014 May 23;12(1):85. DOI: 10.1186/1741-7015-12-85. PMID: 24885375. PMCID: PMC4053283.
  18. Pasqualetti G, Pagano G, Rengo G, Ferrara N, Monzani F. Subclinical Hypothyroidism and Cognitive Impairment: Systematic Review and Meta-Analysis. J Clin Endocrinol Metab. 2015 Nov;100(11):4240–8. DOI: 10.1210/jc.2015-2046. PMID: 26305618.
  19. Samuels MH. Psychiatric and cognitive manifestations of hypothyroidism. Curr Opin Endocrinol Diabetes Obes. 2014 Oct;21(5):377–83. DOI: 10.1097/MED.0000000000000089. PMID: 25122491. PMCID: PMC4264616.
  20. Ross AJ, Medow MS, Rowe PC, Stewart JM. What is brain fog? An evaluation of the symptom in postural tachycardia syndrome. Clin Auton Res. 2013 Dec;23(6):305–11. DOI: 10.1007/s10286-013-0212-z. PMID: 23999934. PMCID: PMC3896080.
  21. Moura DS, Sultan S, Georgin-Lavialle S, Barete S, Lortholary O, Gaillard R, et al. Evidence for cognitive impairment in mastocytosis: prevalence, features and correlations to depression. PLoS ONE. 2012 Jun 20;7(6):e39468. DOI: 10.1371/journal.pone.0039468. PMID: 22745762. PMCID: PMC3379977.
  22. Gava G, Orsili I, Alvisi S, Mancini I, Seracchioli R, Meriggiola MC. Cognition, mood and sleep in menopausal transition: the role of menopause hormone therapy. Medicina (Kaunas). 2019 Oct 1;55(10). DOI: 10.3390/medicina55100668. PMID: 31581598. PMCID: PMC6843314.
  23. Jones KA, Thomsen C. The role of the innate immune system in psychiatric disorders. Mol Cell Neurosci. 2013 Mar;53:52–62. DOI: 10.1016/j.mcn.2012.10.002. PMID: 23064447.
  24. Balter LJ, Bosch JA, Aldred S, Drayson MT, Veldhuijzen van Zanten JJ, Higgs S, et al. Selective effects of acute low-grade inflammation on human visual attention. Neuroimage. 2019 Nov 15;202:116098. DOI: 10.1016/j.neuroimage.2019.116098. PMID: 31415883.
  25. Theoharides TC, Stewart JM, Hatziagelaki E, Kolaitis G. Brain “fog,” inflammation and obesity: key aspects of neuropsychiatric disorders improved by luteolin. Front Neurosci. 2015 Jul 3;9:225. DOI: 10.3389/fnins.2015.00225. PMID: 26190965. PMCID: PMC4490655.
  26. Conti P, D’Ovidio C, Conti C, Gallenga CE, Lauritano D, Caraffa A, et al. Progression in migraine: Role of mast cells and pro-inflammatory and anti-inflammatory cytokines. Eur J Pharmacol. 2019 Feb 5;844:87–94. DOI: 10.1016/j.ejphar.2018.12.004. PMID: 30529470.
  27. Roman P, Estévez AF, Miras A, Sánchez-Labraca N, Cañadas F, Vivas AB, et al. A pilot randomized controlled trial to explore cognitive and emotional effects of probiotics in fibromyalgia. Sci Rep. 2018 Jul 19;8(1):10965. DOI: 10.1038/s41598-018-29388-5. PMID: 30026567. PMCID: PMC6053373.
  28. Frändemark Å, Jakobsson Ung E, Törnblom H, Simrén M, Jakobsson S. Fatigue: a distressing symptom for patients with irritable bowel syndrome. Neurogastroenterol Motil. 2017 Jan;29(1). DOI: 10.1111/nmo.12898. PMID: 27401139.
  29. Lin L, Zheng LJ, Zhang LJ. Neuroinflammation, gut microbiome, and alzheimer’s disease. Mol Neurobiol. 2018 Nov;55(11):8243–50. DOI: 10.1007/s12035-018-0983-2. PMID: 29524051.
  30. Kennedy PJ, Cryan JF, Dinan TG, Clarke G. Irritable bowel syndrome: a microbiome-gut-brain axis disorder? World J Gastroenterol. 2014 Oct 21;20(39):14105–25. DOI: 10.3748/wjg.v20.i39.14105. PMID: 25339800. PMCID: PMC4202342.
  31. Bravo JA, Julio-Pieper M, Forsythe P, Kunze W, Dinan TG, Bienenstock J, et al. Communication between gastrointestinal bacteria and the nervous system. Curr Opin Pharmacol. 2012 Dec;12(6):667–72. DOI: 10.1016/j.coph.2012.09.010. PMID: 23041079.
  32. Morris G, Fernandes BS, Puri BK, Walker AJ, Carvalho AF, Berk M. Leaky brain in neurological and psychiatric disorders: Drivers and consequences. Aust N Z J Psychiatry. 2018 Oct;52(10):924–48. DOI: 10.1177/0004867418796955. PMID: 30231628.
  33. Dopkins N, Nagarkatti PS, Nagarkatti M. The role of gut microbiome and associated metabolome in the regulation of neuroinflammation in multiple sclerosis and its implications in attenuating chronic inflammation in other inflammatory and autoimmune disorders. Immunology. 2018 Jun;154(2):178–85. DOI: 10.1111/imm.12903. PMID: 29392733. PMCID: PMC5980216.
  34. Sun M-F, Shen Y-Q. Dysbiosis of gut microbiota and microbial metabolites in Parkinson’s Disease. Ageing Res Rev. 2018 Aug;45:53–61. DOI: 10.1016/j.arr.2018.04.004. PMID: 29705121.
  35. Zhang Y, Feng Y, Cao B, Tian Q. The effect of small intestinal bacterial overgrowth on minimal hepatic encephalopathy in patients with cirrhosis. Arch Med Sci. 2016 Jun 1;12(3):592–6. DOI: 10.5114/aoms.2015.55675. PMID: 27279853. PMCID: PMC4889679.
  36. Caraceni P, Vargas V, Solà E, Alessandria C, de Wit K, Trebicka J, et al. The use of rifaximin in patients with cirrhosis. Hepatology. 2021 Sep;74(3):1660–73. DOI: 10.1002/hep.31708. PMID: 33421158. PMCID: PMC8518409.
  37. Flamm SL, Mullen KD, Heimanson Z, Sanyal AJ. Rifaximin has the potential to prevent complications of cirrhosis. Therap Adv Gastroenterol. 2018 Sep 28;11:1756284818800307. DOI: 10.1177/1756284818800307. PMID: 30283499. PMCID: PMC6166307.
  38. Abid S, Kamran M, Abid A, Butt N, Awan S, Abbas Z. Minimal Hepatic Encephalopathy: Effect of H. pylori infection and small intestinal bacterial overgrowth treatment on clinical outcomes. Sci Rep. 2020 Jun 22;10(1):10079. DOI: 10.1038/s41598-020-67171-7. PMID: 32572109. PMCID: PMC7308324.
  39. Jatoi S, Hafeez A, Riaz SU, Ali A, Ghauri MI, Zehra M. Low vitamin B12 levels: an underestimated cause of minimal cognitive impairment and dementia. Cureus. 2020 Feb 13;12(2):e6976. DOI: 10.7759/cureus.6976. PMID: 32206454. PMCID: PMC7077099.
  40. Ettleson MD, Raine A, Batistuzzo A, Batista SP, McAninch E, Teixeira MCTV, et al. Brain fog in hypothyroidism: understanding the patient’s perspective. Endocr Pract. 2022 Mar;28(3):257–64. DOI: 10.1016/j.eprac.2021.12.003. PMID: 34890786. PMCID: PMC8901556.
  41. Haskard-Zolnierek K, Wilson C, Pruin J, Deason R, Howard K. The relationship between brain fog and medication adherence for individuals with hypothyroidism. Clin Nurs Res. 2022 Mar;31(3):445–52. DOI: 10.1177/10547738211038127. PMID: 34348493.
  42. Sullivan Mitchell E, Fugate Woods N. Midlife women’s attributions about perceived memory changes: observations from the Seattle Midlife Women’s Health Study. J Womens Health Gend Based Med. 2001 May;10(4):351–62. DOI: 10.1089/152460901750269670. PMID: 11445026.
  43. Onandia-Hinchado I, Pardo-Palenzuela N, Diaz-Orueta U. Cognitive characterization of adult attention deficit hyperactivity disorder by domains: a systematic review. J Neural Transm. 2021 Jul;128(7):893–937. DOI: 10.1007/s00702-021-02302-6. PMID: 33620582.
  44. Wynchank D, Ten Have M, Bijlenga D, Penninx BW, Beekman AT, Lamers F, et al. The Association Between Insomnia and Sleep Duration in Adults With Attention-Deficit Hyperactivity Disorder: Results From a General Population Study. J Clin Sleep Med. 2018 Mar 15;14(3):349–57. DOI: 10.5664/jcsm.6976. PMID: 29458702. PMCID: PMC5837836.
  45. Sciberras E, Mulraney M, Mensah F, Oberklaid F, Efron D, Hiscock H. Sustained impact of a sleep intervention and moderators of treatment outcome for children with ADHD: a randomised controlled trial. Psychol Med. 2020 Jan;50(2):210–9. DOI: 10.1017/S0033291718004063. PMID: 30654852.
  46. Kristensen VA, Valeur J, Brackmann S, Jahnsen J, Brunborg C, Tveito K. Attention deficit and hyperactivity disorder symptoms respond to gluten-free diet in patients with coeliac disease. Scand J Gastroenterol. 2019 May 3;54(5):571–6. DOI: 10.1080/00365521.2019.1608467. PMID: 31050907.
  47. Hontelez S, Stobernack T, Pelsser LM, van Baarlen P, Frankena K, Groefsema MM, et al. Correlation between brain function and ADHD symptom changes in children with ADHD following a few-foods diet: an open-label intervention trial. Sci Rep. 2021 Nov 12;11(1):22205. DOI: 10.1038/s41598-021-01684-7. PMID: 34772996. PMCID: PMC8589974.
  48. Pelsser LM, Frankena K, Toorman J, Rodrigues Pereira R. Diet and ADHD, Reviewing the Evidence: A Systematic Review of Meta-Analyses of Double-Blind Placebo-Controlled Trials Evaluating the Efficacy of Diet Interventions on the Behavior of Children with ADHD. PLoS ONE. 2017 Jan 25;12(1):e0169277. DOI: 10.1371/journal.pone.0169277. PMID: 28121994. PMCID: PMC5266211.
  49. Campbell KL, Zadravec K, Bland KA, Chesley E, Wolf F, Janelsins MC. The Effect of Exercise on Cancer-Related Cognitive Impairment and Applications for Physical Therapy: Systematic Review of Randomized Controlled Trials. Phys Ther. 2020 Mar 10;100(3):523–42. DOI: 10.1093/ptj/pzz090. PMID: 32065236. PMCID: PMC8559683.
  50. Petersen AMW. The anti-inflammatory effect of exercise. J Appl Physiol. 2005 Apr 1;98(4):1154–62. DOI: 10.1152/japplphysiol.00164.2004. PMID: 15772055.
  51. Ticinesi A, Lauretani F, Tana C, Nouvenne A, Ridolo E, Meschi T. Exercise and immune system as modulators of intestinal microbiome: implications for the gut-muscle axis hypothesis. Exerc Immunol Rev. 2019;25:84–95. PMID: 30753131.
  52. Swanson GR, Burgess HJ. Sleep and circadian hygiene and inflammatory bowel disease. Gastroenterol Clin North Am. 2017 Dec;46(4):881–93. DOI: 10.1016/j.gtc.2017.08.014. PMID: 29173529.
  53. Vanuytsel T, van Wanrooy S, Vanheel H, Vanormelingen C, Verschueren S, Houben E, et al. Psychological stress and corticotropin-releasing hormone increase intestinal permeability in humans by a mast cell-dependent mechanism. Gut. 2014 Aug;63(8):1293–9. DOI: 10.1136/gutjnl-2013-305690. PMID: 24153250.
  54. Karl JP, Margolis LM, Madslien EH, Murphy NE, Castellani JW, Gundersen Y, et al. Changes in intestinal microbiota composition and metabolism coincide with increased intestinal permeability in young adults under prolonged physiological stress. Am J Physiol Gastrointest Liver Physiol. 2017 Jun 1;312(6):G559–71. DOI: 10.1152/ajpgi.00066.2017. PMID: 28336545.
  55. Gibson PR, Shepherd SJ. Evidence-based dietary management of functional gastrointestinal symptoms: The FODMAP approach. J Gastroenterol Hepatol. 2010 Feb;25(2):252–8. DOI: 10.1111/j.1440-1746.2009.06149.x. PMID: 20136989.
  56. Gibson PR, Shepherd SJ. Food choice as a key management strategy for functional gastrointestinal symptoms. Am J Gastroenterol. 2012 May;107(5):657–66; quiz 667. DOI: 10.1038/ajg.2012.49. PMID: 22488077.
  57. Lv T, Ye M, Luo F, Hu B, Wang A, Chen J, et al. Probiotics treatment improves cognitive impairment in patients and animals: A systematic review and meta-analysis. Neurosci Biobehav Rev. 2021 Jan;120:159–72. DOI: 10.1016/j.neubiorev.2020.10.027. PMID: 33157148.
  58. Alexandrov P, Zhai Y, Li W, Lukiw W. Lipopolysaccharide-stimulated, NF-kB-, miRNA-146a- and miRNA-155-mediated molecular-genetic communication between the human gastrointestinal tract microbiome and the brain. Folia Neuropathol. 2019;57(3):211–9. DOI: 10.5114/fn.2019.88449. PMID: 31588707.
  59. Phillips MCL. Fasting as a therapy in neurological disease. Nutrients. 2019 Oct 17;11(10). DOI: 10.3390/nu11102501. PMID: 31627405. PMCID: PMC6836141.
  60. Wichman J, Winther KH, Bonnema SJ, Hegedüs L. Selenium Supplementation Significantly Reduces Thyroid Autoantibody Levels in Patients with Chronic Autoimmune Thyroiditis: A Systematic Review and Meta-Analysis. Thyroid. 2016 Dec;26(12):1681–92. DOI: 10.1089/thy.2016.0256. PMID: 27702392.
  61. 61. Drutel A, Archambeaud F, Caron P. Selenium and the thyroid gland: more good news for clinicians. Clin Endocrinol (Oxf). 2013 Feb;78(2):155–64. DOI: 10.1111/cen.12066. PMID: 23046013.

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