Food for Thought: Microbiome and Depression

Induja Nimma, B.A.,MS – 4, University of Louisville School of Medicine

Depression is a severe global health problem. According to the Anxiety and Depression Association of America, 264 million people live with depression globally.  The gut biome can influence the brain’s functions through the microbiota-gut-brain axis.1 A meta-analysis of randomized controlled trials on the effects of probiotics on depression showed a significant reduction in depression in both a healthy population and in patients with major depressive disorder (MDD).2 However, all probiotics may not be beneficial for people with mood disorders. Specific organisms have been associated with improving and worsening symptoms of depression. 

In a parallel study on probiotic formulation, daily administration of Lactobacillus helveticus (R0052) and Bifidobacterium longum (R0175) significantly reduced anxiety-like behavior in rats and reduced psychological distress in healthy human volunteers.3 Additionally, Faecalibacterium, Coprococcus bacteria, and Dialister were depleted in patients with depression even after accounting for the confounding variable of antidepressant effects.4 

However, Firmicutes, Actinobacteria, and Bacteroidetes seem to be associated with an increase in depressive symptoms. In a gut microbiome remodeling study, compared to healthy individuals, patients with MDD had an increase in the afore mentioned bacteria. Fecal transplant in healthy mice with this ‘depression microbiota’ taken from patients with MDD, resulted in “depression-like behaviors” that were not seen in mice transplanted with microbiota from healthy control individuals.5 

Some microbiota seem to confer a positive effect while others a negative effect. This is important to consider since the probiotic supplement industry is not well regulated. If probiotics are to be implemented in the treatment regimen for depression, it is imperative to assess the efficacy and composition of commercially available products that are marketed for depression. This is something to further explore as probiotic use becomes more widely accepted as an adjunct therapy for the treatment of depression.  

References

  1. Cryan JF, O’Riordan KJ, Cowan CSM, et al. The Microbiota-Gut-Brain Axis. Physiol Rev. 2019; 99(4):1877-2013. doi: 10.1152/physrev.00018.2018

2. Huang R, Wang K, Hu J. Effect of Probiotics on Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients. 2016 6;8(8):483. doi: 10.3390/nu8080483   

3. Messaoudi M, Lalonde R, Violle N, et al. Assessment of psychotropic-like properties of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in rats and human subjects. Br J Nutr. 2011;105(5):755-64. doi: 10.1017/S0007114510004319  

4. Valles-Colomer M, Falony G, Darzi Y, et al. The neuroactive potential of the human gut microbiota in quality of life and depression. Nature Microbiolo 2019;4:623-632.    

5. Zheng P, Zeng B, Zhou C, et al. Gut microbiome remodeling induces depressive-like behaviors through a pathway mediated by the host’s metabolism. Mol Psychiatry. 2016; 21(6):786-96. doi: 10.1038/mp.2016.44

ALUMINUM – IS IT A BRAIN TOXIN ?

Steven Lippmann, M.D. Emeritus Professor, University of Louisville School of Medicine 

For decades there have been concerns about whether aluminum is toxic for humans. Does it cause dementias? No conclusive answers, but many people have gotten rid of aluminum cookware, despite still using aluminum foil. Lots of us remember the past frequency of pots and pans made of aluminum. There were questions about whether aluminum incorporation into the body, by oral or dermal means, might induce cognitive declines or other neurological conditions, like parkinsonism, autism, or others.           

There are investigations suggesting that aluminum toxicity is related to early-onset dementia of an Alzheimer disease-like state. However, other research documents no clear etiological leakage. Studies provide no definitive answer. There is much speculation, but a literature review leaves one realizing how little we truly understand. Exposure is widespread because aluminum is the third commonest element in the earth’s crust, and thus, it is in our food supply, medications, and cosmetics.           

Aluminum, in acceptably low levels, is naturally present in many fruits, vegetables meats, fish, and cheeses, etc., but without noting dangerous consequences. Toxicity from this is not recognized. In addition, aluminum is used to facilitate some food preparations like in baking and/or pickling. Baking powder is one of the ingredients of concern, but fortunately aluminum-free baking powders that only contain sodium bicarbonate are ubiquitously available and safe. Exposure can also come through water purification processes and might leach into beverages via aluminum can containers.           

There are many industrial and medical applications. Besides widely available aluminum containing antacids, its hydroxide can also be a vaccine adjuvant. Fear of vaccines has long been an issue; yet, not all vaccines contain aluminum. Our currently available COVID-19 vaccinations contain no aluminum; good news now adays during this pandemic. Reportedly, there is no aluminum in Pfizer, Moderna, Johnson & Johnson, or AstraZeneca vaccines.           Aluminum has antibacterial and antiperspirant qualities, thus it is present in some underarm odor-suppression products. Antiperspirants diminish sweating and that differentiates them from deodorants. Some cosmetic and skin care products also contain aluminum traces, and that also includes styptic pencils or powders, because of their potential to diminish bleeding from small abrasions or cuts, like from razor shaving.           

What about the safety of antiperspirants that contain aluminum? Some marketed products, state clearly up-front in bold lettering that they do not contain aluminum chlorohydrate. That prominent disclosure is sometimes followed in small print on the back label, saying that this product contains potassium alum. Yes, alum is an aluminum salt with potassium, sulfate, sodium, or ammonium. Potassium alum is sometimes called potash alum, proclaimed to be safe, and used in place of aluminum chloride or chlorohydrate.Apparently, this form of chlorohydrate is a small molecule and is easily absorbed through skin, while alum is larger and is thus with less dermal penetration. The implications of these statements opens a question because the product labeling appears to be deceptive. It seemed that the marketers want to convey that their product contains no aluminum and counts on people not reading or understanding potassium alum’s relationship to this metallic element. It might still be safe, but the product labeling prompts concern.           

The pathophysiology of many neurodegenerative conditions remains unknown and proven aluminum toxicity is not obvious. One possible explanation from some sources suggests that aluminum-induced dementias may be due to a physiological predisposition to retain aluminum in the body and/or brain. Thus, vulnerable persons might become toxic while other people evidence no ill effects. However, anyone with a family history of early-onset dementia, probably ought to diminish aluminum exposures.           

Despite lack of clarity about brain toxicity, there are ways to reduce exposures. One can easily avoid aluminum-content antiperspirants, not employ aluminum cookware, even not cooking in its foil form, and not using aluminum-containing baking powders, antacids, and/or vaccinations. Patients and the public should be made aware that no current COVID-19 vaccinations in this country contain aluminum. Also, let people know that many popular antacid tablet brands contain aluminum salts, but calcium carbonate alone and/or with magnesium salt alternative antacids are very widely available. More difficult to identify and harder to rule out is exposure through packaged, prepared baking products. This may not be a major concern, but the degree of presence and risk is not widely known.           We should not become preoccupied with an unproven toxicity, but there are reasonable precautions to minimize adding high aluminum exposures. Time may settle this issue. For now, rely on awareness and prudence.

KPMA Town Hall Meeting

Please join us Thursday, November 11th, 2021, virtually for a Town Hall beginning at 6:30pm.  Our schedule is as follows:

6:30pm – 7:00pm    Sheila Schuster, Ph.D., will discuss assessment thus far from Severe Mental Illness Task Force and tentative recommendations for improving access and care for this patient population.

7:00pm – 7:30pm     Gagandeep Kaur, M.D, will discuss rising number of young adolescent suicidality/attempts, particularly in young girls.

7:30pm – 8:00pm     Allen Brenzel, M.D, will provide a high level overview of current mental health and SUD/OUD climate in Kentucky.  Discuss what strategies/initiative (if any) are being planned at the state level to mitigate for Kentuckians suffering from mental illness/SUD/OUD, with respect to the pandemic.

Registration is free for this virtual event.  You may register using the link below.  A calendar invite is attached as well.

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