From the Editor

It takes guts to be mentally ill: Microbiota and psychopathology

Current Psychiatry. 2018 September;17(9):4-6

References

1. Nasrallah HA. Psychoneurogastroenterology: the abdominal brain, the microbiome, and psychiatry. Current Psychiatry. 2015;14(5):10-11.
2. Dinan TG, Borre YE, Cryan JF. Genomics of schizophrenia: time to consider the gut microbiome? Mol Psychiatry. 2014;19(12):1252-1257.
3. Alam R, Abdolmaleky HM, Zhou JR. Microbiome, inflammation, epigenetic alterations, and mental diseases. Am J Med Genet B Neuropsychiatr Genet. 2017;174(6):651-660.
4. Lach G, Schellekens H, Dinan TG, et al. Anxiety, depression, and the microbiome: a role for gut peptides. Neurotherapeutics. 2018;15(1):36-59.
5. Kelly JR, Kennedy PJ, Cryan JF, et al. Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders. Front Cell Neurosci. 2015;9:392.
6. Rodrigues-Amorim D, Rivera-Baltanás T, Regueiro B, et al. The role of the gut microbiota in schizophrenia: current and future perspectives. World J Biol Psychiatry. 2018;21:1-15.
7. Petra AI, Panagiotidou S, Hatziagelaki E, et al. Gut-microbiota-brain axis and its effect on neuropsychiatric disorders with suspected immune dysregulation. Clin Ther. 2015;37(5):984-995.
8. Lurie I, Yang YX, Haynes K, et al. Antibiotic exposure and the risk for depression, anxiety, or psychosis: a nested case-control study. J Clin Psychiatry. 2015;76(11):1522-1528.
9. He Y, Kosciolek T, Tang J, et al. Gut microbiome and magnetic resonance spectroscopy study of subjects at ultra-high risk for psychosis may support the membrane hypothesis. Eur Psychiatry. 2018;53:37-45.
10. Yuan X, Zhang P, Wang Y, et al. Changes in metabolism and microbiota after 24-week risperidone treatment in drug naïve, normal weight patients with first episode schizophrenia. Schizophr Res. 2018;pii: S0920-9964(18)30274-3. [Epub ahead of print]. doi: 10.1016/j.schres.2018.05.017.
11. Dickerson F, Severance E, Yolken R. The microbiome, immunity, and schizophrenia and bipolar disorder. Brain Behav Immun. 2017;62:46-52.
12. Huang R, Wang K, Hu J. Effect of probiotics on depression: a systematic review and meta-analysis of randomized controlled trials. Nutrients. 2016;8(8):pii: E483. doi: 10.3390/nu8080483.
13. Carding S, Verbeke K, Vipond DT, et al. Dysbiosis of the gut microbiota in disease. Microb Ecol Health Dis. 2015;26:26191. doi: 10.3402/mehd.v26.26191.
14. Thapar A, Cooper M, Eyre O, et al. Practitioner review: what have we learnt about the causes of ADHD? J Child Psychol Psychiatry. 2013;54(1):3-16.
15. Jiang C, Li G, Huang P, et al. The gut microbiota and Alzheimer’s disease. J Alzheimers Dis. 2017;58(1):1-15.
16. Kurokawa S, Kishimoto T, Mizuno S, et al. The effect of fecal microbiota transplantation on psychiatric symptoms among patients with irritable bowel syndrome, functional diarrhea and functional constipation: an open-label observational study. J Affect Disord. 2018;235:506-512.
17. Hillemacher T, Bachmann O, Kahl KG, et al. Alcohol, microbiome, and their effect on psychiatric disorders. Prog Neuropsychopharmacol Biol Psychiatry. 2018;85:105-115.
18. Doré J, Multon MC, Béhier JM; participants of Giens XXXII, Round Table No. 2. The human gut microbiome as source of innovation for health: which physiological and therapeutic outcomes could we expect? Therapie. 2017;72(1):21-38.
19. Vemuri RC, Gundamaraju R, Shinde T, et al. Therapeutic interventions for gut dysbiosis and related disorders in the elderly: antibiotics, probiotics or faecal microbiota transplantation? Benef Microbes. 2017;8(2):179-192.
20. Lombardi VC, De Meirleir KL, Subramanian K, et al. Nutritional modulation of the intestinal microbiota; future opportunities for the prevention and treatment of neuroimmune and neuroinflammatory disease. J Nutr Biochem. 2018;61:1-16.

What is the largest endocrine organ in the human body?

Here is a clue: It is also the largest immune organ in humans!

Still scratching your head? Here is another clue: This organ also contains a “second brain,” which is connected to big brain inside the head by the vagus nerve.

Okay, enough guessing: It’s the 30-foot long gastrointestinal (GI) tract, which is generally associated only with eating and digestion. But it is far more than a digestive tract. It is home to about 100 trillion diverse bacteria, including 1,000 known species, which together are known as “microbiota.” Its combined DNA is called the “microbiome” and is 10,000% larger than the human genome. Those trillions of bacteria in our guts are a symbiotic (commensal) organ that is vital for the normal functions of the human body.¹

While this vast array of microorganisms is vital to sustaining a healthy human existence, it can also be involved in multiple psychiatric disorders, including depression, psychosis, anxiety, autism, and attention-deficit/hyperactivity disorder (ADHD). Humans acquire their unique sets of microbiota as they pass through the mother’s vagina at birth and while breastfeeding, as well as from exposure to various environmental sources in the first few months of life.²

The microbiota in the GI tract are an intimate neighbor of the “enteric brain,” comprised of 100 million neurons plus glia-like support cell structures. This “second brain” produces over 30 neurotransmitters, several of which (dopamine, serotonin, γ-aminobutyric acid [GABA], acetylcholine) have been implicated in major psychiatric disorders.³

The brain and gut have a dynamic bidirectional communication system, mediated by neural, hormonal, and immunological crosstalk and influences. The GI tract secretes dozens of peptides and other signaling molecules that influence the brain. The microbiota also interact with and are regulated by gut hormones such as oxytocin, ghrelin, neuropeptide Y, cholecystokinin, corticotrophin-releasing factor, and pancreatic polypeptide.⁴ The microbiota modulate brain development, functions, and behavior, and maintain the intestinal barrier, which, if disrupted, would result in the gut becoming “leaky” and triggering low-grade inflammation such as that associated with depression.⁵

Continue to: But don't overlook the importance of...

References

Mental illness and the criminal justice system: Reducing the risks

It takes guts to be mentally ill: Microbiota and psychopathology

References

Pages

Next Article: