Counseling and Physiology:
Yoon Suh Moh, Ph.D., NCC, CRC, LPC
Description of Microbes and Microbiomes
Factors Influencing The Composition of Microbiome
Mechanisms of Gut-and-Brain Communication
Relationships between Each Physical and Mental Health, and
An ancient and diverse collection of organisms including bacteria, fungi, and other microscopic organisms (Douthit & Russotti, 2017)
For the purpose of this class, we will limit to bacteria.
You Are What You Eat
- The preferred spot for setting up residence is in the gut.
- With the large intestine being home to the largest population of bacteria in the body
- With estimates that the human intestine harbors 100 trillion bacteria,
the contents of the page intestine can serve up something on the order of
500 million bacteria per teaspoon
- The number of microbiome (fungi, protozoa, Archaea, viruses, and microbiota that reside
that reside within our bodies are estimated to be as much as 10 times greater than the total
cell number in the human body; their genetic information is at least 150-fold greater than that
of the human genome (Jasarevic, Morrison, & Bale, 2015)
- The massive collection of bacteria that we harbor is the microbiome.
Human Gut Microbes
The composition of the microbiome is to some extent, very individualized.
- Whether the individual had a vaginal or cesarean birth
- Whether the individual was breast-fed as an infant
- The degree to which the individual has been administered antibiotics
- The individual's level of exposure to stress
- The amount of food in the person's diet containing bacteria-friendly, water-soluble
fiber that is not digestible by humans
(e.g., bananas, dandelion greens, onions, leeks, garlic) and gut-friendly live-culture
foods (e.g., yogurt)
- The amount of optimal sleep the person gets
- The individual's genes
- The individual's age and sex
A Number of factors influencing the types of bacteria harbored by a given individual
The diverse ecology of bacteria that humans harbor up to 1,600 species
are engaged in a wide array of healthy physiological functions that
maintain our physical and mental health.
In the realm of physical health, bacteria have a relationship to
obesity, diabetes, inflammatory bowel diseases, and certain cancers
In the realm of mental health, an unhealthy bacterial composition is related to
anxiety, depression, autism, and a dysregulated stress response.
"I have a gut feeling."
The centrality of gut functioning to human mental health
- The enteric nervous system (commonly known as the gut) has a collection of nervous
tissue that gives it the distinction of being termed the "second brain"
- Key neurological connections exist between the gut and the brain
Gut Microbiomes and Mental Health
How Does Our Gut Talk to Our Brain?
The vagus nerve, the longest nerve in the human body,
connects the brain with the gut.
The vagus nerve forms a sensory neural circuit with enteroendocrine cells.
This circuit provides the opportunity to determine
how stimuli from food and gut microbes may alter
basic brain behaviors, such as eating or mood.
Gut Feelings in Action
Dr. Diego Bohorquez's website: https://www.gutbrains.com/projects/terasaki-lab-at-university-of-connecticut/
Using volumetric electron microscopy techniques
to uncover the ultrastructural features the points of
contacts between enteroendocrine cells and nerves.
This connection is the first node between nutrient sensing and electrochemical transduction
that modulates brain function and behavior.
Connections between Enteroendocrine Cells and Nerves
Dr. Diego Bohorquez's website: https://www.gutbrains.com/projects/the-first-synapses/
Neuropods in 3D
When the bacterial health and composition is optimal...
Unnecessary use of antibiotics
The Integration of Peripheral and Central Immune, Metabolic and Endocrine Signals
Animal Model Experimentation
- A Japanese scientist (2004)
- Mice raised free of gamers from birth had a a greater output of stress horses under
stressful situations than did mice with a normal bacterial composition
Animal Models of The Microbiome-Mental Health Connection
: Dr. Nobuyuki Sodo and His Colleagues' Work (2004)
- In experimental models of the microbiome-mental health connection is brain-derived
neurotrophic factor (BDNF)
- This substance has major implications for mental health
- Neuron viability, neuroplasticity, and growth of synapses are all dependent on BDNF
- The depletion in the hippocampus and cortex are associated with anxiety and
Microbiome-Gut-Brain-Axis Studies: Brain-Derived Neurotrophic Factor (BDNF)
Microbiome-Gut-Brain-Axis Studies: Serotonin
- Microbiome-related control of circulating serotonin and regulation of serotonin
receptors in the hippocampus and other locations in the brain
- Gut microbiota have an important role in its regulation
- This regulatory function of the microbiome makes it a potential
future target for treating anxiety and depression
- A collaboration of scientists from McMaster University and the University of Cork
led by Javier Bravo
- GABA has an inhibitory effect on the central nervous system - The regulation of the
role of GABA is important in anxiety and depression
- Anxiolytic probiotic consisting of the bacterium Lactobacillus rhamnosus was
administered to mice
- Evidence of decreased anxiety was observed, and GABA production was seen to
simultaneously increase in various brain regions, including the hippocampus,
amygdala, and locus coeruleus
Microbiome-Gut-Brain-Axis Studies: Gamma-Aminobutyric Acid (GABA)
- Certain types of immune responses are implicated in depression
- Clear connections linking chronic stress to inflammation, and in turn, linking
circulating mediators of inflammation called proinflammatory cytokines (PICs)
to the symptoms of depression, including social withdrawal, anhedonia,
dysphoria, and fatigue
- The gut is a major source of PICs and helps to regulate circulating levels of these
- High levels of circulating PICs regulate functioning of both the stress response
and neurotransmitters such as serotonin, explaining their relationship to
- Many brain cells have receptors for PICs, including areas in the hippocampus and
Chronic stress, The Immune System, and Microbiome
" Leaky gut"
- Alessio Fasano, director of the Center for Celiac Research and Treatment at
Massachusetts General Hospital studied extensively a relationship between
the microbiome, inflammation, and depression
- Certain conditions (e.g., chronic stress, infection by particular gut pathogens,
excessive alcohol consumption, high does of non-steroidal anti-inflammatory drugs,
and some cases of antibiotic use) increase the permeability of the intestinal wall,
allowing bacteria and certain bacterial products to penetrate it and trigger harmful
inflammatory response that lead to increases in circulating proinflammatory
- Proinflammatory state is associated with depression
- Female-biased prevalence in functional gastrointestinal disorders (e.g., irritable bowl
syndrome) may result from sex differences in
gastrointestinal transit time,
central nervous system pain processing, and
hormone-dependent effects on gut physiology
- In consideration of sex differences in the gut micro biome across the lifespan provides
novel mechanistic insight into sex differences in disease prevalence,
age of onset and severity, and may ultimately lead to novel interventions and
Sex Differences in Brain-Gut Axis
- Refer clients to experts in nutrition and diet alongside psychotherapy
- To be aware of the literature:
- Studies of probiotic interventions: significant reduction in depression and anxiety
symptoms, sad mood and rumination in as few as four weeks of treatment
- Studies: positive effects of brain activity in regions central to emotional processing and
suppression of overreactive stress responses
- In conjunction with a nutritionist or a medical professional, counselor provide dietary
education based on the empirical effectiveness of specific foods that treat depressed
Clinical Implications: Healthy Eating Plate