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Episode 3: Gut Microbiota influence on Post-Meal Glucose Response  with Richard Sprague

About Richard Sprague

Richard Sprague is a heath technology executive, biohacker, citizen scientist and engineer. He is quite the interesting man.  He is the CEO of Airdoc (a medical technology company).  He has been quite involved with Stool Microbiome testing using 16s rRnA metabolome sequencing. At one point he worked with Ubiome one of the pioneers in stool microbiome testing.  He must own the record for the number of times he has tested his own stool microbiome (over 300).  With this background he brings an interesting perspective on what is actionable within gut microbiome data.


Post meal Glucose Response as it relates to Gut Microbiota


Questions we want to know:

What is the basic principles of post-meal glucose regulation?

What is the need for understanding the gut microbiome influence on  the endocrine system?

How does your microbiota influence Post-meal Glucose basic response?

What is continuous glucose monitoring and how effective is it?

Can your stool microbiome tell you what is the right and precise diet for you to eat?

Can you change your fate? if you have a blood glucose boosting microbiome , can you do anything to change it besides following a restricted diet. 


An introduction to post-meal glucose, heart rate variability, the vagus nerve, polyvagal theory. And a special podcast interview with Dr. Debbie Miller a mind/body medicine expert practicing in Seattle, Washington.

Why is blood sugar dysregulation so concerning?

According to the CDC, in the United States 84 million adults over the age of 18 have been told they have Pre-diabetes.If that is not enough 23 million or 7.4% of the U.S. population has been diagnosed with Diabetes. The number one goal of this conditions

About Heart Rate Variability:  (HRV biofeedback)


A great deal of emphasis is being placed on HRV biofeedback which was originated from the work of Dr. Stephen Porges  Published studies have found that HRV biofeedback helps people with a variety of disorders, including anxiety , depression , hypertension, chronic pain , and other disorders, particularly when they have functional components .


In lay terms: Heart Rate Variability is a measurement  which indicates the variation in your heartbeats within a specific timeframe. It is measured in units of milliseconds. If the intervals between your hearts beats are rather constant then your HRV is low.  If the interval between your heart beat varies then HRV is high.


A high heart rate variability is an indicator of good vagal tone. What is good vagal tone? Good vagal tone is an indicator that the parasympathetic nervous system is acting in good co-ordinance with the sympathetic nervous system. The parasympathetic response from the posterior (dorsal branch of the vagus nerve allows us to “Freeze”. While the sympathetic nervous system allows us to “Fight or Flight”. When the “Freeze” part of our nervous system is not “toned” then we remain in arousal. 


Good  heart rate variability is an indication is indication that the body is adapting to stress responses.


When this takes place according to the Poly Vagal Theory (Porges) then we are able to have more social engagement as the anterior (ventral) branch of the vagus nerve is more tone and we can come from a place of connectedness, mindfulness, and curiosity. We are part of the world and others instead of disconnected or fleeing. My patients hear me talk about approaching life and health from a place of curiosity instead of fear and avoidance all the time. This explains the mechanism!


To unpack this a little further:


Posterior Vagus Nerve (Dorsal Branch) is responsible for (Walker, 2019)




  • Avoidance in the face of fear

  • Insulin activity and Fuel storage

  • Endorphin release to help with pain threshold



  • Metabolism

  • Heart Rate

  • Blood pressure

  • Temperature

  • Muscle Tone

  • Social behavior  (many aspects)

  • Depth of Breath



The Sympathetic Nervous System


  • Blood pressure

  • Heart Rate

  • Respiratory Rate

  • Fuel Mobilization (glucose and fat)

  • Bronchodilation


  • Insulin

  • Digestion

  • Immune response

  • Salivation

The Dorsal Branch of the Vagus Nerve


  • Digestion

  • Motility

  • Resistance to infection

  • Immune response

  • Movement in eyes and head turning

  • Circulation

  • Oxytocin

  • Breathing function


  • Defensiveness

So we can see that this training can help some core biologic processes in the body . 

In part 2 of this article, I will discuss the different ways HRV variability are measured and some of the commercial devices that are available to you. Listen in above Dr. Debbie Miller discusses these topics and mor.


Wearables for Neurofeeback and Biofeedback

Bellabeat LEAF




Oura wellness and activity tracker



Smart Apps for Neurofeedback and Biofeedback

BioZen (Android)

Calm (Android, iOS)

Gratitude Journal (iOS)

Headspace (Android, iOS)

Inner Balance (iOS)

Mindfulness Training (iOS)

MyCalmBeat (Android, iOS)

Omvana (Android, iOS)

Stop, Breathe & Think (Android, iOS

Related Websites on Neurofeeback and Biofeedback

The Daily Routine


Duke Integrative Medicine’s Mindfulness-Based Stress Reduction Program n Flow Genome Project

Greater Good: The Science of a Meaningful Life

Why Gratitude is Good


Heart Math Institute

Mindsight Institute

National Center for Complementary and Integrative Health (NCCIH)

Thnx4 sharable online gratitude journal

Retrain the brain


Altini, M. (2019, 03 06). heart-rate-variability-a-primer. From

heart-rate-variability-basics. (2019, 03 06). From

Walker, R. (2019, 02 21). Poly Vagal Theory. From

Goessl, V. C., Curtiss, J. E., & Hofmann, S. G. (2017). The effect of heart rate variability biofeedback training on stress and anxiety: A meta-analysis. Psychological Medicine, 47(15), 2578–2586.

Lin, G., Xiang, Q., Fu, X., Wang, S., Wang, S., Chen, S., … Wang, T. (2012). Heart Rate Variability Biofeedback Decreases Blood Pressure in Prehypertensive Subjects by Improving Autonomic Function and Baroreflex. The Journal of Alternative and Complementary Medicine, 18(2), 143–152.

SATTAR, F., & VALDIYA, P. (1999). Biofeedback in Medical Practice. Medical Journal Armed Forces India, 55(1), 51–54.


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