Gut Health and Immune System Performance

Dr. Shawn Talbott (Ph.D., CNS, LDN, FACSM, FACN, FAIS) has gone from triathlon struggler to gut-brain guru! With a Ph.D. in Nutritional Biochemistry, he's on a mission to boost everyday human performance through the power of natural solutions and the gut-brain axis.

Best Future YouHarnessing Your Body’s Biochemistry to Achieve Balance in Body, Mind, and Spirit

My 13th book, Best Future You, is out!

Over the next several weeks, I’ll be posting excerpts from the book and blogging frequently about the main concept in the book – which is the idea of harnessing your body’s internal cellular biochemistry to achieve true balance in body, mind, and spirit – and in doing so, help you to become your “Best Future You” in terms of how you look, how you feel, and how you perform on every level.

Chapter 8 – Perform Your Best

Phase 2 – Gut Health (including immune system function)

Gut Health and Immune System Performance

The image of stress-induced ulcers has been with us for decades. You’ve probably seen, on a TV sitcom or other such venue, the stereotypical portrayal of the stressed-out executive. Deadlines loom, stress builds, and the businessman gulps down antacids to quell the burning ulcer in his stomach. Far from being one of the many Hollywood over-exaggerations, the phenomenon of stress-induced ulcers and other digestive problems has been documented in the medical literature for more than fifty years. From a physiological point of view, we know quite clearly that any stressful event will cause digestion to cease. Blood flow is diverted from the digestive organs to the heart and muscles, secretion of saliva and digestive enzymes is slowed, and intestinal contractions and absorption of nutrients stop. This rapid shutdown of the digestive process makes perfect sense, because from the standpoint of long-term survival it is more important to get away from the dangerous stressor (the lion) than to fully digest all your food. There will be plenty of time for digestion later; right now you need to save your life. It is interesting to note, however, that even while a variety of cellular stress signals shutting down digestion, these same signals, when kept elevated for more than a few minutes, are telling us to eat—and eat a lot!

Medical evidence shows quite clearly that ulcers of the stomach (gastric ulcers) and intestine (duodenal ulcers) are much more common in people who are anxious, depressed, or under chronic or repeated stress. In these situations, which are all also examples of chronic cellular stress, many of the digestive actions are curtailed, so the body also backs off from its production of other protective measures—such as the mucus that lines the stomach, and the bicarbonate that counteracts the highly acidic gastric juices. Sounds logical, right? And it is. Why should the body take a lot of protective measures against acid that will never be secreted (because you’re under stress)? The problems start to occur when a person experiences the repeated cycles of high stress followed by low/normal stress that have become commonplace in our modern society. This sets up the digestive system for total confusion. Most of the time the body won’t be able to secrete enough digestive enzymes to properly digest food (producing nausea, constipation, gas, and bloating). During the “lucky” times when a body can secrete enough digestive enzymes to properly break down food, the protective mechanisms are far from fully operational—which puts a person at risk for damage to her gastrointestinal tract (because the enzymes digest the gut’s lining in addition to digesting the food). This scenario says a lot about why several bouts of repeated back-to-back chronic stress are so detrimental to gastrointestinal function – and to the overall function of our immune system, much of which resides in the GI tract.

To compound our “gut” problems, other factors, such as immune-system function and the body’s control of inflammation and wound healing, come into play. It is well described in the medical literature that both repeated periods of acute stress and continuous periods of chronic stress are associated with suppressed immune-system activity. This has a direct bearing on ulcer development, because less immune-system activity means more growth and higher activity of a bacterium called Helicobacter pylori, which infects the stomach and causes ulcers in 80 percent of the people infected with it.

Compounding the tissue damage caused by the accelerated growth of H. pylori is a suppression of the body’s ability to heal that tissue damage because of an inhibition in prostaglandin synthesis. Prostaglandins are typically produced in response to tissue damage, where they help reduce inflammation and accelerate healing. During times of stress, however, the synthesis of prostaglandins is curtailed, which suggests that stress not only increases the rate at which ulcers may form, but also slows the rate at which they are repaired.

Aside from ulcers, the most common stress-related gut disease may be irritable bowel syndrome (IBS). Most of us will experience some degree of IBS during our lifetime. The name “IBS” is really a catchall for a variety of intestinal disorders, including colitis (inflammation of the lining of the large intestine, also known as the colon), in which abdominal pain is accompanied by diarrhea and/or constipation, bloating, gas, and, occasionally, passing of mucus or blood. The majority of the gastrointestinal conditions falling under the IBS umbrella are either caused by or exacerbated by periods of heightened stress.

Stress leads to poor digestion, ulcerated stomachs, and inflamed intestines—not a pretty picture. Heightened stress levels have also been linked to adverse effects on the balance of intestinal microflora, which are known to respond to changes in both diet and stress levels. These beneficial bacteria live in our intestinal tract, and while they are intimately involved with optimal gastrointestinal function, they also play a vital role in helping to support immune function. In a study of fighter pilots preparing for simulated battle (a fairly stressful event), distinct reductions were noted in the numbers of “good” bacteria (lactobacilli and bifidobacteria), along with a corresponding increase in the numbers of “bad” bacteria (E. coli, enterobacteria, and clostridia). The outcome for these pilots was, predictably, a sharp increase in their reported incidence of sore throats, headaches, colds, diarrhea, and upset stomachs.

Let’s take a moment to think about the most predominant sources of stress that could be at the root of these health problems. In many stress-management clinics, the primary determinants of whether or not a given person will get sick include:

  • the number of “major life events” in the past year (divorce, death in the family, change in job or location, etc.)
  • a psychological perception that daily demands exceed coping resources and/or your support system
  • Financial stress – which we can define simply as “worry about money”

Of this short list of three “sickness determinants,” researchers have found that the overall degree of psychological stress is strongly related, in a dose-response fashion, to URTIs (upper-respiratory-tract infections) and other breakdowns in immune-system integrity (such as gastrointestinal health). This means the more stressed out you are, the more likely you are to get sick. Numerous studies in animals and humans have shown that both acute and chronic stress increases susceptibility to infectious diseases. In particular, the risk of URTIs is sharply increased, so that people who are under the greatest stress (or who deal with it poorly) are the ones who most often get these types of sicknesses. Students catch colds during exam week, and accountants get sore throats in April, when they’re filing dozens of last-minute tax returns.

So after all this discussion about the suppression of immune-system function due to stress, who do you think gets sick most often? What demographic group, among all others, suffers from the highest incidence of stress-related disease?

Wealthy investment bankers? No.

Stressed-out college students? No.

Single mothers working two jobs and driving beat-up 1985 Ford Escorts? Yes!

The most direct example of the chronically elevated human stress response can be observed every day in the lives of a large part of the American (and worldwide) population who are battling chronic financial stress. These are the folks who are driving a junker car (and hoping it makes it) to their second job. They are hoping the money from that second paycheck will last until the end of the month when the bills are due. They are not the people whom you see commiserating with each other about their unfulfilling jobs and their “first world problems” such as how they wish they could upgrade their iPhone 5 to a 6. The constant unrelenting stress of making ends meet, job instability, sleep deprivation, poor diet, lack of outlets for stress, and overall lack of control combine to increase the risk of disease by a factor of five to ten.

Many of you reading this book are probably suffering from some degree of financial stress. This is the type of chronic emotional/psychological stress that is always with us. It’s often the first thing that we think of when we wake up in the morning (going to our jobs to make money) – and the last thing that we think of before we go to bed at night (the rent/mortgage, tuition, car payment, groceries, and other bills that we need to pay). It’s the kind of low-grade chronic stress that is with us every time we go to the mailbox (which is filled with credit card bills) or the gas pump. It’s unrelenting for many people.

One interesting study looked at people of varying socioeconomic grades (some were rich and some were poor). Those on the lower end of the socioeconomic ladder (poorer) were significantly more likely to be overweight (with more abdominal obesity – covered in the next section) and to have higher cortisol values in relation to perceived stress. The researchers noted that the “duration of low socioeconomic conditions” (scientific lingo for “being financially-stressed for a long time”) seemed to worsen the effects of cellular stress and strengthen the relationship between cortisol and obesity (meaning that financial stress is bad for health and for your waistline). Overall, the researchers concluded that the stress of a low socioeconomic status is associated with elevated cortisol secretion, cellular stress, and a significant, strong, and consistent relationship with obesity. Closely related to pure socioeconomic studies of stress are the growing arguments that people eat more Big Macs, drink more Coke, and scarf more Oreos not because these companies tell us to eat them (via advertising), but because of stress. Lower socioeconomic populations may eat more junk food because they are more stressed out, not necessarily because Ronald McDonald invites them to “drive thru.” Biology trumps advertising.

Thanks for reading – be sure to tune in for the next installment about, “Phase 3 – Body Fat (especially belly fat).”

Shawn M Talbott, PhD, CNS, LDN, FACSM, FAIS, FACN
Nutritional Biochemist and Author
801-915-1170 (mobile)


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The Secret of Vigor – How to Overcome Burnout, Restore Biochemical Balance, and Reclaim Your Natural Energy
Killer at Large – Why Obesity is America’s Greatest Threat – an award-winning documentary film exploring the causes and solutions underlying the American obesity epidemic
The Cortisol Connection – Why Stress Makes You Fat and Ruins Your Health (Hunter House)
The Cortisol Connection Diet – The Breakthrough Program to Control Stress and Lose Weight (Hunter House)
Cortisol Control and the Beauty Connection – The All-Natural Inside-Out Approach to Reversing Wrinkles, Preventing Acne, And Improving Skin Tone (Hunter House)
Natural Solutions for Pain-Free Living – Lasting Relief for Flexible Joints, Strong Bones and Ache-Free Muscles (Chronicle Publishers – Currant Books)
The Immune Miracle – The All-Natural Approach for Better Health, Increased Energy and Improved Mood (GLH Nutrition, 2012)
A Guide to Understanding Dietary Supplements – an Outstanding Academic Text of 2004 (Haworth Press)
About the Author

Exercise physiologist (MS, UMass Amherst) and Nutritional Biochemist (PhD, Rutgers) who studies how lifestyle influences our biochemistry, psychology and behavior - which kind of makes me a "Psycho-Nutritionist"?!?!

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