An Interview with Steven Sandberg-Lewis, ND, DHANP
Steven Sandberg-Lewis, ND, DHANP, is a naturopathic physician specializing in gastrointestinal health. He has been in practice for 40 years, and on the faculty of the National University of Naturopathic Medicine (NUNM) for more than 20 years. Dr. Sandberg-Lewis teaches courses in advanced gastroenterology and mentors students on clinical rotations. He speaks internationally and is the author of the textbook Functional Gastroenterology: Assessing and Addressing the Causes of Functional GI Disorders.
Bowel discomfort is one of the most common reasons for doctors’ visits. Many patients experience abdominal discomfort and unfavorable changes in bowel habits for reasons that are difficult to explain.
The gastrointestinal (GI) tract doesn’t function alone. It works in concert with the immune, endocrine, nervous, and other body systems. Because of these complex interactions, integrative therapies are well suited to support gut health. By addressing the root cause and supporting the body as a whole, it’s possible to alleviate bowel discomfort.
In this interview with Element Senior Writer Sarah Cook, ND, Steven Sandberg-Lewis, ND, DHANP, describes the science behind integrative therapies to overcome the challenges of bowel discomfort. He also explains how to assess measurable parameters and address organic changes to help patients with abdominal discomfort achieve a better quality of life.
SARAH COOK: What does the term “irritable bowel,” mean, and how does it differ from other functional GI disorders?
STEVEN SANDBERG-LEWIS: Let’s first define functional GI disorders. These are conditions characterized by changes in the healthy function of any part of the gastrointestinal system, from the esophagus to the anus. Functional changes can include altered motility, visceral hypersensitivity, compromised mucosal function, impaired immune function, imbalances in the gut microbiota, or changes in how the brain communicates with the gut.
Symptoms associated with functional GI disorders vary widely. They can range from difficulty swallowing, to heartburn, to nausea, to constipation. When we say a person has an “irritable bowel,” they typically have abdominal discomfort and changes in bowel habits. They might have diarrhea, constipation, or a mix of both.
Functional GI disorders got their name because it used to be thought that functional changes weren’t accompanied by any detectable physical changes. Patients were labeled as having a functional GI disorder when they experienced symptoms in the absence of organic disease. But it turns out that our historical understanding of functional GI disorders was misguided.
Knowledge about gastrointestinal health has advanced so rapidly in recent years that we have now discovered that functional GI disorders are, indeed, accompanied by detectable and measurable organic changes. This is particularly true for an irritable bowel. There are measurable parameters that we can assess and then address with integrative options. We just need to know where to look—what lab tests to run, what stool tests to order, what imaging to evaluate, or what biopsies to perform.
COOK: Could you describe in more detail the parameters that should be tested in irritable bowel cases?
SANDBERG-LEWIS: One measurable organic change that is seen in people with an irritable bowel is an increase in intraepithelial lymphocytes in the rectal tissue. This does require a biopsy, however, and other parameters require less invasive testing.
One consideration is that as many as 75 percent of cases of irritable bowel are associated with a bacterial imbalance in the small intestine. This can be detected with a duodenal culture on upper endoscopy or with a breath test for gases released by bacterial fermentation in the gut. It’s important to note that you won’t see changes on a stool test when there is a small intestinal imbalance.
Many patients with an irritable bowel (as many as half) have a history of food poisoning or traveler’s diarrhea that preceded the functional changes in gut function. In these cases, a blood test can detect antibodies to a toxin called CdtB, or to a protein found in the gut lining called vinculin.
Anti-CdtB antibodies and anti-vinculin antibodies are produced in response to pathogens in the gut. Even after the pathogen is cleared from the body, these antibodies can persist and interfere with the function of the interstitial cells of Cajal, which are the pacemakers of the intestinal tract. That’s why motility changes are often seen in an irritable bowel. Knowledge of these mechanisms shifts our understanding of an irritable bowel from being strictly a functional disorder to being organically interconnected with the immune and enteric nervous systems.
What’s even more exciting is that emerging studies suggest that the presence of anti-CdtB antibodies and anti-vinculin antibodies may be specific to cases of irritable bowel. They are not typically seen in other populations of people. If this holds true, these simple blood tests could revolutionize our ability to identify an irritable bowel without extensive lab work, imaging, or biopsies.
COOK: So if a bacterial imbalance in the small intestines contributes to as many as 75 percent of irritable bowel cases, what factors contribute to the remaining 25 percent?
SANDBERG-LEWIS: This is an important question because we can only be effective in helping people quell the symptoms of bowel discomfort if we assess and address the underlying factors and organic changes involved.
Aside from bacterial imbalance in the small intestine, there can also be imbalances of yeast or parasites. These can be in either the small intestines or large intestines, and can be measured with cultures or blood immune markers.
In people who mainly experience diarrhea, bile acid malabsorption may be a contributing factor. Anywhere from 10 percent to 30 percent of these people have an issue with bile acid absorption in the terminal ileum. The test for this is a blood test for 7-alpha C4.
Some people with bowel discomfort have pancreatic enzyme insufficiency, which can be measured with stool elastase of chymotrypsin. Others have low production of stomach acid, ileocecal valve insufficiency, or food sensitivities. Endometriosis is commonly associated with bowel discomfort in women because it creates abdominal adhesions. In fact, abdominal adhesions from any other cause, such as a ruptured ovarian cyst or perforated ulcer, can also be a contributing factor.
In addition to all of the organic changes that can precede or be associated with bowel discomfort, we also need to consider the emotions. Any person who has experienced trauma or who is under stress might have sympathetic nervous-system dominance. Changes in nervous-system function are intimately related to changes in the enteric nervous system and the bowel.
It used to be that patients with bowel discomfort were told they had no organic disease. They would be referred for cognitive behavioral therapy or counseling. But when all you have is a hammer, everything looks like a nail. The key to helping patients successfully achieve gastrointestinal health is to know what tests to run to elucidate the underlying cause.
Contributors to Bowel Discomfort
- Bacterial imbalance in the small intestine
- Yeast imbalance in the small or large intestine
- Parasites in the small or large intestine
- Bile acid malabsorption
- Pancreatic enzyme insufficiency
- Low production of stomach acid
- Ileocecal valve insufficiency
- Food sensitivities
- Abdominal adhesions
- Emotional trauma or stress
COOK: You mentioned the enteric nervous system. How does that relate to the gut-brain axis?
SANDBERG-LEWIS: The gut-brain axis is a trending term, but I prefer to call it the “gut-brain continuum” because there’s no separation between the gut and the brain.
It’s staggering to consider all of the ways that the gut and the brain interact. They communicate not only with each other, but also with the byproducts of the microbiome (called the metabolome). The blood-brain barrier and the semi-permeable membranes of the GI tract are intricately related. Communication is instantaneous—from the central nervous system to the enteric nervous system and everywhere in between.
The gut also can’t be separated from the endocrine or immune systems. The gut makes more melatonin and serotonin than any other organ. It deconjugates and converts steroid hormones into primary and secondary bile acids. These secondary bile acids interact directly with g-coupled proteins to influence blood-sugar metabolism, central nervous system function, and health of the whole body.
What’s more, the enteric fat in the omentum makes more cytokines than any other body organ. Inflammation in the gut can upregulate systemic inflammation on a massive scale. There is research that shows gingivitis increases the risk of cardiovascular disease, and we’ve come to realize that the health of the whole body really does begin in the gut.
COOK: Let’s switch gears and talk about dietary approaches for bowel discomfort.
SANDBERG-LEWIS: There are a handful of diets that are designed to help achieve better gastrointestinal health. They’re based on eating the right kinds and amounts of fibers, oligosaccharides, and sugars that can be well tolerated without disrupting the balance of bacteria in the intestines.
The most popular diets include the Low-FODMAP Diet, the Specific Carbohydrate Diet, the SIBO Bi-Phasic Diet, the Gut and Psychology Syndrome (GAPS) diet, and the Cedars-Sinai Diet. I start with a diet that was designed by Alison Siebecker, called the SIBO Specific Diet. It’s a combination of the Specific Carbohydrate Diet, the Low-FODMAP Diet, and her own experience.
There is one caveat to recommending the SIBO Specific Diet. It’s one of the most restrictive diets, and isn’t suited for vegetarians or vegans. It doesn’t contain adequate vegetarian sources of protein, and if they try to follow this diet, they’ll become malnourished. The best options for vegetarians are the Low-FODMAP Diet or the Cedars-Sinai Diet.
COOK: What role do fermented foods and probiotics play in bowel discomfort?
SANDBERG-LEWIS: This is highly individual. Fermented foods and probiotics are helpful for some patients, but are aggravating for others. If a person has a bacterial imbalance in the small intestine, taking additional probiotics might worsen their symptoms.
Lactobacillus is one of the most common probiotics found in supplements and foods, but it’s also one of the bacteria that’s most commonly imbalanced in the small intestine. Many patients will do better when taking alternative probiotics. Examples include soil organisms (spores) or Saccharomyces boulardii (yeast).
For those who do feel better when taking probiotics, the benefits come primarily from the byproducts that are produced by the bacteria—rather than the bacteria themselves. These are things like short-chain fatty acids (SCFAs) and lactic acid, which have tremendous effects on health even in tiny amounts. Some studies show that it doesn’t even matter if probiotics are taken alive or dead—as long as the metabolic byproducts are still in the medium.
The other thing to consider when supplementing a probiotic is that patients need to take them indefinitely to continue to see benefits. Although a diet that’s rich in fiber and resistant starches will help maintain the growth of healthy bacteria in the gut, many patients with bowel discomfort feel better on a low-fiber diet. It’s in these cases that specific supplementation with a probiotic product may be beneficial.
COOK: Aside from probiotics, what supplements are helpful for bowel discomfort?
SANDBERG-LEWIS: The main supplement categories to consider are those that support microbiome balancing, mucosal health, and gut motility.
We use many different herbs to support a healthy and balanced microbiome. Berberine-containing herbs are especially useful because they not only have microbiome-balancing effects, but also support a healthy mucosal barrier and a healthy inflammatory response.*
Berberine-containing herbs are best when we detect hydrogen-producing bacteria on a patient’s breath test. Examples are Chinese goldthread (Coptis chinensis), goldenseal (Hydrastis canadensis), Oregon grape (Mahonia aquifolium), and phellodendron (Phellodendron amurense).
Other excellent microbiome-balancing agents for the gastrointestinal tract are oregano (Origanum vulgare) and fructan-free garlic (allicin extract).* These are best when we detect methane-producing bacteria on a breath test.
After using a microbiome-balancing agent for a month or two to support a healthy balance of intestinal bacteria, then we follow up with a motility-support agent. Some motility-support supplements affect the upper gut, and some affect the lower gut. In patients who have constipation, we use both. In those who have diarrhea, we work to support only upper GI motility.
Herbs that support upper GI motility include ginger (Zingiber officinale), artichoke (Cynara scolymus), and d-limonene.* Supplements that contain 5-hydroxytryptophan (5-HTP) and vitamin B6 modulate serotonin receptors in the gut, which can help with occasional constipation.*
Supplements to support a healthy gut mucosa can be taken along with a motility-support agent. Examples include l-glutamine, zinc carnosine, gamma oryzanol, and aloe vera.*
COOK: What other integrative therapies are useful for patients with bowel discomfort
SANDBERG-LEWIS: I’d like to highlight three additional considerations: counseling, toning the vagal nerve, and abdominal visceral manipulation.
Counseling is so important for many patients with changes in GI function. Some have a history of trauma, and many have anxiety related to food and eating. Patients who have limited their diets to a minimal number of foods in order to manage their bowel habits are often afraid to re-introduce foods as they heal. Counseling can be invaluable for these patients
Some patients have unresolved emotional trauma related to eating. If they associate eating with painful experiences as a child, their nervous systems might be programmed to go into sympathetic overdrive around food. I teach my students an emotional-freedom technique and an eye movement–clearing technique as part of their gastroenterology studies, because of the close relationship between emotions and gut function.
Then there’s the importance of toning the vagal nerve. This nerve provides parasympathetic innervation to the gut, and is central to the gut-brain continuum. We can assess vagal tone by checking a patient’s palatal rise. The levator veli palatini muscle is innervated directly by the vagal nerve.
Ask the patient to stick out their tongue and say “aah.” Look at the arches of their palate during this process. These arches should rise briskly, efficiently, and symmetrically. If there’s asymmetry or if the palate rises slowly, then you want to tone the vagal nerve.
You can accomplish this through alternate nasal breathing (pranayama), diaphragmatic breathing, yodeling, or singing loudly. Other vagal-toning methods include gargling aggressively for one minute two to three times a day, or doing heart-rate variability training with biofeedback. Finally, you can consider coffee retention enemas.
The third consideration, in addition to counseling and vagal tone, is abdominal visceral work. We can use abdominal physical therapy and massage to support the ileocecal valve tone and to support healthy motility.
Abdominal work is also helpful in people who have adhesions from previous surgeries or inflammatory processes. I teach my students some techniques for abdominal manipulation, and the Barral Institute offers excellent training programs.
COOK: We’ve covered a lot of information. Do you have any last words of advice for clinicians?
SANDBERG-LEWIS: My final words of advice are to ask detailed questions and run appropriate tests. The best way to help patients with bowel discomfort is to assess and address the root cause.
For example, when a patient says they have diarrhea or constipation, we need to understand the specifics. We need to know how frequent their bowel movements are, what the Bristol type is, and if there’s any pain.
We also need to explore explanations for their symptoms beyond the small or large bowel. Some patients have outlet constipation, which means there are pelvic-floor issues that need to be addressed with physical therapy.
The only way we will succeed in helping patients overcome changes in bowel function is to be thorough in our questions, exam, and testing. When we discover the root cause, we can help patients achieve healthy GI function and a better quality of life.