Digestive complaints are common and can significantly impact quality of life. Not only that but they can also often be dismissed by conventional medical thinking or swept into the bucket of irritable bowel syndrome without much relief offered. In functional medicine, restoring gut health and balance is right at the core of what we do. And one of the increasingly recognized contributors to digestive symptoms is a condition called SIBO.
In this blog, you’ll learn what SIBO is, how we address it, and, importantly, how to look further into underlying causes of the condition that often need to be addressed for healing to occur. Jacquelyn Lombari, one of our nutrition residents, also graciously shares the story of her healing journey from SIBO – what eventually works for her may surprise you. It’s a frank, down-to-earth read and an important lesson or reminder for all of us. Don’t miss the resource links at the bottom of this article for even more info.
What is SIBO?
SIBO is short for small intestinal bacterial overgrowth, meaning there are excessive numbers of bacteria in the small intestine – even of the good kinds. These bacteria act on prebiotic foods in your diet (like onions, garlic, beans, asparagus, and apples), producing hydrogen and/or methane gas that gives rise to symptoms.
Symptoms can include bloating, indigestion, gas, abdominal pain, reflux, diarrhea, and/or constipation. Nutrient malabsorption can occur. In addition, some non-digestive symptoms can be related to underlying SIBO due to the circulation of inflammatory compounds in the gut and nutrient imbalances over time – fatigue, brain fog, skin conditions such as Rosacea, headaches, joint pain, interstitial cystitis, restless legs syndrome weight loss, anemia, and other nutrient deficiencies, for instance.
How is SIBO identified?
If SIBO is suspected, your practitioner can order a SIBO breath test to confirm. If that isn’t available, a trial low-FODMAP diet can be a reasonable indicator – if symptom relief occurs within a day or two and recurs upon discontinuation, SIBO is likely.
What do we think about when addressing SIBO?
A low FODMAPs diet is commonly used to bring relief to SIBO symptoms. FODMAPs are short for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. Essentially, all those probiotic fibers in foods that we seek out to support a healthy gut microbiome – so, if you’re constantly perplexed why many healthy foods make you feel worse, it could be SIBO!
We have an extensive FODMAP dietary guide in house, but you can also find a good guide here from the Monash University website (incidentally, researchers from the Monash University in Australia were really the first to put SIBO on the map with a major study on SIBO and diet that they started in 2005).
Another dietary option is an elemental diet, a specially designed meal replacement that can be used for up to two-to-three weeks, under medical approval and supervision. It is a challenging diet to complete but has good data behind its effectiveness for reversing SIBO. Don’t do this diet on your own, however.
The thing to know about dietary interventions for SIBO is this – they often bring the most dramatic symptom relief, which can be long-lasting. However, they are not intended as a long-term solution since the diets are highly restrictive, and the ongoing restriction of important prebiotic foods can negatively impact the colonic microbiome (remember, SIBO is in the small intestine, not the colon). The microbiome in your colon is an important contributor to your long-term health.
If you’re finding it hard to discontinue your low FODMAP diet after a few months without a return of symptoms, it’s often necessary to look for the original underlying causes of SIBO – what caused the SIBO to occur in the first place – to help restore a balance that doesn’t continually promote overgrowth – more on that below.
In tandem with diet, antimicrobial supplements help dial down excessive bacterial numbers. Professional supplement companies offer a variety of excellent products such as garlic, olive leaf, berberine, thyme, oregano oil, and lemon balm. In one study, specific combinations of these herbal extracts were shown to be as effective as antibiotics in addressing SIBO.
Supplements are also used commonly used to promote better digestive motility. Motility is a key concept in SIBO – in fact, the bacterial overgrowth is often caused initially by some form of stasis – a stalling of the normal movement of the digestive tract that otherwise helps to keep bacterial populations in check. Supplements that promote better motility (termed “prokinetics”) include ginger, artichoke, magnesium, 5-HTP. Iberogast and MotilPro are go-tos in our clinic.
Depending on need, our physicians may also bring in pharmaceutical support in the form of antibiotics (such as rifaximin) and prokinetics (such as low-dose naltrexone or erythromycin).
The temptation can be strong to keep tightening the screws on diet while using rounds of supplements or medications without addressing underlying factors. I call this the ‘recovery trap,’ where we tend to lean heavily into something that has worked pretty effectively in the beginning but stop short of casting a wide enough net to catch the potentially modifiable underlying factors that predispose to, or perpetuate, a condition.
Potential underlying factors for SIBO tend to fall into three main buckets:
#1 Altered motility
Any of the following conditions or situations can impair motility along the digestive tract: hypothyroid, diabetes, stealth infections (such as varicella-zoster, Epstein-Barr virus, and Lyme disease), scleroderma, gastroparesis, chronic opiate use, or long-standing use of other motility-suppressing drugs.
Strictures and other areas where the passage of digestive contents can slow can also cause physical barriers to motility and can arise from chronic inflammation (such as in Crohn’s disease), fistulas, diverticulosis in the small intestine, past infections, or surgeries. Aerobic exercise and SIBO-specific abdominal massage can be enough for some to manage these underlying contributors. Sometimes we refer folks for visceral manipulation to reduce the blocking effects of physical defects and scar tissue. Where issues can’t be fully resolved, their presence can make the case for longer-term maintenance use of prokinetics or herbal antimicrobials.
#2 Altered antimicrobial digestive secretions
Normal digestive secretions play a role in controlling bacterial populations in the gut. One of the most impactful is stomach acid, which dramatically reduces the bacterial populations that are able to enter from the mouth and reach the intestines. Long-term use of acid suppressants or conditions that impair gastric acid secretions can promote bacterial overgrowth in the small intestine.
Another important digestive secretion that has antimicrobial activity is bile acid, which is excreted from the liver and stored in the gallbladder to be released after food is consumed. Gallstones, which inhibit bile acid secretions, can reduce this mechanism of bacterial control. Incidentally, having high estrogen promotes the formation of gallstones – yet another underlying connection to an underlying contributor. Liver diseases, which alter bile acid formation, can also play a role.
#3 Altered immune function
Your immune system is a critical tool for keeping the levels of bacteria in your gut in check. An important immune molecule produced in your gut and used to control bacteria is secretory immunoglobulin A (sIgA). It’s something we can measure in saliva or stool. Since sIgA helps to shape the composition of microbes in your gut (both the good and bad), having low sIgA can allow those microbes to become unruly and grow out of control. Supporting a healthy gut lining through (low FODMAPs) interventions like glutamine, vitamin A, and zinc can improve sIgA levels. sIgA is also very sensitive to stress – chronic stress over time can really tank sIgA production.
Sometimes it’s not SIBO or not SIBO alone…
Here are some relatively common situations that can sometimes be confused with SIBO but require an adjusted approach:
- Intestinal methanogen overgrowth (IMO), the overgrowth of archaea in the small intestine and or large intestine. Archaea are not bacteria and this condition doesn’t always stay within the small intestine. It is often associated with constipation. Atrantil is a supplement worth considering for methane production.
- Hydrogen sulfide overgrowth, the overgrowth of bacteria that produce hydrogen sulfide which is often associated with diarrhea. While this is technically still a form of SIBO, the hydrogen sulfide isn’t detected on available breath tests so your results may look negative even when this type of SIBO is present.
- Small intestinal fungal overgrowth (SIFO), an overgrowth of fungal organisms in the small intestine, rather than bacteria. Herbal antimicrobials usually target all problematic players, including fungi. However, pharmaceutical antibiotics don’t. If someone gets worse on a pharmaceutical antibiotic there’s a chance they might have SIFO. Antifungal medications may be used with success here.
Head on over to this podcast where Dr. Fitzgerald discussed these with SIBO expert Dr. Mark Pimentel on her podcast.
SIBO and Stress
Stress can really impact all three of those underlying factors listed above. Stress switches our nervous system towards fight-or-flight and away from rest and digest. In that mode, energy is diverted away from proper digestive function, including motility and secretions. As I mentioned above, stress really impairs gut immune function.
I will leave you with this wonderful anecdote from our own nutrition resident Jacqueline Lombari, reflecting on her journey of recovery from SIBO. It’s a great reminder that it’s often necessary to keep drilling down to get to those underlying factors of disease and that it is hard (if not impossible) to heal in a higher-stress state.
My SIBO Recovery, by Jacquelyn Lombari (@jacquilombari)
It was about 2016 and I was hiking with a close friend one Saturday morning.
This popular hike is nestled in the city of Phoenix and provides a challenging 1,000 feet of elevation gain over just a mere 1 mile. It is a hike I used to crush weekly, leaping and bounding to the summit in ecstasy.
Today, I was far from “crushing it.”
I recall the fatigue settling in within the first few minutes of our ascent. The sensation of a bloated lower abdomen against the unforgiving waistband of my leggings. “All I had was coffee this morning, why am I already bloated?” I thought to myself.
I asked my friend if we could turn around halfway up the mountain, embarrassed by my lack of endurance and stamina. I was 27 years old at the time.
My friend didn’t mind and suggested we go for fresh juice afterward. Despite the cool breeze, the Phoenix sun was relentless.
“Juice?! I can’t have juice! What kind of FODMAPs are in juice? I am already bloated; I can’t possibly have juice on top of it all,” These anxious thoughts raced through my head and I politely declined.
When we parted ways, I went out for an iced coffee on my own (I was intermittent fasting at this time) and drove to the safety of home where all my “approved” low FODMAP foods were easily accessible.
Reflecting back at this time, I see my 27-year-old self living in a state of constant fear. I let my condition (SIBO, small intestinal bacterial overgrowth) penetrate most aspects of my life. Loneliness and isolation crept in as I rarely went out with friends or possessed the self-confidence to socialize. I listened to every podcast on SIBO and followed every blog on the subject. I carried with me a special supplement container that held the supplements that I so desperately depended on.
But after two years, multiple functional medicine physicians, various protocols, and an extensive stint on a low-FODMAP diet (not recommended by the way), I was nowhere close to a resolution of my illness.
Then there was a big change that occurred in my life – it had little to do with my diet or the right gut healing protocol. It wasn’t even yoga (which I was doing at least 3 days a week) but it did have to do with stress…the stress of my job.
To afford the doctor’s visits, the supplements, all the testing that was recommended, I was working at least 4 days a week as a server in an upscale restaurant in my area. I would average five miles a shift on my feet, a type of work that allowed for no breaks. I thought the flexible schedule suited me and my situation. I could sleep in and work the evenings, but little did I realize the negative impact this work was having on my ability to heal.
Until I quit.
I found a desk job, that paid less but was actually in a field I was interested in. While the 7:00 AM starts frightened me at first, I was surprised by how quickly I adapted. Day by day I began to feel my body exhale and relax for the first time in years. With this new sense of relaxation, I started to expand my diet with merely a sense of curiosity. One day it was an apple, the next a cup of beans. I had demonized so many foods – that this expansion in my diet was almost a homecoming of who I was before. After a few months of this new balanced “me,” my SIBO resolved.
As I enter the field of personalized nutrition and functional medicine, the lessons learned on my own health journey are just as relevant today. For it is the perturbation of stress that hinders the healing process so many people seek. While not every person can up and quit their current job, this knowledge allows for a deeper understanding of healing itself.
More SIBO resources on drkarafitzgerald.com
Dr. Mark Pimentel Presents New Perspectives on SIBO and IBS
Got Good Guts? Clinically Effective Applications for SIBO, SIFO, and Dysbiosis
Must-know Causes for Refractory Sibo with Dr. Steven Sandberg-Lewis
Small Intestinal Microbial Overgrowth: A Conversation with Dr. Vincent Pedre, MD IFMCP
Plant Based Antimicrobials – How to Heal SIBO and other chronic GI Imbalances with Botanical Medicines