Small intestinal bacteria overgrowth causes chronic digestive problems.
For as long as she can remember, Bea (not her real name) has been gluten sensitive. It was never so bad that she sought treatment, but “I’ve always had tummy problems,” she says.
Her gastrointestinal issues became much more severe after she underwent a series of pelvic mesh surgeries after childbirth. She developed associated infections and took massive doses of antibiotics to treat them. For years afterward, she battled nausea and couldn’t tolerate certain foods. Her weight dropped below 100 pounds.
In 2014, nine years after her first abdominal surgery and three years after her last, Bea turned to Amy Burkhart, MD, RD, an integrative medicine and digestive health specialist in Napa, California. Her symptoms sounded familiar to Burkhart, who asked Bea, as part of her evaluation, to breathe into test tubes after consuming a sugar solution containing lactulose.
The diagnosis: small intestinal bacterial overgrowth, or SIBO, which happens when gut bacteria grow out of balance. The overgrowth can be temporary or prolonged.
In proper balance, bacteria in the colon prevent illness, regulate food absorption and digestion and play a role in many body functions. But when bacteria invade and take over the small intestine, they can cause digestive problems (like gas, abdominal bloating, stomach pain), nutrient malabsorption, food sensitivities and more.
“There’s a fine balance and if you disrupt the balance, it affects your overall health,” Burkhart says.
While SIBO has a variety of causes—including antibiotics, which can wreak havoc on gut health—it’s especially common in people with irritable bowel syndrome, inflammatory bowel disease and autoimmune disorders such as celiac disease.
These connections haven’t been extensively studied, but it’s been estimated that as many as one in five people with celiac disease also has SIBO, according to a June 2017 review in the Journal of Neurogastroenterology and Motility. The rate of SIBO is even higher—28 percent—in those with celiac disease who continue to be symptomatic despite a gluten-free diet.
Conditions that affect the gut—including celiac disease, leaky gut syndrome, lactose intolerance and bowel surgeries—can increase the risk of developing SIBO. When the small intestine is damaged by inflammation, infection, surgery or disease, bacteria can flourish there.
Possible risk factors or underlying causes of SIBO include:
- Celiac disease
- Chronic alcohol use
- Crohn’s disease
- Irritable bowel syndrome
- Liver cirrhosis
- Low stomach acid
- Prior bowel surgery
- Recurrent antibiotics
- Renal failure
Those with SIBO may have some of the following symptoms:
- Abdominal pain
- Food sensitivities
- Joint pain
- Weight loss
Source: SIBO Center, Portland, OR
Diagnosis & Treatment
Symptoms of SIBO include gas, diarrhea, abdominal bloating and pain. The condition can cause nutritional deficiencies, unintentional weight loss and osteoporosis.
“SIBO can be very debilitating and life-threatening if you have malabsorption and severe vitamin and mineral deficiencies,” Burkhart says.
The condition can be difficult to diagnose, partly because many primary care physicians aren’t aware of it. Patients often have to conduct their own research and act as their own advocates. Many gastrointestinal specialists are familiar with SIBO, as are most integrative physicians and naturopaths.
A breath test can help determine if you have SIBO. In the test, the patient consumes a sugar solution containing lactulose or glucose. Gut bacteria break down the sugar and produce a gas. If there are a lot of bacteria at work—an overgrowth—they’ll produce an excess amount of that gas, detectable in breath samples.
The test isn’t foolproof, however. Many variables can affect the results, including the patient’s age, supplement use and anatomical differences.
“It’s the test most people use, but it’s by no means perfect. Some doctors don’t rely on it due to its poor accuracy; they proceed with treatment based on symptoms,” Burkhart says.
Physicians can offer different treatments. A gastrointestinal specialist may use antibiotics to correct the bacterial overload; a naturopath may use herbal supplements and diet; an integrative physician may incorporate all three depending on the patient.
Burkhart encourages people with SIBO to get appropriate sleep and exercise, to eat a low-sugar diet, to limit antibiotic use and to avoid surgery in the abdominal area, if possible. Additional, more complicated, diets are also prescribed, but it is recommended to follow those under medical supervision, she says. A low-FODMAP diet may be used to identify foods that cause discomfort.
Burkhart’s primary goal involves treating the underlying condition first.
“So if someone has SIBO and celiac, we have to start with a gluten-free diet,” she says.
Because the bacteria feed off of specific foods—starch, sugar, soluble fiber and certain prebiotics—diet plays a key role in bringing balance back to the digestive system.
Unfortunately, SIBO only completely resolves in patients about 50 percent of the time, Burkhart says. The other half will have a recurrence at some point, depending on the underlying cause.
“If there are surgical adhesions that affect the way the intestines work, the scarring is still there and SIBO is not going to go away,” she says, as an example. “This condition is something you can learn to manage, not necessarily cure.”
Burkhart educates her patients so that if a recurrence does happen, they feel equipped to manage it themselves.
She recalls one patient with celiac disease who had a severe case of SIBO. They worked together for several months on diet treatments and the patient was improving. Then the patient went on vacation, where she went off her diet and disrupted her sleep schedule.
“The SIBO returned and she came back very distressed. I reassured her that this is what we do. We’re going to manage this,” Burkhart says. “Now she knows where the balance lies, so it doesn’t happen as often. It’s important to try to be positive and look forward, to know there are always options.”
SIBO & Food
Healthy foods to manage SIBO include:
- Fish, meat and poultry
- Some beans
- Lactose-free dairy
- Nuts and seeds
- Non-starchy vegetables
Foods to avoid include:
- Starchy vegetables
- Some beans
- Sweeteners other than honey, saccharine and stevia
Source: SIBO Center, Portland, OR
Bea is finally feeling strong again. She worked with Burkhart to develop an eating and supplement plan that includes the gluten-free diet, along with an herbal supplement and probiotics to get her gut bacteria back on track. It took over a year for her system to start working in balance again. Within another year, her appetite returned, and her weight climbed back above 100 pounds. She encourages others experiencing SIBO to act as their own advocates.
“People should recognize that if they don’t feel right, they should ask their doctors and not give up,” she says. “Listening to my body, working with my doctor and learning what to eat really helped my healing process.”
Contributor Katie Scarlett Brandt writes about health, science and the environment. Follow her on Twitter at @katiehappens.