The Mysteries and Underdiagnosis of SIBO
Lapine lives in New York and had not heard about it. Her endocrinologist had warned her of the potential for developing it. The diagnosis was a relief: “It’s not all in my head; the bloating is just sticking to my body like an inner tube,” Lapine, now 36, remembers thinking. The treatment was a long and difficult process. For her to get the bloat under control, it would take six weeks on antimicrobial medications and six additional months of restricted eating to make her stomach feel normal. Lapine is a chef and food writer who chronicled her SIBO experience and posted SIBO-friendly recipes to her blog in 2018. That’s when she learned how lucky she’d been.
“I’ve gotten many, many messages and emails from really sick, desperate people. They reach out from all over the world and are like, ‘No one here where I live knows what this is,’” Lapine says. She answered the first few notes, but when the avalanche didn’t let up, she set up an automatic response with links to online resources.
SIBO, which is often overlooked in diagnosis, may lead to irritable bowel syndrome. Approximately 11% of people worldwide suffer from IBS, a “wastebasket diagnosis” many patients with an array of digestive issues are given when doctors can’t pinpoint a more precise cause. While IBS can be treated with diet and some medications, there was no cure for the condition. “People were relegated to ‘learn to live with it.’ When SIBO came along, it really offered some cures and solutions,” says Dr. Nirala Jacobi, a naturopathic doctor whose online platform “The SIBO Doctor” offers courses on the disorder for both practitioners and patients. Jacobi, along with others, have been a part of a nationwide awareness campaign about SIBO treatment and diagnosis. However many practitioners still fall short. “I still hear from patients every day that they go to the gastroenterologist and it’s still not being recognized,” says Jacobi.
SIBO is the abnormal and prolific growth of either bacteria or archaea—a single-celled organism older than bacteria—in the small intestine. By competing for patients’ food, the bacteria and archaea can disrupt normal digestion. Instead of digesting food in the small intestine and releasing nutrients to the bloodstream, bacteria or archaea go first and ferment it. The bacteria and archaea both release hydrogen during fermentation, which can cause bloating. SIBO was once used to describe both types of overgrowth. Experts now prefer to distinguish them. They refer to the archaea excess in intestinal methanogen overload, also known as IMO. Although certain bacteria may produce hydrogen sulfide gas, this SIBO type does not come with its own name. Other than bloating and gas production issues, fermentation may also cause IBS problems. This includes diarrhea due to hydrogen or hydrogen sulfide, as well constipation caused by methane. However, you can have either one or both. Over time, in addition to bowel discomfort, gas production leads to poor fat, carbohydrate, and protein absorption by damaging the intestinal wall lining, creating what’s called “leaky gut.” This also causes vitamin deficiencies, the most acute of which are B-12 deficiencies, leading to weakness and fatigue (and in advanced cases, mental confusion).
SIBO or IMO are best treated by learning how and why bacteria, archaea and other organisms grow in the small intestine. Although they are digestive disorders, they’re almost always a symptom of another underlying issue: motility dysfunction, or the slow transit of food through the small intestine.
Finding the root cause
By the time patients call up Dr. David Borenstein’s clinic at Manhattan Integrative Medicine, they’ve consulted three GIs before him, on average, without success. One, treatments proved ineffective or the SIBO/IMO relapsed after a brief reprieve. Research has shown that the relapse rate can reach as high at 45%.
“Most of the people who do treat it are gastroenterologists,” says Borenstein, an integrative and functional doctor. “They’ll give you an antibiotic. A lot of the time, it helps, but the SIBO will come right back because they’re not treating the root cause of the problem.”
It is easy to diagnose SIBO or IMO. The noninvasive breath test measures methane and hydrogen gas (or hydrogen sulfide depending on which test it is). Patients are asked to blow into bags or tubes every 30 minutes, for three hours. Although additional testing may be necessary to pinpoint the causes of SIBO and IMO, a patient’s history is the best place for a start.
A bad episode of food poisoning—or several—can have damaged the patient’s migrating motor complex (MMC), a system that sweeps the small intestine clean like a dishwasher every 90 minutes and which, if impaired, may leave food debris and bacteria behind, allowing them to multiply. IBS Smart checks for anti-CdtB antibodies and anti-vinculin. These are food poisoning-fighting antibodies. These antibodies can signal that there is an infection or post-infectious IBS.
Proton pump inhibitors—a common reflux medication that decreases the amount of acid the stomach produces—can have compromised the stomach’s capacity to kill bacteria. It is important to check the stomach acid level in such cases. An underperforming thyroid can have slowed a patient’s MMC, so a full thyroid panel ought to be done. Abdominal surgery—a hysterectomy, a laparoscopy to explore possible endometriosis, a hernia—can have produced scar tissue on the small intestine wall that pinches the intestine and obstructs flow, like a kink in a garden hose. Further exploration and imaging can help detect this.
This allows for a tailored solution. A prokinetic agent is a medication which increases motility.
There are three options for eliminating excess bacteria or archaea. The first option many doctors opt for is a two-week regimen of antibiotics—specifically rifaximin, the first and only U.S. Food and Drug Administration–approved IBS drug, for SIBO, or a combination of rifaximin with either neomycin or metronidazole for IMO, since archaea resist rifaximin alone. Some practitioners recommend herbal antimicrobials like allicin and berberine for four- to six weeks. Some practitioners resort to using the elemental diet. This liquid formulation of nutrients is designed to give the stomach a rest and starve the bacteria. The elemental diet is the nuclear option, as it’s the most challenging one for patients, considering they can’t eat solid food or drink anything besides water for two to three weeks.
Medical and holistic partnership
SIBO research stems from our better understanding of microbiome, and more specifically to Dr. Mark Pimentel’s advances at Cedars-Sinai Medical Center, which is a gastroenterologist. He was also the executive director for the Medically Associated Science and Technology Program (MAST). In 1999—before the term microbiome had even gone mainstream—Pimentel published a paper showing that IBS was not a psychological disorder, as was commonly believed at the time; rather, it was the result of bacterial dysbiosis, or an imbalance of the gut’s microbial community.
Pimentel, along with his Cedars-Sinai team have been studying the bacteria that is found in small intestines for the last two decades. The team published their first paper last year that revealed the microbiome sequences within the colon, jejunum, ileum, and duodenum. SIBO was identified as the key factor in IBS.
Pimentel’s research caught the attention of Allison Siebecker, a naturopathic physician who had been conducting her own SIBO research and leading awareness campaigns in the holistic community. She was one of the pioneers in creating an online resource SIBOinfo.com that provides information on the disorder to both doctors and patients. She invited Pimentel to speak at the 2015 SIBO Symposium, an annual conference she’d started organizing a year prior, where the leading U.S. SIBO researchers presented their findings on the disorder and treatments. Pimentel has continued to work with Siebecker since that time.
“What’s interesting in the naturopathic community is that they tend to see patients that a lot of Western physicians aren’t able to sort out, and I think that was the case for IBS and SIBO in the beginning,” Pimentel says. “The naturopathic community was seeing a lot of these patients and then also recognizing the treatments sooner than Western medicine.”
Pimentel is the one who pioneered the use IBS- and SIBO-specific rifaximin, however, Siebecker was already announcing herbal antimicrobials to be an effective method of treatment.
Awareness is key
Although medical schools now include more information on microbiome, dysbiosis and other topics in their curriculum, practicing physicians may not have had that training.
“I trained to be a doctor 20 years ago, and at the time, SIBO was not known,” explains Dr. Ana Esteban, an intensive-care doctor who now specializes in SIBO. “No one talked about the microbiome. My generation trains the next generation. My generation of professionals is informing themselves but having to find time and money to study, we must also pay out for our courses. There’s no institutional help.”
As more online resources like Siebecker’s and Jacobi’s crop up, patients are increasingly turning down wastebasket diagnoses and seeking out doctors who will truly probe their digestive issues.
“A lot of people are still told to eat fiber and learn to live with their IBS,” says Jacobi. “Now because of the Internet and social media, people are just not willing to put up with that anymore and are looking for answers.”