Bloating. Flatulence. Think SIBO

MAUI, HAWAII – Recognition and effective treatment of small intestinal bowel overgrowth – aka, SIBO – is a highly practical skillset for nongastroenterologists to possess, Uma Mahadevan, MD, said at the 2018 Rheumatology Winter Clinical Symposium.

SIBO is a common accompaniment to a range of chronic diseases, especially as patients age. And it’s not a condition that warrants referral to a gastroenterologist, according to Dr. Mahadevan, professor of medicine and medical director of the Center for Colitis and Crohn’s Disease at the University of California, San Francisco.

 

Bruce Jancin/Frontline Medical News

“To diagnose SIBO properly you need to do a carbohydrate breath test. Those tests are notoriously inaccurate, and it’s not worth it. We just treat. If we think you have SIBO, you do a course of rifaximin. And you can do the same,” she told her audience of rheumatologists.

There is an alternative diagnostic test. It involves obtaining a jejunal aspirate culture that demonstrates a bacterial concentration of more than 1,000 colony-forming units/mL. That’s an invasive and expensive test. Given how common SIBO symptoms are in patients with various underlying chronic diseases and the highly favorable risk/benefit ratio of a course of rifaximin, it’s entirely reasonable to skip formal diagnostic testing and treat empirically when the clinical picture is consistent with SIBO, according to the gastroenterologist.

 

SIBO is a condition in which the small intestine becomes colonized with abnormally high counts of aerobic and anaerobic bacteria normally found in the colon. Bacteria commonly associated with SIBO include Escherichia coli as well as those from the genuses Lactobacillus, Bacteroides, and Streptococcus.

The etiology of SIBO involves diminished intestinal motility and altered mucosal defenses. With reduced GI motility, the small bowel can’t get cleared of debris efficiently. Colonic microbes grab a foothold and bloom. Conditions marked by diminished intestinal motility – and high rates of SIBO – include scleroderma, diabetes, irritable bowel syndrome, chronic pancreatitis, cirrhosis, common variable immunodeficiency, HIV infection, and radiation enteritis. Small bowel diverticula are a setup for SIBO. Long-term proton pump inhibitor–therapy fosters hypochlorydia, which promotes SIBO. Opioid therapy is another common cause of SIBO.

So is bariatric surgery. “Bariatric surgery has caused so much iatrogenic GI disease, it’s just amazing. There is bacterial overgrowth in that population, and it’s a lot more complex than basic SIBO,” Dr. Mahadevan said.

SIBO causes malabsorption across the intestinal microvillus membrane as a result of damage to enterocytes, as well as impaired digestion in the intestinal lumen.

 

The presenting hallmark symptoms of SIBO are bloating, flatulence, early satiety, abdominal discomfort, and in some cases chronic diarrhea.

“You get a lot of gas and bloating. Patients will say, ‘I eat a small amount and feel full; I look like I’m pregnant; I have a lot of gas. What’s wrong with me?’ Chances are they have SIBO,” Dr. Mahadevan said. “The older you get the more SIBO you have.”

First-line treatment, aimed at diminishing small bowel bacteria, is rifaximin at 550 mg three times per day for 10-14 days.

“This is a very low-risk antibiotic. And it’s very effective for SIBO, but patients may need multiple courses,” according to the gastroenterologist.

 

Indeed, 40% of patients will experience recurrent SIBO symptoms within 9 months after a round of rifaximin. Recurrences are more common in patients on chronic proton pump–inhibitor therapy, the elderly, and those who have undergone appendectomy. Such patients may need another course of rifaximin once or twice per year.

“If they need rifaximin every 6 months, fine. Patients will be so grateful to you for that course of rifaximin,” Dr. Mahadevan said.

Patients with methane-predominant bacterial overgrowth, as opposed to hydrogen-predominant overgrowth, often benefit from concomitant neomycin at 500 mg twice per day along with their 10-14 days of rifaximin.

“A lot of our cirrhotic patients are on both,” she noted.

 

Alternatives to rifaximin include amoxicillin/clavulanic acid in combination with metronidazole.

Two measures she routinely recommends to forestall recurrent SIBO are to have patients start probiotics after a course of rifaximin, and also to try the low-FODMAP (fermentable oligo-di-monosaccharides and polyols) diet. The evidence base in SIBO is weak, but the anecdotal experience has been strongly positive.

“These are two interventions you can provide to your patients with a lot of bloating and gas. It’ll make them feel much, much better,” the gastroenterologist said.

FODMAPs are short-chain carbohydrates, and the low-FODMAP diet is an elimination diet. The first 6 weeks are highly restrictive, then the foods on the high FODMAP list are reintroduced one at a time until the offenders are identified. The low-FODMAP diet hasn’t been conclusively proven effective for SIBO in a randomized clinical trial, but it does have a compelling evidence base for treatment of irritable bowel syndrome diarrhea (J Gastroenterol Hepatol. 2010 Feb;25[2]:252-8).

 

“Anecdotally, the use of a low-FODMAP diet in patients with bloating and gas is very effective as well. Patients have a good deal of success with it,” she said.

Audience members were eager to learn what particular specific probiotic microorganism Dr. Madahaven recommends.

“I think the more we understand the microbiome, the further away I’m going from specific probiotics because it’s just too complex for any one probiotic to be effective. I tell patients to try to get it from their diet: yogurt or kefir with live bacteria. That’s what I use now,” she replied.

MAUI, HAWAII – Recognition and effective treatment of small intestinal bowel overgrowth – aka, SIBO – is a highly practical skillset for nongastroenterologists to possess, Uma Mahadevan, MD, said at the 2018 Rheumatology Winter Clinical Symposium.

SIBO is a common accompaniment to a range of chronic diseases, especially as patients age. And it’s not a condition that warrants referral to a gastroenterologist, according to Dr. Mahadevan, professor of medicine and medical director of the Center for Colitis and Crohn’s Disease at the University of California, San Francisco.

 

Bruce Jancin/Frontline Medical News

“To diagnose SIBO properly you need to do a carbohydrate breath test. Those tests are notoriously inaccurate, and it’s not worth it. We just treat. If we think you have SIBO, you do a course of rifaximin. And you can do the same,” she told her audience of rheumatologists.

There is an alternative diagnostic test. It involves obtaining a jejunal aspirate culture that demonstrates a bacterial concentration of more than 1,000 colony-forming units/mL. That’s an invasive and expensive test. Given how common SIBO symptoms are in patients with various underlying chronic diseases and the highly favorable risk/benefit ratio of a course of rifaximin, it’s entirely reasonable to skip formal diagnostic testing and treat empirically when the clinical picture is consistent with SIBO, according to the gastroenterologist.

 

SIBO is a condition in which the small intestine becomes colonized with abnormally high counts of aerobic and anaerobic bacteria normally found in the colon. Bacteria commonly associated with SIBO include Escherichia coli as well as those from the genuses Lactobacillus, Bacteroides, and Streptococcus.

The etiology of SIBO involves diminished intestinal motility and altered mucosal defenses. With reduced GI motility, the small bowel can’t get cleared of debris efficiently. Colonic microbes grab a foothold and bloom. Conditions marked by diminished intestinal motility – and high rates of SIBO – include scleroderma, diabetes, irritable bowel syndrome, chronic pancreatitis, cirrhosis, common variable immunodeficiency, HIV infection, and radiation enteritis. Small bowel diverticula are a setup for SIBO. Long-term proton pump inhibitor–therapy fosters hypochlorydia, which promotes SIBO. Opioid therapy is another common cause of SIBO.

So is bariatric surgery. “Bariatric surgery has caused so much iatrogenic GI disease, it’s just amazing. There is bacterial overgrowth in that population, and it’s a lot more complex than basic SIBO,” Dr. Mahadevan said.

SIBO causes malabsorption across the intestinal microvillus membrane as a result of damage to enterocytes, as well as impaired digestion in the intestinal lumen.

 

The presenting hallmark symptoms of SIBO are bloating, flatulence, early satiety, abdominal discomfort, and in some cases chronic diarrhea.

“You get a lot of gas and bloating. Patients will say, ‘I eat a small amount and feel full; I look like I’m pregnant; I have a lot of gas. What’s wrong with me?’ Chances are they have SIBO,” Dr. Mahadevan said. “The older you get the more SIBO you have.”

First-line treatment, aimed at diminishing small bowel bacteria, is rifaximin at 550 mg three times per day for 10-14 days.

“This is a very low-risk antibiotic. And it’s very effective for SIBO, but patients may need multiple courses,” according to the gastroenterologist.

 

Indeed, 40% of patients will experience recurrent SIBO symptoms within 9 months after a round of rifaximin. Recurrences are more common in patients on chronic proton pump–inhibitor therapy, the elderly, and those who have undergone appendectomy. Such patients may need another course of rifaximin once or twice per year.

“If they need rifaximin every 6 months, fine. Patients will be so grateful to you for that course of rifaximin,” Dr. Mahadevan said.

Patients with methane-predominant bacterial overgrowth, as opposed to hydrogen-predominant overgrowth, often benefit from concomitant neomycin at 500 mg twice per day along with their 10-14 days of rifaximin.

“A lot of our cirrhotic patients are on both,” she noted.

 

Alternatives to rifaximin include amoxicillin/clavulanic acid in combination with metronidazole.

Two measures she routinely recommends to forestall recurrent SIBO are to have patients start probiotics after a course of rifaximin, and also to try the low-FODMAP (fermentable oligo-di-monosaccharides and polyols) diet. The evidence base in SIBO is weak, but the anecdotal experience has been strongly positive.

“These are two interventions you can provide to your patients with a lot of bloating and gas. It’ll make them feel much, much better,” the gastroenterologist said.

FODMAPs are short-chain carbohydrates, and the low-FODMAP diet is an elimination diet. The first 6 weeks are highly restrictive, then the foods on the high FODMAP list are reintroduced one at a time until the offenders are identified. The low-FODMAP diet hasn’t been conclusively proven effective for SIBO in a randomized clinical trial, but it does have a compelling evidence base for treatment of irritable bowel syndrome diarrhea (J Gastroenterol Hepatol. 2010 Feb;25[2]:252-8).

 

“Anecdotally, the use of a low-FODMAP diet in patients with bloating and gas is very effective as well. Patients have a good deal of success with it,” she said.

Audience members were eager to learn what particular specific probiotic microorganism Dr. Madahaven recommends.

“I think the more we understand the microbiome, the further away I’m going from specific probiotics because it’s just too complex for any one probiotic to be effective. I tell patients to try to get it from their diet: yogurt or kefir with live bacteria. That’s what I use now,” she replied.

MAUI, HAWAII – Recognition and effective treatment of small intestinal bowel overgrowth – aka, SIBO – is a highly practical skillset for nongastroenterologists to possess, Uma Mahadevan, MD, said at the 2018 Rheumatology Winter Clinical Symposium.

SIBO is a common accompaniment to a range of chronic diseases, especially as patients age. And it’s not a condition that warrants referral to a gastroenterologist, according to Dr. Mahadevan, professor of medicine and medical director of the Center for Colitis and Crohn’s Disease at the University of California, San Francisco.

 

Bruce Jancin/Frontline Medical News

“To diagnose SIBO properly you need to do a carbohydrate breath test. Those tests are notoriously inaccurate, and it’s not worth it. We just treat. If we think you have SIBO, you do a course of rifaximin. And you can do the same,” she told her audience of rheumatologists.

There is an alternative diagnostic test. It involves obtaining a jejunal aspirate culture that demonstrates a bacterial concentration of more than 1,000 colony-forming units/mL. That’s an invasive and expensive test. Given how common SIBO symptoms are in patients with various underlying chronic diseases and the highly favorable risk/benefit ratio of a course of rifaximin, it’s entirely reasonable to skip formal diagnostic testing and treat empirically when the clinical picture is consistent with SIBO, according to the gastroenterologist.

 

SIBO is a condition in which the small intestine becomes colonized with abnormally high counts of aerobic and anaerobic bacteria normally found in the colon. Bacteria commonly associated with SIBO include Escherichia coli as well as those from the genuses Lactobacillus, Bacteroides, and Streptococcus.

The etiology of SIBO involves diminished intestinal motility and altered mucosal defenses. With reduced GI motility, the small bowel can’t get cleared of debris efficiently. Colonic microbes grab a foothold and bloom. Conditions marked by diminished intestinal motility – and high rates of SIBO – include scleroderma, diabetes, irritable bowel syndrome, chronic pancreatitis, cirrhosis, common variable immunodeficiency, HIV infection, and radiation enteritis. Small bowel diverticula are a setup for SIBO. Long-term proton pump inhibitor–therapy fosters hypochlorydia, which promotes SIBO. Opioid therapy is another common cause of SIBO.

So is bariatric surgery. “Bariatric surgery has caused so much iatrogenic GI disease, it’s just amazing. There is bacterial overgrowth in that population, and it’s a lot more complex than basic SIBO,” Dr. Mahadevan said.

SIBO causes malabsorption across the intestinal microvillus membrane as a result of damage to enterocytes, as well as impaired digestion in the intestinal lumen.

 

The presenting hallmark symptoms of SIBO are bloating, flatulence, early satiety, abdominal discomfort, and in some cases chronic diarrhea.

“You get a lot of gas and bloating. Patients will say, ‘I eat a small amount and feel full; I look like I’m pregnant; I have a lot of gas. What’s wrong with me?’ Chances are they have SIBO,” Dr. Mahadevan said. “The older you get the more SIBO you have.”

First-line treatment, aimed at diminishing small bowel bacteria, is rifaximin at 550 mg three times per day for 10-14 days.

“This is a very low-risk antibiotic. And it’s very effective for SIBO, but patients may need multiple courses,” according to the gastroenterologist.

 

Indeed, 40% of patients will experience recurrent SIBO symptoms within 9 months after a round of rifaximin. Recurrences are more common in patients on chronic proton pump–inhibitor therapy, the elderly, and those who have undergone appendectomy. Such patients may need another course of rifaximin once or twice per year.

“If they need rifaximin every 6 months, fine. Patients will be so grateful to you for that course of rifaximin,” Dr. Mahadevan said.

Patients with methane-predominant bacterial overgrowth, as opposed to hydrogen-predominant overgrowth, often benefit from concomitant neomycin at 500 mg twice per day along with their 10-14 days of rifaximin.

“A lot of our cirrhotic patients are on both,” she noted.

 

Alternatives to rifaximin include amoxicillin/clavulanic acid in combination with metronidazole.

Two measures she routinely recommends to forestall recurrent SIBO are to have patients start probiotics after a course of rifaximin, and also to try the low-FODMAP (fermentable oligo-di-monosaccharides and polyols) diet. The evidence base in SIBO is weak, but the anecdotal experience has been strongly positive.

“These are two interventions you can provide to your patients with a lot of bloating and gas. It’ll make them feel much, much better,” the gastroenterologist said.

FODMAPs are short-chain carbohydrates, and the low-FODMAP diet is an elimination diet. The first 6 weeks are highly restrictive, then the foods on the high FODMAP list are reintroduced one at a time until the offenders are identified. The low-FODMAP diet hasn’t been conclusively proven effective for SIBO in a randomized clinical trial, but it does have a compelling evidence base for treatment of irritable bowel syndrome diarrhea (J Gastroenterol Hepatol. 2010 Feb;25[2]:252-8).

 

“Anecdotally, the use of a low-FODMAP diet in patients with bloating and gas is very effective as well. Patients have a good deal of success with it,” she said.

Audience members were eager to learn what particular specific probiotic microorganism Dr. Madahaven recommends.

“I think the more we understand the microbiome, the further away I’m going from specific probiotics because it’s just too complex for any one probiotic to be effective. I tell patients to try to get it from their diet: yogurt or kefir with live bacteria. That’s what I use now,” she replied.