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SAN DIEGO – Two leading figures in microbiome research took time during the annual Digestive Disease Week to share their perspective with members of the press. Identifying key research presented at the meeting and painting a broader picture of trends and challenges in research on the interplay with the microbiota with gut health, Colleen Kelly, MD, of Brown University, Providence, R.I., cochair and principal investigator, AGA FMT Registry Steering Committee, led off the round table with a discussion of human research on fecal microbial transplantation (FMT) and obesity.
Purna Kashyap, MBBS, of the Mayo Clinic, Rochester, Minn., member, AGA Center for Gut Microbiome Research and Education Scientific Advisory Board, delved into the potential for donor microbiota transplant to address small bowel disorders, such as small intestinal bacterial overgrowth, and provided commentary regarding the potential – and limitations – of using FMT in functional bowel disorders such as irritable bowel syndrome (IBS).
Obesity
Dr. Kelly noted that two abstracts at the conference presented data about FMT in obesity. The first study was presented by Jessica Allegretti, MD, a gastroenterologist at Brigham and Women’s Hospital, Boston; the second study was presented by Elaine Yu, MD, an endocrinologist at Massachusetts General Hospital, Boston.
The two studies shared some similarities, but had some differences, said Dr. Kelly. “They both used lean donor encapsulated FMT ... and they both were placebo controlled, using placebo capsules.” The first study looked at metabolically healthy obese patients, while the second study included patients with mild to moderate insulin resistance.
Dr. Allegretti’s work looked at the effect that FMT from lean donors had on levels of a satiety peptide, glucagonlike peptide–1 (GLP-1), while also looking at changes in weight and microbiota, as well as safety. Patients received an initial 30-capsule dose as well as two later doses of 12 capsules each. The 22-patient study, in which individuals were randomized 1:1 to FMT or placebo capsules, didn’t show statistically significant changes in GLP-1 levels or body mass index with FMT over the 12-week study period. “But they were able to show engraftment, which I think is an important thing that you do wonder about – over this period of time, the bacteria that came from the lean donor actually engrafted into the recipient and affected the diversity. The recipient became more similar to the donor,” said Dr. Kelly.
There were some clues among the findings that engraftment was effecting metabolic change in the recipient, she said, including differences in bile acid conversion among gut bacteria; also, lower levels of the primary bile acid taurocholic acid in recipients after FMT. “So it was a negative study in what she was looking for, but an example of these smaller studies kind of pushing the field along.”
In discussing the study presented by Dr. Yu that examined lean donor FMT in individuals with insulin resistance, Dr. Kelly said, “It was actually pretty sophisticated.” By using hyperinsulinemic euglycemic clamping, the investigators were able to measure insulin sensitivity based on glucose load. In this study of 24 individuals randomized 1:1 to receive FMT or placebo capsules, recipients received weekly doses over a period of 6 weeks. Here again, though Dr. Yu and colleagues again found engraftment, “they did not find the big changes in metabolic parameters that they hoped that they would,” said Dr. Kelly.
These two studies furthered previous work completed in the Netherlands examining lean donor FMT for individuals with metabolic syndrome. “Those [studies] did show both engraftment and some changes in insulin resistance,” but they were also small studies, noted Dr. Kelly. Dr. Kashyap pointed out that the earlier studies had shown in a subgroup analysis that response to FMT was limited to those patients who lacked microbial diversity pretransplant.
This makes some mechanistic sense when thinking about FMT’s greatest success to date: Treating Clostridioides difficile infection, a condition whose very hallmark is dysbiosis characterized by monospecies gut domination, noted Dr. Kashyap.
Added Dr. Kelly, “I think everyone’s hoping there’s going to be this pill that’s going to make us skinny, but I don’t think we’re going to find that with FMT and obesity. I do think these studies are important, because there’s so much animal data already, and we’re kind of like, ‘How much more can you do in mice?’ ” By translating this preclinical work into humans, the mechanisms of obesity and the role of the microbiome can be better understood.
IBS
Turning to functional bowel disorders, Dr. Kelly pointed out a new study examining FMT for IBS. “So far, the research has been pretty disappointing,” she noted. The study, presented by Prashant Singh, MBBS, a gastroenterology fellow at Beth Israel Deaconess Medical Center, Boston, examined FMT for patients with moderate to severe diarrhea-predominant IBS. The study had four arms, randomizing the 44 participants to FMT alone; pretreatment with metronidazole and ciprofloxacin or rifaximin, each followed by FMT; or placebo. “It really didn’t show any differences in their severity of IBS in any group; so no effect: a negative study,” said Dr. Kelly.
“It’s challenging. FMT is an appealing strategy because we don’t have to put a lot of thought process into it,” said Dr. Kashyap, but it’s no panacea. “We aren’t going to be able to treat everybody with FMT.
“The challenge with IBS is that if we look at all the compositional studies, the majority of them show that at least a big subset of patients with IBS already have a normal-appearing microbiome,” said Dr. Kashyap. In those patients, “It’s very hard to know what FMT is doing.” He noted that IBS subclassifications are made by pathophysiology, without regard to the intestinal microbiome, so these classifications may not be useful for determining who may benefit from FMT.
“Again, there’s always an opportunity to learn from these studies,” whether they’re positive or negative, as long as they’re well done, said Dr. Kashyap. “There’s always an opportunity to go back and see, was there a specific subgroup of patients who responded, where there might be one or more causes which might be more amenable” to FMT.
Small intestine
And most intestinal microbial research to date, noted Dr. Kelly, has focused on the colon. “Most of our knowledge is of fecal microbiota.” New techniques including double-balloon enteroscopy of the small bowel have promise to “provide completely new information about patterns of bacteria throughout the small bowel,” and of the role of small bowel bacteria in overall gut health, she said.
“The role of the small bowel has been ignored because of accessibility,” agreed Dr. Kashyap. There’s a current focus on research into enteroscopy and other techniques to sample small intestine microbiota, he said.
In a podium presentation, Eugene Chang, MD, Martin Boyer Professor in the University of Chicago’s department of medicine, gave a broad overview of how the small intestine microbiome modulates lipid regulation. This choice of topic for the Charles M. Mansbach Memorial Lecture shows that gastroenterologists are recognizing the importance of microbiome along the entire span of the gut, said Dr. Kashyap. Dr. Chang’s approach, he added, represents a departure in that “it’s not simply just looking at what’s present and what’s not, but seeing what’s functionally relevant to metabolism.”
“We always have known that the small intestine is the workhorse; that’s where everything happens” in terms of motility, absorption, and digestion, said Dr. Kashyap. “But because of our inability to reach it easily we’ve always chosen to ignore it; we always go after the low-hanging fruit.” Despite challenges, more microbiome research should be small-bowel focused. “Eventually, it’s no pain, no gain.”
Dr. Kashyap is on the advisory board of uBiome, and is an ad hoc advisory board member for Salix Pharmaceuticals. Dr. Kelly reported no conflicts of interest.
This story was updated on July 30, 2019.
SAN DIEGO – Two leading figures in microbiome research took time during the annual Digestive Disease Week to share their perspective with members of the press. Identifying key research presented at the meeting and painting a broader picture of trends and challenges in research on the interplay with the microbiota with gut health, Colleen Kelly, MD, of Brown University, Providence, R.I., cochair and principal investigator, AGA FMT Registry Steering Committee, led off the round table with a discussion of human research on fecal microbial transplantation (FMT) and obesity.
Purna Kashyap, MBBS, of the Mayo Clinic, Rochester, Minn., member, AGA Center for Gut Microbiome Research and Education Scientific Advisory Board, delved into the potential for donor microbiota transplant to address small bowel disorders, such as small intestinal bacterial overgrowth, and provided commentary regarding the potential – and limitations – of using FMT in functional bowel disorders such as irritable bowel syndrome (IBS).
Obesity
Dr. Kelly noted that two abstracts at the conference presented data about FMT in obesity. The first study was presented by Jessica Allegretti, MD, a gastroenterologist at Brigham and Women’s Hospital, Boston; the second study was presented by Elaine Yu, MD, an endocrinologist at Massachusetts General Hospital, Boston.
The two studies shared some similarities, but had some differences, said Dr. Kelly. “They both used lean donor encapsulated FMT ... and they both were placebo controlled, using placebo capsules.” The first study looked at metabolically healthy obese patients, while the second study included patients with mild to moderate insulin resistance.
Dr. Allegretti’s work looked at the effect that FMT from lean donors had on levels of a satiety peptide, glucagonlike peptide–1 (GLP-1), while also looking at changes in weight and microbiota, as well as safety. Patients received an initial 30-capsule dose as well as two later doses of 12 capsules each. The 22-patient study, in which individuals were randomized 1:1 to FMT or placebo capsules, didn’t show statistically significant changes in GLP-1 levels or body mass index with FMT over the 12-week study period. “But they were able to show engraftment, which I think is an important thing that you do wonder about – over this period of time, the bacteria that came from the lean donor actually engrafted into the recipient and affected the diversity. The recipient became more similar to the donor,” said Dr. Kelly.
There were some clues among the findings that engraftment was effecting metabolic change in the recipient, she said, including differences in bile acid conversion among gut bacteria; also, lower levels of the primary bile acid taurocholic acid in recipients after FMT. “So it was a negative study in what she was looking for, but an example of these smaller studies kind of pushing the field along.”
In discussing the study presented by Dr. Yu that examined lean donor FMT in individuals with insulin resistance, Dr. Kelly said, “It was actually pretty sophisticated.” By using hyperinsulinemic euglycemic clamping, the investigators were able to measure insulin sensitivity based on glucose load. In this study of 24 individuals randomized 1:1 to receive FMT or placebo capsules, recipients received weekly doses over a period of 6 weeks. Here again, though Dr. Yu and colleagues again found engraftment, “they did not find the big changes in metabolic parameters that they hoped that they would,” said Dr. Kelly.
These two studies furthered previous work completed in the Netherlands examining lean donor FMT for individuals with metabolic syndrome. “Those [studies] did show both engraftment and some changes in insulin resistance,” but they were also small studies, noted Dr. Kelly. Dr. Kashyap pointed out that the earlier studies had shown in a subgroup analysis that response to FMT was limited to those patients who lacked microbial diversity pretransplant.
This makes some mechanistic sense when thinking about FMT’s greatest success to date: Treating Clostridioides difficile infection, a condition whose very hallmark is dysbiosis characterized by monospecies gut domination, noted Dr. Kashyap.
Added Dr. Kelly, “I think everyone’s hoping there’s going to be this pill that’s going to make us skinny, but I don’t think we’re going to find that with FMT and obesity. I do think these studies are important, because there’s so much animal data already, and we’re kind of like, ‘How much more can you do in mice?’ ” By translating this preclinical work into humans, the mechanisms of obesity and the role of the microbiome can be better understood.
IBS
Turning to functional bowel disorders, Dr. Kelly pointed out a new study examining FMT for IBS. “So far, the research has been pretty disappointing,” she noted. The study, presented by Prashant Singh, MBBS, a gastroenterology fellow at Beth Israel Deaconess Medical Center, Boston, examined FMT for patients with moderate to severe diarrhea-predominant IBS. The study had four arms, randomizing the 44 participants to FMT alone; pretreatment with metronidazole and ciprofloxacin or rifaximin, each followed by FMT; or placebo. “It really didn’t show any differences in their severity of IBS in any group; so no effect: a negative study,” said Dr. Kelly.
“It’s challenging. FMT is an appealing strategy because we don’t have to put a lot of thought process into it,” said Dr. Kashyap, but it’s no panacea. “We aren’t going to be able to treat everybody with FMT.
“The challenge with IBS is that if we look at all the compositional studies, the majority of them show that at least a big subset of patients with IBS already have a normal-appearing microbiome,” said Dr. Kashyap. In those patients, “It’s very hard to know what FMT is doing.” He noted that IBS subclassifications are made by pathophysiology, without regard to the intestinal microbiome, so these classifications may not be useful for determining who may benefit from FMT.
“Again, there’s always an opportunity to learn from these studies,” whether they’re positive or negative, as long as they’re well done, said Dr. Kashyap. “There’s always an opportunity to go back and see, was there a specific subgroup of patients who responded, where there might be one or more causes which might be more amenable” to FMT.
Small intestine
And most intestinal microbial research to date, noted Dr. Kelly, has focused on the colon. “Most of our knowledge is of fecal microbiota.” New techniques including double-balloon enteroscopy of the small bowel have promise to “provide completely new information about patterns of bacteria throughout the small bowel,” and of the role of small bowel bacteria in overall gut health, she said.
“The role of the small bowel has been ignored because of accessibility,” agreed Dr. Kashyap. There’s a current focus on research into enteroscopy and other techniques to sample small intestine microbiota, he said.
In a podium presentation, Eugene Chang, MD, Martin Boyer Professor in the University of Chicago’s department of medicine, gave a broad overview of how the small intestine microbiome modulates lipid regulation. This choice of topic for the Charles M. Mansbach Memorial Lecture shows that gastroenterologists are recognizing the importance of microbiome along the entire span of the gut, said Dr. Kashyap. Dr. Chang’s approach, he added, represents a departure in that “it’s not simply just looking at what’s present and what’s not, but seeing what’s functionally relevant to metabolism.”
“We always have known that the small intestine is the workhorse; that’s where everything happens” in terms of motility, absorption, and digestion, said Dr. Kashyap. “But because of our inability to reach it easily we’ve always chosen to ignore it; we always go after the low-hanging fruit.” Despite challenges, more microbiome research should be small-bowel focused. “Eventually, it’s no pain, no gain.”
Dr. Kashyap is on the advisory board of uBiome, and is an ad hoc advisory board member for Salix Pharmaceuticals. Dr. Kelly reported no conflicts of interest.
This story was updated on July 30, 2019.
SAN DIEGO – Two leading figures in microbiome research took time during the annual Digestive Disease Week to share their perspective with members of the press. Identifying key research presented at the meeting and painting a broader picture of trends and challenges in research on the interplay with the microbiota with gut health, Colleen Kelly, MD, of Brown University, Providence, R.I., cochair and principal investigator, AGA FMT Registry Steering Committee, led off the round table with a discussion of human research on fecal microbial transplantation (FMT) and obesity.
Purna Kashyap, MBBS, of the Mayo Clinic, Rochester, Minn., member, AGA Center for Gut Microbiome Research and Education Scientific Advisory Board, delved into the potential for donor microbiota transplant to address small bowel disorders, such as small intestinal bacterial overgrowth, and provided commentary regarding the potential – and limitations – of using FMT in functional bowel disorders such as irritable bowel syndrome (IBS).
Obesity
Dr. Kelly noted that two abstracts at the conference presented data about FMT in obesity. The first study was presented by Jessica Allegretti, MD, a gastroenterologist at Brigham and Women’s Hospital, Boston; the second study was presented by Elaine Yu, MD, an endocrinologist at Massachusetts General Hospital, Boston.
The two studies shared some similarities, but had some differences, said Dr. Kelly. “They both used lean donor encapsulated FMT ... and they both were placebo controlled, using placebo capsules.” The first study looked at metabolically healthy obese patients, while the second study included patients with mild to moderate insulin resistance.
Dr. Allegretti’s work looked at the effect that FMT from lean donors had on levels of a satiety peptide, glucagonlike peptide–1 (GLP-1), while also looking at changes in weight and microbiota, as well as safety. Patients received an initial 30-capsule dose as well as two later doses of 12 capsules each. The 22-patient study, in which individuals were randomized 1:1 to FMT or placebo capsules, didn’t show statistically significant changes in GLP-1 levels or body mass index with FMT over the 12-week study period. “But they were able to show engraftment, which I think is an important thing that you do wonder about – over this period of time, the bacteria that came from the lean donor actually engrafted into the recipient and affected the diversity. The recipient became more similar to the donor,” said Dr. Kelly.
There were some clues among the findings that engraftment was effecting metabolic change in the recipient, she said, including differences in bile acid conversion among gut bacteria; also, lower levels of the primary bile acid taurocholic acid in recipients after FMT. “So it was a negative study in what she was looking for, but an example of these smaller studies kind of pushing the field along.”
In discussing the study presented by Dr. Yu that examined lean donor FMT in individuals with insulin resistance, Dr. Kelly said, “It was actually pretty sophisticated.” By using hyperinsulinemic euglycemic clamping, the investigators were able to measure insulin sensitivity based on glucose load. In this study of 24 individuals randomized 1:1 to receive FMT or placebo capsules, recipients received weekly doses over a period of 6 weeks. Here again, though Dr. Yu and colleagues again found engraftment, “they did not find the big changes in metabolic parameters that they hoped that they would,” said Dr. Kelly.
These two studies furthered previous work completed in the Netherlands examining lean donor FMT for individuals with metabolic syndrome. “Those [studies] did show both engraftment and some changes in insulin resistance,” but they were also small studies, noted Dr. Kelly. Dr. Kashyap pointed out that the earlier studies had shown in a subgroup analysis that response to FMT was limited to those patients who lacked microbial diversity pretransplant.
This makes some mechanistic sense when thinking about FMT’s greatest success to date: Treating Clostridioides difficile infection, a condition whose very hallmark is dysbiosis characterized by monospecies gut domination, noted Dr. Kashyap.
Added Dr. Kelly, “I think everyone’s hoping there’s going to be this pill that’s going to make us skinny, but I don’t think we’re going to find that with FMT and obesity. I do think these studies are important, because there’s so much animal data already, and we’re kind of like, ‘How much more can you do in mice?’ ” By translating this preclinical work into humans, the mechanisms of obesity and the role of the microbiome can be better understood.
IBS
Turning to functional bowel disorders, Dr. Kelly pointed out a new study examining FMT for IBS. “So far, the research has been pretty disappointing,” she noted. The study, presented by Prashant Singh, MBBS, a gastroenterology fellow at Beth Israel Deaconess Medical Center, Boston, examined FMT for patients with moderate to severe diarrhea-predominant IBS. The study had four arms, randomizing the 44 participants to FMT alone; pretreatment with metronidazole and ciprofloxacin or rifaximin, each followed by FMT; or placebo. “It really didn’t show any differences in their severity of IBS in any group; so no effect: a negative study,” said Dr. Kelly.
“It’s challenging. FMT is an appealing strategy because we don’t have to put a lot of thought process into it,” said Dr. Kashyap, but it’s no panacea. “We aren’t going to be able to treat everybody with FMT.
“The challenge with IBS is that if we look at all the compositional studies, the majority of them show that at least a big subset of patients with IBS already have a normal-appearing microbiome,” said Dr. Kashyap. In those patients, “It’s very hard to know what FMT is doing.” He noted that IBS subclassifications are made by pathophysiology, without regard to the intestinal microbiome, so these classifications may not be useful for determining who may benefit from FMT.
“Again, there’s always an opportunity to learn from these studies,” whether they’re positive or negative, as long as they’re well done, said Dr. Kashyap. “There’s always an opportunity to go back and see, was there a specific subgroup of patients who responded, where there might be one or more causes which might be more amenable” to FMT.
Small intestine
And most intestinal microbial research to date, noted Dr. Kelly, has focused on the colon. “Most of our knowledge is of fecal microbiota.” New techniques including double-balloon enteroscopy of the small bowel have promise to “provide completely new information about patterns of bacteria throughout the small bowel,” and of the role of small bowel bacteria in overall gut health, she said.
“The role of the small bowel has been ignored because of accessibility,” agreed Dr. Kashyap. There’s a current focus on research into enteroscopy and other techniques to sample small intestine microbiota, he said.
In a podium presentation, Eugene Chang, MD, Martin Boyer Professor in the University of Chicago’s department of medicine, gave a broad overview of how the small intestine microbiome modulates lipid regulation. This choice of topic for the Charles M. Mansbach Memorial Lecture shows that gastroenterologists are recognizing the importance of microbiome along the entire span of the gut, said Dr. Kashyap. Dr. Chang’s approach, he added, represents a departure in that “it’s not simply just looking at what’s present and what’s not, but seeing what’s functionally relevant to metabolism.”
“We always have known that the small intestine is the workhorse; that’s where everything happens” in terms of motility, absorption, and digestion, said Dr. Kashyap. “But because of our inability to reach it easily we’ve always chosen to ignore it; we always go after the low-hanging fruit.” Despite challenges, more microbiome research should be small-bowel focused. “Eventually, it’s no pain, no gain.”
Dr. Kashyap is on the advisory board of uBiome, and is an ad hoc advisory board member for Salix Pharmaceuticals. Dr. Kelly reported no conflicts of interest.
This story was updated on July 30, 2019.
EXPERT ANALYSIS FROM DDW 2019