The new nutritional formula changed the microbiomes and improved symptoms of patients in a small, preliminary study.
Taste may no longer be a barrier for people with gut microbial overgrowth who want to try an elemental diet to improve their gut microbiota, new research suggests.
The formula, known as mBiota Elemental, reduced the abundance of some bacteria and reduced symptoms in patients with small intestinal bacterial overgrowth (SIBO) and intestinal methanogen overgrowth (IMO).
“Elemental diets (EDs) are specialised nutritional formulas designed to provide complete or supplemental nutrition in a highly digestible form and contain the required daily allowance of vitamins, major/trace minerals, fat, free amino acids and carbohydrates,” the authors wrote in Clinical Gastroenterology and Hepatology.
“The potential mechanisms of action for ED include their lack of antigenicity, which minimises immune system activation; modulation of the gut microbiome; reduction in proinflammatory cytokines; improving intestinal permeability; high absorption index; reduced faecal load; optimal nutritional composition; and lack of food additives/preservatives.”
While they have shown promise treating people with Crohn’s disease, chronic pancreatitis and eosinophilic esophagitis/gastroenteritis, uptake is limited by their bad taste, smell, look and consistency, the authors said.
To understand whether such diets could be an effective alternative to antibiotics if they were more palatable, the US researchers enrolled 30 adults with positive lactulose breath tests (LBT) for SIBO and/or IMO and gave them this new elemental diet formulation exclusively for two weeks. A normal diet was reintroduced over two weeks and breath tests and stool tracking was undertaken over the study period.
This prospective, open-label trial found all subjects tolerated the diet, three in four normalised their breath test, 83% reported symptom relief on the subjective global assessment
Significant drops were found in the relative abundance of Prevotella_9 and Fusobacterium – and researchers also found reductions in Methanobrevibacter smithii, which correlated with average daily methane levels.
No serious or severe side effects were reported in the study, which was funded by the formula manufacturer.
Gastroenterologist, Distinguished Laureate Professor Nick Talley AC, director of the NHMRC Centre of Research Excellence in Digestive Health at the University of Newcastle, said the tolerability of the elemental diet was a “big advance” compared to the unpalatable elemental diets that patients were previously offered.
While there was a reasonable improvement in symptoms, the study was limited by its lack of control group and long-term data, Professor Talley said.
“So is this definitive data? No. Is this very interesting? Yes,” he said.
Unravelling the role of bacterial overgrowth in chronic gut disorders was complex, with some tests – like the lactulose breath test – possibly causing false positives, Professor Talley said.
“But there certainly is evidence of bacterial change in the intestines of people with so-called functional gut disorders,” he said.
“Treating that is difficult because antibiotics are not something we like to throw around these days for lots of good reasons – and that includes the non-absorbable or poorly absorbable antibiotics like rifaximin, which, by the way, are also very expensive.”
He pointed to trials of rifaximin to treat symptoms of irritable bowel syndrome, which indicated the antibiotic had about a 10% improvement on placebo, from around a 30% response on placebo compared to 40% on the antibiotic.
Professor Talley said this study was further evidence that dietary interventions for people with functional gut disorders was something that should be more of a first line approach than the last resort.
“I’m more and more convinced that food is one of the key drivers of these functional gut disorders,” he said.
“It may be bacterial overgrowth, but it’s possible that, in fact, it’s got nothing to do with overgrowth and that it’s got more to do with bacteria interacting with food, leading to the exposure of the intestine to food antigens that drive disease.”
There were several different diets that provided benefits, including the low FODMAP diet.
“It’s certainly interesting that this elemental diet approach was able to modulate the microbiome in what seemed like a positive way, while the low FODMAP diet hasn’t shown that sort of a positive microbiome change – but has certainly shown positive symptom improvement,” he said.
While this research added to the picture that changing a patient’s diet to modulate the intestinal bacteria could improve treatment approaches down the track, Professor Talley said more research was needed before this specific treatment would be incorporated into standard care.
