Prebiotic fiber supplement reduces body fat in overweight children by altering gut microbiome
Overweight and obese children had significant reductions in body fat after taking a prebiotic fiber supplement in a randomized controlled trial.
The study is the first of its kind to comprehensively evaluate gut microbiota alterations in obese and overweight children following supplementation with prebiotics, which are different from live probiotics as they are non-digestible food ingredients that benefit the gut microbiota. The study results suggest prebiotic supplementation may be an effective early intervention for preventing obesity-associated morbidity and mortality in adulthood, according to a press release.
“This is a well-designed trial that demonstrates how a prebiotic could potentially help combat one of the most prevalent and costly conditions afflicting children in the developed world — overnutrition — by targeting the gut microbiome,” Geoffrey A. Preidis, MD, PhD, a member of the AGA Center for Gut Microbiome Research and Education scientific advisory board, said in the press release. “It is promising to see this evidence that alteration of the gut microbiota can be used to restore health. As a clinician, I hope that continued research into prebiotics will lead to a new strategy for the treatment of obesity.”
To evaluate the effects of prebiotic supplementation with oligofructose-enriched inulin on body composition, inflammatory markers, bile acids in stool samples, and gut microbiota profiles in overweight and obese children, Raylene A. Reimer, PhD, RD, professor and researcher in the faculty of kinesiology at University of Calgary, and colleagues randomly assigned 42 children to receive 8 g of the prebiotic supplement or placebo once daily for 16 weeks. The children were aged 7 to 12 years and were overweight or obese but otherwise healthy.
“Powdered fiber, mixed in a water bottle, taken once a day is all we asked the children to change, and we got, what we consider, some pretty exciting results — it has been fantastic,” Reimer said in the press release.
The children who received the prebiotic lost 3.1% in body weight z-scores, 2.4% body fat and 3.8% trunk fat, which were significant reductions compared with the placebo group, who gained 0.5% in body weight z-scores, gained 0.05% body fat and lost 0.3% trunk fat.
Based on these data, the annual projected body weight increase in the prebiotic group was within the healthy range at 6.6 pounds (3 kg), while that of the placebo group was almost three times higher at 17.6 pounds (8 kg), according to the press release.
“To me, what is so meaningful about this study is you can stop this trajectory of continuing to gain more and more weight,” Reiner said in a separate press release. “Being overweight in childhood tends to persist into teenage years then into adulthood. This study, literally, allowed these kids to meet what would be considered normal growth rates for their age.”
The investigators also evaluated changes in inflammatory markers, and found that the children who received the prebiotic had 15% lower levels of interleukin 6 compared with baseline, a significant reduction compared with those in the placebo group, which increased by 25%. Other changes in serum inflammatory markers were marginal. In terms of metabolic outcomes, those who received the prebiotic had significantly lower serum triglycerides, which dropped by 19%.
Notably, the investigators showed that the prebiotic supplement caused specific changes to the gut microbiome compared with placebo. Quantitative PCR showed the children who received the prebiotic had significantly increased Bifidobacterium spp. compared with those who received placebo, and 16S rRNA sequencing showed the prebiotic group also had significantly increased Bifidobacterium and reduced Bacteroides vulgatus. Further, stool samples from the placebo group, but not the prebiotic group, showed increased primary bile acids.
The researchers concluded that a larger clinical trial in warranted based on the metabolic and microbial findings of this study.
“We have also recently shown (in the American Journal of Clinical Nutrition) that prebiotic supplement can suppress appetite — which is one part of helping manage weight,” Reimer said in the press release. “Since we know that intestinal bacteria can influence what happens in the brain, we will continue to study how appetite and other functions in the brain are changed by diet and particularly fiber.” – by Adam Leitenberger
Disclosures: Reimer reports previous funding from the manufacturer of the prebiotic fiber supplement for a project unrelated to this study.