The microbiomes of those who lost weight had higher bacterial growth rates and were enriched in genes that divert dietary nutrients toward bacterial cell growth.
Conversely, microbiomes in those resistant to weight loss had lower growth rates, combined with a higher capacity for breaking down non-absorbable fibres and starches into absorbable sugars.
These results underscore the fact that gut microbiome is an important filter between the food we consume and our bloodstream.
Researchers also examined determinants of successful weight loss that were independent of BMI. People with higher baseline BMIs tend to lose more weight following an intervention based on the “regression-to-the-mean” effect.
This effect means specific bacteria (Prevotella and other Bacteroidetes genera) are more efficient at using the degradation products from complex starches and fibres to fuel the energy required for the body and reduces calories from consumed food.
This efficiency of gut microbes present in intestine may improve weight loss responses to lifestyle interventions and better metabolic health.
“At a minimum, this work may lead to diagnostics for identifying individuals who will respond well to moderate healthy lifestyle changes, and those who may require more drastic measures to achieve weight loss,” said ISB Assistant Professor Dr. Sean Gibbons, corresponding author on the paper.
This understanding of selective microbes and metabolic processes that promote weight loss can help design targeted prebiotic and probiotic interventions for a weight-loss resistant gut microbiome.