Gut Microbiome Decides Success or Failure of Weight Loss Attempts: Study

COVID-19 pandemic and its subsequent stay-at-home scenario forced people to renew focus on themselves and choose healthy options over a sedentary lifestyle. Some people achieved great success in losing that extra flab but others were a little less successful. What could be the reason behind this discrepancy? While there could be several variables — including diet and workout patterns — a new study says the genetic capacity of the gut microbiome is also a significant factor that influences how much weight a person is likely to lose with simple lifestyle changes. The gut microbiome, having trillions of bacteria, fungi, and other microbes, plays a key role in digestion. It also benefits the immune system.

Researchers studied 105 people during a commercial wellness programme, which included healthy lifestyle coaching. Half of them showed consistent weight loss (1 percent of their body weight per month over 6–12 months), the other half maintained a stable body mass index (BMI).

The study was published in the open-access American Society for Microbiology journal mSystems.

Those who lost weight easily had higher bacterial growth rates in their microbiomes. They were also enriched in genes. Those who showed resistance in losing weight had lower bacterial growth rates and higher capacity for breaking down non-absorbable fibres and starches into absorbable sugars, said the study by Institute for Systems Biology (ISB) researchers.

“In this study, we set out to better understand interactions between baseline BMI, metabolic health, diet, gut microbiome functional profiles, and subsequent weight changes in a human cohort that underwent a healthy lifestyle intervention. Overall, our results suggest that the microbiota may influence host weight loss responses through variable bacterial growth rates, dietary energy harvest efficiency, and immunomodulation,” the researchers, led by Dr. Christian Diener, said.

The researchers said they studied factors of successful weight loss that were independent of BMI. People with higher baseline BMIs lose more weight after an intervention. Research has already shown that a change in diet can change the composition of bacteria in the gut. So, this study shows if someone's bacterial gene composition is resisting weight loss, perhaps a change in diet can be helpful.