Sometimes, no matter how hard people try to lose weight, they just cannot seem to shed off those pounds.

Even if they followed their weight loss routine closely and made virtually no missteps, they are still disappointed at what the weighing scale shows.

A new study says it might not always be their fault. A team of Mayo Clinic researchers wanted to understand exactly why some people have difficulty losing weight.

While others are able to just cruise through it without much effort, even though they follow the same exact dietary routines. Gut bacteria, according to the researchers, might be to blame.

Gut Bacteria, Weight Loss, And You

The human body is a wellspring of microbes. In fact, the total number of microbes in and on people's bodies outnumber cells 10 to one and there has been a growing evidence that these bacteria can impact overall health.

For this study, researchers gathered stool samples from 26 people between the ages of 18 and 65 who signed up for the Mayo Clinic Obesity Treatment Research program from August to September 2013.

They defined successful weight loss as a person losing at least 5 percent of their baseline weight after following the same regime for three months. They discovered that those who failed the program and those who succeeded had different types of gut bacteria.

Specifically, they found that a bacteria called phascolarctobacterium was associated with successful weight loss. Dialister, meanwhile, was found on those who did not manage to shed their pounds off.

An Important Thing To Know Before Choosing A Weight Loss Plan

The study indicates that for a person to successfully lose weight, they must first take their gut bacteria into consideration, especially before crafting a weight loss plan. Alternatively, the person's gut bacteria makeup must be changed before fully adopting a diet plan.

"The potential use is to develop personalized strategies for weight loss based on an individual's gut bacterial makeup rather than using a one-size-fits-all approach," said Purna Kashyap, a gastroenterologist who co-authored the study. "The good part is, unlike our genes we can in fact manipulate the gut bacteria by using probiotics and diet."

He stressed that individuals who have trouble losing weight should consider whether their gut bacteria is hindering them from achieving their desired weight.

"So people need to keep in mind, if they are following a weight loss regimen and in spite of doing everything right are unable to lose weight, this may be because the weight loss program is not the right one based on their gut microbiome," said Kashyap.

The findings were published in the Mayo Clinic Proceedings journal. The researchers noted that their sample size was small and that further research is needed to see if the same results will show up in a large-scale setting.