Recently, more & more emphasis has been placed on maintaining a healthy gut.

 And according to a new study, your gut bacteria could affect your capacity to lose or gain weight.

New study by the Department of Nutrition, Exercise & Sports at the University of Copenhagen has shown that differing size of gut bacteria can decide how much weight a person is able to lose - the research suggest that a “one size fits all” approach does not work.

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The news could come as consolation to those of us who have tried innumerable diets that seem to work wonders for our friends to no avail.

Researchers enrolled 62 participants who all had large waist circumferences.

They were told to follow either the New Nordic Diet (dark greens, berries, whole grains) or the Average Danish Diet (lean meat, eggs, lettuce, coffee, no grains) & were grouped based on how much of 2 different types of bacteria – Prevotella & Bacteroides – they had in their gut.

The 2 diets vary greatly in the amount of fiber you eat, with the New Nordic Diet being much more fiber-rich.

Participants followed the diets for 26 weeks, with their body measurements taken before & after. After this first period, all participants followed the New Nordic Diet for one more year.

The researchers found that those who had a higher ratio of Prevotella to Bacteroides & followed the New Nordic Diet lost more body fat compared to those with the same ratio following the Average Danish Diet.

When the ratio was upturned, there was no difference in weight loss between the 2 diets.

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 “People with a high Prevotella/Bacteroides ratio were more vulnerable to body fat loss on a diet rich in fiber & wholegrain compared to an average Danish diet,” study co-author Mads Hjorth explains.

“The health promoting aspects of the New Nordic Diet in terms of body weight regulation seem mainly to apply to a subset of the population,” he adds. “This could apply to as much as half of the population.”

The research reinforces the idea that nutrition should be personal, & what works for one person will not necessarily work for another.

If you get a stool sample taken, you will be able to find out your bacteria ratio & address your diet as a result - it is advisable to see a doctor before making any radical changes though.

“These results are a breakthrough demonstrating that certain bacterial species play a decisive role in weight regulation & weight loss,” said lead researcher Arne Astrup.

“Now we can explain why a high fiber diet does not always lead to weight loss. Human intestinal bacteria is an important part of the answer & will from now on play a role in the treatment of the overweight.”