Obesity can be an inherited trait, and scientists may have gotten one step closer to discovering why. In a recent study conducted by researchers at King’s College London, scientists discovered that some forms of bacteria are inherited after investigating fecal matter samples from more than 3,600 twins, BBC reported Monday. The stool samples were measured against six factors of obesity including body mass index (BMI) and different types of body fat.

The study’s lead author, Dr. Michelle Beaumont of King’s College London’s department of twin research and genetic epidemiology, said last month there was a clear connection between fecal bacteria and obesity and that the link was the strongest in regards to stool and visceral fat. Twins who had more diversity of bacteria in their poop had lower levels of visceral fat, which is the leading harmful fat that resides in areas of the stomach that are close to critical organs like liver, pancreas and intestines. Research has linked high levels of visceral fat to cardiovascular disease and diabetes.

While Beaumont said it was very unlikely researchers would be able to explain why the connection between stool and obesity existed, one of the theories the doctor listed in the study suggested that a lack of variety in fecal bacteria could lead to more aggressive levels of gut microbes that are known for turning carbohydrates into fat. Beaumont recommended more research to be gathered on microbes to help support the theory. However, the team’s latest findings may indicate that gut bacteria may have a deeper association with obesity.

In the United States, more than 36.5 percent of adult suffer from obesity, according to a 2014 study by the Centers for Disease Control. After comparing obesity statistics in the country from 1999 to 2000 – in which adult obesity only accounted for 30.5 percent – to those from 2013 to 2014, the CDC determined obesity rates had increased significantly.

About eight in every 10 Americans eat at fast-food restaurants at least monthly while half admitted to eating fast food at least weekly in 2013, a Gallup poll found. With nutrition and diet also playing a major role in obesity, Beaumont suggested following a wide-ranging diet with different types of food could help promote diversity of microbes in our feces that are passed down, which could reduce visceral fat.