Probiotic reduces weight gain in mice

In a landmark probiotic study, European researchers have demonstrated the effect of a particular probiotic strain on body fat mass and glucose tolerance. The naturally occurring strain Bifidobacterium lactis 420 (B420), originally isolated from dairy products, was tested in two high-fat diet models: obese mice with metabolic disorders and diabetic mice.

B420 has been studied by the Active Nutrition Research Group of the DuPont Nutrition & Health Research Centre, Finland, over many years, mainly focusing on its anti-inflammatory properties and more recently on its effect on metabolism. In this latest study, the centre collaborated with Professor Remy Burcelin, the director of the National Institute of Health & Medical Research (INSERM), France.

The strain was found to drastically reduce body fat mass as well as to improve glucose tolerance, which was impaired in the mouse models. Treatment also reduced liver inflammatory markers in the diabetic mice to the level of healthy control mice. The liver is one of the most important organs controlling metabolism and has a central role in the development of obesity-related metabolic diseases; this finding therefore indicates that probiotic treatment may have further widespread effects on metabolism.

Intestinal mechanisms were also explored in the diabetic mouse model, with B420 shown to reduce adhesion of certain pathogenic bacteria onto the small intestinal mucosa. These bacteria hold a highly inflammatory surface molecule called lipopolysaccharide (LPS). Elevated blood LPS concentration, ie, metabolic endotoxemia, is blamed by many scientists for low-grade inflammation, insulin resistance and even obesity. The strain was able to completely normalise plasma LPS levels in diabetic mice.

The study implies that probiotics and prebiotics could potentially help fight obesity and its related metabolic disorders when those disorders are related to an imbalance (dysbiosis) of gut microbiota - a condition whose effect on body weight gain was initially theorised a decade ago, according to Professor Burcelin.

“Ever since, this field has become a major research and economical axis that has not yet identified strategies with clear, added clinical value,” he continued. “Today, new avenues are open thanks to well-characterised probiotics. The corresponding mechanisms are being uncovered, which reinforce the opportunity of efficiently targeting the gut microbiota for the physiological control of metabolism.”

Martin Kullen, health and protection technology leader of DuPont Nutrition & Health, said the new research area “may open up new opportunities for probiotics in functional foods in the future”. He added that the company has “developed a research program on the effects of probiotics on metabolic diseases”.