Science Update

Can probiotics help prevent obesity?

In a recent study researchers at Vanderbilt tested a bacteria that can produce a therapeutic compound in the gut. The results showed that it stopped weight gain insulin resistance and other health complications. 

Past research has demonstrated that gut bacteria plays a role in the development of obesity diabetes and cardiovascular disease.  According to Sean Davis PhD assistant professor of pharmacology at Vanderbilt The types of bacteria you have in your gut influence your risk for chronic diseases.

Researchers at Vanderbilt selected a safe strain of bacteria that colonizes the human gut -Escherichia coli Nissle 1917. This particular bacteria is used as a probiotic treatment for diarrhea. They genetically modified this strain so it would produce N-acyl-phosphatidylethanolamine (NAPE) a lipid produced in the small intestine when we eat and is quickly converted to N-acylethanolamide (NAE) which is a compound that can reduce food intake (and thus help with obesity).

The researchers wanted to see whether the NAPE-producing bacteria could lower food intake and weight gain in mice that were fed a high-fat diet. During the 8 week trial some of the mice had the modified bacteria added to their drinking water while others received the control bacteria.

The results showed that the mice that received the NAPE-producing bacteria had significantly reduced food intake body fat and fatty liver compared to the mice that received the control bacteria.

This is exciting; however we do not need to modify bacteria to help decrease the risk of obesity. There is a ton of research on the intestinal microbiota and its association with obesity.

The two predominant bacterial groups in the gut are Bacteroidetes and Firmicutes. Past research has discovered a relationship between the balance of these two groups and obesity. Firmicutes can secrete a compound that results in increased activity of lipoprotein lipase in adipocytes resulting in enhanced storage of these lipids. The Bacteroidetes are not as efficient in this function; therefore the balance of these two groups can significantly affect the accumulation of fat stores in the body. Obese individuals may have populations of bacteria that force a more efficient extraction and storage of energy than lean individuals that have a different balance of beneficial bacteria. In the gut a decrease in Bacteriodetes relative to Firmicutes is associated with a noted accumulation of body fat.

The use of specific diets and pre- or probiotic therapies can significantly affect microbial populations that influence fat storage.

 

Source: J Clin Invest. 2014 Aug 1;124(8):3391-406. doi: 10.1172/JCI72517. Epub 2014 Jun 24.  Incorporation of therapeutically modified bacteria into gut microbiota inhibits obesity.