Gut Bacteria Implicated in Obesity

A little while ago, we wrote about a study considering the role that gut bacteria potentially play in the development of obesity. So we were not surprised when two more studies were published in Nature last week. Here we consider the implications of the new findings.

The studies, which were both published in Nature, covered two separate studies from the same research team. The largest of the two studies included a total of 169 obese individuals and 123 lean controls. In the initial analysis, the researchers analysed the participants’ stools and found that obese individuals displayed lower genetic diversity in their microbiome. This is turn was associated with higher inflammation and greater insulin resistance. The researchers then conducted a follow up study nine years later, and found that the lower diversity individuals had had in their gut biota in the initial study, the higher their weight gain was nine years later.

The findings from the above study were corroborated by a smaller study where 49 obese or overweight individuals took part. In that study the researchers measured the genetic diversity of participants’ mircobiomes and then enforced a low calorie diet. The key findings were intriguing as they suggested that individuals who had shown low genetic diversity of microbiomes improved as the low calorie diet led to their genetic diversity of microbiomes to increase. Yet, this was not the case for individuals whose genetic diversity of microbiomes was high before the low calorie diet.

What these findings appear to suggest is that individuals whose genetic diversity of microbiota is greater, may also be able to gain less weight than those with a relatively low diversity of microbiota. One of the reasons for that is that it could potentially imply that some obese people are less likely to get metabolic illness and that some people may lose weight more easily by starting a low calorie diet. However, there are a few areas that research would still need to iron out before these findings could have an impact on clinical treatments.

Firstly, due to the correlational nature of the studies to date, it is not known whether there was some factor relating to obesity that affected the amount of genetic diversity of microbiomes the individuals showed. Secondly, the limited samples which mixed obese and overweight individuals may have muddled the statistical significance of the findings. Lastly, none of the studies appeared to have a baseline for what was considered a standard amount of genetic diversity of microbiomes.

Having said that, it is clear that these findings highlight an emerging area of research that may be useful for the treatment of obesity and metabolic diseases. Understanding the interaction of a multitude of gut bacteria in various populations, how they are affected by environment (such as diet) and genetic vulnerability is no small task that can be done overnight. We expect more studies to emerge and are keen to see what progress they make in this field of research.

You can read more about htis study here – http://www.nature.com/news/bacteria-from-lean-cage-mates-help-mice-stay-slim-1.13693