Obesity has become a significant healthcare problem throughout the United States. Interestingly enough, new research shows that the bacteria in the gut of obese people may have much less diversity than the microbiome of thin people. The research goes on to illustrate that this outcome has been found in dogs.

The Science Magazine reports on a study in which researchers fed seven beagles an unrestricted diet for six months. The dogs gained an average of 4.93 kilograms. A second control group of seven beagles was fed a portion-controlled diet for the same time period and no dogs in this aggregation gained weight. The same commercial food ad libitum was distributed among the two groups of dogs with one receiving an unrestricted amount while the other beagles were given a limited supply.

Waste samples were collected and analyzed from both groups. Both adipokine and serotonin levels were inspected in the lean and obese dogs. The findings show that the gut bacteria of the obese dogs were less diverse than the other set of beagles. In the lean dogs, microbes from the phylum Firmicutes were more common while Gram-negative bacteria called Proteobacteria were more likely to be seen in the obese canines.

This study was published in the Journal of Veterinary Internal Medicine in November 2014. One hypothesis the investigators developed is that a large amount of Proteobacteria may bring about a rise in lipopolysaccharides. This particular saccharide is a common part of the cell wall in Gram-negative bacteria. It has even been associated with weight gain in mouse models.

The published paper starts out discussing how neuronal signaling and the hypothalamus controls energy consumption. Additionally, the gut microbiome plays a part in affecting neuronal signaling, which means it may influence the development of obesity.

It was discovered that leptin levels were higher among the obese dogs while the levels of adiponectin and 5-hydroytryptamine of cerebrospinal fluid were greater among the lean group of canines. Through the use of gene pyrosequencing analysis, the most important finding unearthed is that the diversity of the microbiome was low among the obese animals.

The researchers conclude that decreased levels of serotonin among the obese group may put the animals at greater jeopardy because of an increased appetite. Additionally, microflora filled with gram-negative bacteria may lead to chronic inflammation among the overweight canines.

The study also illustrated that dogs can become overweight over months or years after being exposed to a prolonged energy imbalance, which is a similar phenomenon in humans. Studying mammals in the laboratory setting can provide more answers about the development of obesity in humans.

However, it will take more time and research to determine exactly how obesity and gut bacteria are linked. It is likely that animal models will play a big role in future studies of the digestive tract and obesity.

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Categories: Obesity