The Gut Microbiome and Obesity

The microbiome is tailored to each individual and environmental factors like antibiotics and western diets may impact the bacteria profile of the gut even more. 

This can lead to gut dysbiosis (higher amounts of pathogenic gut bacteria compared to healthy gut bacteria) which can lead to irritable bowel syndrome. 

Research has suggested that obese individuals have higher amounts of Firmicutes compared to Bacteroidetes phyla in their intestinal tract. The Firmicutes phyla are gram-positive bacteria that play a role in host metabolism through short-chain fatty acids. 

Ways the gut microbiome may impact weight management:

• Communicates to organs like the liver, brain, and adipose tissue through short-chain fatty acids. Short-chain fatty acids help to promote fat cell formation and prevent the breakdown of stored fat cells. They also can affect hunger-suppressing hormones like leptin
• Communicates via the vagus nerve to affect appetite and satiety
• Affects bile acid metabolism and can modify hepatic triglyceride and glucose regulation 

Several studies have shown that probiotics may help reverse gut dysbiosis by introducing more healthy gut bacteria into the GI tract and minimizing pathogenic bacteria. There has been some research to suggest that probiotic supplements may help to promote weight loss as well as reduce intestinal inflammation.

In animal studies the following bacteria strains have been correlated to weight loss and correcting the Firmicutes to Bacteroidetes ratio:

-       L. rhamnosus

-       L. sakei

-       L. paracasei

-       L. salivarius

-       B. amyloliquefaciens

-       S. boulardii

This is very promising research regarding obesity. 

With more human studies observing the effects of these specific probiotics, hopefully, there may be a more tailored approach to treating obesity and weight management. We continually learn more about the gut microbiome and its diversity in human health. If you are curious and want to try probiotics to see how it affects your weight loss journey, talk to a registered dietitian and try to find a probiotic with the above strains. Otherwise, try eating yogurt or drinking kefir- both are rich in probiotics. 

_{Stojanov S, Berlec A, Štrukelj B. The influence of probiotics on the Firmicutes/bacteroidetes ratio in the treatment of obesity and inflammatory bowel disease. Microorganisms. 2020;8(11):1715. doi:10.3390/microorganisms8111715}