The Positive Impact of a Plant-Based Diet on Our Health

The scientific and healthcare communities have long understood that adopting a low-fat, plant-based diet can have a positive impact on individuals’ health. However, until now, we haven’t fully understood why. My colleagues from George Washington University and Physicians Committee for Responsible Medicine and I are investigating two ways in which a vegan diet affects the gut microbiome and health – by facilitating weight loss, and decreasing inflammatory markers – and we received a grant from uBiome to assist in our research.

Our first study investigates whether the adoption of a low-fat, vegan diet increases postprandial metabolism (the mechanism that converts food into energy). If postprandial metabolism increases as a result of this diet change, it may explain why individuals lose weight while following this diet.

We decided to include microbiome analysis in our 16-week study to track changes in gut bacteria when adopting a vegan diet to see whether these changes have any correlation with our hypothesis. Through its academic grant program, uBiome awarded us over 300 gut microbiome kits to help us conduct our research. We collected samples for all 80 participants – in both the control and intervention groups – at baseline and after 16 weeks of the study. We are currently analyzing the data.

Beyond its effect on metabolism, we have been exploring how a vegan diet affects the gut microbiome to decrease inflammation in the body. We already know that two major bacterial phyla colonize the human gut, the Firmicutes (Lactobacillus, Enterococcus, Clostridium, and Ruminococcus) and the Bacteroidetes (Bacteroides and Prevotella). Some of them are considered pathobionts, which are bacteria linked to disease processes. When dysbiosis occurs, these harmful bacteria tend to produce specific toxins that cause inflammation and might initiate an immune response from the host. This, in turn, might be associated with the development of specific inflammatory and autoimmune disorders.

Previous studies comparing different types of diets (omnivore, vegetarian, and vegan) have shown that individuals following a vegan diet have a very distinct gut microbiome, with reduction in potentially harmful types of bacteria and substantial increases of protective bacteria.  Additionally, several studies have shown a decrease in inflammatory markers in individuals following a vegan diet, especially those with autoimmune diseases.

Our second study focuses on individuals with rheumatoid arthritis (RA), and explores whether a low-fat, vegan diet free of foods commonly identified as triggers for arthritis pain can reduce pain and disease activity, as well as improve patients’ quality of life and mood. With results from our uBiome microbiome testing kits, we can determine if changes in the gut microbiome influence inflammation and pain. We have recently been awarded a second grant from uBiome for this project.

As we conclude our analysis and begin writing our manuscript for publication, we look forward to sharing our findings in greater detail. We hope that this research will add to our collective understanding of diet, weight management, and the role that gut management plays in our health.

Hana Kahleova, M.D., Ph.D., is the director of clinical research at the nonprofit Physicians’ Committee for Responsible Medicine. Dr. Kahleova has published extensively in her field, including more than a dozen nutrition studies, as well as the book Vegetarian Diet in the Treatment of Diabetes (Maxdorf, 2013). She also wrote the chapter about using a plant-based diet to treat diabetes in Vegetarian and Plant-Based Diets in Health and Disease Prevention (Academic Press, 2017). Dr. Kahleova earned her doctorate in nutrition and diabetes and her medical degree from Charles University in Prague, Czech Republic. You can read more about Dr. Kahleova’s research in PubMed and view her recent news articles online.