In a tiny trial, researchers at the National Institutes of Health saw quick and noticeable improvements in the immune systems of those who made the switch to a vegan or ketogenic (commonly known as keto) diet. For two weeks, in random order, scientists observed the physiologic reactions of participants following vegan and ketogenic diets.
They discovered that although the keto diet elicited responses linked to adaptive immunity—pathogen-specific immunity developed via exposure to everyday stimuli and vaccination—the vegan diet elicited responses linked to innate immunity, the body’s non-specific first line of defense against infections.
The microbiomes of the participants—communities of bacteria that reside in the gut—saw modifications and metabolic changes as well. Further investigation is required to ascertain the potential advantages or disadvantages of these alterations, as well as their potential impact on dietary therapies for ailments like cancer or inflammatory illnesses.Â
There is a lack of scientific knowledge regarding the effects of various diets on the human microbiota and immune system. There is a lack of knowledge on therapeutic nutritional treatments, which entail modifying diets to enhance health, and little research has examined the effects of various diets directly. The ketogenic diet is often high in fat and low in carbohydrates. A vegan diet tends to be low in fat and rich in fiber, as it excludes animal products.  Â
At the Metabolic Clinical Research Unit in the NIH Clinical Center, researchers from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and the National Institute of Allergy and Infectious Diseases (NIAID) carried out the study. The body mass index (BMI), age, gender, race, and ethnicity of the 20 subjects were all varied.
Every individual followed a different diet for two weeks, consuming as much as they pleased on either the vegan or ketogenic diet. Individuals who followed the vegan diet, which consisted of roughly 10% fat and 75% carbs, made the decision to eat less calories than those who followed the keto diet, which consisted of roughly 76% fat and 10% carbs.
For analysis, samples of blood, urine, and stool were taken during the research period. A “multi-omics” method was used to investigate the impact of diets, evaluating the body’s immunological, cellular, metabolic, and biochemical reactions in addition to alterations in the microbiome by analyzing several data sets. Because the participants stayed put for the full month-long research, the food modifications could be carefully monitored.Â
Upon adopting the study meals exclusively, every participant experienced significant changes. The innate immune system’s pathways, particularly those involving antiviral responses, were profoundly affected by the vegan diet. Conversely, the ketogenic diet resulted in a notable upsurge in biochemical and cellular mechanisms connected to adaptive immunity, including those involving T and B cells. Compared to a vegan diet, the ketogenic diet impacted blood plasma protein levels and proteins from a greater variety of tissues, including the brain, bone marrow, and blood.
The increased iron content of the vegan diet may have contributed to the promotion of more red blood cell-linked pathways, including those involved in heme metabolism. Furthermore, the two diets altered the participants’ microbiomes, which resulted in variations in the quantity of gut bacterial species that had previously been connected to the diets.
The higher protein intake on the ketogenic diet may be the reason for the changes in amino acid metabolism linked to it. Specifically, there was a decrease in microbial pathways and an increase in human metabolic pathways for the synthesis and breakdown of amino acids.Â
Despite the vast range of backgrounds among the subjects, the two diets were found to elicit unique alterations in the immune system and metabolism, demonstrating that dietary modifications regularly impact multiple interrelated and widely distributed pathways in the body. To find out how these dietary treatments impact particular immune system components, more research is required. The study’s findings, according to the authors, show that nutritional changes cause the immune system to react unexpectedly quickly. According to the scientists, meals might be customized to either avoid or enhance the effects of existing diseases, for example, by delaying the progression of cancer or neurological disorders.Â
Journal Reference Â
National Institute of Health, https://www.nih.gov/news-events/news-releases/switching-vegan-or-ketogenic-diet-rapidly-impacts-immune-system. Â
