Best Diet for a Healthy Microbiome/Vitamin D and the Microbiome
Best Diet for a Healthy Microbiome
At the University Medical Center Groningen, in the Netherlands, researchers studied four groups of people (the general population, and those with Crohn’s disease, ulcerative colitis, and IBS), in order to analyze the relationship between dietary patterns, and gut microbiota.
Participants provided stool samples, which were analyzed and then compared with the results of a food frequency survey.
The research team identified 61 food items associated with microbial populations, and 49 correlations between food patterns and microbial groups, finding that those with a diet of legumes, bread, fish, nuts, and red wine, were more likely to have high levels of healthy gut bacteria. They determined that plant-based foods, and a Mediterranean-style diet, helped bacteria with anti-inflammatory properties to thrive.
“A diet characterized by nuts, fruit, greater vegetable and legume intake than animal protein, combined with moderate consumption of animal derived foods like fish, lean meat, poultry, fermented low fat dairy, and red wine, and a lower intake of red meat, processed meat and sweets, is beneficially associated with the gut ecosystem in our study.” said lead author, Laura Bolte. Adding that, “The results indicate that diet is likely to become a significant and serious line of treatment or disease management for diseases of the gut – by modulating the gut microbiome”. (Study)
For more information on the health benefits of wine, have a read of this older blog: Wine for Health
Vitamin D and the Microbiome
It is well established that being deficient in vitamin D leads to a higher risk of developing certain diseases, including multiple sclerosis (MS), and inflammatory bowel diseases. Research into the gut microbiome indicates that our microbial flora also may play a significant role in these conditions.
But what links vitamin D to our intestinal microbiota?
A team of researchers from UBC, in Vancouver, set out to see if there was a link between vitamin D and intestinal flora, by examining how the microbiome responded to UV light.
Their study included 9 females who took vitamin D supplements for 3 months prior to the experiments, and 12 who did not. (All participants had fair skin.) The 9 subjects who had taken the supplements had vitamin D levels classified as adequate, while all but one of those who had not taken the supplements were vitamin D deficient.
The volunteers who were deficient in vitamin D where given three full body sessions of UVB exposure, which resulted in an increase in vitamin D levels in all of them. Researchers then compared each individual’s gut microbiome as it was before the treatment, to how it looked after the UVB treatment.
What they discovered was, not only did their vitamin D levels rise, but their gut microbiome also changed, becoming more akin to the microbiomes of those other women who were not vitamin D deficient. And they found the most significant changes in microbial composition occurred in those who had been most deficient in vitamin D.
“Prior to UVB exposure, these women had a less diverse and balanced gut microbiome than those taking regular vitamin D supplements,” said study author Prof. Bruce Vallance. “UVB exposure boosted the richness and evenness of their microbiome to levels indistinguishable from the supplemented group, whose microbiome was not significantly changed.”
When we look at some of the specific results of this experiment we see that the participants deficient in vitamin D (after UVB treatment) showed an increase in “firmicutes” and “proteobacteria”, and a decrease in “bacteroidetes”, bringing their levels of these bacteria in line with the microbiomes of those participants who had taken vitamin D supplements.
Here is an interesting fact about those bacteria: “Bacteria that can’t use oxygen are called anaerobes. … Of the many types of anaerobes, the two that are most directly involved with obesity are the Bacteroidetes and Firmicutes. Most studies have shown that the more Bacteroidetes you have (compared to your Firmicutes), the leaner you will be.” (Source)
Dr. Else S. Bosman, another of the authors of this study stated: “We found that vitamin D production was the main driver of the shift in the microbiome. It is well known that UVB light produces vitamin D, and we now start to understand that vitamin D is important to maintain a healthy gut.” However, “this study made use of a very selective group of participants, e.g., healthy, female, pale skin. It would be very interesting to repeat the study with participants that have a lot more variety in ages and with bigger study groups to confirm the results. It would also be great if we can test if the phototherapy is useful for people with intestinal inflammation to promote their gut health.” (Study)