Seasonal changes of circulating 25-hydroxyvitamin D correlate with the lower gut microbiome composition in inflammatory bowel disease patients

Abstract

Higher probability of the development of Crohn's disease (CD) and ulcerative colitis (UC) as a possible consequence of the north-south gradient has been recently suggested. Living far north or south of the equator is manifested in fluctuation of vitamin D (vitD) levels depending on the season in both healthy and affected individuals. In the present study we investigate the possible link between the seasonal serum vitD level to the microbial composition of the lower gut of Inflammatory Bowel disease (IBD) patients using 16S rRNA sequencing. Decrease of serum vitD level in winter/spring season in a cohort of 35 UC patients and 39 CD patients was confirmed. Low gut microbiota composition of patients with IBD correlated with the serum level of 25(OH)D that directly coupled to seasonal variability of the sunshine in the central European countries. It is supposed to be related to increased abundance of Actinobacteria and Proteobacteria in UC and Actinobacteria, Fusobacteria, Firmicutes and Bacteroidetes in CD. In summer/autumn period, we observed a reduction in abundance of bacterial genera typical for inflammation like Eggerthella lenta, Fusobacterium spp., Bacteroides spp., Collinsella aerofaciens, Helicobacter spp., Rhodococcus spp., Faecalibacterium prausnitzii; and increased abundance of Pediococcus spp. and Clostridium spp. and of Escherichia/Shigella spp. Inflammatory bowel disease (IBD) is a modern lifestyle disease with a worldwide prevalence. IBD involves mainly Crohn's disease (CD) and ulcerative colitis (UC) the etiology of which differs, so the clinical determination of the disease is difficult. Chronic inflammation of the gastrointestinal tract defined as cycling of the acute inflammation phase and remission is typical for IBD, both CD and UC. While in UC the disease is specifically localized to the colon with different degree of continuous inflammation proximally from the rectum, the CD can manifest anywhere in the gut. To date, there is no clear evidence of a single factor causing the IBD. It is affected by genetic susceptibility, microbiome composition, immune response dysregulation as well as various environmental factors 1. The vitD defficiency is common among IBD patients 2,3 and it has been speculated, that a low level of vitD might be one of the risk factors influencing the IBD 4-6. The current epidemiological studies of IBD show and upward dynamics in countries distant from the equator 7 , strongly suggesting a correlation between IBD incidence

Vitamin D Modulates Intestinal Microbiota in Inflammatory Bowel Diseases

“…Unlike other studies, low levels of vitamin D were associated with a more balanced composition of the microbiome. It should be noted that it was not a randomized controlled trial (RTC), but vitamin D levels were correlated with changes in the microbiome in individuals with IBD [ 97 ].…”

Vitamin D Signaling in Gastro-Rheumatology: From Immuno-Modulation to Potential Clinical Applications

“…In particular, they identified lower level of Escherichia/Shigella in stool of UC patients and increased level of Bacteroidetes in the stool of CD patients accompanied by lower proportion of Clostridium spp . and higher proportion of Firmicutes in the mucosa [ 90 ]. Another study that evaluated samples of the intestinal mucosa found a decrease in gammaproteobacteria and increased Bacteroidetes in the microbiome of the upper gastrointestinal tract of patients receiving vitamin D supplementation without significant effects on terminal ileum, ascending colon, sigmoid colon, and stools [ 91 ].…”

Vitamin D Modulates Intestinal Microbiota in Inflammatory Bowel Diseases

“…Unlike other studies, low levels of vitamin D were associated with a more balanced composition of the microbiome. It should be noted that it was not a randomized controlled trial (RTC), but vitamin D levels were correlated with changes in the microbiome in individuals with IBD [80].…”