{"id":8302,"date":"2016-05-30T07:35:00","date_gmt":"2016-05-30T07:35:00","guid":{"rendered":"http:\/\/www.wjst.de\/blog\/?p=8302"},"modified":"2019-07-08T13:09:00","modified_gmt":"2019-07-08T13:09:00","slug":"bacteria-vitamin-d-and-allergy","status":"publish","type":"post","link":"https:\/\/www.wjst.de\/blog\/sciencesurf\/2016\/05\/bacteria-vitamin-d-and-allergy\/","title":{"rendered":"Bacteria, vitamin D and allergy"},"content":{"rendered":"

Bacterial<\/a> (and\u00a0fungal<\/a>) gut diversity are believed to influence primary allergic sensitization\u00a0as well as\u00a0early\u00a0vitamin D supplementation<\/a>.\u00a0The question \u00a0is – again – \u00a0could there be any connection?<\/p>\n

No doubt, there\u00a0are numerous antagonistic mechanisms of\u00a0the \u00a0human host linking\u00a0bacteria flora and allergen recognition\/presentation.\u00a01952<\/a>: “Hay factor”, 2004<\/a>: LPS\/D3 antagonism,\u00a02005<\/a>: D3 blocks DC maturation,\u00a02007<\/a>: DCs need a co-inflammatory signal, 2009<\/a>: bacteria-induced vitamin D receptor dysfunction,\u00a02010<\/a>: Salmonella \u00a0more aggressive with turned off vitamin D receptor…<\/p>\n

But what happens when ingesting overdoses of vitamin D supplements? 500-1000 kU vitamin D is an about 100fold overdose compared to physiological intake of\u00a0a newborn. AFAIK bacteria do not utilize vitamin D, so it is rather unlikely that there are direct host-independent effects.<\/p>\n

Only recently I found a paper already published last year<\/a> “Effects of high doses of vitamin D3 on mucosa\u2010associated gut microbiome vary between regions of the human gastrointestinal tract”. As a main outcome Bashir et al.\u00a0observe a reduction in opportunistic pathogens and an increase in bacterial richness:<\/p>\n

Vitamin D3 supplementation changed the gut microbiome in the upper GI tract (gastric corpus, antrum, and duodenum). We found a decreased relative abundance of Gammaproteobacteria including Pseudomonas spp. and Escherichia\/Shigella spp. and increased bacterial richness. No major changes occurred in the terminal ileum, appendiceal orifice, ascending colon, and sigmoid colon or in stools, but the CD8+ T cell fraction was signicantly increased in the terminal ileum.<\/p><\/blockquote>\n

Like the authors, I do not know of any similar study. The mechanism is rather unclear leading the authors to speculate<\/p>\n

Reducing such an inflammatory environment by vitD3 could diminish the competitive advantage of opportunistic pathogens, such as Escherichia\/Shigella spp. or Pseudomonas spp. which are evolutionary better adapted to inflammation and can outcompete commensal bacteria. In return, a low inflammatory environment allows beneficial bacteria such as Bacteroidetes to outcompete opportunistic pathogens, resulting in increased phylotype richness which we found in this study.<\/p><\/blockquote>\n

The only paper I remember from the literature is Cantorna et al 2013<\/a> cited but not evaluated by Bashir 2015:<\/p>\n

Cyp KO and VDR KO mice had more bacteria from the Bacteroidetes and Proteobacteria phyla and fewer bacteria from the Firmicutes and Deferribacteres phyla in the feces compared with wild-type … The mechanisms by which the dysbiosis occurs in VDR KO and Cyp KO mice included lower expression of E-cadherin on gut epithelial and immune cells and fewer tolerogenic dendritic cells that resulted in more gut inflammation in VDR and Cyp KO mice compared with wild-type mice.<\/p><\/blockquote>\n\n

 <\/p>\n

\n CC-BY-NC Science Surf , accessed 20.04.2026<\/span>\n <\/div>","protected":false},"excerpt":{"rendered":"

Bacterial (and\u00a0fungal) gut diversity are believed to influence primary allergic sensitization\u00a0as well as\u00a0early\u00a0vitamin D supplementation.\u00a0The question \u00a0is – again – \u00a0could there be any connection?   CC-BY-NC Science Surf , accessed 20.04.2026<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9],"tags":[1096],"class_list":["post-8302","post","type-post","status-publish","format-standard","hentry","category-computer-software","tag-farming"],"_links":{"self":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts\/8302","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/comments?post=8302"}],"version-history":[{"count":6,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts\/8302\/revisions"}],"predecessor-version":[{"id":8312,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts\/8302\/revisions\/8312"}],"wp:attachment":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/media?parent=8302"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/categories?post=8302"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/tags?post=8302"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}