Do this first for gut health before anything else!

If there is one thing to optimize for gut health, it would be this.

Vitamin D.

My first line of attack would be sunlight, then UV lights (lamps or beds) combined with red light and lastly supplements (either oral, topical, or sublingual). Supplements are obviously the most convenient, but some people get side effects from them.

Sunlight

Sunlight has so many different benefits other than just for the synthesis of vitamin D. Check out the following article to learn more about the must-have benefits of sunlight.

> Shedding light on the 1 thing an Alpha Energy Male needs to do more of

UV light & red light

With UV light you still get the benefits of UV light, but UV light can damage the skin if done for too long. So that’s why I recommend combining it with red light, since red light will inhibit the inflammation and aging induced by UV light.

Vitamin D supplements

2000-5000IU daily should be enough to main a good level of vitamin D in the body. Much larger doses can be used safely to fix a deficiency quickly.

The problem is, some people react negatively to oral supplementation, and benefit more from applying vit D topically. But obviously, doses need to be much higher to get the same effect. Usually 5 times higher.

Furthermore, some people take vitamin D and their levels don’t go up, but they can have success by using vit D drops sublingually.

Why vitamin D

Vitamin D is an essential vitamin that is actually a steroid. It is now known that at least 1,000 different genes governing virtually every tissue in the body are now thought to be regulated by activating vitamin D (1,25-dihydroxyvitamin D₃).

A few reasons why it’s so good for the gut.

Anti-microbial peptides

Vitamin D induces antimicrobial peptide gene expression giving it ‘antibiotic’ effects. Prior to the development of antibiotics, cod liver oil, sunlight (both sources of vitamin D) and pharmacologic doses of vitamin D were used to treat TB. This fell out of favor following the development of very effective antibiotic therapy (R).

These antimicrobial peptides (AMPs) include alpha and beta-defensins and cathelicidin; hCAP18/LL-37.

Decreased expression of hCAP18 is reported in human diseases whose common denominator is enhanced susceptibility to infection (R).

Pathogens from the gut (usually created by bacteria) bind to the TLR receptors, which upregulate the enzyme, CYP27B1, which converts vit D to its active form, which then enhances the production of AMPs. The ability of human macrophages to induce cathelicidin expression in response to TLR activation was directly proportional to serum vitamin D status (R).

However, when vitamin D levels are low, bacteria inhibit the vitamin D receptor (VDR) and LL-37 responses in peritoneal macrophages as a mechanism to evade antibacterial defense. Vitamin D supplementation could up-regulate peritoneal macrophage VDR and LL-37 expressions, which resulted in an enhanced immunological defense against spontaneous bacterial peritonitis in patients with cirrhosis and ascites (R).

In summary, normal/high vitamin D will enable your body to release optimal amounts of these AMPs, which will keep bacteria, viruses, fungi, etc., in check.

Vitamin D is protective against many bacteria, including H pylori infection. Multiple studies have shown that the higher someone’s vitamin D is, the more likely they are able to eradicate H pylori and prevent it from coming back (R).

In severe cases of gut problems, such as IBD, vitamin D is also very helpful. Many studies have now shown that vitamin D reduces IBD symptoms and those with IBD are more likely to have low vitamin D. In fact, hypovitaminosis D is reported to be as high as 60% in IBD patients (R).

In addition, people living in areas at high latitudes that receive little sun exposure synthesize low levels of vitamin D and have higher incidences of IBD (R, R).

Positive shifts in the microbiome

Vitamin D has been shown to change the microbiota composition which leads to an increase in beneficial bacteria, such as Ruminococcaceae, Akkermansia, Faecalibacterium, and Coprococcus while decreasing Firmicutes. Adequate levels of vitamin D are very important in improving the composition of the gut microbiota (R).

These “beneficial” bacteria, e.g. lactobacillus and bifidobacterium, can produce B-vitamins (R). More B-vitamins production usually equals better energy production and overall health.

A lot of these beneficial bacteria are butyrate producers and butyrate has anti-inflammatory effects on the gut. Butyrate has also been shown to enhance the vitamin D receptor, thus enhancing the effects of vitamin D in a feedforward loop.

Reduces excess serotonin production

Roughly 95% of all serotonin in the body is produced in the gut via the rate-limited enzyme tryptophan hydroxylase 1 (TPH1).

Excess serotonin in the gut causes inflammation, depletes cellular NAD and ATP (because of the inflammation), causes gut permeability, damages the villi and lowers nutrient absorption (due to the inflammation) and messes with the immune system (R, R).

Vitamin D has been shown to downregulate TPH1 (R).

Vitamin D has also been shown to enhance the detoxification of toxin bile acids and is inversely correlated with secondary bile (R, R, R).

Deoxycholate, a secondary bile acid, is a very strong inducer of TPH, and vitamin D has been shown to lower it, thus lowering TPH1 activation (R).

Renin-angiotensin-aldosterone system (RAAS)

When we hear/read of RAAS, we think of hypertension. But angiotensin II, which is responsible for causing vasoconstriction can also induce inflammation in the gut.

Low vitamin D leads to enhanced colonic RAAS activation. And treatment with angiotensin II receptor blocker losartan markedly alleviated colitis (R).

Gut permeability and inflammation

Many of the above beneficial aspects of vitamin D, such as lowering serotonin and pathogenic bacteria, lead to less inflammation and better gut integrity.

Activation of the vitamin D receptor plays a critical role in mucosal barrier homeostasis by preserving the integrity of junction complexes and the healing capacity of the colonic epithelium. Therefore, vitamin D deficiency may compromise the mucosal barrier, leading to increased susceptibility to mucosal damage and increased risk of IBD (R).

This study found that mice fed a vitamin D deficient diet had significantly decreased colon mucosa thickness, as well as a marked increase in serum pro-inflammatory cytokine levels. Gut barrier integrity markers such as claudin, CLD-3, CLD-7, and zonulin-1 protein expressions were significantly decreased and upregulated mRNA expression of jejunum zonulin and elevated serum zonulin were found in the vitamin D deficient group (R). Meaning, loss of proper gut barrier function and health.

Intestinal autophagy

A good balance of anabolism and autophagy is always required. Too much or too little is bad. Rapamycin, which inhibits mTOR, upregulates intestinal autophagy and can lead to inflammation.

On the other hand, inadequate autophagy is also bad. Low vitamin D can lead to insufficient intestinal autophagy.

“Intestinal epithelial VDR downregulates expressions of ATG16L1 and lysozyme, and impairs antimicrobial function of Paneth cells. Gain and loss-of-function assays showed that VDR levels regulate ATG16L1 and lysozyme at the transcriptional and translational levels. Moreover, low levels of intestinal epithelial VDR correlated with reduced ATG16L1 and representation by intestinal Bacteroides in patients with IBD.” (R)

Supercharge it

I’m always interested in supercharging things. Upping vitamin D on its own can be very helpful, but sometimes due to inflammation, the vitamin D receptor is downregulated. The following help to upregulate the VDR or act on it as well. Some of the others, such as bile acids, work in synergy by acting on a heterodimer vitamin D receptor, such as FXR.

Here are a few:

• Sodium butyrate (R)
• Bile acids (FXR agonists) (e.g. ox bile) (R)
• Curcumin (R)
• Bifidobacterium longum (R) – vitamin D receptor activation is required for probiotic protection in colitis (gut inflammation) (R).
• Korean Kimchi. Consumption of this dish increased mRNA expression of the vitamin D receptor and its target genes cathelicidin (R).
• LL-37. In some people, upping vitamin D doesn’t necessarily increase LL-37, so taking some alongside vitamin D can be very helpful. 100-200mcg daily should do the trick.
• Bonus: Niclosamide. As far as I know it doesn’t have anything to do with vitamin D signalling, but in my experience (and other anecdotes I’ve seen) it’s great for improving gut health. Initially you might get some diarrhea/loose stool, but after a few days it goes away and you’re left with awesome transit time and bowel movements.