Japanese knotweed extract may reduce risk from harmful microbial metabolites and protect from viral infections

Our health is sometimes endangered not by what we eat but by what our gut microbiome eats. The study below provides just one such example of the gut microbiome-heart connection: 

Romano et al. (2015) Intestinal microbiota composition modulates choline bioavailability from diet and accumulation of the proatherogenic metabolite trimethylamine-N-oxide

While choline is rightfully recognized as an essential nutrient, it turns out that some gut bacteria can steal choline and turn it into trimethylamine (TMA), a precursor of a proatherogenic substance trimethylamine-N-oxide (TMAO), thus depleting a beneficial nutrient and at the same time turning it into a harmful one. What are those bacteria?

While testing 79 bacterial species isolated from the human gut, researchers found eight species that showed significant choline consumption and TMA accumulation: Anaerococcus hydrogenalis, Clostridium asparagiforme, Clostridium hathewayi, Clostridium sporogenes, Escherichia fergusonii, Proteus penneri, Providencia rettgeri, and Edwardsiella tarda. 

Seeding either Clostridium sporogenes alone or all eight of these bacterial strains into the mouse gut has confirmed that these bacteria deplete choline from fecal matter, reduce plasma concentration of choline, and produce TMA, significantly increasing plasma levels of TMAO.

Those who happen to harbor these choline-depleting/TMA-producing gut bacteria are in a precarious double bind: consume choline — and you are in trouble with your cardiovascular health due to choline-to-TMA conversion, don't consume choline — and you are also in trouble with your cardiovascular health (and much more) due to choline deficiency.  In fact, choline is a precursor for several important substances: (a) phosphatidylcholine (PC), a phospholipid required for structural integrity of any cell membrane, including endothelium; (b) acetylcholine, a neurotransmitter; and (c) betaine, a player in the methylation cycle that helps convert homocysteine into methionine. Choline deficiency would therefore negatively impact many organs and systems.  

But Mother Nature already thought of a way out. It turns out that in the above experiments, mice where given free choline. However, in foods like eggs or sunflower seeds, most choline is already in the form of phosphatidylcholine, which is much better absorbed than free choline anyway.  And for some reason, TMA-producing bacteria are not as keen on consuming phosphatidylcholine.  

For example, a study found that if human subjects were given 600 mg of choline, their serum TMAO levels would go up (with the degree of TMAO elevation depending on the individual’s microbiome features).  But, if subjects were instead given 600 mg of phosphatidylcholine, their TMAO levels wouldn't rise.  However, a much larger dose of phosphatidylcholine (6.9 g), could still bring TMAO levels up in a different study.  

The bottom line is: because most choline exists as phosphatidylcholine in foods in the amounts that usually do not exceed 600 mg (for example, one egg only has 147 mg of choline), it is safe and crucial to consume foods naturally rich in choline, as Mother Nature intended.  

But if consuming choline as a supplement, one needs to make sure it’s a phosphatidylcholine (PC) form rather than free choline form (choline chloride or choline bitartrate). And even supplemental PC (sometimes consumed as part of lecithin) should be taken in measured amounts.

There is also a way to make one's microbiome reduce its TMA production — by consuming foods/beverages or herbal extracts high in resveratrol. A mouse study found that resveratrol decreased serum levels of TMAO by inhibiting commensal microbial TMA production (from choline) via gut microbiota remodeling and increase in beneficial species, such as Lactobacillus and Bifidobacterium. Bile acid metabolism was also improved by resveratrol in the study.

One of the richest sources of resveratrol is Japanese knotweed (other names: Polygonum cuspidatum or Hu Zhang).

The added benefit of consuming the whole herbal extract, rather than its isolated component resveratrol, is the presence of other useful substances in Polygonum cuspidatum. For example, emodin, another famous constituent of this herb, is known to inhibit replication of more than 10 types of viruses, including EBV, influenza A and coronavirus. Polygonum cuspidatum extract as a whole also appears to block the cell entry via the Spike protein of a certain novel coronavirus that everyone seems to be afraid of since the end of 2019.

Disclaimer: This information is for educational purposes only and is not intended as medical advice.

References

For a study showing better absorption of phosphatidylcholine compared to that of free choline supplement, click HERE.

For a study showing the difference between choline and phosphatidylcholine consumption on TMAO levels, click HERE.

For a study showing that way too much of phosphatidylcholine will also cause the increase in TMAO levels, click HERE. 

For a study showing the effect of resveratrol on gut microbiota, bile acid metabolism, and TMAO levels, click HERE.

For a summary of other protective effects of resveratrol, click HERE.

For a table listing concentrations of resveratrol in foods and herbs, click HERE.

As immune science educator, I offer a lecture-course Natural Immunity Fundamentals and weekly science-intensive study groups at Building Bridges in Children’s Health (BBCH Community). Visit BBCH website to become a member.