An Introduction to a New “Old Friend”: Christensenella (to Treat Anxiety and Depression?)

Last week I found what amounts to a business news press release announcing that a microbiome company called LNC Therapeutics has licensed the use of a specific strain of a gut bacteria called Christensenella (which I had never heard of) from the National Research Council in Spain, giving them “…exclusive research, manufacturing, and commercialization rights of the microbiome-based therapies when developed for the treatment of mood disorders.”[i]  As you all know, one of my many particular interests is in natural treatments for these so-called “mental” disorders, which are for the most part, actually physiological in nature, often stemming from alterations in the gut biome.  So I decided to do a little investigation.

Scientists at the Spanish council have done preclinical work on this bacteria; they’d found that it “…regulates the stress response, reducing the overproduction of [the stress hormone] corticosterone [cortisol]…”  The mechanism is currently unknown, but what we do know now, apparently, is that the species is a keystone organism of the human biome, very much responsible for ensuring the health of the biome as a whole, including promoting the growth of other beneficial species of bacteria.  This seems to help the body regulate serotonin levels (bearing in mind that at least 90% of the serotonin in the body is produced in the gut), which, in turn, helps regulate inflammation and mood.

The idea is for LNC Therapeutics to create a new “drug” for anxiety and depression with this particular strain of Christensenella that appears most effective.   I’m sure I’ll be reading about clinical trials in the not-very-distant future, so stay tuned for that.

Not having ever heard of Christensenella, I looked around for some information on it for all of us.  I found a great article from National Geographic, from 2014, which was absolutely fascinating.[ii]  Believe it or not, the Christensenella family was only discovered in 2011.  This article describes research out of Cornell University wherein the gut microbes of 416 pairs of British twins was analyzed in order to look at which gut microbes are most strongly influenced by our genetics.  The big standout was a bacterium called Christensenella minuta: “Christensenella also seems to sit at the centre of a large network of microbes; if it’s there, these others are likely to show up too. And it influences our weight: it’s more common in lean people, and it can reduce weight gain in mice.”

Christensenella is the most inheritable bacteria:  “…some people have it and others don’t, and around 40 percent of that variation is down to our genes.”  And that leads to a myriad of other questions:  what genes affect the presence of the bacteria and how?  Is this why some families seem more prone to obesity/thinness than others?  How much does diet then affect the situation?

I cannot find a lot of research on Christensenella in PubMed, but it seems like a pretty important bacteria; I will most certainly watch to see where the research into using it for mood disorders goes.

Two  more interesting facts that I also came across in snooping around:

In 2017, a study in the journal Gut Pathogens mentions that “Gut microbiome studies have indicated that Christensenella minuta controls obesity in mice, Faecalibacterium prausnitzii protects mice against intestinal inflammation and Akkermansia muciniphila reverses obesity and insulin resistance by secreting endocannabinoids.”[iii]  Three years had gone by between that National Geographic article and the publication of this one, and still, the relationship of Christensenella to obesity had still only been studied in mice.  I can find nothing of note on this in the 3 years following the Gut Pathogens article, which I find odd.

I also found an article looking at the fecal microbiota of those with rheumatoid arthritis (RA) versus osteoarthritis (OA), which is worth mentioning (I’ve added the bold highlights to make it stand out for you):  “At the species level, the abundance of certain bacterial species was significantly lower in the RA group, such as Fusicatenibacter saccharivorans, Dialister invisus, Clostridium leptum, Ruthenibacterium lactatiformans, Anaerotruncus colihominis, Bacteroides faecichinchillae, Harryflintia acetispora, Bacteroides acidifaciens, and Christensenella minuta. The microbial properties of the gut differed between RA and OA patients, and the RA dysbiosis revealed results similar to those of other autoimmune diseases, suggesting that a specific gut microbiota pattern is related to autoimmunity.”[iv]

Autoimmune disease is highly associated with high levels of inflammation, as are both obesity and depressing and anxiety.  It will be really interesting to follow all this, as the upcoming trials using  Christensenella  for depression and anxiety may well yield positive results in other unexpected ways.

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[i] https://www.labiotech.eu/microbiome/lnc-therapeutics-microbiome/

[ii] https://www.nationalgeographic.com/science/phenomena/2014/11/06/the-most-heritable-gut-bacterium-is-wait-what-is-that-2/#close

[iii] Shivaji, S. We are not alone: ac case for the human microbiome in extra intestinal diseases. Gut Pathogens. 2017;9(13). doi: 10.1186/s13099-017-0163-3

[iv] Lee, JY, et. al. Comparative analysis of fecal microbiota composition between rheumatoid arthritis and osteoarthritis. Patients. Genes. 2019;10(10):748.  doi: 10.3390/genes10100748.