Lactobacillus Lacrimosa

I don’t know why you’d cry about lactobacilli, or LB as those of us in the know call them. I guess if you hated yogurt maybe. Who doesn’t like some good Greek yogurt or kefir? Pro tip: the literal king of yogurt (it’s the actual name so it must be true) is Juju Dhau. Best yogurt ever, from Nepal, made in clay jars and alone it would be worth a vacation there as if you needed another reason to fly to Nepal. I digress, now that you know about the king of yogurt let’s all cry over LB together shall we?

LB is an aerotolerant, anaerobic, gram positive, rod shaped, non spore forming bacteria found in our gut, on our genitals, and in our mouths as well as other places. You’ve probably seen the 498,367 articles about probiotics and the importance of your gut microbiome as it relates to everything from depression to IBD to why you’re single and why the ice cream shop is always out of your favorite flavor. Does it actually though? Read my previous articles on gut pathogens and I won’t see so far fetched that it is the reason you’re single, C. diff (CD) diarrhea is gnarly. Too far? Maybe. 

One of those scientists credited with the discovery of how important our gut microbes are is Ilya Ilyich Mechnikov, dear Mechi as his friends call him. He noted that Bulgarians who ate more yogurt and fermented food lived longer that those (generally wealthy) who didn’t have to eat those foods. Dear Mechi drew the conclusion that since the same process which fermented or cultured foods stopped them from becoming “putrified” and thought that so too would those who eat fermented foods resist purification. See my dumb comments on CD, he might not have been that wrong. Fun fact: the composition of our microbiomes is different across geographical regions. Seems like it makes sense given variety in diet and environment but still cool. 

Though we know now that so much more goes into how long we live, it makes sense that since we eat to live, and ideally all the eated (yes) stuff goes through the gut, the stuff that helps break down the eated stuff is important to our health. This eated stuff could be good or harmful substances (food poisoning, etc…) so our gut microbes, GM from here on out, must play some role in our immune system and health overall. Let's start with our gut.

LB is a big genus with many species, some of which we host others we do not. For this blog I am referring to those in our gut. Some of these are L. acidophilus, L. rhamnosus, and L. salivarius to name but a few. The first thing that LB does for the host is to help breakdown food alongside the enzymes in our digestive tract, from saliva to stomach acid and more. This is not the main way that humans get nutrients from their foods but a small part, it is really the benefit for the LB, we eat, they eat. The real area in which LB is the VIP is in protection from pathogenic bugs. 

I've talked about CD and other gut bugs but that is a small part of what can go wrong when your GI tract gets infected. Take oral thrush, candida infection, we associate that with immunodeficiency and antibiotic use. Vaginal yeast infections and bacterial vaginosis, also more common with immunodeficiency and antibiotic use. See a pattern? Immunodeficiency is somewhat self explanatory, but antibiotic use? The destruction of our normal microbiome allows for pathogens such as H. pylori, C. diff, and candida species to fill in the niche left by those now deceases friendly bugs. 

In the name we see the word lacto-, sounds like lactic acid? Yup, most LB produce lactic acid as a byproduct of metabolism. Other byproducts of LB metabolism include hydrogen peroxide and reuterin, an antimicrobial substance to name a few. Starting with lactic acid, few bacteria like acidic environments. Hydrogen peroxide? Another antimicrobial along with reuterin. These molecules inhibit the grown and pathogenicity of various organisms like C. albicans, S. aureus, H. pylori, and pseudomonas species. Not bad. The flip side is when we use antibiotics, and I am NOT saying we should not use them, we kill off the cute little LB and give the above pathogens and their cronies a chance to climb to the top of the intestinal hierarchy.   More antibiotics (or antifungals) are then needed and can compound the issue and bring about harsh side effects from the drugs themselves (antibiotics are not benign). The use of LB in probiotic pills or from food are also linked to decreased relapse in some of these pathogenic microbes.

From here on, you can find a study and its equal and opposite study on these topics, so take them with a grain of salt substitute that these are not as well studied as one would hope. Certain LB species are associated with the release of anti-inflammatory cytokines possibly reducing incidence and severity of atopic dermatitis, GERD, and IBS. LB may also help to repair damage done by GERD to esophageal tissue, which may lead to reduced risk of certain pre-malignant and malignant conditions, looking at you Barrett's Esophagus. Some of the benefits might come from LB balancing, or bringing back to balance, restoring the gut flora to its base state. A few studies found that patients with IBS had lower levels of LB and higher levels of E. coli, Clostridia, and Enterobacter species. There are studies and podcasts on the link between your gut microbiome and cancer, depression, risk of lightning strikes, obesity, Parkinson's diseases, and shark attacks that you can dive into. I have several on my phone that I have not yet made it to, but I still recommend the MedScape InDiscussion series podcasts, they have a few and no, I have nothing to do with MedScape. They wouldn't touch me with a 39 1/2 foot pole.

If we want this protection, how do we get LB to come back to the relationship? Looking on the back of many yogurt containers, kombucha bottles, and probiotic containers you've probably noticed "contains live and active cultures" or "contains lactobacillus XXXX" which may bring you back to my opening. Unless you've stricken it from your mind which I would not blame you for. Probiotics are coming into focus more and more as whole person health moves to the forefront of healthcare (at least notionally). Are these the cure all we've been looking for? Were the Bulgarians right about yogurt? Did that factor into their success as Cold War assassins? Were Marko Boshnakov and Georgi Markov's assassin both fans of the local yogurt joint? If they had been lactose intolerant would they have been nicer people? We will never know. But I could keep going on about yogurt's tie to the Mongol Hordes, the Gabon nuclear reactor, and Machu Picchu, conspiracy baby. 

This really turned into a post on the importance of our microbiome more than LB, but LB is the one most people know of off the top of their head. However, we also have a skin microbiome which differs between location, skin type, and more. Super cool. In most instances they, the normal host microbes, are beneficial when they are located in their proper place. When dislocated, say acne bacteria into a cut, staph into a wound or eye, GI bacteria anywhere else, and others, the effects can be bad. Normally we can handle it, but surgical patients, immunocompromised, sick, elderly people are more vulnerable. Even just patients treated with antibiotics might be at risk. It reminds me of the disruption that introduction of, or deletion of a species in the environment can change everything pretty drastically. Think about the introduction of rats to Mauritius and the much maligned Dodo bird, honored now through insults in their name. You Dodo.  What about the removal of wolves across America in the 19th century? Overpopulation of grazing animals. Introduction of MTB to the lungs, leads to disease. Removal of LB from the gut? Just might lead to disease. 

This is a very simple look at why LB is pretty cool and how the gut rules everything. It is true that the way to a man's heart is is stomach. Also the way to the psych ward is the gut as well it may turn out to be. I am looking more at this and will probably type some more about it in the future. The way our bodies maintain homeostasis, the part played by each of our microbes, and how that protects us or reduces the risk of many diseases is amazing. Plus, yogurt will make you immortal and/or make you into a Bulgarian assassin.*

References 

A taxonomic note on the genus Lactobacillus: Description of 23 novel genera, emended description of the genus Lactobacillus Beijerinck 1901, and union of Lactobacillaceae and Leuconostocaceae by Zheng et al., in the International Journal of Systematic and Evolutionary Microbiology April 2020

Combinations of Probiotic Bacteria (Lactobacillus helveticus, Bifidobacterium longum, Lactobacillus rhamnosus, Sacchammyces boulardii) Restores the Skin Microbiome in Atopic Dermatitis by Bisyuk et al., in the Journal of Allergy and Clinical Immunology February 2023

Gut microbiome and human health: Exploring how the probiotic genus Lactobacillus modulate immune responses by Rastogi & Singh in Frontiers in Pharmacology October 2022

Irritable bowel syndrome and microbiome; Switching from conventional diagnosis and therapies to personalized interventions by Ghaffari et al., in the Journal of Translational Medicine April 2022

Lactobacillus sp. Facilitate the Repair of DNA Damage Caused by Bile-Induced Reactive Oxygen Species in Experimental Models of Gastroesophageal Reflux Disease by Bernard et al., in Antioxidants June 2023

Metagenomic analysis reveals distinct patterns of gut lactobacillus prevalence, abundance, and geographical variation in health and disease from the journal Gut Microbes September 2022 by Shankar Ghosh et al.

The Role of Probiotic Lactic Acid Bacteria and Bifidobacteria in the Prevention and Treatment of Inflammatory Bowel Disease and Other Related Diseases: A Systematic Review of Randomized Human Clinical Trials by Jose Saez-Lara et al., in BioMed Research International February 2015

Image "Overview of the strategy on vaginosis treatment with probiotics" from NPJ Biofilms and Microbes by Wu et al., 2022

Irritable Bowel Syndrome and the Gut Microbiome: A Comprehensive Review by Shaikh et al., in the Journal of Clinical Medicine  April 2023

Lactobacillus spp. for Gastrointestinal Health: Current and Future Perspectives by Dempsey & Corr from Frontiers in Immunology April 2022

Lifestyles in transition: evolution and natural history of the genus Lactobacillus by Duar et al., in FEMS Microbiology Reviews August 2017

NIH, WHO, CDC pages on Lactobacillus

*Not evaluated by the FDA