Why Supplementing With Probiotics May Make You Ill – Part 4: D-lactate

Why Supplementing With Probiotics May Make You Ill – Part 4: D-lactate

Many people with digestive issues cannot tolerate probiotics. Some people mention that when they ingest probiotics, their brain fog worsens.

Does the increase of cognitive issues from ingesting probiotics occur only from immune system up-regulation and die off, or could it be caused by something else?

What is the Difference Between L-lactate and D-lactate?

Lactic acid bacteria in our gut produce both L-lactate and D-lactate from carbohydrate fermentation.

L-lactate is produced in our body from lactic acid bacteria in our microbiome and is a natural byproduct produced during the Kreb’s cycle for metabolism. L-lactate is also up-regulated during exercise because of the increased need for mitochondrial energy and oxygen to support our muscles. L-lactate is oxidized back into glucose by our liver and is further used for energy production by our body. Finally, our brain can metabolize lactate for energy. 1 2 3

D-lactate is not produced by our body and is only produced by the lactic acid bacteria in our microbiome. There is no issue with the d-lactate that is produced by the lactic acid bacteria within our gut. Little D-lactate is produced by these bacteria unless there is a significant overgrowth of these bacteria or severe carbohydrate malabsorption. Also, most microbiome produced d-lactate is eliminated through our stool or broken down by the enzyme d-lactate dehydrogenase. 4 5 6 7 8

The Issue With Too Much D-lactate and Leaky Gut

D-lactate acidosis does exist in medical literature but is a very rare occurrence. It is documented to occur in short bowel syndrome, a medical condition where carbohydrate malabsorption occurs from the absence of the small intestine causing overgrown of lactic acid bacteria. Increased d-lactate over time produced by these bacteria and having leaky gut issues creates d-lactate acidosis. Symptoms of d-lactate acidosis include: 9 10 11 12 13

  • Delirium
  • Ataxia
  • Violent behavior
  • Slurred Speech
  • Brain Fog
  • Headaches
  • Fatigue
  • Reduction of mitochondrial function.
  • Leaky gut.

D-lactate acidosis has also rarely been diagnosed in people with severe leaky gut including people suffering from IBD. 14

Is it possible for people who ingest d-lactate probiotics or probiotic food to develop a buildup of d-lactate in the blood and cause issues similar to d-lactate acidosis? Possibly, if they have a severe enough leaky gut and brain that allow the d-lactate to cross the intestinal barrier and the BBB. 15

Most of the studies, however, with d-lactate acidosis and SBS show that it takes awhile for the body to build up enough d-lactate from excessive carbohydrate fermentation to cause severe notable health issues. In most cases, the body can metabolize d-lactate quickly and reduce concentrations of it in the bloodstream before it causes issues. Finally, severe leaky gut and brain would also need to occur for side effects of excessive d-lactate in the bloodstream to be noticed. 16 17 18 19 20

Reduction of SCFA production has been theorized in people with d-lactate overgrowth which may contribute to the development of leaky gut. The reduction of SCFA is also hypothesized to cause a reduction of neurotransmitters and ATP being produced by the gut microbiome causing neurological and lack of energy symptoms. 21

Finally, many people have adverse side effects from ingesting probiotics that produce d-lactate, which include the strains, Lactobacillus acidophilus, L. bulgaricus, L. fermentum, and L. delbrueckii subsp lactis. Their sensitivities from ingesting these probiotics, however, might stem from other issues besides d-lactate sensitivity. That being said, if you suffer from headaches, brain fog, or fatigue when ingesting d-lactate producing probiotic strains, I would avoid them and search out a d-lactate free probiotic.

16 Comments
  1. Hi – bit late to respond here but I am having disturbing reactions to GutPro. I have my kids on it and so far, they seem fine, but I have tried it twice now and it appears to cause severe symptoms. For the record, I’ve started with a tip of the ‘drop’ serve and I only need one or two days of that and I react. Symptoms include general increase of CFS symptoms – weakness and aggravation of nervous system or adrenals so more weak and shaken type feelings but also very distinct perhaps neurological reaction where my head feels woozy and spacey and like it’s floating – massive increase in anxiety and feelings of derealisation. It’s hard to believe I’m getting all this from a tiny amount of this product but it does appear to be the culprit. Any thoughts?

  2. Hi, thanks for this article!

    I just wanted to point out that “which include the strains, Lactobacillus acidophilus, L. bulgaricus, L. fermentum, and L. delbrueckii subsp lactis.” – none of these are strains. Those are the genus and species.

    • Correct, but I thought in low level taxonomy strains are species? Lactobacillus is the genus, acidophilus is the species, both together are the individual strain?

  3. Hi John,

    Are you able to recommend probiotics that are d-lactate free?

  4. Hi! I have this exact issue. I had many antibiotics that contributed to gut dysbiosis then decided to consume coconut keifer which was lactic acid lactobacillus galore! Now I struggle with SEVERE lactic acid build up! I take bifido bacteria to hopefully one day starve off some of those lactobacillus bacteria but do you have any pointers on how I can do this with a quickness?

    • Why not you take some diluted ceylon cinammon oil and lactoferrin to see if it will reduce the Lacto overgrowth and then rebuild your gut from there? Of course ask your doctor first. Lacto live in the upper gut and Bifido in the colon so taking them probably will not do much.

  5. John, you mention

    “Reduction of SCFA production has been theorized in people with d-lactate overgrowth which may contribute to the development of leaky gut. The reduction of SCFA is also hypothesized to cause a reduction of neurotransmitters and ATP being produced by the gut microbiome causing neurological and lack of energy symptoms.21”

    I am wondering, is the the solution to then increase SCFA? And how might I go about doing this? Is there an optimal diet that includes necessary foods for this to occur, and are there certain kinds of foods that one would definitely want to avoid to fix an issue like this? Thank you so much for any insight.

  6. Is Bifidobacterium lactis the same as d or l lactate?

  7. I never had a problem taking my non dairy probiotic. After a few years of not taking I took some and within seconds my head felt like it was not my own and i felt really ill, had to lie down. every now and again i try them if my tummy is upset/gurgling and instantly the same. Last time i ate some fresh mango right away when i felt so ill and the symptoms started to calm down. Do you think this is Herx? If it’s a non dairy probiotic there shouldn’t be a problem with D-L. Interestingly the ingredients list a bulking agent and i’m wondering if this contains gluten.

  8. Wow, what a complex issue! Hard to know if these probiotics are causing die-off symptoms or d-lactate acidosis.

  9. Would be L-lactic acid safe to drink in such products as molkosan?

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