“You should be taking probiotics.”
“I heard probiotics are good for you.”
“Oh, probiotics are so important.”
Yes / Yes. These are all true statements. But they are wide. Which probiotics? Which varieties for which purpose? Simply saying “probiotics” tells us very little about what to take. It’s like saying, “You should eat.” Technically accurate and yet operationally unusable.
Today I will correct that. I will describe the best probiotic strains for whatever purpose you want as there isn’t a single strain that can rule them all. The probiotic strain that is best for anxiety may not be the best probiotic strain for allergies and so on.
Of course, this is not the last word. What follows is the best evidence available as it exists today. That can change tomorrow. And it will surely change based on your individual makeup.
With that in mind, let’s get started right away.
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Best probiotic for anxiety
The existence of the gut-brain axis – that mysterious thoroughfare from the gut to the brain and back again – and the presence and even production of neurotransmitters along the gut suggest that “gut feelings” describe real phenomena. Mental health and gut health are closely related, and it is most likely a two-way relationship in which the two influence each other. You already know that, don’t you?
We have all felt fear or discomfort in our bowels.
We all had instinctive responses to certain people that seemed to manifest in our stomachs (and were later proven).
These are real. They are not inventions of our imagination.
For example, we know that some gut bacteria strains can produce GABA, the “chill-out” neurotransmitter that is responsible for sleep and relaxation. We know that feeding people prebiotics (bacteria feed) can lower their cortisol and make them focus on positive stimuli rather than negative stimuli. We know that the more fermented foods such as yoghurt, kefir, kimchi or sauerkraut are consumed, the lower the frequency of social anxiety.
The best candidate for fear is Lactobacillus rhamnosus. Although there are no human anxiety studies (yet) for this strain, there are numerous animal studies to support this. One notable paper found that dosing mice with L. rhamnosus increased cortical expression of GABA genes and decreased cortisol- and fear-like behavior.
Best probiotic for IBS
Irritable bowel syndrome is irritating. Even more irritating is the fact that it describes a confluence of symptoms rather than a specific illness; Two people with “IBS” each can have disorders with completely different causes. This complicates the probiotic you choose.
In one study, IBS patients took a combination of Saccharomyces boulardii, Bifidobacterium lactis, Lactobacillus acidophilus and Lactobacillus plantarum The symptoms improved by 73% – but only if they also showed an overgrowth of the small intestinal bacteria (SIBO). IBS patients without SIBO showed only a 10% improvement.
(Side note: since gastroesophageal reflux disease, or GERD, usually occurs with SIBO, there is a good chance this set of strains could help there, too)
Another article, a 2019 meta-analysis, looked at which strains are best for IBS patients. Although they didn’t find a predominant strain, they found that multi-strain probiotics generally worked better than single-strain probiotics, and that too Lactobacillus acidophilus appeared in all successful multi-strain studies.
Get Primal Probiotics, which contains 4 of my favorite strains plus a prebiotic mix (food for friendly bacteria) so they can take root – all in one convenient capsule
Best Probiotic for Leaky Gut
The intestinal mucosa is not a passive, inert barrier, but a dynamic, selective filter. Lining the intestine are epithelial cells whose cell membranes fuse into protein complexes known as tight connections. The close connections serve as bouncers: their job is to distinguish what belongs inside and what does not. In a perfect world, these close connections keep pathogens, antigens and toxins away while allowing nutrients and water in. But it’s not a perfect world, and sometimes the intestinal close connections sleep on the post. Sometimes the bowel is leaky.
Treating leaky gut isn’t as simple as picking up a few pills. Beating it down takes a multi-faceted approach that includes sleep, diet, exercise, sun, and all of the other regular lifestyle items I covered in previous posts. But certain probiotic strains seem to really help. For example, in children with atopic dermatitis L. rhamnosus and L. reuteri Dietary supplements reduce leaky gut and improve symptoms. L. rhamnosus also helps restore the intestinal barrier in children with acute gastroenteritis. And in rats with leaky intestines, yogurt improves the intestinal barrier function. We’re not rats, but yogurt is a surefire thing (just like the Lactobacillus acidophilus this is found in most yogurts).
Best probiotic for diarrhea
Diarrhea after a round of antibiotics is a common side effect, especially in children. An analysis of 23 studies with a total of nearly 4,000 pediatric subjects from 2016 found that probiotics were effective in reducing the risk of antibiotic-related diarrhea L. rhamnosus and Saccharomyces boulardii as the safest bets.
In adults who stop taking antibiotics, a combination of Lactobacillus acidophilus NCFM, Lactobacillus rhamnosus Lr-32, Bifidobacterium breve M-16V, Bifidobacterum longum BB536, Bifidobacterium lactis BL-04 and Bifidobacterium bifidum BB-02 was effective in reducing diarrhea.
Best probiotic for constipation
Among young college aged women with constipation a combination Bifidobacterium lactis BL 04, Bifidobacterium bifidum Bb-06, Lactobacillus acidophilus, Lactobacillus casei and Lactococcus lactis improved symptoms and quality of life. Another study found that B. lactis reduced symptoms in adults with constipation.
That being said, the rest of the constipation / probiotics literature is pretty inconclusive and skimpy. What seems to help is combining probiotics with prebiotics – that is, food for the bowel bugs. Probiotic fortified artichokes are probably my favorite incarnation of this concept.
Best probiotic for allergies
Probably the best probiotic strain for allergies is Lactobacillus paracasei.
A number of studies have shown that L. paracasei improves symptoms in patients with hay fever. In adults with hay fever with grass pollen, fermented milk made with L. paracasei reduced itching and nasal congestion. L. paracasei reduced itching, sneezing, and swelling of the eyes in children with hay fever.
L. paracasei also reduces eczema, likely by strengthening the skin barrier and improving water retention.
Best probiotic for immunity
The gut is the first line of our immune system in many ways. Some of the infectious diseases that do not normally affect you as the intestines can enter and spread through the intestines. For example, COVID-19 often exhibits gastrointestinal symptoms, and researchers are investigating whether probiotic supplementation can help reduce the risk of severe COVID.
A meta-analysis of studies in elite athletes found that a number of probiotic strains are helpful in maintaining immune function during extreme exercise. Athletes are a great population to study because their exercise puts an incredible strain on their immune systems. I remember running hundreds of miles a week, I kept coming down with something or over something else. So which probiotics help?
Once again the big names of the genera Lactobacillus and Bifidobacterium rule:
Overall, these tribes are from the Genera of Lactobacillus and Bifidobacterium are best studied for most applications. They are often what is found in the human intestines and in the fermented foods that we have eaten for many thousands of years. One can assume that we are well adapted hosts for them.
There are so many more exotic strains out there. There are soil-based bacteria. There are tribes that are unique to the Hadza hunters and gatherers in Tanzania. There are likely some interesting tribes living in other traditional peoples in other regions. And I imagine that many of them have the potential to do a lot of good for us all. But they can also have undesirable, unexpected effects.
The thing about probiotics is that you never really know which one works best until you try. It’s a very personal thing. Each strain will respond differently to your unique gut ecosystem and genome. What we can say with fairly strong confidence is that probiotics are generally very safe. Not every strain recommended here will work for everyone, but luckily, there’s no harm in trying.
Which strains are your favorites? What have you tried? What didn’t work
Let me know below Thank you for reading!
About the author
Mark Sisson is the founder of Marks Daily Apple, godfather of the Primal Food and Lifestyle movement, and the New York Times best-selling author of The Keto Reset Diet. His latest book is Keto for Life, which describes how he combines the keto diet with an original lifestyle for optimal health and longevity. Mark is also the author of numerous other books, including The Primal Blueprint, which is credited with the growth of the Primal / Paleo movement in 2009. After three decades of researching and educating people about why food is the key component to achieving optimal wellbeing, Mark launched Primal Kitchen, a real food company, the Primal / Paleo, Keto and Whole30-friendly kitchen staples manufactures.
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