THE TOP PROBIOTIC STRAINS FOR A HEALTHY GUT
What the science reveals
A good balance of a variety of gut bacteria is essential for a healthy digestive and immune system. Some 70% of your immune system is controlled via your gut.
A recent Harvard Medical School article also confirmed that a healthy gut influences your heart health and plays a key role in healthy ageing and longevity (Ref).
And the existence of the gut-brain pathway via the vagus nerve means that a healthy gut has a direct impact on emotional wellbeing (Ref.), mood and mental health (Ref.).
This article is written by Colin Rose, a Senior Associate Member of the Royal Society of Medicine, and Fellow of the Royal Society of Arts.
He is the Founder and Director of Research and Innovation of Uni-Vite Healthcare and author of a recent book: Delay Ageing: Healthy to 100, where he reveals how to slow ageing and, therefore, help prevent later-life illness.
A variety of probiotic good bacteria are needed for health
You will typically have over 400 different probiotic strains in your body that live in various parts of the upper and lower intestines.
A high variety of intestinal bacteria is associated with longevity. In contrast, a lack of diversity in probiotic strains has been linked to obesity, digestive issues and many other health issues.
Bacterial balance in your microbiome can be disturbed – a condition called dysbiosis. Common causes of this disturbance include antibiotics, which kill off both good and bad bacteria, pesticides, dietary change or excess sugar in the diet.
The result of an unbalanced microbiome can be:
> Yeast infections like Candida and Thrush
> Chronic inflammation – causing issues like IBS
> Reduced immunity – increasing vulnerability to infection
> Constipation & bloating
> Food intolerances (gluten or lactose)
> Brain fog, depression, and anxiety
> Vitamin deficiencies
How to choose a supplement with the best probiotic strains
A well formulated probiotic supplement, containing the right strains of ‘friendly’ bacteria, in adequate amounts, can help to improve all these conditions.
“Well formulated” means a probiotic supplement with a wide enough range of beneficial bacteria, and a significant level of colony forming units (CFUs). That’s because a probiotic supplement increases the ratio of good to ‘bad’ microbes. The beneficial bacteria crowd out and overwhelm the bad microbes – that include fungi as well as bacteria.
Above all it means including specific strains that not only provide proven health benefits but survive the acidity of the stomach and reach the gut – the intestines where they work.
Different probiotic strains have different benefits
There are hundreds of different types of bacteria living in the gut. Lactobacillus varieties largely function in the longer small intestine, while most of the Bifidobacterium varieties work in the large intestine.
Different strains have different shapes, functions and benefits, so an effective probiotic supplement needs to have a range of strains. It also must have strains able to survive the harsh journey through stomach acid and into your gut. Not all do.
Here is a guide to the best and most effective probiotic strains.
The best probiotic strains 2: Lactobacillus rhamnosus
Lactobacillus rhamnosus is related to L. casei, is extensively studied and is a very versatile probiotic strain. Research (Ref.) shows it to be effective in:
> Reducing gastrointestinal infections and stopping persistent diarrhoea, (Ref.)
> Tackling Clostridium difficile and H pylori infections and associated diarrhoea (Ref.)
> Reducing inflammation and the severity of irritable bowel syndrome IBS
> Addressing non-alcoholic fatty liver disease
> Significantly stimulating natural tumour killing mechanisms (Ref.)
> Helping protect against urinary tract infection (Ref.)
When in combination with another two strains – Bacillus lactis and Bacillus longum – L. rhamnosus significantly reduced inflammation, underlying its real potential for addressing IBS. (Ref.)
Another significant advantage of Lactobacillus rhamnosus is that it improves immune response so effectively that it is being combined with a new class of tumour drugs to inhibit tumour growth. (Ref.)
The best probiotic strains 3: Bifidobacterium lactis
Scientific studies have proven that Bifidobacterium lactis is a powerful strain that has multiple benefits:
> Enhances immunity by increasing T cell activity - and thus reducing colds & flu
> Combats tumour growth,
> Improves digestion and normalises bowel function
> Can help lower cholesterol levels and increase HDL (good) cholesterol
The prime function of Bifidobacterium lactis is to break down body waste and aid in the absorption of various vitamins and minerals.
In a 2015 study (Ref.) Bifidobacterium lactis probiotics were able to reduce pathogen counts by 10,000-fold in laboratory settings – and work is now being done to combine this probiotic with traditional antibiotics to slow the development of antibiotic resistance.
Multiple studies have shown that B. lactis enhances immune function (Ref.) and this is confirmed again in a further study (Ref.) that concluded:
“... relatively short-term dietary regime (6 weeks) is sufficient to impart measurable improvements in immunity that may offer significant health benefits to consumers”.
Bifidobacterium lactis certainly has intestinal anti-inflammatory properties which means it can – combined with other strains like Lactobacillus acidophilus – have a role in the treatment of Inflammatory Bowel Syndrome – IBS. (Ref.)
Severe intestinal inflammation – as in colitis – can lead to a type of colon cancer and there is some evidence that B. lactis may reduce this risk. (Ref.)
The best probiotic strains 4: Bifidobacterium longum
Bifidobacterium longum is another ‘super-strain’ of acid resistant probiotics with multiple health benefits.
B. longum:
> Reduces inflammation
> Stimulates the immune system and helps fight infection
> Can help reduce anxiety
> Can – with other strains – reduce the level of fungal microbes to fight Candida
While both Lactobacillus and Bifidobacterium produce lactic acid in the body, Bifidobacterium strains also produce acetic acid in the intestines, helping to reduce the growth of yeast.
A large body of evidence suggests that B. longum is essential for a healthy gut. Specifically, it can help reduce inflammation in the gut (Ref.) and restore the balance of your gut microbiome.
Animal studies suggest B. longum can increase the production of essential fatty acids, especially butyrate (see above) and hence help maintain the integrity of your intestinal wall, which can prevent dangerous microbes from getting into your bloodstream. (Ref.)
There is a pathway now known as the gut-brain axis (Ref.). Bifidobacterium longum appears to activate enteric nerves in a way that can calm anxiety – by reducing inflammation.(Ref.)
The best probiotic strains 5: Lactobacillus plantarum
Research shows that Lactobacillus plantarum is extremely hardy and vigorously attacks pathogenic, bacteria – ensuring the ‘good’ bacteria increase.
L. plantarum:
> Improves your digestion, supports your body to produce vitamins like vitamin K and absorb calcium
> Increases your immunity against eg C difficile, E coli and fungal infections
> Produces its own natural antibiotics
> Is an anti-inflammatory and helps fight IBS
> Has been shown to alleviate stress and anxiety – while improving cognition.
L. plantarum has been shown to protect the integrity of the gut wall and therefore protect against ‘leaky gut’ - which itself is involved in allergies and autoimmune conditions. (Ref.)
Lactobacillus plantarum is one of the most effective strains to boost immune response – according to double-blind placebo-controlled trials – the gold standard in such trials. (Ref.)
Lactobacillus plantarum is a strain that has also been shown to improve vaginal health by improving bacterial balance there and counteracting yeast infections like Candida. (Ref.)
Lactobacillus plantarum may help protect cardiovascular health in postmenopausal women with metabolic syndrome – ie. women who may be pre-diabetic.
A small study published in Nutrition on 24 postmenopausal women with metabolic syndrome showed that after 90 days, those treated with Lactobacillus plantarum showed greater improvements in several cardiovascular risk factors (such as high blood sugar levels) than the control.
The best probiotic strains 6: Bifidobacterium bifidum
Infants start out with a healthy level of Bifidobacterium bifidum (from the mother during birth), but these levels significantly decline as we age.
Bifidobacterium bifidum has been proven to:
> Increase immunity function and counteract E. coli infections
> Fight yeast overgrowths and Candida
> Decrease inflammation
> Treat acute diarrhoea
> Reduce allergenic reactions
> Improve fatty liver condition (Ref.)
Bifidobacterium bifidum directly competes with Candida and yeast overgrowths and Candida infections are commonly associated with low concentrations of B. bifidum.
Fortunately, Bifidobacterium bifidum produces natural antibiotics that kill bad bacteria – so it is another strain that boosts immune function. (Ref.)
Bifidobacterium bifidum also lowers inflammation and therefore should be in any probiotic supplement that seeks to tackle IBS. A 2011 randomised trial showed significant improvements in IBS symptoms and improved quality of life. (Ref.)
Research even suggests that re-populating the gut with B. bifidum can reduce ADHD effects in children with the condition. (Ref.) So it must also have an effect on the gut-brain axis.
The best probiotic strains 7: Lactobacillus casei
Lactobacillus casei studies show significant benefits in immunity (Ref.), allergies, cholesterol levels and digestion (Ref.)
Specifically, Lactobacillus casei:
> Significantly inhibits and reduces diarrhoea episodes
> Reduces the risk and symptoms of IBS
> Helps inhibit the growth of colorectal and bladder tumours
> Lowers susceptibility to allergies caused by pollen and asthma symptoms
> Inhibits candida
Several studies have shown that Lactobacillus casei is able to generally activate the immune system (Ref.) and a specific study suggested that the strain might “contribute to prevention against colorectal cancer” (Ref.).
One of the benefits of L. casei – and L. plantarum and L. rhamnosus – is their ability to reduce the danger of toxins breaching the gut cell wall and entering the blood stream – a condition called intestinal permeability or ‘leaky gut syndrome’.
L.casei and 'leaky gut syndrome' (intestinal permeability) in cancer treatment and obesity
Not only does this condition cause inflammation, but it is linked to obesity (Ref.) and immunity (Ref.). These probiotics help solve leaky gut by increasing a fatty acid called butyrate which effectively ‘seals up’ tiny breaches in the gut cell wall. Consequently, an increasing number of obesity specialists are trialling the use of prebiotics – in conjunction with dietary improvements.
The ability of some probiotics to help heal an overly porous intestinal wall can be important for patients receiving radio chemotherapy. As an important 2021 review in Frontiers in Oncology Probiotics in Cancer (researchgate.net) (Ref.) stated:
"Radio chemotherapy kills intestinal cells, and the stress response it causes leads to destruction of the intestinal mucosal barrier."
The report confirms that this increased permeability of the intestinal wall means that toxins can enter the bloodstream causing uncontrolled “systemic inflammation and multiple organ failure”.
Preventing this permeability (a better phrase than leaky gut) can help prevent the common side effect of gastrointestinal discomfort and pain of radio chemotherapy.
Even better, the same report also noted that probiotics might facilitate the effect of chemotherapy and that:
“In vitro studies have found that probiotics induce tumor cell apoptosis (apoptosis is the natural programmed death of a cell) and inhibit tumor cell proliferation and metastasis”.
Should this situation unfortunately arise, it is worth exploring probiotic supplementation with an oncologist.
The best probiotic strains 8: Streptococcus thermophilus
Streptococcus thermophilus can help reduce bloating which can occur when the digestion system is unable to process lactose properly. The probiotic helps in digesting lactose and transforming it into lactic acid. But that is certainly not its only benefit.
Streptococcus thermophilus has been found in university research to:
> Increase ceramide in skin, meaning extra hydration and suppleness (Ref.)
> Reduce gut permeability, therefore reduce inflammation and therefore decrease IBS symptoms (Ref.)
> Produce natural antibiotic compounds to help prevent infections like pneumonia, C. difficile and H. pylori
> Increase HDL (good) cholesterol (Ref.)
> Help prevent candida (Ref.)
The best probiotic strains 9: Lactobacillus acidophilus
Why put Lactobacillus acidophilus last, considering it is the most researched strain of probiotic? And that it is essential to health? And that decades of research shows it has all the following benefits?
> Can improve blood pressure and cholesterol levels (Ref.)
> Fights viral, bacterial and fungal infections (Ref.)
> Reduces allergy severity
> Produces natural internal antibiotics like acidolin and lactocin
> Tackles urinary tract infections – coupled with L. plantarum and L. rhamnosus (Ref.)
> Increases nutrient absorption of eg calcium and B vitamins
> Reduces inflammation and alleviates IBS (Ref.)
> Stops recurrence of bacterial vaginosis and alleviates candida (Ref.)
> Enhances immunity and decreases allergies. (Ref.)
The answer is that you DO need Lactobacillus acidophilus in any effective probiotic supplement – but many of the sub-species used in supplements are cheaper versions and fail to reach the gut in large numbers. That means they do not colonise well – which is essential to improve the good to bad bacterial ratio.
One strain, however, is exceptionally hardy. It is Lactobacillus acidophilus DDS-1 – a super-strain developed at the University of Nebraska, which is the academic facility which has researched probiotics for the longest time.
Over 35 years of evidence from laboratory and human clinical studies show that Lactobacillus acidophilus DDS-1 can:
> Successfully colonize the gastrointestinal tract (Ref.) and (Ref.)
> Shorten the duration of antibiotic-associated diarrhoea (Ref.)
> Stimulate the immune system (Ref.)
Lactobacillus acidophilus DDS-1 is particularly effective when combined with other strains. For example, combined with Bifidobacterium lactis, DDS-1 shortened acute respiratory infection in preschool and elementary children in a randomized, double-blind, placebo-controlled study.
Combined again with Bifidobacterium lactis, DDS-1 "significantly improved symptom severity in participating subjects with Irritable Bowel Syndrome (IBS)". (Ref.)
Psycho-biotics and the gut-brain axis
What affects the gut often affects the brain and indeed vice versa. This is because there is a two-way connection between brain and gut called the gut-brain axis.
You’ll have seen that many of these top strains have a positive effect on the immune system. Of course, that benefits health generally, especially as we get older.
Recently, however, researchers have discovered that ‘immune dysregulation’ has a direct effect on psychological state, mood, stress and even conditions like ADHD (Ref. )
Consequently, supporting the immune system with probiotics and changing diet to include foods that increase the level and range of probiotics can improve mental state. For example, a 12-week supplementation with Lactobacillus plantarum showed a clear link between ‘gut modulation’ and stress and anxiety. (Ref.)
This new fast-expanding research field is called psycho-biotics (Ref.)
Probiotics, however, may well influence mood and psychological state via a second route. There is clear evidence that inflammation is a key driver of very many age-related diseases – and intestinal inflammation is highly likely to influence neuro inflammation. Consequently, any strain that calms inflammation should almost certainly benefit mental status – and the strains we have reported on do so.
Nevertheless, the huge variability in people’s diet, microbiomes and genetic make-up means that the ability of a probiotic to improve mood or reduce stress cannot easily be predicted.
However, even a 3-month course of a probiotic with proven effect on immune function and inflammation may be worth trying. That’s what a recent Harvard Health report concluded. (Ref.)
Summary of the best probiotic strains to supplement with
Probiotic supplements have the ability to address a wide range of conditions. We have reviewed the 9 probiotics with the best clinical science support.
With a supplement that combines the top 9 probiotic strains, you can expect to help:
> Improve inflammatory issues like IBS symptoms and even arthritis
> Improve immunity response - reducing vulnerability to infection
> Address infections like Candida and Thrush
> Decrease constipation and bloating
> Reduce brain fog, depression, and anxiety
> Stop ‘leaky gut’ symptoms
> Restore gut health after antibiotics
There is even a case to try a multi-strain probiotic in cases of low mood and anxiety when there is no obvious environmental cause.
It is on the basis of all this research that Microbiotic Plus was developed – one of the very few probiotic supplements to contain all 9 top strains.
And which are the best probiotic foods?
There will be times when a probiotic supplement is advisable to quickly increase the level and strains you need for quicker resolution of issues.
You should, however, make sure your diet includes foods that continuously promote a healthy gut. These include
> Fermented dairy like yoghurt, kefir and aged cheeses
> Sauerkraut
> Miso
> Pickles
Plus the prebiotic foods your beneficial bacteria like to eat themselves – high fibre foods like beans, peas and whole grains, together with fruits and especially leafy green vegetables.
Colin Rose
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