Should you be taking a probiotic?

Our gut microbiome is a new frontier in health — but how can probiotics help your immune health?

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April 23, 2020


Diet & Lifestyle, Gut Health, Nutrition Articles

Our gut microbiome is a new frontier in health — but how can probiotics help your immune health?

What is a probiotic?

From kombucha to kimchi, ‘probiotic’ foods are the latest trend taking the culinary world by storm. But it’s by no means a new concept. In fact, it’s believed humans have been consuming fermented foods (and fermented dairy, in particular) for over 8,000 years [1]. 

But what exactly is a probiotic? The scientific definition is: ‘Live microorganisms which when administered in adequate amounts confer a health benefit to the host.’ [2]

In other words, probiotics are ‘good’ bacteria that help to keep us healthy. Probiotic products come in several forms: 

  • Capsules
  • Powders
  • Tablets
  • Lozenges
  • Medicinal yoghurts

Some of the bacteria used in these products have been cultured from the human gut, but not all. Other bacteria are originally taken from animals, soil, fermented food and even breast milk. Common probiotics include strains of
Bifidobacterium lactis and Lactobacillus acidophilus.

Technically, fermented foods and active cultures are distinct from the modern definition of a probiotic—but more on that later.

What are probiotics used for?

Probiotic products have long been used to address gastrointestinal complaints [3]. These include:

However, newer research has shown that the gut microbiome affects far more than our digestion [
4]. This mass of bacteria and other organisms is thought to play a role in several disease processes, which means the clinical applications of probiotics are broader than originally thought. 

Recent studies have found a benefit of probiotic use with the following [5]:

How do probiotics work?

The old view of probiotics was that they ‘reseeded’ the gut. However, new and more accurate research methods have shown that this isn’t always the case, leading to confusion that probiotics don’t work. 

The fact is that probiotics function in a much more nuanced fashion. They can cling to the gut wall temporarily, but that’s not all they do. They have several different ways of working:

They help to combat bad bacteria. They have a number of tricks up their sleeve, including competing for space, producing anti-microbial substances and binding to viruses [6]. A healthy gut microbiome should include lots of different types of bacteria—probiotics contribute to this because they modulate the gut microbiome, preventing one type of bacteria from taking precedence.

They train and balance the immune system. Generally speaking, the exposure of the immune system to lots of different types of bacteria helps to prevent it from becoming oversensitive. More specifically, probiotics increase gut sIgA production, which is a key protective antibody in the gut [7].

They produce helpful substances. These include short chain fatty acids, which the intestinal cells use as fuel, and certain compounds that help to reduce inflammation [8].

They modify gut transit time. In other words, they can help you to poop more regularly if you need to, or they can help you to poop less regularly if required [9]. By altering the speed with which our food moves through the digestive system, probiotics also have a knock-on effect on nutrient absorption. 

They strengthen the intestinal barrier. Probiotics can help to increase mucous production in the gut, which serves as a protective coating [10].

The above is just a taster of what probiotics can do. Of course, it’s worth bearing in mind that both the gut and its microbiome have a far-reaching influence—so when you enhance the health of the gut, you can affect everything from your digestion to your emotions [11].

What are the limitations of probiotics?

It’s important to understand that the science of probiotics is very much in its infancy. With this comes limitations, such as:


In an ideal world, we’d take a probiotic and its bacteria would start to colonise our digestive tract. Studies show that this can happen, but it tends to be temporary [12]. 

This doesn’t mean they can’t help, though. Think of probiotics as tidy house guests: they only stay for a while, but they help to neaten everything up while they’re there.


A good probiotic product should have trials showing that the bacterial strains can survive all the way until the intestines. What’s more, the strain should remain viable (functional) all the way until the end of its shelf life. 

However, there are limited regulations—and not products are created equally. Choose a high-quality formulation, or seek advice from a functional medicine practitioner.


Your gut microbiome is a wild place. Let’s imagine its inhabitants, your gut bacteria, as a pack of wolves. 

In order to define its health benefit, a probiotic strain has to undergo several tests and stages. This is kind of like domesticating an animal: you’re left with a highly trained dog capable of doing exactly what you tell it to do, but it’s unlikely to take control over a pack of wild wolves. 

Taking a probiotic supplement is akin to throwing a dog into a pack of wolves. It cannot, therefore, be expected to conquer dysbiosis overnight.

What about probiotic foods?

Fermented and live foods (think kefir, kombucha, sauerkraut and kimchi) have variable numbers and types of bacterial strains, which may change from batch to batch. 

For this reason, they’re technically not probiotics (going by the modern definition) as their ‘health benefit’ isn’t specific and measurable.

That’s not to say they can’t help, though. As ancient cultures show us, eating a wide variety of fermented foods is good practice, and over time can contribute to a healthy, balanced microbiome.

What probiotic should I take?

When it comes to probiotics, most of the research is strain-specific. This means that researchers have looked at particular types of bacteria—and it can’t be presumed that the effects are the same for other types, even if they’re in the same family.

The last part of the probiotic name indicates the strain. For example, L. rhamnosus GG and L. rhamnosus GR-1 sound very similar. However, research shows that L. rhamnosus GR-1 can reduce the recurrence of urinary tract infections, while L. rhamnosus GG cannot [13, 14].

This means that if you want to take a probiotic to support a particular condition, you need to know which strain would help. Here are some examples:

IBS: research shows that L. Plantarum 299v can effectively combat symptoms of irritable bowel syndrome [15].

Dysbiosis: those who suffer from imbalanced gut bacteria can benefit from taking the strain L. rhamnosus GG [16].

Thrush: ladies suffering from a fungal infection down below may find the stain L. acidophilus LA5 brings relief [17].

Traveller’s diarrhoea: the strain B. lactis Bb12 can help to bring overactive bowels back into balance [18].

Food allergies: this is another condition that can be helped by the much-researched L. rhamnosus GG [19].

Like eating fermented foods, there’s also a place for taking a probiotic with lots of different strains. Generally speaking, a good minimum daily dose is 10–50 billion colony-forming units (CFUs).

Probiotics should not be regarded as a magic pill (remember the dog and the wolves analogy?)—but that doesn’t mean they’re not valuable. Clinically, targeted probiotics can make all the difference if they complement appropriate diet and lifestyle changes. The key is knowing which approach is best for you.

For personalised support, please feel free to get in touch or schedule a FREE 15 minute consultation.

Hand holding skin supplements

The sebaceous gland - located in the dermis - is responsible for producing an oily substance called sebum. Sebum provides lubrication to the skin and helps to make it waterproof. In some people, the sebaceous glands can produce too much oil which leads oily skin. The most common condition caused by excessive sebum production is acne. The key the successful treatment of oily skin is to identify and address the following underlying causes:

  • Genetic factors - a positive family history is often a good indicator.
  • Imbalance of the skin’s and the gut’s microbiome (the gut-skin axis).
  • Systemic inflammation.
  • Insulin resistance - exacerbates oily and acne prone skin by increasing the proliferation of keratinocytes and it also stimulates the synthesis of androgens.
  • High androgens - testosterone and dihydrotestosterone (DHT, the more metabolically active form of testosterone) cause the sebaceous glands to produce more sebum in the skin.
  • Changes in female hormone levels - before menstruation, oestrogen and progesterone levels fall and result in proportionally higher levels of testosterone.
  • Stress and other environmental factors.


The best vitamins to consider when treating oily, acne prone skin:

Vitamin A is by far the most researched vitamin in relation to oily and acne prone skin. Vitamin A is well known for its role in supporting barrier function, it also heals the skin and modulates sebum production. Consuming dietary beta carotene, the precursor of Vitamin A, may be the most optimal option to achieve good levels of Vitamin A in the body.

Vitamin E stimulates skin regeneration and has anti-inflammatory properties, making it a promising tool in the treatment of oily, acne prone skin.

Vitamin C has also been shown to improve oily skin due to its anti-inflammatory properties.Vitamin C may help to reduce redness and swelling and is good for accelerating the healing process of the skin.

Vitamin B3 and B5 regulate the amount of oil the sebaceous glands produce and prevent them from going overdrive (9).


What vitamins are good for hair, nails and skin?


The skin, together with hair and nails, forms the integumentary system, a major protective barrier which guards us from chemicals, pathogens and other elements of our environment. Both hair and nails develop from the epidermis and are composed of (dead stratified squamous) epithelium cells which are rich in protein, especially keratin. Strong nails and glossy hair are considered great signs of health and vitality. From a naturopathic point of view, brittle nails and dry, lifeless hair can be a good indicator that some of the key vitamins and minerals are deficient.

The best vitamins for skin, hair and nails and their mechanisms discussed below:

Vitamin C and Vitamin E may be useful in supporting the integumentary system. There is growing evidence to suggest that oxidative stress is a pivotal mechanism behind hair graying and hair loss (10) thus ensuring these nutrients are adequate should be part of your intervention.

Biotin is one of the B vitamins and has many vital roles relating to the health of skin, hair and nails (11). It helps to protect your skin from water loss and regulates fatty acid metabolism and it has been shown to promote hair growth, particularly in people who are deficient (12). Brittle nails, scaly scalp, hair loss and dandruff can be signs of biotin deficiency.

Vitamin B12 and iron are essential for the production of red blood cells and haemoglobin and deficiency of these nutrients have been implicated in hair loss (13).

Nutrients that are essential in providing the building blocks for hair and nail growth: zinc, iron, copper, selenium, silicon, calcium and magnesium, silica. Proteins are also crucial for the health and vitality of our skin, hair and nails, especially the amino acids methionine, lysine, cysteine, glycine and proline.


What vitamins are good for skin elasticity?


Skin elasticity is the skin’s ability to return to its original shape after stretching. Your skin gets its stretchiness and resilience from two important proteins, collagen and elastin. The loss of elasticity, called elastosis, is a natural part of the ageing process which starts to appear in our 30s or in your 40s - if you’re one of the lucky ones (14). This ageing process is a result of both intrinsic (as with all internal organs) and extrinsic factors (sun exposure, stress, poor nutrition, high alcohol intake, smoking and air pollution) (15). Hormonal changes are also key factors, particularly the natural decline in oestrogen (16) and testosterone (17) production. 

Here are the best vitamins essential for skin elasticity:

Vitamin A (retinol) is converted to retinoic acid in the skin and it has been shown to modulate gene expression and influence cellular processes in both the epidermis and dermis, thereby exerting potent anti-ageing effects on our skin. Vitamin A has a key role in the prevention and treatment of UV-induced skin damage (18), making it the most important vitamin in the prevention of wrinkles and loss of elasticity.

Vitamin C is vital for the formation of collagen and elastin. This great but humble vitamin is also a powerful antioxidant, which means that it can trap free radicals that contribute to many processes of ageing, including loss of elasticity of the skin.

Vitamin E is another skin-friendly antioxidant and has been extensively investigated for its role in UV damage protection (19). Vitamin E appears to improve skin elasticity and vitality.

B vitamins – contribute to the production of collagen in the human body. Studies have shown that deficiency of Vitamin B2 & B6 is directly correlated with low collagen content of the skin so including a good B complex may be beneficial.

Get in touch and find out more about our Skin and beauty IV therapy, available here at our clinic in London.


What vitamins are good for skin with eczema?


Eczema is an inflammatory skin condition, characterised by red, dry and itchy patches. It’s commonly found on the skin of our neck, hands, feet, elbows and the back of the legs. Atopic eczema (atopic means ‘with a genetic predisposition’) is the most common form affecting 1 in 5 children and 1 in 12 adults in the UK (20).

Usually, healthy skin cells are tightly packed together creating a good natural barrier for immune defence. When you have eczema this barrier function is impaired and the skin’s delicate balance of beneficial bacteria is disrupted. This disruption allows toxins and pathogens to enter the skin (a process similar to leaky gut), which leads to an immune response and ultimately to an inflamed, irritated skin.

The best vitamins and nutrients for the management of eczema:

Vitamin D has been shown to alleviate the symptoms of eczema through its immune-regulatory, anti-inflammatory and antimicrobial activities in the skin. Vitamin D deficiency is very common in eczema (21) and supplementation of at least 1000IU daily has been shown to reduce symptoms. Your practitioner will be able to assess your vitamin D levels through a simple finger prick test.

Vitamin A - the great ‘skin-vitamin’ - strengthens the skin’s protective layer and supports healing (22) and has been implicated in the treatment of eczema.

Vitamin E accumulates in the mitochondria within skin cells and promotes collagen and fibroblast synthesis. In a recent study, 400iu of vitamin E significantly improved the severity of eczema symptoms, including itching (23).

Vitamin C has anti-inflammatory properties, it’s a natural antihistamine and due to its effect on collagen production it’s a really useful vitamin for the treatment of eczema. Vitamin C might also help alleviate redness, itchiness and long-term damage to the skin.


Eczema is a multifactorial condition and its development often starts as early as birth so it’s important to approach it with a holistic, in-depth and comprehensive support. Read more about our expert practitioners who can offer more personalised support and advice.


Which is the best vitamin for skin complexion and makes your skin glow?


I’m sure we’ve all met someone who has a beautiful, blemish-free skin with an inner glow and luminance to it. Great skin is a true reflection of our inner wellbeing and you can achieve it by having good nutrition and looking after your physical and mental health.

The best vitamins for a healthy glow and great complexion:

Vitamin C, as mentioned above, is a powerful antioxidant that stimulates collagen production (24) making it your number one ticket to a luminescent skin. When applied topically Vitamin C has been shown to brighten the skin by reducing the appearance of hyperpigmentation.

Vitamin A again. Vitamin A has the ability to even skin tone and to give your skin a beautiful, healthy glow.

Biotin, helps to protect your skin from water loss and regulates fatty acid metabolism, giving your skin a healthy complexion.

Vitamin B3 is known to increase keratin, a protein that keeps your skin firm and healthy.

Glutathione  is one of the most important ‘free radical scavengers’ in the human body. This great antioxidant has been shown to reduce the appearance of wrinkles, hyperpigmentation and melasma (25).


IV- nutrient therapy with glutathione can give your skin a natural ‘refreshed’ glow and may even reduce pigmentation and redness of the skin.


Do Multivitamins help skin?


A well-balanced multivitamin that contains the key nutrients discussed above can be a great tool to support your skin health and your overall wellbeing. Choose a carefully formulated complex that is effective, pure, ethical and contains therapeutic doses of vitamins and minerals in their most bioavailable and easily absorbed from. Look for Vitamin D3 vs D2, methylfolate vs folic acid, iron citrate vs iron sulphate and so on. For the best skin support, choose a good multi that contains the most important nutrients: vitamins A, C, D, E, B complex, zinc, iron, selenium and chromium. Any plant derived antioxidants like green tea, rosehip, blueberry, turmeric is a bonus!


Have you tried IV nutrient therapy before? Here, at the London Clinic of Nutrition, we offer a range of conventional and bespoke infusions to revitalise our clients’ health and help them reverse chronic disease. Find out more here.


Dietary and lifestyle considerations for a healthy and glowing skin

Foods for skin health
  • If your skin complaints continue to persist, consider eliminating allergens such as wheat, dairy and eggs.


  • Include probiotic rich foods such as kombucha, kimchi, sauerkraut, fermented tofu and kefir to support the skin’s (and gut) microbiome.


  • Take a good quality and pure omega 3 supplement to support skin hydration and regulate inflammatory response of the skin (26).


  • Consider supplementing with marine collagen, a natural source of type 1 collagen that is easily absorbed.


  • Support methylation and detoxification with vitamins and minerals like methylfolate, methylcobalamine, vitamin B6, zinc and copper.


  • Consume organic produce wherever possible.


  • Although sun exposure is vital for vitamin D production and our circadian rhythm, a sensible approach is recommended to avoid sun damage.


  • Protect your skin from damage with antioxidants. Eat plenty of vegetables and (some) fruits of rainbow of colours. Particularly green and orange ones for their carotenoid and polyphenol content.


  • Include protein rich foods - protein supports the growth and maintenance of collagen and elastin fibres. Amino acids proline and lysine work together with vitamin C to enhance the formation of collagen.


  • Choose more natural household products to minimise exposure to environmental toxins.


  • Manage stress through mindfulness, meditation and yoga. Improve sleep hygiene by reducing blue light in the evenings.


Consult one of our expert team members to discuss functional tests to assess gut issues, liver function, hormonal irregularities and genetic predisposition for vitamin inefficiencies (for example MTHFR and VDR).


Call us today on 020 3332 0030 and a member of the team will be available to answer any queries you have.



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