Suffering from acne? Discover the curative effects of your gut microbes


60 second summary

  • Probiotics are microorganisms beneficial for maintaining a healthy gut bacteria community
  • Acne can be caused by hormonal and inflammatory imbalances
  • Supplementing with fermented foods such as yoghurt and saukraut may balance cells in the body responsible for inflammation control.

What causes acne?

Acne is a skin condition affecting 85% of individuals between the age of 12 and 25.

The science: It is can be caused by several factors: excess secretion of sebum, an oily substance produced by the skin; release of molecules causing inflammation or hyperkeratosis.

Hyperkeratosis-  when the protein keratin builds up in the connective tissue surrounding a hair.


Acne is a multifactorial disorder which means several aspects of your life can influence whether you acquire it. One suggestion is a diet too high in refined carbohydrates because of their high glycemic load.

Glycemic load- a measurement of the quantity of sugars in a portion of food alongside how fast it raises your blood glucose levels.[1]

The science: A diet with a high glycemic load is known to increase acne-triggering molecules such as IGF-1 (insulin like growth factor 1). Additionally IGF-1 promotes release of hormones such as testosterone with increases production of oils in the skin.[2]


The usual treatment for acne is the use of broad spectrum antibiotics yet this is not only a long process but also comes hand in hand with side effects such as unpleasant changes in skin color. Over the past few years the use of probiotics to treat skin conditions has become a hot topic in medical research. Probiotics are microorganisms which can alter and restore health to your gut microbiome due to their anti-inflammatory and anti-microbial effects.

In one study on 300 patients supplemented with L. acidophilus and Lactobacillus bulgaricus, 80% of the patients showed clinical improvement in their acne. In another experiment patients taking Lactobacillus and Bifidobacterium supplements in addition to antibiotics had significantly less acne lesions than the group just on antibiotics.


Probiotics are known to decrease inflammation through regulating the release of molecules like interleukin 1 alpha, a type of pro-inflammatory cytokine.

Inflammatory cytokines- substances affecting the body’s reaction to infection and disease and can be pro-inflammatory, making the disorder worse or anti-inflammatory, promoting healing.

The science: Therefore by decreasing release of interleukin 1 alpha, probiotics can decrease skin trauma.

Another mechanism by which probiotics act is by balancing the ratio of cells important in immune function such as T cells, where T stands for thymus because it is where the cells mature. Effector T cells defend the body through mechanisms like cell death, whilst regulatory T cells suppress the formation of effector T cells. An imbalance between these may lead to autoimmune disorders, one of which is of course acne.

Acne and stomach acid?

Another association between acne and gut microbe problems relates to the hydrochloric acid in one’s stomach. The acid’s function is not only to help in food digestion but also to prevent growth of unwanted bacteria. Studies have shown people with acne and inflammation of the skin are likely to have hypochlorhydria.[3]

Hypochlorhydria- production of too little hydrochloric acid.

The science: This leads to the migration of microbes from the large intestine ( the terminal part of the digestive tract) upwards, to the small intestine where they can impair one’s absorption of nutrients like zinc. Research has confirmed people with acne have lower levels of zinc in their blood than those with clear skin. [4]

The bacteria shown to control acne to the greatest extent are: Staphylococcus, Streptococcus, Lactococcus, Lactobacillus, and Enterococcus. Interested in controlling your outbreaks? Try supplementing your diet with probiotics such as:

1. Kefir

2. Sauerkraut

3. Pickles


[1] (n.d.). Glycemic Load. [online] Available at: [Accessed 10 Jul. 2019].

[2] International Journal of Microbial Sciences. (2017). Edible Plants and Their Influence on the Gut Microbiome and Acne. Available at: [Accessed 10 Jul. 2019].

[3] PMC. (2018). The Gut Microbiome as a Major Regulator of the Gut-Skin Axis. Available at: [Accessed 10 Jul. 2019]. c

Your gut bacteria on fermentation: a matter of survival


60 second summary

  • Fermentation is the process by which bacteria release energy
  • Its it is important in allowing the recycling of molecules to restart the biological cycle for energy release
  • Fermented food tastes sour because of the lactic acid produced by bacteria in fermentation

Fermentation- a word we commonly hear associated with yoghurt, beer, sauerkraut and more. But what does it actually mean? Fermentation is a type of biological mechanism called respiration, which you’ll be an expert on after reading the below article.

What is respiration?

Respiration- the release of energy in living organisms

Overall, this may be classified into to main categories:

  • Aerobic respiration= with oxygen
  • Anaerobic respiration and fermentation= without oxygen.

Some cells are unable to respire using oxygen because they do not have the correct genes or enzymes required . An example or a anaerobic bacterium is E.coli.

Some organisms have evolved the adaptation that if environmental conditions change and oxygen does become available, they may switch on genes allowing them to respire aerobically .[1] These are called facultative organisms.

ATP- the energy currency in cells

In cells some ATP is produced via a mechanism called glycolysis, which is a fancy word for the breaking down of the sugar glucose.

If oxygen is present, aerobic respiration can occur. If it is not either fermentation or anaerobic respiration occurs.

The main difference between the two is that the fermentation produces lactic acid ( which is what causes cramps during exercise! )whilst anaerobic respiration’s final product is a molecule called pyruvate.

Glycolysis can continue again and again in an endless cycle even without any oxygen. But how can this be?

Surely all organisms need oxygen to survive? The answer is that required molecules are regenerated, essentially a recycling system. Many biological systems work on opposites to balance reactions out.

The science– In glycolysis a molecule called NAD+ is reduced forming NADH. Later the same molecule is oxidised reforming NAD+ [2].

Oxidation= loss of electrons

Reduction= gain of electrons

They are opposites!

Energy production in respiration with vs without oxygen

Respiration without oxygen releases 2 molecules of ATP per glucose molecules. This may seem reasonable but in the presence of oxygen 38 ATP’s per glucose can be formed, making aerobic respiration much more efficient.

Fermented foods

One of the reasons why many fermented foods taste sour is because of lactic acid produced as a by product of fermentation.

The science: The equation which summarises the process, is as follows:

Pyruvate  +  NADH ↔ lactic acid  + NAD+ [3]

Note that the through fermentation the NAD+, a substrate in the initial step of glucose breakdown mentioned above, is reformed!

Common lactic acid producting bacteria include Lactobacillus Leuconostoc and Streptococcus.

Types of fermentation

Overall there are 2 types of fermentation.

  1. Homolactic fermentation- where the only product is lactic acid. Commonly used in yoghurt production
  2. Heterolactic fermentation- where lactic acid, ethanol and carbon dioxide is produced. Seen in fermentation of vegetables like cucumbers into pickles.

The particular flavour of each fermented food is determined by the types of other organic acids produced in side reactions.

Overall, fermentation is an essential pathway for keeping bacteria alive as it allows the regeneration of molecules for respiration, the release of energy. Humans take advantage of this process by fermenting foods which portrays its benefits as an ancient preservation process as well as taste enhancer and a superb probiotic!

[1] Openstax. (n.d.). Microbiology. [online] Available at: [Accessed 10 Jul. 2019]. [2] Thoughtco. (2019). The Difference Between Fermentation and Anaerobic Respiration. Available at: [Accessed 10 Jul. 2019].

[3] Pink Monkey. (n.d.). Fermentation. [online] Available at: [Accessed 10 Jul. 2019].

Reduce your cholesterol levels with probiotic kefir


60 second summary

  • Kefir is a drink made by fermenting milk
  • Lactobacillus is one bacteria thought to decrease cholesterol levels
  • Gut microbes can ever alter cholesterol production by altering our DNA through the release of molecules called short chain fatty acids

What is kefir?

Kefir is a type of fermented cow’s milk drink with a slightly acidic flavor and thick consistency. Its unique texture is caused by kefiran which is an exopolysaccharide.[1]

Exopolysaccharide-  a large molecule made of sugar which are secreted by microbes into the extracellular environment.

Its health beneficial functions are driven by its ability to balance out communities of gut bacteria, a feature shared by other probiotic foods such as yoghurt and saukraut.

How is kefir made?

Commercially, kefir is made in bulk by fermenting milk using starter cultures of microbes which allows the products to be consistent but traditional kefir making requires a kefir grain. [2]A kefir grain is made up of long sugar chains such as kefiran mentioned above. It provides a perfect environment for the proliferation of yeast cultures and bacteria which live in a symbiotic relationship in other words, a close physical association.

The main bacterial strains include Lactobacillus , Lactococcus ,Streptococcus and Leuconostoc, whilst the main yeast species are Saccharomyces, Kluyveromyces, and Candida.[3]

One of kefir’s most studied properties is its effects on cardiovascular health in particular cholesterol levels.

Cholesterol – type of lipid and despite its often negative connotations, is an essential component of cell membranes and a precursor in production of molecules such as vitamin D.

Kefir and cholesterol synthesis modification

The science: Cholesterol can of course come from diet but 80% of it is produced in the liver and intestines. High cholesterol, also called hypercholesterolemia, is dangerous because it may form fatty deposits in arteries leading to them narrowing and potentially becoming obstructed. In experiments with animals, fermented milk products have shown to decrease serum cholesterol levels by 41-84% , decrease its production by the liver, as well as increase its excretion as bile, a dark yellow fluid.

Serum cholesterol- measurement of blood cholesterol levels

Which bacteria in kefir is thought to affect cholesterol levels?

On of the main bacterial strain thought to be majorly responsible for the altered biological mechanisms is Lactobacillus.[5]

Lactobacillus is a type of probiotic which resides in areas of the digestive tract like the small intestine where it affects the metabolism of bile acids and cholesterol.

The science– In the intestine Lactobacillus is able to produce enzymes which deconjugate bile acids, increasing the rate by which they are excreted from the body.

Deconjugation- a reaction disrupting a system of conjugated double bonds

Cholesterol itself is made of bile acids and to replace the bile which was excreted, it converts itself to the acids thereby reducing its overall concentration.[7]

Other excreted products also include propionic acid which decrease cholesterol synthesis by inhibiting one of the steps in the biosynthesis pathway. [4]

How do bacteria affect cholesterol metabolism on a genetic level?

Molecules released by bacteria in kefir are able to modify the production and degradation of chemicals our body produces naturally.

The science– In one study, the Niemann-Pick C1-like 1 (NPC1L1) gene, a crucial gene in absorption of cholesterol was shown to be downregulated where rats were fed bacteria present in kefir.[6] Gut bacteria can modify production of proteins in our body through release of molecules called short chain fatty acids.

Overall, kefir is a simple and effective dietary component which acts as a probiotic enhancing your gut microbial flora. Interestingly, it is even suitable for those who are sensitive to dairy products because despite being based on milk, the lactose in it is consumed by the culture releasing acids and a pleasant tangy flavour. [8] It should be available to buy in regular supermarkets or in European food stores. Enjoy!

[1] PMC. (2016). The Microbiota and Health Promoting Characteristics of the Fermented Beverage Kefir. [online] Available at: [Accessed 9 Jul. 2019].

[2] Dr Axe. (2019). 7 Kefir Benefits, Including Boosting Immunity and Helping to Heal the Gut. [online] Available at: [Accessed 9 Jul. 2019].

[3] Wikipedia. (2019). Kefir. [online] Available at: [Accessed 9 Jul. 2019].

[4] Karger. (2018). Mechanisms of Action of Kefir in Chronic Cardiovascular and Metabolic Diseases. [online] Available at: [Accessed 9 Jul. 2019].

[5] PLOS ONE. (2018). Cholesterol-lowering effect of Lactobacillus rhamnosus BFE5264 and its influence on the gut microbiome and propionate level in a murine model. Available at: [Accessed 9 Jul. 2019].

[6] Frontiers in Microbiology. (2016). The Microbiota and Health Promoting Characteristics of the Fermented Beverage Kefir. Available at: [Accessed 9 Jul. 2019].

[7] PMC. (2012). Cholesterol-Lowering Probiotics as Potential Biotherapeutics for Metabolic Diseases. [online] Available at: [Accessed 9 Jul. 2019].

[8]Cultures for health. (2019). Reducing The Lactose Content Of Kefir. [online] Available at: [Accessed 9 Jul. 2019].

Prebiotics- an essential for your colon’s health


60-second summary

  • Prebiotics are types of fiber which enhance growth of beneficial gut bacteria
  • Gut bacteria release metabolically important molecules such as short chain fatty acids
  • Short chain fatty acids decrease small intestinal pH, therefore making the lower digestive tract less susceptible to disease causing microorganisms

What are prebiotics?

Prebiotics are types of fiber which escapes digestion in the upper gut and can affect the proliferation and ecosystem of bacteria mostly residing in the large bowel, which feed off our undigested carbohydrates. Generally carbohydrates are classified in terms of their chain length where the prefix is the number of molecules in the chain:

mono- meaning one

di- meaning two

oligo- meaning 3-6

poly- meaning more than six

and the suffix being -saccharide, from Latin saccharum meaning sugar.[1]Our main source of prebiotics comes from oligosaccharides which are plant derived carbohydrates such as beta glucans found in oats. Archaeological analysis of preserved faeces of hunter gatherers has shown us a typical male would consume an average of 135g of inulin a day, a prebiotic found in several root plants such as chicory and garlic. [2]

Main bacteria involved:

The main bacteria involved in the fermentation of prebiotic fiber are Bifidobacterium and Lactobacillus, which contain several genes encoding enzymes that break down carbohydrates. In terms of digestion, these enzymes act as biological scissors, breaking the bonds between individual sugars in a chain so that they may be more easily absorbed.

In comparison to the microbiome the human body itself contains a miniscule amount of its own carbohydrate digesting enzymes: certain bacteria such as Bacteroides thetaiotaomicron can produce 260 alone! The bacteria benefit from this sugar fermenting process because it releases energy which they need for survival and proliferation, such that for every 100g of carbohydrate fermented 30g of bacteria is produced. Our interaction with the bacteria is certainly a two way contract because we too benefit from them releasing important biological molecules such as short chain fatty acids (SCFA).[3]

Short chain fatty acids- fatty acids with less than 6 Carbon molecules produced by bacterial fermentation in the large intestine

Prebiotics and short chain fatty acids

One of the main functions of SCFA is promoting a healthy large intestine. Your large intestine is a tube absorbing water and storing faeces until they are ready to be released. An imbalanced microbiome can’t serve its protective function against inflammatory diseases such as IBS (irritable bowel syndrome) which is estimated to affect 2 in 10 people in the UK[4].

Bowel- section of the digestive tract including the small bowel (small intestine) and large bowel (large intestine and rectum)

Given their acidic nature, Short chain fatty acids decrease the pH of the colon reducing the risk of proliferation of dangerous bacteria. Arguably the most important SCFA for colon health is butyrate which is the preferred metabolic fuel for colonocytes.

Colonocyte- cell lining the large intestine/colon

In laboratory experiments butyrate has also shown to promote DNA repair in colonocytes, reducing the risk of colonic carcinogenesis, in other words cancer of the small intestine. [5]

Common prebiotic food examples

  1. Garlic-11% of its fiber content is prebiotic
  2. Barley-contains 3-8g of beta glucan per 100g serving
  3. Apples– 50% of their fibre contant comes from pectin[6]


Just like with any food, prebiotics should be eaten in moderation. Introducing them to your diet may initially induce bloating and gas production as a result of carbon dioxide and hydrogen gases being produced from bacterial fermentation, but don’t let this put you off! It is only temporary and a sign your microbiome is flourishing but note that if you do feel unusually unwell consult your doctor as soon as possible.

Remodel your microbiome, revolutionise your health, reconstruct your life







An introduction to the microbiome


60-second summary

  • The microbiota is the variety of microbes present that may be found in several places around the body such as skin gut and vagina
  • The relationship between us and many of our gut microbes is mutualistic which means that both sides benefit
  • Immune cells have pattern recognition receptors which can identify pathogen associated molecular patterns present on pathogens.
  • The term “good microbe” is subjective because the same microbe can be anti and proinflammatory in different diseases

What is the microbiota?

Your microbiota is the collection of organisms living in harmony with your own cells. Their genes, outnumbering your own 100 to 1, are called the microbiome. [1]

Gene– sequence of DNA coding for a particular protein

Microbes can be found in a variety of bodily areas such as the skin, conjunctiva (lining of inside of eyelids), gut, bladder, vagina, placenta, uterus, lung, oral cavity and biliary tract.

But what type of microbes are present?

Aside from commonly known bacteria other organisms include fungi, archaea and viruses.

Archaea-a type of single celled organism. Note each human has an average of 37.2 trillion cells!

The 4 main categories or so called phyla of bacteria in the gut are- Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria of which some are pathogenic.

Pathogenic– a microorganism with the potential to causes disease

For instance bacteria in residing in the mouth such as Actinomyces viscosus may contribute to tooth decay by secreting acid which dissolves tooth enamel. In the gut too, certain types of bacteria have been associated with disease such as an increased proportion of the Firmicutes microbe, which has been associated to the development of obesity.

Microbiome and disease?

Dysbiosis– imbalances between different communities gut microbes

Dysbiosis is a key contributing factor to not only the development of diseases affecting the gastrointestinal tract but also neurological and psychological conditions. This is a phenomenon known as co morbidity and evidence has shown that people with depression and anxiety often also have diseases such as inflammatory bowel disease (IBD) and Crohn’s disease.

Crohn’s disease– chronic condition where the lining of the gut is inflammed

In terms of anxiety, it has also been shown that mice raised in environments free of any microorganisms tend to have higher stress levels and portray cognitive deficits. Establishment of a varied gut microbiome from birth is essential and is influenced by a variety of factors including maternal genetics, stress levels and type of birth: babies born by cesarean section typically show to have more pathogenic bacteria such as Escherichia coli. With a lower proportion of beneficial bacteria, it is not frivolous to link a deficient microbiota to the fact that C section born babies are 5 times more likely to develop allergies than their vaginally born counterparts.

These microbes have a special relationship with us as their hosts- a mutualistic one. It used to be thought that the relationship was mostly commensal, meaning that one side benefits and the other neither gains or loses anything. Yet evidence points towards mutualistic friendship, with both sides benefitting. Bacteria are given a habitat and energy supply through our diet and we are provided with a variety of metabolites and chemicals such as Vitamin K, essential for health.

Distinguishing good and bad microbes

In a healthy individual it is crucial for the body to distinguish the beneficial from the harmful microbes and this is regulated by the innate immune system.[2]

Innate immune system– Mechanisms you are born with giving you non specific protection against pathogens

On these cells you may find receptors called pattern recognition receptors which can recognise cellular structures on unwanted bacteria (such as flagellin, a protein common in certain bacteria forming a tail like structure called the flagellum). These cellular structures are collectively called pathogen associated molecular patterns (PAMPs).

When the receptors detect these PAMPs they initiate a variety of responses to try and eliminate the harmful microorganism.[3] One example is the release of a molecule called Interlukin 8 which encourages the recruitment of other immune related cells to destroy the pathogen. [4] Therefore in a healthy individual only pathogenic bacteria will be targeted.

But do our ‘good’ microbes always stay good?

In a recent study in Yale university on individuals with antiphospholipid syndrome scientists found an association between an apparently ‘good’ microbe- Roseburia intestinalis, and inflammation.

Antiphospholipid syndrome- disorder where the body’s immune system destroys a type of protein essential in blood thinning without which a person is at risk of blood clotting.

Experiments in mice even showed that this microbe could trigger the disease implying that a microorganism protecting from one disease may simultaneously induce another. [5]

All in all microbes microbes play a huge role in our health; disease causing or not, they influence our metabolism, mood and longevity.

[1] The Psychobiotic revolution, Scott C. Anderson

[2] BMJ. (2018). Role of gut microbiota in nutrition and health. [online] Available at: [Accessed 5 Jul. 2019].

[3] BMJ. (2018). Human gut microbiome: hopes, threats and promises. [online] Available at: [Accessed 5 Jul. 2019].

[4] Wikipedia. (2019). Interlukin 8. [online] Available at: [Accessed 5 Jul. 2019].

[5] New scientist. (2019). A severe autoimmune condition may be triggered by ‘good’ gut bacteria. [online] Available at: [Accessed 5 Jul. 2019].