Category: Longevity & Health

What are Probiotics?

Probiotics are the beneficial bacteria that inhabit our bodies. They can assist with digestion, immunity, brain function, metabolism, sleep and neurotransmitter production to name but a few areas of health. Some can inhibit and crowd out pathogens too. In essence, they are a cornerstone of good systemic health.

“Probiotics are live microorganisms which, when administered in adequate amounts, confer a health benefit on the host.”

-The International Scientific Association for Probiotics & Prebiotics consensus statement on the scope & appropriate use of the term probiotic.

There are many intriguing questions yet to be answered and the science is provisional, so when below, I associate a benefit with a particular bacterial strain, that’s what recent research has suggested. Despite a great many studies, no health claims for probiotics are yet permitted by regulatory authorities in the UK or Europe.

Research is challenging because each of us has a unique community of microorganisms living in and on us (the microbiome) and it has been shaped by diet, exercise, age and stress. Some good quality research into the benefits of certain bacterial strains, is now emerging however.

Some common bacterial strains & what research suggests about their benefits

Lactobacillus (actually over 200 species) is naturally present in the gut, mouth and vagina (3). It can help preserve gut barrier integrity, modulate the immune system and help guard against digestive discomfort. It converts sugars to lactic acid, creating an acidic environment which limits pathogens. In the gut, it produces vitamin K2 (3) which helps guide dietary calcium to our bones, so it may be useful in osteoporosis.

Lactobacillus acidophilus can stick to the intestinal wall and prevent overgrowth of pathogenic bacteria. It may help acute gastroenteritis, as in food poisoning, and may shorten the duration of diarrhoea (4). It may help IBS (5).

Lactobacillus rhamnosus (now renamed Lacticaseibacillus rhamnosus, although probiotic product labels often still use the old name) can benefit gut resilience, vaginal health and IBS. It may be as helpful for bloating as a low FODMAP diet (6). It may provide cognitive support in older adults (7). It may also enhance sleep duration and efficiency. A small four week trial suggested it helped students with exam stress (1). It may also help diarrhoea associated with both travel and a course of antibiotics (2).

Lactobacillus plantarum benefits immune equilibrium, reducing pro-inflammatory cytokines and increasing anti-inflammatory cytokines. It may benefit healthy adults, and also those whose overall health comes under mild stress, from students to athletes (8). It has been associated with small improvements in fasting glucose and insulin stability so may be helpful in type 2 diabetes. It may give a modest reduction in visceral fat ie the fat which is deep in your abdomen surrounding your vital organs, and higher levels of which are unhealthy.

Bifidobacterium (9) may help us digest fibre and produce short chain fatty acids which are good for health. It may assist with gut barrier integrity, immune modulation and healthy ageing.

Bifidobacterium bifidum may adhere to the intestinal lining and ease us through digestive issues brought about by travel or dietary changes. It may assist with chronic constipation and combat an overgrowth of pathogenic bacteria, namely some strains of prevotella, which have been associated with inflammation and autoimmune disease.

Bifidobacterium animalis subsp. lactis may help with stool frequency and consistency. It survives stomach acid, and seems useful for immune balance in later life. For acid reflux, it may be as good as PPI drugs eg omeprazole (10).

Bifidobacterium longum may improve sleep quality (11).

One more strain that may be of interest is streptococcus thermophilus because it supports the growth of lactobacillus and bifidobacterium. It may also aid lactose digestion in those people with mild intolerance, and promote immune system balance.

I’m interested in a particular bacterial strain: which products would I find it in?

One or two particular benefits in the above lists may have caught your attention, so let’s look and see what is contained in some easily-available supermarket products: Yeo Valley yoghurt, Onken yoghurt, Biotiful kefir, and if you’re dairy-free, The Coconut Collab yoghurt.

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I’ve confined this small review to fresh products found in the chiller cabinet rather than bacteria capsules that come in a bottle. My preference is for real food where appropriate.

My suggestion would be you simply experiment. If you haven’t had any probiotic products before, start with small quantities daily and anticipate a possible alteration in your bowel habit as your microbiome adjusts.

References

(1) Probiotic-mediated modulation of gut microbiome in students exposed to academic stress: a randomized controlled trial. nature: npj biofilms & microbiomes, 21 July 2025.)

(2) The Potential Impact of Probiotics on Human Health: An Update on Their Health-Promoting Properties. Microorganisms, 23 January 2024.)

(3) Importance of Lactobacilli for Human Health. Microorganisms, 21 November 2024.)

(4) A Systematic Review & Meta-Analysis: Lactobacillus acidophilus for Treating Acute Gastroenteritis in Children. Nutrients, 6 February 2022.

(5) A 2-strain mixture of Lactobacillus acidophilus in the treatment of irritable bowel syndrome: A placebo-controlled randomized clinical trial. Digestive & Liver Disease, May 2020.)

(6) Ehealth: Low FODMAP diet vs Lactobacillus rhamnosus GG in irritable bowel syndrome. World Journal of Gastroenterology, 21 November 2014.

(7) Cognitive and Emotional Effect of a Multi-species Probiotic Containing Lactobacillus rhamnosus and Bifidobacterium lactis in Healthy Older Adults: A Double-Blind Randomized Placebo-Controlled Crossover Trial. Probiotics & Antimicrobial Proteins, 27 June 2024.

(8) Meta-Analysis: Randomized Trials of Lactobacillus plantarum on Immune Regulation Over the Last Decades. Frontiers in Immunology, 22 March 2021.

(9) Bifidobacteria and Their Role as Members of the Human Gut Microbiota. Frontiers in Microbiology. 15 June 2016.

(10) Efficacy of Bifidobacterium animalis subsp.lactis BL-99 in the treatment of functional dyspepsia: a randomized placebo-controlled clinical trial. nature – nature communications, 3 January 2024.

(11) Bifidobacterium longum 1714 improves sleep quality and aspects of well-being in healthy adults: a randomized, double-blind, placebo-controlled clinical trial. nature – scientific reports, 14 February 2024.

Introduction

Here, I offer you a brief insight into ancient Chinese wisdom, and show with the aid of some examples, how well it resonates with the results of modern medical research. If you take away a flavour of this short article and change just one thing in your life as a result, then your time reading it will have been well spent.

The Chinese have long been interested in lengthening life and maintaining youth, and this has informed medical practice since ancient times. “Chang shou” or long life, is considered a blessing of heaven: it is a reward to be reaped for following the teachings of traditional Chinese medicine, about work, rest, diet, dress etc. (For some specific examples of these teachings, please read some of my Seasonal Tips.)

The idea of such preventative medicine appears in the classic texts of two millennia ago: “To wait for the battle before forging the weapons, to wait until one is thirsty before digging the well, is this not too late?” It is often said that people in those days, would therefore attend for acupuncture and advice at regular intervals during the year, most usually at the change of seasons, because that is when we are more vulnerable to imbalance.

Now we shall look at just two categories from a long list which the Chinese refer to as the causes of disease: these will be our emotional life, and our diet/eating habits. Bear in mind that moderation in all things, serves us well: to overemphasise exercise, at the expense of say diet, is not helpful.

Our Emotions & Their Health Implications

“When faced with something exasperating, one should calmly consider which is more important, anger or health.” (Cao Tong, Qing dynasty AD 1644-1912).

Emotions are considered in Chinese medicine, to harm us when we experience them too intensely or for too long: to be annoyed about a speeding ticket the day you have opened the envelope, would be understandable; to be completely enraged, or to still be angry six months later, would not! Indeed modern research shows a bout of intense anger increases the risk of a stroke within 2 hours, by a factor of 14 (Neurology Journal 2004), and increases by a factor of 17, the likelihood of a potentially fatal heart rhythm disturbance (Circulation Journal 2004). By comparison:

“Laughing makes you ten years younger.” (Chinese saying)

If things frequently wind you up, try to practise creating a space between the trigger, and your reaction. You then have a better chance of seeing that you’ve a choice between your old habitual reaction, and a new response which is less harmful to you.

For good health and a sense of well being, we need to promote a harmonious flow of Qi in the body. This is achieved by meditation, relaxation, exercise, happiness, and by cultivating a free flow of all our emotions, such that particular ones do not significantly linger or predominate.

“Flow with whatever is happening and let your mind be free. Stay centred by accepting whatever you are doing.” (Chuang Tzu c. BC369-286)

A lack of the more positive feelings, is seen as equally unhelpful: “People have illness because they do not have love in their life and are not cherished.” (Sun Simiao AD581-682) From the modern medical profession,”Those who feel lonely, depressed or isolated, are 3 to 5 times more likely to suffer premature death or disease. I don’t know of anything else across medicine that has such a broad and powerful impact.” (Dr Dean Ornish, Clinical Professor of Medicine at the University of California.) In the UK nowadays, depression is one of the top five conditions people seek acupuncture treatment for.

Diet & Recommendations on How to Eat

“Taking medicine but neglecting diet, wastes the skill of the physician.”  (Chinese proverb)

Diet is a cornerstone of good health. Chinese medicine can guide not only what we eat, but how we eat it. The ancient Yellow Emperor’s Classic of Internal Medicine, advised “The five cereals are staple food; the five fruits are auxiliary; the five meats are beneficial; the five vegetables should be taken in abundance.” 2500 years later, these priorities resonate strikingly with the UK’s “5-(portions of fruit & veg) a-Day” campaign. Over the centuries, subsequent texts reveal sophisticated developments in the use of food, including the transition to cooked food, made possible by drilling wood to create fire. Yi Yin in the Shang dynasty (BC1600-1046) emphasised that physicians should use the right kinds of food to help cure disease; food had now become equal to medicine.

In essence, we should supplement the mild, bland foods such as rice, vegetables and potatoes, with smaller amounts of nourishing, richer foods, such as fish, meat and dairy. To this can be added modest quantities of stronger flavours from spices or sugar. The balance between all these constituents is not rigid, but depends on our daily activity eg manual labour or lots of sport, versus a desk job. It also needs to accommodate our stage in life eg the growing teenage years, or pregnancy. It should even pay heed to the climate in which we live or work.

Foods today are chosen to support the patient’s Qi, balance yin and yang, and to treat illness. So when recommending particular foods to a patient, an acupuncturist will take account of a host of factors, including the person’s complaint, age, constitution, living and working environment etc. You do not have to be unwell to benefit from advice on the most appropriate diet for you; we should all choose foods which help maintain our health.

Finally, there is how we eat. Never skip breakfast. “People who eat breakfast are significantly less likely to be obese and suffer from diabetes than those who usually do not.” (American Heart Association’s 43rd Annual Conference on Cardiovascular Disease & Prevention). The emerging field of chrononutrition is exploring how the timing of what we eat, affects our health and wellbeing. Research suggests that consuming more of our calories earlier in the day aligns better with our circadian rhythms and supports metabolic health.

Try to take in most of your food up to and including lunchtime. Eat sitting, and relaxed, and not when stressed or angry.

Think about the food you are tasting, rather than devouring an entire plateful absentmindedly. Eat slowly and chew your food well.

“The stomach has no teeth”  (Chinese saying)

Eat only to 7/10 full. After the meal, rub your abdomen with a circular motion, 25 times clockwise then 25 times anti-clockwise. Finally, after a short rest at the table, take a stroll. The Chinese say,”Walk a hundred paces after a meal, and one can live ninety-nine years.”

Below, you will find some modern medical research from which you might wish to take a few healthy living tips.

Doing a mix of exercise every week may be the key to a longer and more healthy life, according to a new American study.

It suggests future health guidelines should promote engagement in a diverse range of activity types, alongside increasing total activity levels.

Research has previously suggested that aerobic exercise improves cardiorespiratory fitness by increasing peak oxygen consumption, but it has little effect on muscular strength. Conversely, resistance training enhances muscular strength without substantially changing peak oxygen consumption. Thus individuals might benefit more from engaging in multiple physical activities with complementary benefits.

Over 111 000 participants who reported engaging in physical activity were followed for 30 years. The cohort comprised over 71 000 women and over 41 000 men. Detailed activity data was collected at the outset in 1986 and thereafter every two years. Activities included walking, jogging, running, cycling, swimming, rowing, tennis and squash. Activities such as weight training, yoga, stretching and gardening were added as the study progressed. In case individuals simply reduced activity because of illness, the researchers stopped updating activity data if participants developed  diabetes, cardiovascular disease, cancer, respiratory disease, or neurological problems.

The key finding was that physical activity variety was inversely associated with all cause mortality, so a greater mix of exercise is associated with a longer life. Compared with the reference group, participants ranked highest for both total physical activity and variety had 21% lower mortality.

Up to around 20 hours of activity per week, the team found a lower risk of death from cardiovascular disease, cancer, and respiratory disease then this largely plateaued. (Activities which pushed the resting metabolic rate up more, effectively counted for more hours.)

 For cardiovascular disease and respiratory disease mortality, running, tennis, squash, or racquetball, climbing flights of stairs, and weight training or resistance exercises were associated with significantly lower risk. 

(Physical activity types, variety, and mortality: results from two prospective cohort studies. BMJ Medicine, 20 January 2026.)

Your chronotype describes your natural preferences for when you like to rise in the morning, and the time by which you’d prefer to go to bed at night. You will be aware of your most energetic and productive time of day, and conversely, when you start to lag. Put simply, we’re describing a spectrum running from morning types (larks) to evening types (night owls), with some of the population lying in between.

Due to work and other commitments, our schedules often cannot accord with our natural inclinations. It’s worth thinking about our chronotype because then we can be aware of any associations it may have with a greater tendency towards certain behaviours, imbalances or even disease.

The Different Chronotypes

Chronotype can shift during life: children are often larks, become night owls in their teens, then can shift back in adulthood. Older people may often be larks once again. It can also be influenced by genetics, cultural norms and light exposure.

Around 15% of the population are early risers, and particularly productive from dawn until noon. Another 30% are night owls, and productive at night; creative and artistic types can fall into this category. Most people, that is 40%, are most productive between 11am and 6pm, and their activity aligns with the sun. The final 15% of the population has difficulty establishing a sleep routine. Their productivity window may be from 10am to 2pm.

Insufficient sleep can affect anyone’s health, but if you are a night owl who needs to be up early for work, college or to get the kids ready, then follow all the usual sleep hygiene measures and try to establish a regular bedtime.

Chronotypes and Health

Although chronotype is just one of many health determinants, it’s useful to be aware of some of the associations that research has uncovered. That way, you can try to make sure that other, controllable factors aren’t going to conspire to further increase your risk of developing certain problems. Being a night owl may slightly increase the risk of anxiety, depression, eating disorders, obesity, type 2 diabetes and sleep apnoea for example.

Elderly individuals with an evening chronotype are more likely to be current smokers, have more sleep disturbance, engage in more sleep-interfering behaviours (evening caffeine or alcohol consumption, heavy meals before bedtime), and to have lower physical activity.

A Finnish study found evening types had a 2.5 fold increased risk of developing type 2 diabetes compared with morning types. Evening chronotype may be more associated with diabetes in men and metabolic syndrome in women.

Chronotypes and Eating Habits

Curious dietary patterns have emerged in various studies. Remember these are associations, some of which are not altogether surprising, but causality has not been established. In adolescents, evening types consume more coffee, energy drinks, alcohol and fast food. Young adult evening types can have inadequate intakes of several minerals and vitamins.

Morning chronotypes exhibit greater regularity in their eating behaviour. Adolescent evening types exhibit greater differences between weekday and weekend breakfast times. This is concerning given that patterns at this age can be laid down for life and that irregularity of meal patterns has been identified as a risk factor for cardiometabolic disorders.

Turning to adults, in a UK survey morning types consume 25% more servings of fruit and 13% more servings of vegetables per day compared with evening types. In a Finnish survey, those with a leaning towards the morning chronotype consumed more wholegrains, rye, potatoes and vegetables, while those leaning towards the evening type consumed more alcohol, sugar and chocolate. Evening types were more likely to be smokers, physically inactive, and have lower perceived health quality.

Adults with an evening chronotype skip breakfast more often than do individuals with a morning chronotype, and breakfast skipping has been related to lower physical activity in some studies.

Summary

A good deal of further research will be needed to establish causality in the above health observations. On the face of it, data suggests being a night owl is not particularly good for us. For now, if it just makes you consider how a later bedtime might in subtle ways lead to less healthy habits and eventually poorer health, then this will have been a useful read.

From the traditional Chinese medicine perspective, you may recognise that aligning our rhythms broadly with sunrise and sunset, and cultivating regularity of mealtimes, are principles that have been taught for centuries.

Further reading: (1) Chronotype: Implications for Epidemiologic Studies on Chrono-Nutrition and Cardiometabolic Health. Advances in Nutrition, January 2019. (2) Editorial: Chrononutrition and health. Frontiers in Nutrition, 14 November 2024.

Research from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London, suggests that viewing original works of art in a gallery setting can reduce key saliva markers associated with stress and chronic disease.

Fifty volunteers aged 18-40 were recruited from staff and students at Kings College. Half the group spent twenty minutes viewing original artworks at The Courtauld Gallery in London. The other half viewed reproductions of the same paintings in a matched, non-gallery environment. Participants were monitored for heart rate variability and skin temperature using digital watches to track levels of interest and arousal. Saliva samples were collected before and after viewing.

Levels of cortisol, a key stress hormone, fell by an average of 22% in the gallery group, compared to 8% in the reproduction group. Those viewing original art also had more dynamic heart activity, indicating that art engages the body through both emotional arousal and stress regulation.

Pro-inflammatory cytokines (IL-6 and TNF-alpha), which are linked to stress and a number of chronic diseases, dropped by around 28% for those viewing original art, while no change was observed in the reproduction group. This suggests art has a potential calming effect on the body’s inflammatory responses.

Dr Tony Woods, the study’s senior author from King’s IoPPN said, “Our unique and original study provides compelling evidence that viewing art in a gallery is ‘good for you’ and helps to further our understanding of its fundamental benefits. In essence, art doesn’t just move us emotionally — it calms the body too. Stress hormones and inflammatory markers like cortisol, IL-6 and TNF-alpha are linked to a wide range of health problems, from heart disease and diabetes to anxiety and depression. The fact that viewing original art lowered these markers suggests that cultural experiences may play a real role in protecting both mind and body.”

(The Physiological Impact of Viewing Original Artworks vs. Reprints:
A Comparative Study. Institute of Psychiatry, Psychology and Neuroscience, Department of Psychological Medicine, King’s College London. Kings College News Centre, accessed 28 October 2025.)