The human gut is home to bacteria that help us digest our food, produce vitamins and perform many other tasks that influence our health.

But while most research focuses on benefits from individual microbial species, new research from Kings College London, published in the journal Nature Communications, shows that gut microbial species work in teams to perform different functions. This takes our understanding of the microbiome into a whole new direction, suggesting that cultivating certain groups of bacteria is more important than single species.

The researchers studied the gut bacteria, blood and stool of over a thousand twins who take part in TwinsUK. This allowed the team to run the first large study on the link between gut bacterial species, their functions and the metabolism in the gut and blood of the participants.

The team found that while unrelated people share only 43% of gut bacteria species, they still share 82% of functions carried out by groups of gut bacteria. This is because different bacterial species can contribute to the same function and so different groups can work together to can carry out similar activities.

They then measured hundreds of molecules in the gut and in the bloodstream – representative of microbial and human metabolism – and checked if their abundance was more strongly linked to the presence of particular microbial species or the microbial functions performed by microbial teams.

Again, microbial functions were found to be more important than single microbes, as they showed a larger number of associations with the molecular composition of both gut and blood environments.

A new focus

This research therefore suggests that health treatments designed to target gut bacteria – and our metabolism – should focus on groups of gut bacteria that carry out a particular function, rather than individual bacterial species.

Lead author Dr Mario Falchi, senior lecturer of Bioinformatics at King’s College London, explained:

“We can think of our gut bacteria like Lego bricks – the colour of the bricks doesn’t matter as much compared with how they fit together to make something. With gut bacteria, the individual species don’t matter as much as the group working together to carry out a function.”

“This is the first large study to explore the metabolic potential of the entire gut bacteria ecosystem. Our findings underline the importance of studying groups of bacteria and their functions overall, rather than focusing on specific species. These results add to the growing body of evidence that gut bacteria are intrinsically linked with human health.”

Falchi and colleagues suggest that an extensive dialog goes on between the gut environment and our blood and that 93% of this dialog involves microbial functions. This, they say, which may explain why gut microbes are so strongly linked to our health.

A study conducted by researchers from the US, Canada, France and Israel, has discovered that adults over the age of 60 are significantly cleverer at the start of autumn compared with spring. The difference between the autumn and spring equinox say the scientists, was equivalent to four years of ageing.

The study analysed data involving more than 3,000 people in North America and Europe, most of whom were over 70. They had each been given annual tests of memory and processing speed, with their testing spread randomly throughout the year.

Doctors had assumed that the month the testing occurred was irrelevant, but the paper in the online journal Plos Medicine found that the seasons did matter. In fact, cognitive performance was shown to be higher in the summer and autumn compared with winter and spring. It peaked at the autumn equinox then dropped off until the spring equinox six months later.

Important considerations for dementia testing

For some participants, the researchers also looked at levels of proteins associated with Alzheimer’s disease. This revealed seasonal rhythms in Alzheimer-disease-related proteins in the spinal fluid, and in the expression of specific genes in the brain, giving us a window into the underlying mechanisms.

They found a 30% greater chance of meeting diagnostic criteria for mild cognitive impairment or dementia if cognitive tests are carried out in late-winter or early-spring. “The difference in performance was enough to impact the clinical impression of what diagnostic category a patient was going to be in,” said one of the researchers Andrew Lim, from the University of Toronto.

The team could only speculate on the cause of such a change. Light, temperature, the body’s hormone levels or vitamin D consumption could be to blame, Lim said. But on the bright side, the study opens up the possibility that “good cognition” could be extended beyond that peak time to prevent or slow the onset of Alzheimer’s disease.

One theory is that our lifestyle and health habits vary with the season, we may for instance eat, sleep and exercise differently.

Lead researcher Philip De Jager, from Columbia University, said another theory was that during winter our brains experienced something akin to a mild hibernation. “The underlying rhythms are similar to those that regulate many other mammals and animals,” he said. “They probably help us minimise activity in months when fewer resources are available and take advantage of them at a time when they are abundant.”

• For more on the connection between weather and health see our article Must be the weather

A secondary analysis of the UK National Diet and Nutrition Survey, published in Frontiers in Nutrition, highlights a tendency to report micronutrients intakes collectively for adults, with broad age ranges being used. This means that certain sub-population groups such as younger adults are often overlooked.

The current analysis, which looked at these subpopulations, noted that improvements in dietary quality are needed in young adulthood and mid-life. To achieve this, they note, supplementation strategies could help young adults be where they should be at these ages – in their “nutritional prime.”

The analysis found sizeable deficiencies in several important nutrients. For magnesium in both men and women, 19% of young people in their twenties having intakes below the Lowest Recommended Nutrient Intake (LRNI). There were also considerable gender gaps in dietary selenium intakes, with 50% females and 26% of males having total intakes beneath the LRNI.

Furthermore, a quarter of women had both iron and potassium intakes below the LRNI, while among UK males, vitamin A and zinc shortfalls were apparent.

The researchers say that an adequate micronutrient profile for women is not only important for fertility but also to prepare the body for the extensive physiological demands should pregnancy occur. Selenium, for example, has been highlighted as a crucial nutrient for women seeking to become pregnant.

By increasing their risk of preeclampsia, mothers with low selenium levels may also be at increased risk for heart disease, stroke and high blood pressure later in life. The summary calls for higher levels of supplementation of high selenium yeast to combat heart health threats.

Male fertility at risk too

Zinc, of course, is a known antioxidant with research showing that fertile males tend to have higher seminal zinc levels than their infertile men. Zinc also helps to support immunity and avert age-related diseases.

Zinc shortfalls are somewhat surprising to see, the researchers add, especially among males, given that meat and meat products are one of the main providers of zinc. It is possible that younger men in their twenties are eating less meat which could have contributed to lower zinc intakes in this age group, the researchers note. This is an important finding and worthy of consideration in the context of public health given current trends toward plant-based diets, they explain.

In terms of the low vitamin A intake found in males, the researchers found that young men’s mean intakes of fruit and vegetables were slightly lower at 3.9 portions daily compared with 4.1 portions daily among women aged 19 to 64 years. It has also been found that fruit and vegetable variety tends to be lower in men, especially in instances where education and social class is lower.

Why are levels so low?
Adequate nutrition at this stage of life can also help to future-proof health against debilitating and chronic diseases that can occur in later life.

The researchers suggested that when it comes to women’s nutritional shortfalls, societal pressures around body image could be a factor. They cite a recent survey of 1,035 social media tweets typically used by young adults that found that 67% related to body image, eating disorders, fitness, food or dieting. This, in turn, could have wider ramifications impacting on dietary habits and micronutrient profiles of young women.

Emerging food trends and the avoidance of food groups could also be impacting on micronutrient intakes. For example, the consumption of eggs, milk, and dairy correlates strongly against female nutritional iodine status while veganism has also been found to impact on vitamin D, calcium and vitamin B12, iodine and selenium intakes. They further add that UK females having diets lower in red meat (less than 40 g daily) have reduced micronutrient intakes, especially zinc and vitamin D.

“It is imperative to continue raising awareness about the importance of healthy and balanced diets and adequate micronutrient intakes. The implications of ‘cutting back or cutting out’ certain food groups also need to be communicated, especially to younger generations who are strongly influenced by social media which is not subject to peer review or monitoring systems,” says author Dr. Emma Derbyshire, Public Health Nutritionist and an advisor to the Health & Food Supplements Information Service (HSIS).

A daily insurance policy
The current research found that females and young adults are at particular risk of micronutrient shortfalls. In an environment, where the public are being encouraged to reduce their energy intakes, it is important to ensure that younger people get the nutrient they need sand that multivitamin and mineral supplements could help.

Supplement, of course, are no substitute for a healthy diet, but as the nutrient content of our food declines and food fads become more prevalent, they may be an important insurance policy for health. For information on choosing the best supplements see our article What to look for in supplements.

Burnout is an increasingly common experience in a busy world. According to US research, fatigue affects 25% of adults and can produce troublesome symptoms like lack of energy, always feeling tired, and lapses in memory and concentration.

However in a new study, published in Minerva Medica​​​, a daily dose of oak wood extract from France (sold under the name Robuvit) for four weeks was associated with lower feelings of fatigue and improved tolerance in young surgeons and business managers.

Participants included 42 young surgeons in training and 66 managers. Over a 4 week period half were given 300 mg per day of Robuvit and half were given standard management focused on maintaining and improving interactions, professional ability, and retraining to make them able to operate with satisfaction and efficiency.

Reducing the stress and strain

The data indicated that Robuvit supplementation helped to alleviate fatigue (43% improvement in the surgeons and 27% in the managers), improve tolerance levels (45% improvement in the surgeons and 31% in the managers, versus between 0 and 13% in the control group), and reduced feelings of strain from interactions (21 % for the surgeons and 12 % for managers, compared to a worsening in both control groups).

Both groups also experienced improved feelings of satisfaction in their career path (31% and 35% for surgeons and managers, respectively, compared to worsening scores in the control groups).

Plasma free radicals levels, used as a marker of oxidative stress, also improved in both groups – by 11% in the young surgeons and by 19% in the managers – while no significant changes were observed the control groups.

“In this pilot supplement study on BOS [burnout syndrome] – a condition not easy to evaluate, measure or manage – Robuvit appears to control fatigue (the primary symptom in these groups) and the associated oxidative stress with most important symptoms associated to BOS,”​ wrote researchers led by Dr Gianni Belcaro from Irvine3 Labs in Pescara, Italy.

A flavonoid-rich extract

Tea consumption has been shown to have many benefits on mood and attention, such as improving relaxation and concentration, reducing tiredness and psychological distress. But now scientists in Japan are looking in to not just at overall benefits of tea, but how specific components that make of the flavour and aroma of tea might influence health and wellbeing.

In a small study, published in the Journal of Physiological Anthropology​, researchers at the University of Shizuoka, Chubu University, Mitsui Norin Co Ltd and Tokai University conducted a study to determine the effects of two kinds of black tea aromas on physical and psychological stress.

They recruited 18 healthy student volunteers (5 males, 13 females) aged around 21 years, and subjected them to a stressful psycho-diagnostic mathematics test which needed to be solved within 30 minutes. This was split into two 15-minute sessions. In between sessions, participants had one minute to inhale either black tea aroma (Assam or Darjeeling), or be exposed to warm water as a control.

The students were told to avoid consuming anything except water for three hours prior to the start of each trial.

The researchers then salivary levels a stress hormone chromogranin-A (CgA, a protein found in and released from neuroendocrine cells in response to stress) to determine the effect of inhaling black tea aroma in the participants.

They reported that compared to those in the control group, those who inhaled black tea aroma had lower salivary CgA concentration levels after half an hour of mentally stressful tasks.

Aromatherapy in a cup

They added that both the teas had the same effect, despite Darjeeling tea aroma having a higher concentration of anti-stress components, including hexanal and hexanol (green, herbaceous aromas, with some citrus notes), which have been reported to reduce mental stress response in laboratory animals, and linalool (a clean light floral also with citrus notes), which has sedative effects.

These same compounds are present in many essential oils which are also known to have anti-stress properties including vetiver, mandarin and other citrus oils, neroli, lavender and basil.

Olive oil – the aroma of which has been found to induce a feeling of satisfaction and fullness after a meal – is also rich in hexanol and hexanal.

The researchers noted that although the anti-stress effect of black tea aroma did not differ between the two types of tea the high levels of anti-stress aromatics in Darjeeling tea decreased the tension and/or anxiety more quickly.

“The above results indicated that inhaling black tea aroma may diminish stress levels caused by arithmetic mental stress tasks, and Darjeeling tea aroma tended to improve (the) mood before mental stress load.​

“More studies elucidating the mechanism of anti-stress responses are needed to help improve human adaptability stress…and to create a healthy and comfortable living environment.”​

• See also How to brew the healthiest cup of tea and Hot tea or cold tea – which is healthiest?

“It has been shown that RA-associated antibodies, such as anti-citrullinated protein antibodies, are present well before any evidence of joint disease. This suggests they originate from a site outside of the joints,” said study author Dr Kulveer Mankia of Leeds Institute of Rheumatic and Muscoskeletal Medicine and the Leeds Biomedical Research Centre.

“Our study is the first to describe clinical periodontal disease and the relative abundance of periodontal bacteria in these at-risk individuals. Our results support the hypothesis that local inflammation at mucosal surfaces, such as the gums in this case, may provide the primary trigger for the systemic autoimmunity seen in RA.”

Mankia presented the results of his work at the recent Annual European Congress of Rheumatology (EULAR 2018).

Gum disease a consistent risk factor

The study included 48 at-risk individuals. Their level of risk was determined by the for anti-citrullinated protein antibodies, musculoskeletal symptoms but no clinical synovitis (inflammation of the synovial membrane). It also included 26 patients with RA and 32 healthy controls. The three groups were balanced for age, gender and smoking.

In results from the study, dentists diagnosed clinical gum disease in significantly more at-risk individuals than in healthy controls (73% vs. 38%). In addition, measurements of pocket depth, bleeding on probing, periodontal disease, and active periodontal disease, were all significantly greater in the at-risk individuals compared to controls. Even in non-smokers, periodontal disease and active peridontal disease were more prevalent in at-risk individuals compared to controls.

Another step towards prevention

Rheumatoid arthritis is a chronic inflammatory disease that affects a person’s joints, causing pain and disability. It can also affect internal organs. Rheumatoid arthritis is more common in older people, but there is also a high prevalence in young adults, adolescents and even children, and it affects women more frequently than men.

The prevalence of gum disease is increased in patients with RA and could be a key initiator of RA-related autoimmunity. This is because autoimmunity in RA is characterised by an antibody response to citrullinated proteins and the oral bacterium Porphyromonas gingivalis (Pg) is the only human pathogen known to be involved in the generation citrullinated proteins.

Gum disease is a known risk factor for chronic inflammatory diseases such as diabetes and cardiovascular disease, and there is also previous research to connect it with and rheumatoid arthritis. It has also recently been linked to a higher risk of cancer.  This data adds to what we know about the interactions between what are often considered separate parts of the body and body systems and the importance of whole body health.

“We welcome these data in presenting concepts that may enhance clinical understanding of the key initiators of rheumatoid arthritis,” said Professor Robert Landewé, Chairperson of the Scientific Programme Committee, EULAR. “This is an essential step towards the ultimate goal of disease prevention.”

• See also Naturally healthy teeth and gums and Beyond brushing – healthy teeth and gums protect the body in multiple ways

It’s long been assumed that their benefits stem from the healthy oils found in nuts. But according to a new study from the University of Illinois, the way walnuts impact the gut microbiome – the trillions of bacteria in the gastrointestinal tract – may be behind some of those health benefits.

Walnuts are just one of a number of foods that contain dietary fibre and have interested scientists for their impact on the microbiome and health. Dietary fibre acts as a food source for gut microbiota, helping the bacteria to do their jobs – breaking down complex foods, providing us nutrients, or helping us feel full, for example.

Fruits, vegetables, whole grains, nuts, and legumes are important plant sources of dietary fibre. Eating a variety of these foods helps promote a diverse gut microbiota, which in turn helps to support health.

Findings from the study, published in The Journal of Nutrition, show that consuming walnuts not only impacted the gut microbiota and microbial derived secondary bile acids, but also reduced LDL-cholesterol levels in the adults participating in the study; good news for cardio, metabolic, and gastrointestinal health.

Beneficial metabolites

“We found that when you consume walnuts it increases microbes that produce butyrate, a beneficial metabolite for colonic health. So the interaction of walnuts with the microbiome is helping to produce some of those health effects,” says Hannah Holscher, assistant professor of food science and human nutrition at University of Illinois, and lead author of the study. “It is about getting to the ‘black box’ that is all the microbes in our GI tract to see how they are interfacing with the food we eat and having downstream health effects.

“Some of those health effects are hypothesized to be related to the metabolites bacteria produce,” she adds.

For the controlled-feeding study, 18 healthy male and female adults consumed diets that either included no walnuts or 42 grams – about a third cup or a palm-full – of walnuts for two, three-week periods. Faecal and blood samples were collected at the beginning and end of each period to assess secondary outcomes of the study, including effects of walnut consumption on faecal microbiota and bile acids and metabolic markers of health.

Walnut consumption resulted in higher relative abundance of three bacteria of interest: Faecalibacterium, Roseburia, and Clostridium.

“The microbes that increased in relative abundance in this walnut study are from one of the Clostridium clusters of microbes, and there’s increased interest in those because they have the ability to make butyrate,” Holscher says. “Unfortunately in this study we didn’t measure butyrate, so we can’t say that just because these microbes increased that butyrate did increase. We still need to answer that question.

Reducing inflammation

“There is a lot of interest in Faecalibacterium because it has also been shown in animals to reduce inflammation. Animals with higher amounts also have better insulin sensitivity. There is also growing interest in Faecalibacterium as a potential probiotic bacteria, and so we are trying to follow up on foods that help support Faecalibacterium.”

The findings also show, with walnut consumption, a reduction in secondary bile acids compared to the control. “Secondary bile acids have been shown to be higher in individuals with higher rates of colorectal cancer,” Holscher explains. “Secondary bile acids can be damaging to cells within the GI tract, and microbes make those secondary bile acids. If we can reduce secondary bile acids in the gut, it may also help with human health.”

Previous research that prompted this microbial research showed that the amount of energy (calories) derived from walnuts after we eat them is less than previously thought.

“When you do calculations to determine how much energy we predicted we would get from eating walnuts, it didn’t line up with the energy that was absorbed,” Holscher says. “You’re really only absorbing around 80% of the energy from walnuts that labels say. That means that the microbes get access to that extra 20% of calories and the fats and fibre left in them, and so what happens then? Does it produce a positive health outcome, or a negative health outcome? Our study provides initial findings that suggest that the interactions of microbes with the undigested walnut components are producing positive outcomes.” Holscher says.

Oedema is a major risk factors of deep vein thrombosis (DVT) and can result from lack of activity or being confined in a small space, like an airplane or car, for long periods of time. Those who are overweight, smoke, have high blood pressure or are taking the combined contraceptive pill or hormone replacement therapy (HRT) are most at risk.

DVT can be painful and, given the risk of a blood clot, it can be dangerous as well so finding ways of controlling it are important.

A natural solution

For the he study, published in Minerva Cardioangiologica, the Italian research team tested 295 people at varying risk levels for thrombosis, flying in economy class twice a week for more than eight hours. Participants were divided into three groups – a control group, a group wearing compression stockings and a group supplementing with Pycnogenol. These participants supplemented with 150mg of Pycnogenol daily during the three days leading up to their travel, and the three days following.

The supplement dose in this study was 150 mg per day delivered in three capsules per day. Supplementation started three days before the flights and stopped three days after the second flight.

Study participants were tested using D-dimer tests to detect blood clots and ultrasound scanning to study vein compression before and after each flight. Results show that those who supplemented with Pycnogenol experienced greater reduction of oedema in the lower legs and ankle circumference compared to control groups.

There was also a significant decrease in leg pain after flights (6% in those taking Pycnogenol compared to 19 and 17% respectively in the compression stocking and control groups).

Easing jet lag too

In addition to the reported benefits for oedema symptoms, participants in this new research also showed notable improvement in jet lag symptoms including improved sleep quality and cognitive function, reduced fatigue and visual impairment, better body clock synchronisation.

Pycnogenol is powerfully antioxidant and decades of research has shown it can boost blood circulation and act as a natural anti-inflammatory. This new study supports previous research – much of it performed by the same Italian team, linking the extract to better conditions post-travel, such as reduced venous thrombosis​​ and improvements in jet lag symptoms​​.

Pycnogenol supplements are widely available in health stores.