An active lifestyle and the microbiome

A targeted combination of beneficial bacteria Streptococcus thermophilus FP4 and Bifidobacterium breve BR03, micronised polyphenols, vitamins B1, B6, B7 and B12 and magnesium.

The combination of probiotic bacteria Streptococcus thermophilus FP4 and Bifidobacterium breve BR03, micronised polyphenols from sweet orange, vitamins B1, B6, B7 and B12 and magnesium was chosen on the basis of their scientifically demonstrated positive effects on performance, as well as on easing the inflammatory reactions associated with training and increasing the overall immune response of active people.

I. Clinical study

• 4-week
• randomised
• double-blind
• placebo-controlled
• in a group of 39 healthy trained men

The study is the first convincing report that supplementation with micronised citrus polyphenols can improve exercise performance, as shown by a marked increase in performance during the exercise test.

Micronised polyphenols for strength and energy

Food supplements are commonly used by athletes to improve their physical performance (1). Supplementation with vitamins, antioxidants, creatine, protein and carbohydrates with the aim of improving performance and muscle recovery has become the subject of great interest in recent years, as these supplements may favourably influence metabolic activity, strength and overall athletic performance (2, 3, 4).

Polyphenols are compounds that occur naturally in plants. They can be divided into various classes on the basis of their chemical structure, the largest group being flavonoids. More recent studies have demonstrated anti-inflammatory and antioxidant effects of polyphenols present in fruit such as blueberries, cherries, pomegranates and citrus fruit (5,6).

Micronisation is a term for the process of reducing particles to a size of less than 10 microns. The particle size of active substances is crucial because it can significantly affect their bioavailability (7).

Most non-micronised polyphenols are not absorbed in the small intestine, because they are too large or bound to fibre. They therefore travel to the colon, where they are broken down by the gut microbiota, producing metabolites that are absorbed into the blood, but with a delay and in limited amounts.

In contrast, micronised polyphenols have a larger specific surface area, which means they dissolve faster in the digestive juices. A larger share of such polyphenols is absorbed already in the small intestine, which leads to a faster and higher appearance of polyphenols (or their aglycones) in the blood (8).

The efficacy of micronised polyphenols from sweet orange on athletic performance was clinically tested in two placebo-controlled, double-blind studies, as well as in two in vitro studies.

Methods

The clinical study was carried out in a group of 39 athletes. The intervention group (n=19) received an oral dose of 500 mg of micronised polyphenols a day, while the placebo group (n=20) received 500 mg of maltodextrin. Energy expenditure and oxygen consumption were measured during a ten-minute all-out exhaustion test.

Results

Performance

As for performance, a significant effect of the micronised polyphenols was observed in the intervention group, with a marked increase in anaerobic performance, followed by a sustained excellent aerobic performance throughout the duration of the exercise (Fig. 1).

A trend towards an increase in peak power during the first 3 seconds of exercise was also observed. In practice this would mean an increase in explosive power at the start of exercise, which is highly relevant for anaerobic sports. In addition, after 4 weeks of supplementation, performance in the intervention group increased markedly compared with placebo, by 5% on average.

Ratio of oxygen consumption (VO₂) to power output

Oxygen consumption (VO₂) in the intervention group and the placebo group did not change from baseline. However, the VO₂/power ratio fell significantly in the intervention group after 4 weeks of supplementation. This change suggests that more energy was generated for the same oxygen consumption, which points to a significant improvement in energy efficiency.

II. Clinical study

• 8-week
• randomised
• double-blind
• placebo-controlled
• in a group of 61 lightly trained participants

The study shows that daily intake of micronised polyphenols led to an increase in anaerobic capacity and peak power during high-intensity exercise in lightly trained individuals without affecting maximum heart rate.

Methods

The study was carried out on a sample of 61 lightly trained healthy men and women. Participants were randomly divided into two groups: a group taking 400 mg of micronised polyphenols (n=30) and a group taking placebo (n=31), with supplementation taking place daily for 8 consecutive weeks. The Wingate anaerobic test was used to assess anaerobic capacity and power at the start of the study, after 4 weeks and after 8 weeks.

Results

The Wingate anaerobic test showed an increased mean anaerobic power after 4 weeks of taking micronised polyphenols, which differed significantly from the placebo group (Fig. 2).

This result adds to an otherwise limited body of literature on the effect of polyphenol supplementation on anaerobic performance in exercise. The study succeeded in showing that an intake of 400 mg of micronised polyphenols for 4 weeks could increase anaerobic capacity in lightly trained individuals with a large effect size.

In addition, a significant increase in peak power (W) during the first five seconds of exercise was shown in the intervention group, which is markedly higher than with placebo (Fig. 3).

Conclusion

Clinical studies focused on athletic performance have shown a significant increase in peak and mean power in both high-intensity and endurance exercise. Thanks to micronisation, they are also absorbed quickly into the bloodstream, which makes it possible to increase performance from the very start of exercise to its end.

Mitochondria as the cell’s engine

All cells in the body need energy to maintain and develop their functions. The energy in them is produced by mitochondria in the form of adenosine triphosphate (ATP). An in vitro study carried out by Maastricht University suggested the ability of hesperetin to increase mitochondrial efficiency in producing larger amounts of ATP (9).

Micronised citrus polyphenols improve mitochondrial efficiency by preventing possible leakage of protons between the intermembrane space and the mitochondrial matrix. This helps maintain a high electrochemical gradient and facilitates the necessary recycling of ADP to ATP under anaerobic conditions. Supplementation with micronised polyphenols may therefore be a promising strategy for recreational and professional athletes who want to increase their strength and improve anaerobic performance.

In vitro study

Introduction

Muscle stem cells, known as satellite cells, are activated in response to intense physical activity or muscle damage. Once activated, they migrate as myoblasts to repair damaged muscle fibres. While normal physiological levels of oxidative stress are necessary for the proper function of stem cells, excessive oxidative stress can reduce their efficiency (10). Polyphenol supplements may help address this problem by reducing oxidative stress and thus supporting muscle repair.

Methods

Muscle cells were cultured with hesperetin, the main active component of the micronised polyphenols, in the presence and absence of oxidative stress (induced by menadione sodium bisulphite).

Results

In cells exposed to oxidative stress, hesperetin increased the expression of myosin heavy chain by 35% compared with cells exposed to oxidative stress alone after 5 days. In addition, treatment with hesperetin in cells exposed to oxidative stress increased cell fusion compared with oxidative stress alone and with the control group.

These findings suggest that hesperetin has potential as a nutritional strategy to support tired muscles after strenuous exercise. Increased expression of myosin heavy chain points to the regeneration and growth of muscle tissue, which helps restore strength and function after strain or injury.

The gut microbiota and training

The gut microbiota plays a key role in human health. A sedentary lifestyle, poor dietary habits and psychophysical difficulties are all linked to gut dysbiosis (11). Given the ability of the gut microbiota to modulate pathophysiological processes, gut dysbiosis has been found capable of inducing various health conditions. For this reason, probiotics, as modulators of the gut microbiota, are a key component to be incorporated into a healthy and active lifestyle in order to strengthen the immune system, focus on gut health and the function of the intestinal barrier, address obesity and metabolic diseases, support mental wellbeing and antioxidant status and, last but not least, improve physical performance and recovery after training (12 - 15).

The training of athletes often includes unaccustomed exercises, particularly eccentric (braking) ones, which cause damage to muscle fibres. The damage occurs when an active muscle is forcibly lengthened, leading to micro-tears and disruption of the muscle membrane. The initial response leads to pain, swelling and a loss of strength, followed by a secondary inflammatory response that is necessary for recovery. Although inflammation promotes the adaptation of muscles to training, athletes in demanding training or competitive conditions may benefit from reduced inflammation and faster recovery in order to maintain performance. Moreover, regular high-intensity training leads to faster adaptation and improved performance.

A randomised, double-blind, placebo-controlled crossover study with a 21-day washout in between, in 15 healthy men, examined what anti-inflammatory effects supplementation with the probiotic bacteria Streptococcus (S.) thermophilus FP4 and Bifidobacterium (B.) breve BR03 has — these having previously been identified as anti-inflammatory and colonising different parts of the digestive tract — and their effect on performance, damage and tension of the skeletal muscle after intense exercise.

Clinical study

• 21-day
• randomised
• double-blind
• crossover design
• placebo-controlled
• in a group of 15 healthy men doing strength training

The results suggest that supplementation with the probiotic strains S. thermophilus FP4 and B. breve BR03 eases the decline in performance and muscle tension in the days after muscle-damaging strength training.

Methods

The study involved 15 healthy men who regularly did strength training and had not taken any food supplements or anti-inflammatory drugs for a longer period beforehand. The aim was to find out whether 21 days of supplementation with the probiotic strains Streptococcus thermophilus FP4 and Bifidobacterium breve BR03 at a concentration of 5x10^9 AFU/g of each strain would affect inflammation, muscle soreness and performance after exercise that damages muscle fibres. The study had a so-called crossover design – each participant completed two rounds: in one they took the probiotics, in the other placebo, with a 21-day break between the rounds, and a different arm was tested in each round. During testing, muscle strength (isometric power), pain, range of motion at the elbow, arm circumference and blood levels of inflammatory markers such as IL-6 and creatine kinase were measured. Participants performed a series of eccentric (braking) exercises for the biceps, which are known to cause micro-damage to muscle. Measurements were repeated immediately after exercise and 24, 48 and 72 hours later. All results were processed with statistical methods so as to take into account even small differences that could matter for recovery and athletic performance.

Results

Isometric peak torque (strength)

After 21 days of probiotic supplementation, baseline (pre-exercise) strength was probably slightly lower compared with placebo (Fig. 4A). After eccentric exercise, performance fell in both groups (intervention and placebo), which confirmed that the exercise caused muscle damage. However, in the days after exercise (24, 48 and 72 hours) participants taking the probiotic strains showed a higher mean isometric peak power than when taking placebo – the difference was greatest after 48 hours (Fig. 4B).

Interleukin-6 (IL-6) levels

IL-6 is a prototypical cytokine for maintaining homeostasis. When homeostasis is disrupted by tissue damage, IL-6 immediately begins to be produced, thereby contributing to defence against the emerging stress through activation of the acute phase and immune responses (16). After 21 days of supplementation, levels of the inflammatory marker IL-6 fell slightly in the intervention group, while they rose in the placebo group. The comparison between the groups showed an anti-inflammatory effect of the probiotics before exercise (a fall in IL-6). This effect persisted for 48 hours after exercise, although it had faded by 72 hours.

Conclusion

Supplementation with the strains Bifidobacterium breve BR03 and Streptococcus thermophilus FP4 in healthy men doing strength training eased the decline in performance and range of motion after exercise that causes muscle damage. In addition, reduced levels of the inflammatory marker IL-6 were observed at rest, and this effect persisted for 48 hours after exercise. These results suggest that specific probiotic strains may help with recovery after demanding eccentric training.

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