According to the official definition of probiotics “Probiotics are live microorganisms which, when administered in adequate amounts, confer a health benefit on the host.” 6, 7
Microbes are found throughout the external and internal surfaces of the human body, including the gastrointestinal tract, skin, saliva, oral mucosa, and conjunctiva. In fact, this community of microorganisms has about 30% more cells than the number of cells in the body,1 and the majority of them live in our gastrointestinal system.
Our modern lifestyle with widespread use of antibiotics, drugs, alcohol, infections, diarrhea, obesity, poor diet and stress have been known to adversely influence the gut’s microbiome, and consequently cause a number of negative health effects, including systemic and intestinal inflammation, gastrointestinal diseases, immune disorders, liver and kidney disease, development of cancer (such as gastrointestinal cancer and prostate cancer), obesity, insulin resistance, and even alteration of behavior through the central nervous system. 2, 3, 4, 5
Thus, probiotics offer an effective way to restore gut microbiome, which may in turn, ameliorate or prevent gut inflammation and other intestinal or systemic diseases. 6, 7, 8
Let’s look at some research that found positive consequences of probiotic use!
PROBIOTICS AND IMMUNE SYSTEM
A number of clinical studies found that specific strains of bacteria, when consumed in adequate amounts, are able to modulate immune responses. 6, 7, 8, 9, 10 A review published in The Cochrane Database of Systematic Reviews analyzing the results of 13 individual trials, found that probiotics were better than placebos in reducing the number of participants experiencing episodes of acute upper respiratory tract infections, as well as the mean duration of an infection. 11
A 12 week trial published in the European Journal of Nutrition, found that intake of a probiotic mixture reduced the incidence of acquiring one or more common colds by 18%, and the number of days with common cold symptoms by 28%. 12
PROBIOTICS AND WEIGHT-LOSS
Recently, gut microbiota has been implicated as a major driving force in the pathogenesis of a number of metabolic diseases and obesity. Clinical investigations shave shown that obesity as compared with normal weight, is associated with a disease-specific dysbiotic shift in the gut microbiota. 37, 38
A critical review published in Nutrition & Metabolism showed that modulation of gut microbiota by probiotic treatment can affect food intake and appetite, body weight and composition, and metabolic functions. 41
Another systematic review of 15 individual trials, found that administration of probiotics resulted in a significantly larger reduction in body weight and fat percentage compared to the control group during interventions ranging from 3 to 12 weeks. 40
PROBIOTICS AND SPORT PERFORMANCE
Accumulating evidence shows that consuming probiotics exerts a beneficial effect on athletic performance. For example, reviews published in the Journal of Sport and Health Science and in the Current Sports Medicine Reports concluded that modifying the microbiota through the use of probiotics could be an important tool to improve athletes’ performance, recovery from fatigue and energy availability while controlling inflammation and redox levels. 31, 32
Interestingly, it has also been found that regular exercises may induce modifications in the gut microbiota composition. Such modifications include increased microbial diversity, which contribute to a healthier gut environment and a healthier metabolic profile. 31, 33
PROBIOTICS AND MENTAL PERFORMANCE
Recently a strong association has been discovered between the gut microbiota and brain function. Researchers identified a so-called “gut-brain axis”, and demonstrated that the composition of our gut flora can alter mental health and behavior through the central nervous system. 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 34, 35, 36
A systematic review of 38 individual trials published in the Journal of Neurogastroenterology and Motility, concluded that modifying the gut microbiota through the use of probiotics may possess efficacy in improving memory abilities, including spatial and non-spatial memory, and psychiatric disorder-related behaviors including anxiety, depression, autism spectrum disorder (ASD), obsessive-compulsive disorder. 34
PROBIOTICS AND SKIN HEALTH
It has been found that skin functioning and attractiveness are highly dependent on gut microbial balance. Researchers as far back as 1930 suspected a link between gut and skin health, and modern research has now confirmed the importance of this relationship. Evidence shows a clear association between gut problems, impaired intestinal microflora and skin disorders. 49, 50, 51, 52 In such cases, probiotics seem to improve skin conditions, skin barrier, skin sensitivity, skin hydration, and also might play a role in mitigating the detrimental effects of UV exposure, and in acne therapy. 42, 43, 44, 45, 46, 47, 48
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